NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02
Route: NOT APPLICABLE                                                                                             Time: 11:05:35

                                                      lifetime/draft/mice

       Facility:  TSI Mason Research

       Chemical CAS #:  MOUSEAGE

       Lock Date:  01/08/93

       Cage Range:  All

       Reasons For Removal:    All

       Removal Date Range:     All

       Treatment Groups:       Include All

a  Number of animals examined microscopically at site and number of animals with lesion

                                                              Page   1

NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially in Study                         300                                                                            
  Early Deaths                                                                                                                      
    Moribund                                         134                                                                            
    Dead                                             130                                                                            
    Accident                                           2                                                                            
  Survivors                                                                                                                         
    Terminal Sacrifice                                34                                                                            
                                                                                                                                    
  Animals Examined Microscopically                   300                                                                            
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (297)                                                                         
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                         3 (1%)                                                                       
   Gallbladder                                        (211)                                                                         
      Adenocarcinoma                                   1                                                                            
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Histiocytic                   2 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   8 (4%)                                                                       
      Lymphoma Malignant Mixed                        12 (6%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    9 (4%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              2 (1%)                                                                       
   Intestine Large, Colon                             (274)                                                                         
      Lymphoma Malignant Lymphocytic                   5 (2%)                                                                       
      Lymphoma Malignant Mixed                         8 (3%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Uterus        1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              3 (1%)                                                                       
   Intestine Large, Rectum                            (281)                                                                         
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   5 (2%)                                                                       
      Lymphoma Malignant Mixed                        11 (4%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    5 (2%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              3 (1%)                                                                       
   Intestine Large, Cecum                             (241)                                                                         
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   8 (3%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   2                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
      Lymphoma Malignant Mixed                        19 (8%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    3 (1%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              4 (2%)                                                                       
   Intestine Small, Duodenum                          (243)                                                                         
      Adenoma                                          1                                                                            
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Lymphocytic                  10 (4%)                                                                       
      Lymphoma Malignant Mixed                        14 (6%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant                            1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              1                                                                            
   Intestine Small, Jejunum                           (244)                                                                         
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                  11 (5%)                                                                       
      Lymphoma Malignant Mixed                        10 (4%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    4 (2%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              2 (1%)                                                                       
   Intestine Small, Ileum                             (236)                                                                         
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Leiomyosarcoma                                   1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                  12 (5%)                                                                       
      Lymphoma Malignant Mixed                        15 (6%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    3 (1%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              2 (1%)                                                                       
   Liver                                              (298)                                                                         
      Fibrosarcoma, Metastatic, Skin                   4 (1%)                                                                       
      Hemangiosarcoma                                  3 (1%)                                                                       
      Hepatocellular Carcinoma                        33 (11%)                                                                      
      Hepatocellular Carcinoma, Multiple               3 (1%)                                                                       
      Hepatocellular Adenoma                          87 (29%)                                                                      
      Hepatocellular Adenoma, Multiple                32 (11%)                                                                      
      Leiomyosarcoma, Metastatic, Lymph Node           1                                                                            
      Lymphoma Malignant Histiocytic                   7 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  49 (16%)                                                                      
      Lymphoma Malignant Mixed                        78 (26%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   15 (5%)                                                                       
      Mast Cell Tumor Malignant                        1                                                                            
      Osteosarcoma, Metastatic, Bone                   1                                                                            
      Plasma Cell Tumor Malignant                      1                                                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   3                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
      Rhabdomyosarcoma, Metastatic, Skeletal Muscle    1                                                                            
      Sarcoma Stromal, Metastatic, Uterus             15 (5%)                                                                       
      Squamous Cell Carcinoma, Metastatic, Stomach,                                                                                 
           Forestomach                                 1                                                                            
   Mesentery                                          (34)                                                                          
      Fibrosarcoma, Metastatic, Skin                   1 (3%)                                                                       
      Hemangioma                                       1 (3%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      2 (6%)                                                                       
      Leiomyosarcoma, Metastatic, Lymph Node           1 (3%)                                                                       
      Lymphoma Malignant Mixed                         3 (9%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    4 (12%)                                                                      
      Sarcoma Stromal, Metastatic, Uterus              3 (9%)                                                                       
      Squamous Cell Carcinoma, Metastatic, Stomach,                                                                                 
           Forestomach                                 1 (3%)                                                                       
   Pancreas                                           (295)                                                                         
      Adenocarcinoma, Metastatic, Gallbladder          1                                                                            
      Fibrosarcoma, Metastatic, Skin                   5 (2%)                                                                       
      Fibrosarcoma, Metastatic, Tissue NOS             1                                                                            
      Lymphoma Malignant Histiocytic                   5 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  42 (14%)                                                                      
      Lymphoma Malignant Mixed                        74 (25%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   16 (5%)                                                                       
      Osteosarcoma, Metastatic, Bone                   1                                                                            
      Plasma Cell Tumor Malignant                      1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              7 (2%)                                                                       
      Squamous Cell Carcinoma, Metastatic, Skin        1                                                                            
   Pharynx                                            (283)                                                                         
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                         5 (2%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Squamous Cell Carcinoma                          1                                                                            
   Salivary Glands                                    (294)                                                                         
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        1                                                                            
      Hemangioma                                       1                                                                            
      Hemangiosarcoma                                  1                                                                            
      Lymphoma Malignant Histiocytic                   3 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                  30 (10%)                                                                      
      Lymphoma Malignant Mixed                        37 (13%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    7 (2%)                                                                       
   Stomach, Forestomach                               (295)                                                                         
      Lymphoma Malignant Lymphocytic                  12 (4%)                                                                       
      Lymphoma Malignant Mixed                         8 (3%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   4                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
      Lymphoma Malignant Undifferentiated Cell Type    4 (1%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              3 (1%)                                                                       
      Squamous Cell Carcinoma                          1                                                                            
      Squamous Cell Papilloma                          5 (2%)                                                                       
   Stomach, Glandular                                 (296)                                                                         
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                  22 (7%)                                                                       
      Lymphoma Malignant Mixed                        28 (9%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    5 (2%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              1                                                                            
      Squamous Cell Carcinoma                          1                                                                            
      Squamous Cell Carcinoma, Extension               1                                                                            
   Tongue                                             (1)                                                                           
      Squamous Cell Papilloma                          1 (100%)                                                                     
   Tooth                                              (2)                                                                           
