National Cancer Institute 

CARCINOGENESIS 

Technical Report Series 

No. 48 

1978 

BIOASSAY OF 

PYRAZINAMIDE 

FOR POSSIBLE CARCINOGENICITY 

CAS No. 98-96-4 

NCI-CG-TR-48 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE 

Public Health Service 

National Institutes of Health 

BIOASSAY OF
 

PYRAZINAMIDE
 

FOR POSSIBLE CARCINOGENICITY
 

Carcinogenesis Testing Program
 

Division of Cancer Cause and Prevention
 

National Cancer Institute
 

National Institutes of Health
 

Bethesda, Maryland 20014
 

U.S. DEPARTMENT OF HEALTH, EDUCATION, AND WELFARE
 

Public Health Service
 

National Institutes of Health
 

DREW Publication No. (NIH) 78-848
 

BIOASSAY OF
 

PYRAZINAMIDE
 

FOR POSSIBLE CARCINOGENICITY
 

Carcinogenesis Testing Program
 

Division of Cancer Cause and Prevention
 

National Cancer Institute
 

National Institutes of Health
 

CONTRIBUTORS; This report presents the results of the bioassay
 

of pyrazinamide conducted for the Carcinogenesis Testing Program,
 

Division of Cancer Cause and Prevention, National Cancer
 

Institute (NCI), Bethesda, Maryland. The bioassay was conducted
 

by Southern Research Institute, Birmingham, Alabama, initially
 

under direct contract to NCI and currently under a subcontract to
 

Tracer Jitco, Inc., prime contractor for the NCI Carcinogenesis
 

Testing Program.
 

The experimental design and doses were determined by Drs. D. P.
 

Griswoldl, J. D. Prejean*, E. K. Weisburger^, and J. H.
 

Weisburger^'3. Ms. J. Belzer^ and Mr. I. Brown-"- were responsible
 

for the care and feeding of the laboratory animals. Data management and retrieval were performed by Ms. C. A. Dominick.1.
 

Histopathologic examinations were performed by Drs. S. D.
 

Kosanke* and J. C. Peckham , and the diagnoses included in this
 

report represent their interpretation.
 

Animal pathology tables and survival tables were compiled at EG&G
 

Mason Research Institute^. The statistical analyses were performed by Dr. J. R. Joiner-*, using methods selected for the
 

bioassay program by Dr. J. J. Gart°. Chemicals used in this
 

bioassay were analyzed under the direction of Dr. E. Murrill ,
 

and the analytical results were reviewed by Dr. C. W. Jameson^.
 

This report was prepared at Tracer Jitco^ under the direction of
 

NCI. Those responsible for the report at Tracer Jitco were
 

Dr. Marshall Steinberg, Director of the Bioassay Program; Dr. L.
 

A. Campbell, Deputy Director for Science; Drs. J. F. Robens and
 

C. H. Williams, toxicologists; Dr. R. L. Schueler, pathologist;
 

ill
 
Dr. G. L. Miller, Ms. L. A. Waitz, and Mr. W. D. Reichardt,
 

bioscience writers; and Dr. E. W. Gunberg, technical editor,
 

assisted by Ms. Y. E. Presley.
 

The statistical analysis was reviewed by members of the
 

Mathematical Statistics and Applied Mathematics Section of NCI6:
 

Dr. John J. Gart, Mr. Jun-mo Nam, Dr. Hugh M. Pettigrew, and Dr.
 

Robert E. Tarone.
 

The following other scientists at NCI were responsible for
 

evaluating the bioassay experiment, interpreting the results, and
 

reporting the findings:
 

Dr. Kenneth C. Chu
 

Dr. Cipriano Cueto, Jr.
 

Dr. J. Fielding Douglas
 

Dr. Dawn G. Goodman
 

Dr. Richard A. Griesemer
 

Dr. Harry A. Milman
 

Dr. Thomas W. Orme
 

Dr. Robert A. Squire**
 

Dr. Jerrold M. Ward
 

Southern Research Institute, 2000 Ninth Avenue South,
 

Birmingham, Alabama.
 

^Carcinogenesis Testing Program, Division of Cancer Cause and
 

Prevention, National Cancer Institute, National Institutes of
 

Health, Bethesda, Maryland.
 

%ow with the Naylor Dana Institute for Disease Prevention,
 

American Health Foundation, Hammond House Road, Valhalla,
 

New York.
 

Mason Research Institute, 1530 East Jefferson Street,
 

Rockville, Maryland.
 

5

Tracor Jitco, Inc., 1776 East Jefferson Street, Rockville,
 

Maryland.
 

iv
 
"Mathematical Statistics and Applied Mathematics Section,
 

Biometry Branch, Field Studies and Statistics, Division of
 

Cancer Cause and Prevention, National Cancer Institute, National
 

Institutes of Health, Bethesda, Maryland.
 

^Midwest Research Institute, 425 Volker Boulevard, Kansas City,
 

Missouri.
 

%ow with the Division of Comparative Medicine, Johns Hopkins
 

University, School of Medicine, Traylor Building, Baltimore,
 

Maryland.
 

SUMMARY
 

A bioassay of the tuberculostatic drug pyrazinamlde for possible
 

carcinogenicity was conducted by administering the test chemical
 

in feed to Fischer 344 rats and B6C3F1 mice.
 

Groups of 35 rats and 35 mice of each sex were administered
 

pyrazinamide at one of two doses, either 5,000 or 10,000 ppm, for
 

78 weeks, and then observed for an additional 26 or 27 weeks.
 

Matched controls consisted of groups of 15 untreated rats and 15
 

untreated mice of each sex. High-dose male mice died or were
 

killed by week 92; all other surviving animals were killed at
 

weeks 104 or 105.
 

Mean body weights of the dosed male rats were slightly lower than
 

those of the matched controls, while mean body weights of the
 

dosed females were more nearly comparable to those of the
 

controls. A sufficient number of rats in each group was at risk
 

to termination of the study at weeks 104-105 for the development
 

of late-appearing tumors.
 

In mice, administration of pyrazinamide had no consistent effect
 

on mean body weights. Survival to termination of the study was
 

low, particularly among the control groups.
 

In rats, no lesions could clearly be related to administration of
 

the chemical.
 

In mice, interstitial and suppurative myocarditis in the dosed
 

animals and suppurative bronchopneumonias in both dosed and
 

matched-control mice of each sex were associated with increased
 

deaths. In the females, there was a significant positive dose-


related trend (P = 0.037) in the incidence of lymphoma (matched
 

controls 0/13, low-dose 2/25, high-dose 6/29); however, the
 

incidences in each of the dosed groups were not significant when
 

vii
 
compared with that in the matched controls. In addition, the
 

poor survival and the small size of the control group precluded
 

making a clear association of the incidence of these tumors with
 

administration of the chemical.
 

It is concluded that under the conditions of this bioassay, the
 

early deaths and small size of the control group precluded a
 

conclusion regarding the carcinogenicity of pyrazinamide in
 

female B6C3F1 mice. Pyrazinamide was not carcinogenic for
 

Fischer 344 rats or for male mice.
 