      Adamantinoma Malignant                           1 (50%)                                                                      
      Sarcoma Stromal, Metastatic, Uterus              1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (300)                                                                         
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        2 (1%)                                                                       
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Lymphocytic                  21 (7%)                                                                       
      Lymphoma Malignant Mixed                        36 (12%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    9 (3%)                                                                       
      Osteosarcoma, Metastatic, Bone                   1                                                                            
      Plasma Cell Tumor Malignant                      1                                                                            
      Rhabdomyosarcoma, Metastatic, Skeletal Muscle    1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              2 (1%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (284)                                                                         
      Adenoma                                          1                                                                            
      Carcinoma                                        1                                                                            
      Hepatocellular Carcinoma, Metastatic, Liver      1                                                                            
      Lymphoma Malignant Lymphocytic                  10 (4%)                                                                       
      Lymphoma Malignant Mixed                         9 (3%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   5                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - cont                                                                                                             
      Rhabdomyosarcoma, Metastatic, Skeletal Muscle    1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              1                                                                            
      Capsule, Adenoma                                 2 (1%)                                                                       
      Capsule, Carcinoma                               1                                                                            
      Capsule, Fibrosarcoma, Metastatic, Skin          4 (1%)                                                                       
      Capsule, Hepatocellular Carcinoma,                                                                                            
          Metastatic, Liver                            1                                                                            
      Capsule, Lymphoma Malignant Histiocytic          2 (1%)                                                                       
      Capsule, Lymphoma Malignant Lymphocytic         21 (7%)                                                                       
      Capsule, Lymphoma Malignant Mixed               38 (13%)                                                                      
      Capsule, Lymphoma Malignant Undifferentiated                                                                                  
          Cell Type                                   11 (4%)                                                                       
      Capsule, Sarcoma Stromal, Metastatic, Uterus     6 (2%)                                                                       
      Capsule, Squamous Cell Carcinoma, Metastatic,                                                                                 
           Skin                                        1                                                                            
   Adrenal Medulla                                    (278)                                                                         
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Pheochromocytoma Benign                          3 (1%)                                                                       
   Islets, Pancreatic                                 (292)                                                                         
      Adenoma                                          6 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                   5 (2%)                                                                       
      Lymphoma Malignant Mixed                        11 (4%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
   Parathyroid Gland                                  (223)                                                                         
      Lymphoma Malignant Lymphocytic                   6 (3%)                                                                       
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
   Pituitary Gland                                    (279)                                                                         
      Pars Distalis, Adenoma                          58 (21%)                                                                      
      Pars Distalis, Adenoma, Multiple                 4 (1%)                                                                       
      Pars Distalis, Carcinoma                         5 (2%)                                                                       
      Pars Distalis, Lymphoma Malignant Histiocytic    1                                                                            
      Pars Distalis, Lymphoma Malignant Lymphocytic    5 (2%)                                                                       
      Pars Distalis, Lymphoma Malignant Mixed          5 (2%)                                                                       
      Pars Distalis, Lymphoma Malignant                                                                                             
          Undifferentiated Cell Type                   1                                                                            
      Pars Distalis, Squamous Cell Carcinoma,                                                                                       
          Metastatic, Ear                              1                                                                            
      Pars Intermedia, Adenoma                         3 (1%)                                                                       
      Pars Intermedia, Carcinoma                       1                                                                            
      Pars Intermedia, Lymphoma Malignant                                                                                           
          Lymphocytic                                  1                                                                            
      Pars Intermedia, Lymphoma Malignant                                                                                           
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   6                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ENDOCRINE SYSTEM - cont                                                                                                             
          Undifferentiated Cell Type                   1                                                                            
      Pars Nervosa, Lymphoma Malignant                                                                                              
          Undifferentiated Cell Type                   1                                                                            
   Thyroid Gland                                      (299)                                                                         
      Leiomyosarcoma, Metastatic, Uncertain                                                                                         
          Primary Site                                 1                                                                            
      Lymphoma Malignant Lymphocytic                  11 (4%)                                                                       
      Lymphoma Malignant Mixed                        13 (4%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      C-Cell, Carcinoma                                1                                                                            
      Follicular Cell, Adenoma                         9 (3%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   Tissue NOS                                         (3)                                                                           
      Fibrosarcoma                                     1 (33%)                                                                      
      Lymphoma Malignant Mixed                         1 (33%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Clitoral Gland                                     (8)                                                                           
      Plasma Cell Tumor Malignant                      1 (13%)                                                                      
   Ovary                                              (286)                                                                         
      Choriocarcinoma                                  1                                                                            
      Cystadenoma                                      7 (2%)                                                                       
      Dysgerminoma Malignant                           1                                                                            
      Fibrosarcoma, Metastatic, Skin                   2 (1%)                                                                       
      Fibrosarcoma, Metastatic, Tissue NOS             1                                                                            
      Granulosa-Theca Tumor Benign                     5 (2%)                                                                       
      Hemangioma                                       2 (1%)                                                                       
      Hemangiosarcoma                                  1                                                                            
      Leiomyosarcoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
      Lymphoma Malignant Histiocytic                   6 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  64 (22%)                                                                      
      Lymphoma Malignant Mixed                        82 (29%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   14 (5%)                                                                       
      Mast Cell Tumor Malignant                        1                                                                            
      Mixed Tumor Benign                               7 (2%)                                                                       
      Mixed Tumor Malignant                            1                                                                            
      Sarcoma Stromal, Metastatic, Uterus             12 (4%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   7                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
GENITAL SYSTEM - cont                                                                                                               
   Uterus                                             (300)                                                                         
      Adenocarcinoma                                   5 (2%)                                                                       
      Adenoma                                          1                                                                            
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Hemangioma                                       1                                                                            
      Hemangiosarcoma                                  1                                                                            
      Lymphoma Malignant Histiocytic                   3 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                  39 (13%)                                                                      
      Lymphoma Malignant Mixed                        43 (14%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    7 (2%)                                                                       
      Mixed Tumor Benign                               1                                                                            
      Mixed Tumor Malignant                            1                                                                            
      Polyp Stromal                                   10 (3%)                                                                       
      Sarcoma Stromal                                 20 (7%)                                                                       
   Vagina                                             (2)                                                                           
      Granular Cell Tumor Benign                       1 (50%)                                                                      
      Hemangioma                                       1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (300)                                                                         
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Hemangioma                                       3 (1%)                                                                       
      Hemangiosarcoma                                  2 (1%)                                                                       
      Lymphoma Malignant Histiocytic                   2 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   5 (2%)                                                                       
      Lymphoma Malignant Mixed                         9 (3%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    3 (1%)                                                                       
      Osteosarcoma, Metastatic, Bone                   1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              4 (1%)                                                                       
   Lymph Node                                         (196)                                                                         
      Axillary, Lymphoma Malignant Lymphocytic         1 (1%)                                                                       