viii
 
TABLE OF CONTENTS
 

Page
 

I. Introduction 1
 

II. Materials and Methods 3
 

A. Chemical 3
 

B. Dietary Preparation 3
 

C. Animals 4
 

D. Animal Maintenance 4
 

E. Subchronic Studies 7
 

F. Designs of Chronic Studies 8
 

G. Clinical and Pathologic Examinations 8
 

H. Data Recording and Statistical Analyses 12
 

III. Results - Rats 17
 

A. Body Weights and Clinical Signs (Rats) 17
 

B. Survival (Rats) 17
 

C. Pathology (Rats) 20
 

D. Statistical Analyses of Results (Rats) 21
 

IV. Results - Mice 23
 

A. Body Weights and Clinical Signs (Mice) 23
 

B. Survival (Mice) 23
 

C. Pathology (Mice) 25
 

D. Statistical Analyses of Results (Mice) 28
 

V. Discussion 29
 

VI. Bibliography 33
 

APPENDIXES
 

Appendix A Summary of the Incidence of Neoplasms in
 

Rats Fed Pyrazinamide in the Diet 35
 

Table Al Summary of the Incidence of Neoplasms in
 

Male Rats Fed Pyrazinamide in the Diet 37
 

Table A2 Summary of the Incidence of Neoplasms in
 

Female Rats Fed Pyrazinamide in the Diet 40
 

IX
 
Page 

Appendix B Summary of the Incidence of Neoplasms in 

Mice Fed Pyrazinamide in the Diet 43 

Table Bl Summary of the Incidence of Neoplasms in 

Male Mice Fed Pyrazinamide in the Diet 45 

Table B2 Summary of the Incidence of Neoplasms in 

Female Mice Fed Pyrazinamide in the Diet 48 

Appendix C Summary of the Incidence of Nonneopiastic 

Lesions in Rats Fed Pyrazinamide in the Diet 51 

Table Cl Summary of the Incidence of Nonneoplastic 

Lesions in Male Rats Fed Pyrazinamide 

in the Diet 53 

Table C2 Summary of the Incidence of Nonneoplastic 

Lesions in Female Rats Fed Pyrazinamide 

in the Diet 57 

Appendix D Summary of the Incidence of Nonneoplastic 

Lesions in Mice Fed Pyrazinamide 

in the Diet 61 

Table Dl Summary of the Incidence of Nonneoplastic 

Lesions in Male Mice Fed Pyrazinamide 

in the Diet 63 

Table D2 Summary of the Incidence of Nonneoplastic 

Lesions in Female Mice Fed Pyrazinamide 

in the Diet 67 

Appendix E Analyses of the Incidence of Primary Tumors 

in Rats Fed Pyrazinamide in the Diet 71 

Table El Analyses of the Incidence of Primary Tumors 

in Male Rats Fed Pyrazinamide in the Diet 73 

Table E2 Analyses of the Incidence of Primary Tumors 

in Female Rats Fed Pyrazinamide 

in the Diet 78 

x
 
Page 

Appendix F Analyses of the Incidence of Primary Tumors 

in Mice Fed Pyrazinamide in the Diet 85 

Table Fl Analyses of the Incidence of Primary Tumors 

in Male Mice Fed Pyrazinamide in the Diet 87 

Table F2 Analyses of the Incidence of Primary Tumors 

in Female Mice Fed Pyrazinamide in the Diet 89 

TABLES 

Table 1 Design of Pyrazinamide Chronic Feeding 

Studies in Rats 8 

Table 2 Design of Pyrazinamide Chronic Feeding 

Studies in Mice 9 

FIGURES 

Figure 1 Growth Curves for Rats Fed Pyrazinamide 

in the Diet 18 

Figure 2 Survival Curves for Rats Fed Pyrazinamide 

in the Diet 19 

Figure 3 Growth Curves for Mice Fed Pyrazinamide 

in the Diet 24 

Figure 4 Survival Curves for Mice Fed Pyrazinamide 

in the Diet 26 

xi
 

I. INTRODUCTION
 

Pyrazinamide (pyrazinecarboxamide; CAS 98-96-4; NCI C01785) is a
 

tuberculostatic agent which differs from nicotinamide by the
 

replacement of the pyridine ring with a pyrazine ring. The
 

inhibition of bacterial growth that pyrazinamide causes is
 

believed to be due to its promotion of an acidic environment
 

(Smith, 1977). Pyrazinamide is used in the treatment of
 

lymphadenitis, and pulmonary, miliary, renal, and meningeal
 

tubercular infections caused by Mycobacterium tuberculosis and
 

atypical mycobacteria. It is administered only where resistance
 

has developed to primary drugs, or where there has been no
 

response to these drugs (Pratt, 1973; Weinstein, 1975). It is
 

one of the more toxic antitubercular agents; its most common and
 

serious side effect is liver damage. Pyrazinamide is given
 

orally at a daily dose not greater than 3 grams, and always in
 

combination with another antitubercular drug (Weinstein, 1975;
 

Smith, 1977). Pyrazinamide was selected for testing in the
 

carcinogenesis program in an attempt to evaluate the
 

carcinogenicity of certain drugs that may be used in humans for
 

prolonged periods.
 

II. MATERIALS AND METHODS 

A. Chemical
 

Pyrazinamide was obtained in several batches from the Aldrich
 

Chemical Company, Inc., Milwaukee, Wisconsin. The purity and
 

identity of the batch (Lot No. 083027) used in the chronic study
 

was confirmed by analysis at Midwest Research Institute. The
 

melting point was 190-192°C (literature: 189-191°C). Elemental
 

analyses (C, H, N) were correct for C5H5N30, the molecular
 

formula of pyrazinamide. Nuclear magnetic resonance, infrared,
 

and ultraviolet spectra were in agreement with the structure.
 

The chemical used for the chronic study was stored in the
 

original container at 5°C.
 

B. Dietary Preparation
 

Test diets containing pyrazinamide were prepared every 2 weeks by
 

mixing a known amount of the sifted chemical with a small amount
 

of Wayne® Lab Blox animal meal (Allied Mills, Inc., Chicago,
 

111.) in a portable mixer. The mixture was then added to the
 

required amount of animal meal and mixed in a twin-shell blender
 

for 10 minutes.
 

The prepared diets were stored at room temperature in sealed
 
plastic containers. No analyses for concentration or stability
 

of pyrazinamide in feed were performed.
 

C. Animals
 

For the subchronic study, male Sprague-Dawley rats and male Swiss
 

mice were obtained from Charles River Breeding Laboratories,
 

Inc. , Wilmington, Massachusetts.
 

For the chronic study, Fischer 344 rats and B6C3F1 mice of both
 

sexes were obtained from Charles River Laboratories under a
 

contract with the Division of Cancer Treatment, National Cancer
 

Institute. The animals were 30 days of age on arrival at the
 

laboratory and were quarantined for 12 days. Animals with no
 

clinical signs of disease were then assigned to control and
 

treated groups and earmarked for individual identification.
 

D. Animal Maintenance
 

All animals were housed in temperature- and humidity-controlled
 

rooms. The temperature range was 20-24°C, and the relative
 

humidity was maintained at 40-60%. The air was changed 15 times
 

per hour, and passed through both intake and exhaust fiberglass
 

roughing filters. In addition to natural light, illumination was
 

provided by fluorescent light for 9 hours per day. Food and
 

water were supplied daily and were available ad libitum.
 
Rats were housed five per cage and mice seven per cage in solid-


bottom stainless steel cages (Hahn Roofing and Sheet Metal Co. ,
 

Birmingham, Ala.). The bottoms of the rat cages were lined with
 

(D
 Iso-Dri hardwood chips (Carworth, Edison, N.J.), and cage tops
 

were covered with disposable filter bonnets; mouse cages were
 

provided with Sterolit® clay bedding (Englehard Mineral and
 

Chemical Co., New York, N.Y.). Bedding was replaced once per
 

week; cages, water bottles, and feeders were sanitized at 82°C
 

once per week; and racks were cleaned once per week.
 

The rats and mice were housed in separate rooms. Control animals
 

were housed with respective treated animals. Animals treated
 

with pyrazinamide were maintained in the same rooms as animals of
 

the same species being treated with the following chemicals:
 

RATS
 

Feed Studies
 

4-acetyl-N-((eyelohexylamino)carbonyl)benzenesulfonamide
 

(acetohexamide) (CAS 968-81-0)
 

anthranilic acid (CAS 118-92-3)
 

l-butyl-3-(p-tolylsulfonyl)urea (tolbutamide) (CAS 64-77-7)
 

4-chloro-N-((propylamino)carbonyl)benzenesulfonamide
 

(chlorpropamide) (CAS 94-20-2)
 

5-(4-chlorophenyl)-6-ethyl-2,4-pyrimidinediamine
 

(pyrimethamine) (CAS 58-14-0)
 

2,6-diamino-3-(phenylazo)pyridine hydrochloride
 

(phenazopyridine hydrochloride) (CAS 136-40-3)
 

L-tryptophan (CAS 73-22-3)
 

N-9H-fluoren-2-ylacetamide (CAS 53-96-3)
 

N-(p-toluenesulfonyl)-N'-hexamethyleniminourea
 

(tolazamide) (CAS 1156-19-0)
 

1-phenethylbiguanide hydrochloride (phenformin) (CAS 114-86-3)
 
4,4'-sulfonyldianiline (dapsone) (CAS 80-08-0)
 

4,4'-thiodianiline (CAS 139-65-1)
 

ethionamide (CAS 536-33-4)
 

MICE
 

Feed Studies
 

4-acetyl-N-((cyclohexylamino)carbonyl)benzenesulfonamide
 

(acetohexamide) (CAS 968-81-0)
 

anthranilic acid (CAS 118-92-3)
 

l-butyl-3-(p-tolylsulfonyl)urea (tolbutamide) (CAS 64-77-7)
 

4-chloro-N-((propylamino)carbonyl)benzenesulfonamide
 

(chlorpropamide) (CAS 94-20-2)
 

5-(4-chlorophenyl)-6-ethyl-2,4-pyrimidinediamine
 

(pyrimethamine) (CAS 58-14-0)
 

2,6-diamino-3-(phenylazo)pyridine hydrochloride
 

(phenazopyridine hydrochloride) (CAS 136-40-3)
 

L-tryptophan (CAS 73-22-3)
 