      Axillary, Lymphoma Malignant Mixed               3 (2%)                                                                       
      Axillary, Lymphoma Malignant                                                                                                  
          Undifferentiated Cell Type                   1 (1%)                                                                       
      Bronchial, Alveolar/Bronchiolar Carcinoma,                                                                                    
           Metastatic, Lung                            1 (1%)                                                                       
      Bronchial, Fibrosarcoma, Metastatic, Skin        1 (1%)                                                                       
      Bronchial, Lymphoma Malignant Histiocytic        3 (2%)                                                                       
      Bronchial, Lymphoma Malignant Lymphocytic       42 (21%)                                                                      
      Bronchial, Lymphoma Malignant Mixed             58 (30%)                                                                      
      Bronchial, Lymphoma Malignant                                                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   8                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
          Undifferentiated Cell Type                  12 (6%)                                                                       
      Bronchial, Osteosarcoma, Metastatic, Bone        1 (1%)                                                                       
      Bronchial, Plasma Cell Tumor Malignant           1 (1%)                                                                       
      Bronchial, Rhabdomyosarcoma, Metastatic,                                                                                      
           Skeletal Muscle                             1 (1%)                                                                       
      Bronchial, Sarcoma Stromal, Metastatic,                                                                                       
          Uterus                                       2 (1%)                                                                       
      Deep Cervical, Lymphoma Malignant Mixed          1 (1%)                                                                       
      Deep Cervical, Lymphoma Malignant                                                                                             
          Undifferentiated Cell Type                   1 (1%)                                                                       
      Iliac, Fibrosarcoma, Metastatic, Skin            2 (1%)                                                                       
      Iliac, Lymphoma Malignant Histiocytic            1 (1%)                                                                       
      Iliac, Lymphoma Malignant Lymphocytic            1 (1%)                                                                       
      Iliac, Lymphoma Malignant Mixed                 10 (5%)                                                                       
      Iliac, Lymphoma Malignant Undifferentiated                                                                                    
          Cell Type                                    1 (1%)                                                                       
      Inguinal, Leiomyosarcoma, Metastatic,                                                                                         
          Intestine Small, Ileum                       1 (1%)                                                                       
      Inguinal, Lymphoma Malignant Lymphocytic         3 (2%)                                                                       
      Inguinal, Lymphoma Malignant Mixed               5 (3%)                                                                       
      Inguinal, Lymphoma Malignant                                                                                                  
          Undifferentiated Cell Type                   1 (1%)                                                                       
      Lumbar, Fibrosarcoma, Metastatic, Skin           1 (1%)                                                                       
      Lumbar, Hemangiosarcoma                          1 (1%)                                                                       
      Lumbar, Leiomyosarcoma                           1 (1%)                                                                       
      Lumbar, Lymphoma Malignant Histiocytic           1 (1%)                                                                       
      Lumbar, Lymphoma Malignant Lymphocytic           4 (2%)                                                                       
      Lumbar, Lymphoma Malignant Mixed                29 (15%)                                                                      
      Lumbar, Lymphoma Malignant Undifferentiated                                                                                   
          Cell Type                                    6 (3%)                                                                       
      Lumbar, Sarcoma Stromal, Metastatic, Uterus      1 (1%)                                                                       
      Lumbar, Squamous Cell Carcinoma, Metastatic,                                                                                  
           Skin                                        1 (1%)                                                                       
      Mediastinal, Fibrosarcoma, Metastatic, Skin      2 (1%)                                                                       
      Mediastinal, Leiomyosarcoma, Metastatic,                                                                                      
           Intestine Small, Ileum                      1 (1%)                                                                       
      Mediastinal, Lymphoma Malignant Histiocytic      6 (3%)                                                                       
      Mediastinal, Lymphoma Malignant Lymphocytic     38 (19%)                                                                      
      Mediastinal, Lymphoma Malignant Mixed           72 (37%)                                                                      
      Mediastinal, Lymphoma Malignant                                                                                               
          Undifferentiated Cell Type                  16 (8%)                                                                       
      Mediastinal, Mast Cell Tumor Malignant           1 (1%)                                                                       
      Mediastinal, Plasma Cell Tumor Malignant         1 (1%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page   9                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
      Mediastinal, Rhabdomyosarcoma, Metastatic,                                                                                    
           Skeletal Muscle                             1 (1%)                                                                       
      Mediastinal, Sarcoma Stromal, Metastatic,                                                                                     
           Uterus                                      4 (2%)                                                                       
      Pancreatic, Lymphoma Malignant Lymphocytic       2 (1%)                                                                       
      Pancreatic, Lymphoma Malignant Mixed            12 (6%)                                                                       
      Pancreatic, Lymphoma Malignant                                                                                                
          Undifferentiated Cell Type                   5 (3%)                                                                       
      Pancreatic, Sarcoma Stromal, Metastatic,                                                                                      
           Uterus                                      1 (1%)                                                                       
      Popliteal, Lymphoma Malignant Lymphocytic        1 (1%)                                                                       
      Popliteal, Lymphoma Malignant Mixed              1 (1%)                                                                       
      Prefemoral, Lymphoma Malignant Lymphocytic       1 (1%)                                                                       
      Renal, Fibrosarcoma, Metastatic, Skin            1 (1%)                                                                       
      Renal, Lymphoma Malignant Lymphocytic            4 (2%)                                                                       
      Renal, Lymphoma Malignant Mixed                 22 (11%)                                                                      
      Renal, Lymphoma Malignant Undifferentiated                                                                                    
          Cell Type                                    6 (3%)                                                                       
   Lymph Node, Mandibular                             (270)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      1                                                                            
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        1                                                                            
      Carcinoma, Metastatic, Zymbal's Gland            1                                                                            
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Hemangioma                                       1                                                                            
      Leiomyosarcoma                                   1                                                                            
      Lymphoma Malignant Histiocytic                   4 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                  50 (19%)                                                                      
      Lymphoma Malignant Mixed                        63 (23%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   12 (4%)                                                                       
      Plasma Cell Tumor Malignant                      1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              1                                                                            
   Lymph Node, Mesenteric                             (256)                                                                         
      Adenocarcinoma, Metastatic, Gallbladder          1                                                                            
      Fibrosarcoma, Metastatic, Skin                   4 (2%)                                                                       
      Fibrosarcoma, Metastatic, Tissue NOS             1                                                                            
      Hemangiosarcoma                                  2 (1%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      1                                                                            
      Lymphoma Malignant Histiocytic                   6 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  42 (16%)                                                                      
      Lymphoma Malignant Mixed                        79 (31%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   16 (6%)                                                                       
      Plasma Cell Tumor Malignant                      1                                                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  10                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
      Rhabdomyosarcoma, Metastatic, Skeletal Muscle    1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              6 (2%)                                                                       
   Spleen                                             (298)                                                                         
      Fibrosarcoma, Metastatic, Skin                   2 (1%)                                                                       
      Hemangioma                                       1                                                                            
      Hemangiosarcoma                                  9 (3%)                                                                       
      Lymphoma Malignant Histiocytic                   6 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  85 (29%)                                                                      
      Lymphoma Malignant Mixed                        95 (32%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   17 (6%)                                                                       
      Mast Cell Tumor Malignant                        1                                                                            
      Plasma Cell Tumor Malignant                      1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              3 (1%)                                                                       
   Thymus                                             (208)                                                                         
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                  34 (16%)                                                                      
      Lymphoma Malignant Mixed                        54 (26%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   10 (5%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Mammary Gland                                      (264)                                                                         
      Adenocarcinoma                                   9 (3%)                                                                       
   Skin                                               (299)                                                                         
      Epidermis, Squamous Cell Carcinoma               1                                                                            
      Subcutaneous Tissue, Basosquamous Tumor                                                                                       
          Malignant                                    1                                                                            
      Subcutaneous Tissue, Fibrosarcoma               24 (8%)                                                                       