N-9H-fluoren-2-ylacetamide (CAS 53-96-3)
 

N-(p-toluenesulfonyl)-N'-hexamethyleniminourea
 

(tolazamide) (CAS 1156-19-0)
 

1-phenethylbiguanide hydrochloride (phenformin) (CAS 114-86-3)
 

4,4'-sulfonyldianiline (dapsone) (CAS 80-08-0)
 

4,4'-thiodianiline (CAS 139-65-1)
 

ethionamide (CAS 536-33-4)
 

Gavage Studies
 

cholesterol (p-(bis(2-chloroethyl)amino)phenyl)acetate
 

(phenesterin) (CAS 3546-10-9)
 

estradiol bis((p-(bis(2-chloroethyl)amino)phenyl)acetate)
 

(estradiol mustard) (CAS 22966-79-6)
 

Intraperitoneal Injection Studies
 

4'-(9—acridinylamino)methansulfon-m-aniside monohydrochloride
 

(MAAM) (NSC 141549)
 

acronycine (CAS 7008-42-6)
 

5-azacytidine (CAS 320-67-2)
 

beta-2'-deoxy-6-thioguanosine monohydrate (beta-TGdR)
 

(CAS 789-61-7)
 

1,4-butanediol dimethanesulfonate (busulfan) (CAS 55-98-1)
 

emetine dihydrochloride tetrahydrate (CAS 316-42-7)
 

3,3'-iminobis-l-propanol dimethanesulfonate (ester)
 

hydrochloride [IPD] (CAS 3458-22-8)
 
(+)-4,4'-(l-methyl-l,2-ethanediyl)bis-2,6-piperazinedione
 

(ICRF-159) (CAS 21416-87-5)
 

N,3-bis(2-chloroethyl)tetrahydro-2H-l,3,2-oxazaphosphorin-2­

amine-2-oxide (isophosphamide) (CAS 3778-73-2)
 

N-(2-chloroethyl)-N-(l-methyl-2-phenoxyethyl)benzylamine
 

hydrochloride (phenoxybenzamine) (CAS 63-92-3)
 

N-(l-methylethyl)-4-((2-methylhydrazino)methyl)benzamide
 

monohydrochloride (procarbazine) (CAS 366-70-1)
 

tris(l-aziridinyl)phosphine sulfide (thio-TEPA) (CAS 52-24-4)
 

2,4,6-tris(dimethylamino)-s-triazine (CAS 645-05-6)
 

E. Subchronic Studies
 

Subchronic feeding studies were conducted to estimate the maximum
 

tolerated doses of pyrazinamide, on the basis of which low and
 

high concentrations (hereinafter referred to as "low doses" and
 

"high doses") were determined for administration in the chronic
 

studies. In the Subchronic studies, pyrazinamide was added to
 

the animal feed in concentrations of 1,000, 5,000, 10,000,
 

25,000, or 50,000 ppm for both male Sprague-Dawley rats and male
 

Swiss mice. Treated groups each consisted of five animals.
 

Control groups consisted of 19 untreated male rats and 20
 

untreated male mice. The treated groups were fed the test diets
 

for 45 days, then observed for an additional 45 days.
 

In rats, one animal receiving 50,000 ppm died during week 10 of
 

the study. After 45 days, mean body weight gains of the groups
 

of rats at 1,000 to 10,000 ppm were 93-94% of the gains of the
 

control group, gains of rats at 25,000 ppm were 70%, and gains of
 

rats at 50,000 ppm were 43%. After 90 days, mean weight gains in
 
all treated groups of rats were at least 90% of those of the
 

controls except in the 50,000 ppm group, where they were only
 

77%. No gross abnormalities were found at necropsy. The low and
 

high doses for the chronic studies using rats were set at 5,000
 

and 10,000 ppm.
 

In mice, two animals receiving 50,000 ppm died during week 4,
 

four animals at 25,000 ppm died during week 7, and one animal at
 

10,000 ppm died during week 13. Three control animals also died.
 

After 45 days, mean body weight gains in the groups of mice
 

treated at 1,000 and 5,000 ppm were comparable to those of the
 

control groups, gains in mice at 10,000 and 25,000 ppm were 80%
 

of those of the controls, and gains in mice at 50,000 ppm were
 

33%. After 90 days, mean weight gains in all treated groups of
 

mice were comparable to those of the controls, except at 50,000
 

ppm, where gains were 83% of those of the controls. No gross
 

abnormalities were found at necropsy. The low and high doses for
 

the chronic studies using mice were set at 5,000 and 10,000 ppm.
 