      Subcutaneous Tissue, Fibrosarcoma, Multiple      1                                                                            
      Subcutaneous Tissue, Hemangioma                  2 (1%)                                                                       
      Subcutaneous Tissue, Hemangiosarcoma             3 (1%)                                                                       
      Subcutaneous Tissue, Leiomyosarcoma,                                                                                          
          Metastatic, Intestine Small, Ileum           1                                                                            
      Subcutaneous Tissue, Lymphoma Malignant                                                                                       
          Histiocytic                                  1                                                                            
      Subcutaneous Tissue, Lymphoma Malignant                                                                                       
          Lymphocytic                                 15 (5%)                                                                       
      Subcutaneous Tissue, Lymphoma Malignant Mixed   20 (7%)                                                                       
      Subcutaneous Tissue, Lymphoma Malignant                                                                                       
          Undifferentiated Cell Type                   3 (1%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  11                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
INTEGUMENTARY SYSTEM - cont                                                                                                         
      Subcutaneous Tissue, Myxosarcoma                 1                                                                            
      Subcutaneous Tissue, Neurofibrosarcoma           2 (1%)                                                                       
      Subcutaneous Tissue, Rhabdomyosarcoma,                                                                                        
          Metastatic, Skeletal Muscle                  1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Bone                                               (300)                                                                         
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Osteoma                                          1                                                                            
      Osteosarcoma                                     3 (1%)                                                                       
   Skeletal Muscle                                    (300)                                                                         
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        1                                                                            
      Fibrosarcoma                                     1                                                                            
      Fibrosarcoma, Metastatic, Skin                   3 (1%)                                                                       
      Hemangiosarcoma                                  3 (1%)                                                                       
      Hemangiosarcoma, Multiple                        1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                  33 (11%)                                                                      
      Lymphoma Malignant Mixed                        37 (12%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    5 (2%)                                                                       
      Plasma Cell Tumor Malignant                      1                                                                            
      Rhabdomyosarcoma                                 4 (1%)                                                                       
      Sarcoma                                          1                                                                            
      Squamous Cell Carcinoma, Metastatic, Skin        1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (300)                                                                         
      Astrocytoma Benign                               1                                                                            
      Carcinoma, Metastatic, Pituitary Gland           5 (2%)                                                                       
      Lymphoma Malignant Histiocytic                   2 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   9 (3%)                                                                       
      Lymphoma Malignant Mixed                         6 (2%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    4 (1%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              4 (1%)                                                                       
   Peripheral Nerve                                   (300)                                                                         
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Lymphocytic                  22 (7%)                                                                       
      Lymphoma Malignant Mixed                        25 (8%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  12                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
NERVOUS SYSTEM - cont                                                                                                               
      Lymphoma Malignant Undifferentiated Cell Type    5 (2%)                                                                       
   Spinal Cord                                        (300)                                                                         
      Lymphoma Malignant Lymphocytic                   8 (3%)                                                                       
      Lymphoma Malignant Mixed                         6 (2%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (283)                                                                         
      Carcinoma, Metastatic, Thyroid Gland             1                                                                            
      Leiomyosarcoma, Metastatic, Uncertain                                                                                         
          Primary Site                                 1                                                                            
      Lymphoma Malignant Lymphocytic                   5 (2%)                                                                       
      Lymphoma Malignant Mixed                         8 (3%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
   Lung                                               (300)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      3 (1%)                                                                       
      Adenocarcinoma, Metastatic, Mammary Gland        1                                                                            
      Alveolar/Bronchiolar Adenoma                    21 (7%)                                                                       
      Alveolar/Bronchiolar Adenoma, Multiple           2 (1%)                                                                       
      Alveolar/Bronchiolar Carcinoma                  21 (7%)                                                                       
      Alveolar/Bronchiolar Carcinoma, Multiple         1                                                                            
      Carcinoma, Metastatic, Pituitary Gland           1                                                                            
      Carcinoma, Metastatic, Uncertain Primary Site    1                                                                            
      Carcinoma, Metastatic, Zymbal's Gland            1                                                                            
      Carcinoma, Metastatic, Adrenal Cortex            1                                                                            
      Dysgerminoma Malignant, Metastatic, Ovary        1                                                                            
      Fibrosarcoma, Metastatic, Skin                   3 (1%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver     12 (4%)                                                                       
      Lymphoma Malignant Histiocytic                   7 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  63 (21%)                                                                      
      Lymphoma Malignant Mixed                        74 (25%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   16 (5%)                                                                       
      Osteosarcoma, Metastatic, Bone                   1                                                                            
      Plasma Cell Tumor Malignant                      1                                                                            
      Rhabdomyosarcoma, Metastatic, Skeletal Muscle    1                                                                            
      Sarcoma Stromal, Metastatic, Uterus             14 (5%)                                                                       
   Nose                                               (298)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      1                                                                            
      Lymphoma Malignant Lymphocytic                   9 (3%)                                                                       
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  13                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - cont                                                                                                           
      Sarcoma Stromal, Metastatic, Uterus              3 (1%)                                                                       
   Trachea                                            (297)                                                                         
      Leiomyosarcoma, Metastatic, Uncertain                                                                                         
          Primary Site                                 1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                         1                                                                            
      Schwannoma Benign                                1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Ear                                                (2)                                                                           
      Squamous Cell Carcinoma                          1 (50%)                                                                      
   Eye                                                (286)                                                                         
      Lymphoma Malignant Lymphocytic                   4 (1%)                                                                       
      Lymphoma Malignant Mixed                         7 (2%)                                                                       
      Iris, Melanoma Malignant                         1                                                                            
   Harderian Gland                                    (10)                                                                          
      Adenocarcinoma                                   4 (40%)                                                                      
      Adenoma                                          5 (50%)                                                                      
      Lymphoma Malignant Mixed                         1 (10%)                                                                      
   Zymbal's Gland                                     (2)                                                                           
      Carcinoma                                        1 (50%)                                                                      
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (300)                                                                         
      Alveolar/Bronchiolar Carcinoma, Metastatic,                                                                                   
           Lung                                        1                                                                            
      Carcinoma                                        1                                                                            
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Histiocytic                   5 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  58 (19%)                                                                      
      Lymphoma Malignant Mixed                        67 (22%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type   14 (5%)                                                                       
      Osteosarcoma, Metastatic, Bone                   1                                                                            
      Plasma Cell Tumor Malignant                      1                                                                            
      Sarcoma Stromal, Metastatic, Uterus              7 (2%)                                                                       
   Urinary Bladder                                    (290)                                                                         
      Fibrosarcoma, Metastatic, Skin                   1                                                                            
      Lymphoma Malignant Histiocytic                   2 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                  36 (12%)                                                                      
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  14                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
URINARY SYSTEM - cont                                                                                                               
      Lymphoma Malignant Mixed                        45 (16%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    8 (3%)                                                                       
      Sarcoma Stromal, Metastatic, Uterus              2 (1%)                                                                       
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
                                                                                                                                    
   Multiple Organs                                   *(300)                                                                         
      Lymphoma Malignant Histiocytic                   7 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  89 (30%)                                                                      
      Lymphoma Malignant Mixed                       104 (35%)                                                                      
      Lymphoma Malignant Undifferentiated Cell        18 (6%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
     *   Number of animals with any tissue examined microscopically                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  15                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE FEMALE                        LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)           282                                                                           
     Total Primary Neoplasms                          712                                                                           
                                                                                                                                    
   Total Animals with Benign Neoplasms                187                                                                           
     Total Benign Neoplasms                           288                                                                           
                                                                                                                                    
   Total Animals with Malignant Neoplasms             270                                                                           
     Total Malignant Neoplasms                        424                                                                           
                                                                                                                                    
   Total Animals with Metastatic Neoplasms             66                                                                           
     Total Metastatic Neoplasm                        247                                                                           
                                                                                                                                    
   Total Animals with Malignant Neoplasms               1                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
                                                                                                                                    
____________________________________________________________________________________________________________________________________
a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  16                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
DISPOSITION SUMMARY                                                                                                                 
                                                                                                                                    
  Animals Initially in Study                         300                                                                            
  Early Deaths                                                                                                                      
    Dead                                             142                                                                            
    Moribund                                         123                                                                            
    Accident                                           1                                                                            
  Survivors                                                                                                                         
    Terminal Sacrifice                                31                                                                            
    Dead                                               3                                                                            
                                                                                                                                    
  Animals Examined Microscopically                   300                                                                            
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ALIMENTARY SYSTEM                                                                                                                  
                                                                                                                                    
   Esophagus                                          (293)                                                                         
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
      Hepatocellular Carcinoma, Metastatic, Liver      1                                                                            
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         1                                                                            
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
   Gallbladder                                        (190)                                                                         
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1 (1%)                                                                       
      Adenoma                                          1 (1%)                                                                       
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   1 (1%)                                                                       
      Lymphoma Malignant Mixed                         8 (4%)                                                                       
   Intestine Large, Colon                             (259)                                                                         
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         3 (1%)                                                                       
   Intestine Large, Rectum                            (264)                                                                         
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         7 (3%)                                                                       
   Intestine Large, Cecum                             (236)                                                                         
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Jejunum                                     1                                                                            
      Hemangioma                                       1                                                                            
      Leiomyosarcoma                                   1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  17                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
      Lymphoma Malignant Lymphocytic                   5 (2%)                                                                       
      Lymphoma Malignant Mixed                         9 (4%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Intestine Small, Duodenum                          (225)                                                                         
      Adenocarcinoma                                   3 (1%)                                                                       
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                         9 (4%)                                                                       
      Mixed Tumor Malignant                            1                                                                            
   Intestine Small, Jejunum                           (219)                                                                         
      Adenocarcinoma                                   3 (1%)                                                                       
      Adenoma                                          2 (1%)                                                                       
      Leiomyosarcoma, Metastatic, Epididymis           1                                                                            
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                        18 (8%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Intestine Small, Ileum                             (210)                                                                         
      Adenocarcinoma                                   1                                                                            
      Leiomyosarcoma, Metastatic, Epididymis           1                                                                            
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                        11 (5%)                                                                       
   Liver                                              (298)                                                                         
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
      Hemangiosarcoma                                 14 (5%)                                                                       
      Hepatoblastoma                                   1                                                                            
      Hepatocellular Carcinoma                        90 (30%)                                                                      
      Hepatocellular Carcinoma, Multiple              26 (9%)                                                                       
      Hepatocellular Adenoma                          68 (23%)                                                                      
      Hepatocellular Adenoma, Multiple                83 (28%)                                                                      
      Hepatocholangiocarcinoma                         1                                                                            
      Leiomyosarcoma, Metastatic, Epididymis           1                                                                            
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Histiocytic                   9 (3%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  18                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
      Lymphoma Malignant Lymphocytic                   9 (3%)                                                                       
      Lymphoma Malignant Mixed                        37 (12%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
      Neurofibrosarcoma, Metastatic, Skin              1                                                                            
      Schwannoma Malignant, Metastatic, Salivary                                                                                    
          Glands                                       1                                                                            
   Mesentery                                          (22)                                                                          
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1 (5%)                                                                       
      Hemangiosarcoma                                  1 (5%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      6 (27%)                                                                      
      Leiomyosarcoma, Metastatic, Epididymis           1 (5%)                                                                       
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1 (5%)                                                                       
      Lymphoma Malignant Lymphocytic                   1 (5%)                                                                       
      Lymphoma Malignant Mixed                         1 (5%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1 (5%)                                                                       
      Pheochromocytoma Malignant, Metastatic,                                                                                       
          Adrenal Medulla                              1 (5%)                                                                       
   Pancreas                                           (298)                                                                         
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
      Fibrosarcoma, Metastatic, Seminal Vesicle        1                                                                            
      Hemangiosarcoma, Metastatic, Lymph Node,                                                                                      
           Mesenteric                                  1                                                                            
      Hepatocellular Carcinoma, Metastatic, Liver      2 (1%)                                                                       
      Leiomyosarcoma, Metastatic, Epididymis           1                                                                            
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Histiocytic                   3 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   8 (3%)                                                                       
      Lymphoma Malignant Mixed                        35 (12%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    3 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Pharynx                                            (277)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      1                                                                            
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
      Squamous Cell Carcinoma                          1                                                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  19                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
ALIMENTARY SYSTEM - cont                                                                                                            
   Salivary Glands                                    (297)                                                                         
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   4 (1%)                                                                       
      Lymphoma Malignant Mixed                        11 (4%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Schwannoma Malignant                             1                                                                            
   Stomach, Forestomach                               (297)                                                                         
      Leiomyosarcoma                                   1                                                                            
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                         3 (1%)                                                                       
      Squamous Cell Carcinoma                          1                                                                            
      Squamous Cell Papilloma                          4 (1%)                                                                       
   Stomach, Glandular                                 (296)                                                                         
      Adenoma                                          1                                                                            
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                        10 (3%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Tongue                                             (3)                                                                           
      Squamous Cell Papilloma                          1 (33%)                                                                      
   Tooth                                              (32)                                                                          
      Adamantinoma Benign                              1 (3%)                                                                       
      Lymphoma Malignant Mixed                         3 (9%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 CARDIOVASCULAR SYSTEM                                                                                                              
                                                                                                                                    