F. Designs of Chronic Studies
 

The designs of the chronic studies are shown in tables 1 and 2.
 

G. Clinical and Pathologic Examinations
 

All animals were observed twice daily for signs of toxicity, and
 
Table 1. Design of Pyrazinamide Chronic Feeding Studies in Rats
 

Sex and 

Test 

Initial 

No. of 

Pyrazinamide 

in Dietb 

Time 

Treated 

on Study 

Untreated 

Group Animals3 (ppm) (weeks ) (weeks ) 

Male 

Matched-Control 15 0 105 

Low-Dose 35 5,000 78 26 

High-Dose 36C 10,000 78 26 

Female 

Matched-Control 15 0 105 

Low-Dose 35 5,000 78 27 

High-Dose 34c 10,000 78 26 

a

All animals were 42 days of age when placed on study.
 

^Treated animals were fed test diets 5 days per week and control
 

diets 2 days per week. All treated animals were fed control
 

diets for 3 days during week 66.
 

C

0ne high-dose animal was missexed at the start of the study.
 
Table 2. Design of Pyrazinamide Chronic Feeding Studies in Mice
 

Sex and 

Test 

Group 

Initial 

No. of 

Animals3 

Pyrazinamide 

in Dietb 

(ppm) 

Time 

Treated 

(weeks ) 

on Study 

Untreated 

(weeks ) 

Male 

Matched-Control 15 0 104 

Low-Dose 35 5,000 78 26 

High-Dose 35 10,000 78 14C 

Female 

Matched-Control 15 0 104 

Low-Dose 35 5,000 78 26 

High-Dose 35 10,000 78 26 

a

All animals were 42 days of age when placed on study.
 

^Treated animals were fed test diets 5 days per week and control
 

diets 2 days per week. All mice at 10,000 and 5,000 ppm were
 

fed control diets for 3 days during week 66.
 

C

A11 high-dose male mice died or were killed by week 92.
 

10
 
animals that were moribund were killed and necropsied, except for
 

those dying prior to day 100, due, presumably, to toxicity of the
 

test chemical. Rats and mice were weighed individually once
 

every 2 weeks for 20 months and once per month thereafter.
 

Palpation for masses was carried out at each weighing.
 

The pathologic evaluation consisted of gross and microscopic
 

examination of major tissues, major organs, and all gross lesions
 

from killed animals and from animals found dead. The following
 

tissues were examined microscopically: skin, muscle, lungs and
 

bronchi, trachea, bone and bone marrow, spleen, lymph nodes,
 

thymus, heart, salivary gland, liver, gallbladder and bile duct
 

(mice), pancreas, esophagus, stomach, small intestine, large
 

intestine, kidney, urinary bladder, pituitary, adrenal, thyroid,
 

parathyroid, mammary gland, prostate or uterus, testis or ovary,
 

brain, and sensory organs. Peripheral blood smears were prepared
 

from each animal killed. Occasionally, additional tissues'were
 

also examined microscopically. The different tissues were preserved in 10% buffered formalin, embedded in paraffin, sectioned,
 

and stained with hematoxylin and eosin. Special staining techniques were utilized when indicated for more definitive diagnosis.
 

A few tissues from some animals were not examined, particularly
 

from those animals that died early. Also, some animals were
 

missing, cannibalized, or judged to be in such an advanced state
 

11
 
of autolysis as to preclude histopathologic evaluation. Thus,
 

the number of animals from which particular organs or tissues
 

were examined microscopically varies, and does not necessarily
 

represent the number of animals that were placed on study in each
 

group.
 

H. Data Recording and Statistical Analyses
 

Pertinent data on this experiment have been recorded in an automatic data processing system, the Carcinogenesis Bioassay Data
 

System (Linhart et al., 1974). The data elements include descriptive information on the chemicals, animals, experimental design,
 

clinical observations, survival, body weight, and individual
 

pathologic results, as recommended by the International Union
 

Against Cancer (Berenblum, 1969). Data tables were generated for
 

verification of data transcription and for statistical review.
 

These data were analyzed using the statistical techniques
 

described in this section. Those analyses of the experimental
 

results that bear on the possibility of carcinogenicity are
 

discussed in the statistical narrative sections.
 