   Heart                                              (299)                                                                         
      Fibrosarcoma, Metastatic, Skeletal Muscle        1                                                                            
      Hemangiosarcoma                                  1                                                                            
      Lymphoma Malignant Histiocytic                   2 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   4 (1%)                                                                       
      Lymphoma Malignant Mixed                        16 (5%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  20                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 ENDOCRINE SYSTEM                                                                                                                   
                                                                                                                                    
   Adrenal Cortex                                     (285)                                                                         
      Adenoma                                          7 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                         8 (3%)                                                                       
      Capsule, Adenoma                                10 (4%)                                                                       
      Capsule, Hemangiosarcoma, Metastatic, Lymph                                                                                   
          Node, Mesenteric                             1                                                                            
      Capsule, Leiomyosarcoma, Metastatic, Stomach,                                                                                 
           Forestomach                                 1                                                                            
      Capsule, Lymphoma Malignant Lymphocytic          3 (1%)                                                                       
      Capsule, Lymphoma Malignant Mixed               12 (4%)                                                                       
      Capsule, Lymphoma Malignant Undifferentiated                                                                                  
          Cell Type                                    3 (1%)                                                                       
   Adrenal Medulla                                    (275)                                                                         
      Lymphoma Malignant Mixed                         6 (2%)                                                                       
      Pheochromocytoma Malignant                       3 (1%)                                                                       
      Pheochromocytoma Benign                          6 (2%)                                                                       
      Pheochromocytoma Benign, Multiple                1                                                                            
   Islets, Pancreatic                                 (295)                                                                         
      Adenoma                                          9 (3%)                                                                       
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
   Pituitary Gland                                    (223)                                                                         
      Pars Distalis, Adenoma                           4 (2%)                                                                       
      Pars Distalis, Lymphoma Malignant Lymphocytic    2 (1%)                                                                       
      Pars Distalis, Lymphoma Malignant Mixed          2 (1%)                                                                       
      Pars Intermedia, Adenoma                         1                                                                            
      Pars Intermedia, Carcinoma                       1                                                                            
   Thyroid Gland                                      (291)                                                                         
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
      Follicular Cell, Adenoma                        16 (5%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENERAL BODY SYSTEM                                                                                                                
                                                                                                                                    
   None                                                                                                                             
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  21                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 GENITAL SYSTEM                                                                                                                     
                                                                                                                                    
   Coagulating Gland                                  (24)                                                                          
      Lymphoma Malignant Lymphocytic                   1 (4%)                                                                       
      Lymphoma Malignant Mixed                         1 (4%)                                                                       
   Epididymis                                         (296)                                                                         
      Leiomyosarcoma                                   1                                                                            
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   4 (1%)                                                                       
      Lymphoma Malignant Mixed                        21 (7%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Preputial Gland                                    (138)                                                                         
      Adenoma                                          1 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                         4 (3%)                                                                       
   Prostate                                           (295)                                                                         
      Lymphoma Malignant Lymphocytic                   6 (2%)                                                                       
      Lymphoma Malignant Mixed                        18 (6%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Seminal Vesicle                                    (299)                                                                         
      Fibrosarcoma                                     1                                                                            
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                        15 (5%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Testes                                             (300)                                                                         
      Lymphoma Malignant Mixed                         8 (3%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Interstitial Cell, Adenoma                       9 (3%)                                                                       
      Interstitial Cell, Adenoma, Multiple             1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  22                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 HEMATOPOIETIC SYSTEM                                                                                                               
                                                                                                                                    
   Bone Marrow                                        (299)                                                                         
      Hemangiosarcoma                                  2 (1%)                                                                       
      Lymphoma Malignant Histiocytic                   3 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
   Lymph Node                                         (97)                                                                          
      Axillary, Hemangiosarcoma                        1 (1%)                                                                       
      Axillary, Lymphoma Malignant Mixed               1 (1%)                                                                       
      Bronchial, Adenocarcinoma, Metastatic,                                                                                        
          Intestine Small, Ileum                       1 (1%)                                                                       
      Bronchial, Fibrosarcoma, Metastatic,                                                                                          
          Skeletal Muscle                              1 (1%)                                                                       
      Bronchial, Leiomyosarcoma, Metastatic,                                                                                        
          Stomach, Forestomach                         1 (1%)                                                                       
      Bronchial, Lymphoma Malignant Histiocytic        4 (4%)                                                                       
      Bronchial, Lymphoma Malignant Lymphocytic        6 (6%)                                                                       
      Bronchial, Lymphoma Malignant Mixed             23 (24%)                                                                      
      Bronchial, Lymphoma Malignant                                                                                                 
          Undifferentiated Cell Type                   3 (3%)                                                                       
      Bronchial, Mixed Tumor Malignant, Metastatic,                                                                                 
           Intestine Small, Duodenum                   1 (1%)                                                                       
      Iliac, Alveolar/Bronchiolar Carcinoma,                                                                                        
          Metastatic, Lung                             1 (1%)                                                                       
      Iliac, Hemangiosarcoma                           1 (1%)                                                                       
      Iliac, Hepatocellular Carcinoma, Metastatic,                                                                                  
           Liver                                       1 (1%)                                                                       
      Iliac, Lymphoma Malignant Histiocytic            1 (1%)                                                                       
      Iliac, Lymphoma Malignant Mixed                  6 (6%)                                                                       
      Inguinal, Lymphoma Malignant Lymphocytic         2 (2%)                                                                       
      Inguinal, Lymphoma Malignant Mixed               5 (5%)                                                                       
      Inguinal, Lymphoma Malignant                                                                                                  
          Undifferentiated Cell Type                   1 (1%)                                                                       
      Lumbar, Hepatocellular Carcinoma, Metastatic,                                                                                 
           Liver                                       1 (1%)                                                                       
      Lumbar, Lymphoma Malignant Histiocytic           1 (1%)                                                                       
      Lumbar, Lymphoma Malignant Lymphocytic           2 (2%)                                                                       
      Lumbar, Lymphoma Malignant Mixed                 9 (9%)                                                                       
      Lumbar, Mixed Tumor Malignant, Metastatic,                                                                                    
           Intestine Small, Duodenum                   1 (1%)                                                                       
      Mediastinal, Adenocarcinoma, Metastatic,                                                                                      
           Intestine Small, Ileum                      1 (1%)                                                                       
      Mediastinal, Fibrosarcoma, Metastatic,                                                                                        
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  23                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
          Skeletal Muscle                              1 (1%)                                                                       
      Mediastinal, Lymphoma Malignant Histiocytic      2 (2%)                                                                       
      Mediastinal, Lymphoma Malignant Lymphocytic      7 (7%)                                                                       
      Mediastinal, Lymphoma Malignant Mixed           26 (27%)                                                                      
      Mediastinal, Lymphoma Malignant                                                                                               
          Undifferentiated Cell Type                   3 (3%)                                                                       
      Pancreatic, Hepatocellular Carcinoma,                                                                                         
          Metastatic, Liver                            1 (1%)                                                                       
      Pancreatic, Lymphoma Malignant Lymphocytic       3 (3%)                                                                       
      Pancreatic, Lymphoma Malignant Mixed             3 (3%)                                                                       
      Pancreatic, Lymphoma Malignant                                                                                                
          Undifferentiated Cell Type                   1 (1%)                                                                       
      Renal, Hepatocellular Carcinoma, Metastatic,                                                                                  
           Liver                                       1 (1%)                                                                       
      Renal, Lymphoma Malignant Lymphocytic            1 (1%)                                                                       
      Renal, Lymphoma Malignant Mixed                 14 (14%)                                                                      
      Thoracic, Hemangiosarcoma                        1 (1%)                                                                       
      Thoracic, Lymphoma Malignant Mixed               1 (1%)                                                                       
   Lymph Node, Mandibular                             (264)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      1                                                                            
      Hemangiosarcoma                                  2 (1%)                                                                       
      Lymphoma Malignant Histiocytic                   3 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   6 (2%)                                                                       
      Lymphoma Malignant Mixed                        21 (8%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mast Cell Tumor Malignant                        1                                                                            
   Lymph Node, Mesenteric                             (261)                                                                         
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
      Fibrosarcoma, Metastatic, Seminal Vesicle        1                                                                            
      Hemangioma                                       2 (1%)                                                                       
      Hemangiosarcoma                                  4 (2%)                                                                       
      Hemangiosarcoma, Metastatic, Spleen              2 (1%)                                                                       
      Hepatocellular Carcinoma, Metastatic, Liver      1                                                                            
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Histiocytic                   5 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  17 (7%)                                                                       
      Lymphoma Malignant Mixed                        60 (23%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Spleen                                             (296)                                                                         
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  24                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
HEMATOPOIETIC SYSTEM - cont                                                                                                         
      Fibrosarcoma, Metastatic, Seminal Vesicle        1                                                                            
      Hemangioma                                       6 (2%)                                                                       
      Hemangiosarcoma                                 21 (7%)                                                                       
      Lymphoma Malignant Histiocytic                   5 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  21 (7%)                                                                       
      Lymphoma Malignant Mixed                        54 (18%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
      Neurofibrosarcoma, Metastatic, Skin              1                                                                            
   Thymus                                             (156)                                                                         
      Fibrosarcoma, Metastatic, Skeletal Muscle        1 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   6 (4%)                                                                       
      Lymphoma Malignant Mixed                        16 (10%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1 (1%)                                                                       
      Schwannoma Malignant                             1 (1%)                                                                       
      Thymoma Malignant                                1 (1%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 INTEGUMENTARY SYSTEM                                                                                                               
                                                                                                                                    
   Skin                                               (300)                                                                         
      Epidermis, Squamous Cell Carcinoma               1                                                                            
      Subcutaneous Tissue, Fibrosarcoma                2 (1%)                                                                       
      Subcutaneous Tissue, Hemangioma                  4 (1%)                                                                       
      Subcutaneous Tissue, Hemangiosarcoma             4 (1%)                                                                       
      Subcutaneous Tissue, Lymphoma Malignant                                                                                       
          Histiocytic                                  2 (1%)                                                                       
      Subcutaneous Tissue, Lymphoma Malignant                                                                                       
          Lymphocytic                                  4 (1%)                                                                       
      Subcutaneous Tissue, Lymphoma Malignant Mixed   11 (4%)                                                                       
      Subcutaneous Tissue, Neurofibroma                1                                                                            
      Subcutaneous Tissue, Neurofibrosarcoma           2 (1%)                                                                       
      Subcutaneous Tissue, Pinna, Melanoma                                                                                          
          Malignant                                    1                                                                            
      Subcutaneous Tissue, Pinna, Rhabdomyosarcoma     1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  25                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 MUSCULOSKELETAL SYSTEM                                                                                                             
                                                                                                                                    
   Skeletal Muscle                                    (300)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      1                                                                            
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
      Fibrosarcoma                                     1                                                                            
      Hemangiosarcoma                                  2 (1%)                                                                       
      Hemangiosarcoma, Metastatic, Liver               1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                        10 (3%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 NERVOUS SYSTEM                                                                                                                     
                                                                                                                                    
   Brain                                              (299)                                                                         
      Astrocytoma Malignant                            1                                                                            
      Carcinoma, Metastatic, Pituitary Gland           1                                                                            
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Mixed                         3 (1%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
   Peripheral Nerve                                   (296)                                                                         
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                         6 (2%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
   Spinal Cord                                        (299)                                                                         
      Lymphoma Malignant Histiocytic                   1                                                                            
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         1                                                                            
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 RESPIRATORY SYSTEM                                                                                                                 
                                                                                                                                    