Probabilities of survival were estimated by the product-limit
 

procedure of Kaplan and Meier (1958) and are presented in this
 

report in the form of graphs. Animals were statistically
 

censored as of the time that they died of other than natural
 

12
 
causes or were found to be missing; animals dying from natural
 

causes were not statistically censored. Statistical analyses for
 

a possible dose-related effect on survival used the method of Cox
 

(1972) for testing two groups for equality and Tarone's (1975)
 

extensions of Cox's methods for testing for a dose-related trend.
 

One-tailed P values have been reported for all tests except the
 

departure from linearity test, which is only reported when its
 

two-tailed P value is less than 0.05.
 

The incidence of neoplastic or nonneoplastic lesions has been
 

given as the ratio of the number of animals bearing such lesions
 

at a specific anatomic site (numerator) to the number of animals
 

in which that site is examined (denominator). In most instances,
 

the denominators included only those animals for which that site
 

was examined histologically. However, when macroscopic examination was required to detect lesions prior to histologic sampling
 

(e.g., skin or mammary tumors), or when lesions could have
 

appeared at multiple sites (e.g., lymphomas), the denominators
 

consist of the numbers of animals necropsied.
 

The purpose of the statistical analyses of tumor incidence is to
 

determine whether animals receiving the test chemical developed a
 

significantly higher proportion of tumors than did the control
 

animals. As a part of these analyses, the one-tailed Fisher
 

exact test (Cox, 1970) was used to compare the tumor incidence of
 

13
 
a control group with that of a group of treated animals at each
 

dose level. When results for a number of treated groups (k) are
 

compared simultaneously with those for a control group, a
 

correction to ensure an overall significance level of 0.05 may be
 

made. The Bonferroni inequality (Miller, 1966) requires that the
 

P value for any comparison be less than or equal to 0.05/k. In
 

cases where this correction was used, it is discussed in the
 

narrative section. It is not, however, presented in the tables,
 

where the Fisher exact P values are shown.
 

The Cochran-Armitage test for linear trend in proportions, with
 

continuity correction (Armitage, 1971), was also used. Under the
 

assumption of a linear trend, this test determines if the slope
 

of. the dose-response curve is different from zero at the one-


tailed 0.05 level of significance. Unless otherwise noted, the
 

direction of the significant trend is a positive dose relationship. This method also provides a two-tailed test of departure
 

from linear trend.
 

A time-adjusted analysis was applied when numerous early deaths
 

resulted from causes that were not associated with the formation
 

of tumors. In this analysis, deaths that occurred before the
 

first tumor was observed were excluded by basing the statistical
 

tests on animals that survived at least 52 weeks, unless a tumor
 

was found at the anatomic site of interest before week 52. When
 

14
 
such an early tumor was found, comparisons were based exclusively
 

on animals that survived at least as long as the animal in which
 

the first tumor was found. Once this reduced set of data was
 

obtained, the standard procedures for analyses of the incidence
 

of tumors (Fisher exact tests, Cochran-Armitage tests, etc.) were
 

followed.
 

When appropriate, life-table methods were used to analyze the
 

incidence of tumors. Curves of the proportions surviving without
 

an observed tumor were computed as in Saffiotti et al. (1972).
 

The week during which an animal died naturally or was sacrificed
 

was entered as the time point of tumor observation. Cox's
 

methods of comparing these curves were used for two groups;
 

Tarone's extension to testing for linear trend was used for three
 

groups. The statistical tests for the incidence of tumors which
 

used life-table methods were one-tailed and, unless otherwise
 

noted, in the direction of a positive dose relationship.
 

Significant departures from linearity (P < 0.05, two-tailed test)
 

were also noted.
 

The approximate 95 percent confidence interval for the relative
 

risk of each treated group compared to its control was calculated
 

from the exact interval on the odds ratio (Gart, 1971). The
 

 wnere

 Pt is tne
 relative risk is defined as Pt/Pc true binomial
 

probability of the incidence of a specific type of tumor in a
 

15
 
treated group of animals and pc is the true probability of the
 

spontaneous incidence of the same type of tumor in a control
 

group. The hypothesis of equality between the true proportion of
 

a specific tumor in a treated group and the proportion in a
 

control group corresponds to a relative risk of unity. Values in
 

excess of unity represent the condition of a larger proportion in
 

the treated group than in the control.
 