   Larynx                                             (281)                                                                         
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         2 (1%)                                                                       
   Lung                                               (297)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      5 (2%)                                                                       
      Adenocarcinoma, Metastatic, Intestine Small,                                                                                  
           Ileum                                       1                                                                            
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  26                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
RESPIRATORY SYSTEM - cont                                                                                                           
      Alveolar/Bronchiolar Adenoma                    51 (17%)                                                                      
      Alveolar/Bronchiolar Adenoma, Multiple           8 (3%)                                                                       
      Alveolar/Bronchiolar Carcinoma                  57 (19%)                                                                      
      Alveolar/Bronchiolar Carcinoma, Multiple         8 (3%)                                                                       
      Fibrosarcoma, Metastatic, Seminal Vesicle        1                                                                            
      Fibrosarcoma, Metastatic, Skeletal Muscle        1                                                                            
      Hepatocellular Carcinoma, Metastatic, Liver     33 (11%)                                                                      
      Leiomyosarcoma, Metastatic, Stomach,                                                                                          
          Forestomach                                  1                                                                            
      Lymphoma Malignant Histiocytic                   5 (2%)                                                                       
      Lymphoma Malignant Lymphocytic                  14 (5%)                                                                       
      Lymphoma Malignant Mixed                        26 (9%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mesothelioma Benign                              1                                                                            
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
      Schwannoma Malignant, Metastatic, Salivary                                                                                    
          Glands                                       1                                                                            
      Squamous Cell Carcinoma, Metastatic, Skin        1                                                                            
   Nose                                               (295)                                                                         
      Adenocarcinoma, Metastatic, Harderian Gland      1                                                                            
      Astrocytoma Malignant, Metastatic, Brain         1                                                                            
      Lymphoma Malignant Histiocytic                   2 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                   2 (1%)                                                                       
      Lymphoma Malignant Mixed                         5 (2%)                                                                       
      Polyp                                            2 (1%)                                                                       
      Schwannoma Malignant, Metastatic, Salivary                                                                                    
          Glands                                       1                                                                            
   Trachea                                            (293)                                                                         
      Lymphoma Malignant Lymphocytic                   1                                                                            
      Lymphoma Malignant Mixed                         3 (1%)                                                                       
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SPECIAL SENSES SYSTEM                                                                                                              
                                                                                                                                    
   Eye                                                (288)                                                                         
      Lymphoma Malignant Mixed                         1                                                                            
      Iris, Melanoma Malignant                         1                                                                            
   Harderian Gland                                    (34)                                                                          
      Adenocarcinoma                                  19 (56%)                                                                      
      Adenoma                                         15 (44%)                                                                      
      Lymphoma Malignant Histiocytic                   1 (3%)                                                                       
      Lymphoma Malignant Mixed                         2 (6%)                                                                       
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                             Page  27                                                               
                                                                                                                                   
NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
____________________________________________________________________________________________________________________________________
                                                                                                                                    
         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
                                                                                                                                    
 URINARY SYSTEM                                                                                                                     
                                                                                                                                    
   Kidney                                             (298)                                                                         
      Adenoma                                          8 (3%)                                                                       
      Carcinoma                                        8 (3%)                                                                       
      Fibrosarcoma, Metastatic, Skeletal Muscle        1                                                                            
      Hemangioma                                       2 (1%)                                                                       
      Hemangiosarcoma                                  3 (1%)                                                                       
      Hemangiosarcoma, Metastatic, Lymph Node,                                                                                      
           Mesenteric                                  1                                                                            
      Hepatocellular Carcinoma, Metastatic, Liver      1                                                                            
      Leiomyosarcoma, Metastatic, Epididymis           1                                                                            
      Lymphoma Malignant Histiocytic                   3 (1%)                                                                       
      Lymphoma Malignant Lymphocytic                  16 (5%)                                                                       
      Lymphoma Malignant Mixed                        36 (12%)                                                                      
      Lymphoma Malignant Undifferentiated Cell Type    2 (1%)                                                                       
      Mixed Tumor Malignant, Metastatic, Intestine                                                                                  
          Small, Duodenum                              1                                                                            
      Neurofibrosarcoma, Metastatic, Skin              1                                                                            
   Urinary Bladder                                    (286)                                                                         
      Hemangiosarcoma                                  1                                                                            
      Lymphoma Malignant Lymphocytic                   3 (1%)                                                                       
      Lymphoma Malignant Mixed                        15 (5%)                                                                       
      Lymphoma Malignant Undifferentiated Cell Type    1                                                                            
                                                                                                                                    
____________________________________________________________________________________________________________________________________
                                                                                                                                    
 SYSTEMIC LESIONS                                                                                                                   
                                                                                                                                    
   Multiple Organs                                   *(300)                                                                         
      Lymphoma Malignant Histiocytic                   9 (3%)                                                                       
      Lymphoma Malignant Lymphocytic                  25 (8%)                                                                       
      Lymphoma Malignant Mixed                        69 (23%)                                                                      
      Lymphoma Malignant Undifferentiated Cell         3 (1%)                                                                       
      Mesothelioma Benign                              1 (%)                                                                        
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     *   Number of animals with any tissue examined microscopically                                                                 
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
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NTP Experiment-Test: 05126-02               INCIDENCE RATES OF NEOPLASMS BY ANATOMIC SITE (a)                     Report: PEIRPT02
Study Type: CHRONIC-LIFETIME                                MOUSE AGEING STUDY                                    Date: 11/06/02  
Route: NOT APPLICABLE                                                                                             Time: 11:05:35  
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         B6C3F1 MICE MALE                          LIFETIME                                                                         
                                                                                                                                    
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TUMOR SUMMARY                                                                                                                       
                                                                                                                                    
   Total Animals with Primary Neoplasms (b)           282                                                                           
     Total Primary Neoplasms                          733                                                                           
                                                                                                                                    
   Total Animals with Benign Neoplasms                211                                                                           
     Total Benign Neoplasms                           327                                                                           
                                                                                                                                    
   Total Animals with Malignant Neoplasms             252                                                                           
     Total Malignant Neoplasms                        406                                                                           
                                                                                                                                    
   Total Animals with Metastatic Neoplasms             63                                                                           
     Total Metastatic Neoplasm                        132                                                                           
                                                                                                                                    
   Total Animals with Malignant Neoplasms                                                                                           
   Uncertain Primary Site                                                                                                           
                                                                                                                                    
   Total Animals with Neoplasms Uncertain-                                                                                          
   Benign or Malignant                                                                                                              
     Total Uncertain Neoplasms                                                                                                      
                                                                                                                                    
                                                                                                                                    
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a  Number of animals examined microscopically at site and number of animals with lesion                                             
b  Primary tumors: all tumors except metastatic tumors                                                                              
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
                                                                                                                                    
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