The lower and upper limits of the confidence interval of the
 

relative risk have been included in the tables of statistical
 

analyses. The interpretation of the limits is that in
 

approximately 95% of a large number of identical experiments, the
 

true ratio of the risk in a treated group of animals to that in a
 

control group would be within the interval calculated from the
 

experiment. When the lower limit of the confidence interval is
 

greater than one, it can be inferred that a statistically
 

significant result (P < 0.025 one-tailed test when the control
 

incidence is not zero, P < 0.050 when the control incidence is
 

zero) has occurred. When the lower limit is less than unity, but
 

the upper limit is greater than unity, the lower limit indicates
 

the absence of a significant result while the upper limit
 

indicates that there is a theoretical possibility of the
 

induction of tumors by the test chemical, which could not be
 

detected under the conditions of this test.
 

16
 
III. RESULTS - RATS
 

A. Body Weights and Clinical Signs (Rats)
 

Mean body weights of both low- and high-dose male rats were
 

slightly lower than those of the matched controls throughout the
 

study; those of the low- and high-dose female rats were similar
 

to those of the matched controls during most of the study, except
 

for several months in the second year when the weights of the
 

high-dose group were lower (figure 1). Fluctuations in the
 

growth curve may be due to mortality; as the size of the group
 

diminishes, the mean body weight may be subject to wide
 

variation. Yellowish discoloration of the hair and skin on the
 

ears and feet appeared in a number of treated rats.
 

Some animals showed signs of respiratory disease, and all were
 

treated with oxytetracycline in the drinking water at doses of
 

0.6 mg/ml during weeks 40-44 and 0.3 mg/ml during weeks 44-46.
 

B. Survival (Rats)
 

The Kaplan and Meier curves estimating the probabilities of
 

survival for male and female rats fed pyrazinamide in the diet at
 

the doses of this experiment, together with those of the matched
 

controls, are shown in figure 2.
 

In each sex, the Tarone test result for positive dose-related
 

17
 
MEAN BODY W

MEAN BODY WEIGHT (G) 

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PROBABILITY OF SURVIVAL PROBABILITY OF SU

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trend in mortality over the period is not significant. In male
 

rats, 30/36 (83%) of the high-dose, 29/35 (83%) of the low-dose,
 

and 11/15 (73%) of the matched-control animals lived to the end
 

of the study. In female rats, 29/34 (85%) of the high-dose,
 

21/35 (60%) of the low-dose, and 13/15 (87%) of the matched-


control animals survived to termination of the study. A
 

sufficient number of rats of each sex was at risk for the
 

development of late-appearing tumors.
 

C. Pathology (Rats)
 

Histopathologic findings on neoplasms in rats are summarized in
 

Appendix A, tables Al and A2; findings on nonneoplastic lesions
 

are summarized in Appendix C, tables Cl and C2.
 

A variety of neoplasms occurred in both the control and treated
 

groups. Some types of neoplasms occurred only, or with a greater
 

frequency, in rats of the treated groups when compared with the
 

controls. These lesions, however, are not uncommon in this
 

strain of rat independent of any chemical administration. Few
 

malignant tumors were observed, and tumor metastases were present
 

in only two treated rats.
 

In addition to the neoplastic lesions, a number of degenerative,
 

proliferative, and inflammatory changes were also encountered in
 

20
 
animals of the treated and control groups (Appendix C). These
 

nonneoplastic lesions are commonly seen in aged rats.
 

In the judgment of the pathologists, pyrazinamide was not
 

carcinogenic when fed to Fischer 344 rats under the conditions of
 

this study.
 

D. Statistical Analyses of Results (Rats)
 

Tables El and E2 in Appendix E contain the statistical analyses
 

of the incidences of those primary tumors that occurred in at
 

least two animals in one group and with an incidence of at least
 

5% in one or more than one group.
 

In male rats, the results of the Cochran-Armitage test for dose-


related trend and of the Fisher exact test for direct comparison
 

of the incidences of tumors in the treated groups with those in
 

the matched-control group are not significant in a positive
 

direction. The results of the Cochran-Armitage test for the
 

incidence of leukemia are significant (P = 0.037), but in the
 

negative direction, since the incidence in the control group
 

exceeds those in the treated groups, but the Fisher exact test
 

results were not significant.
 

In female rats, the result of the Cochran-Armitage test for the
 

combined incidence of chromophobe adenoma and carcinoma of the
 

21
 
pituitary is not significant. The Fisher exact test shows that
 

the incidence in the low-dose group is higher than that in the
 

matched controls (P = 0.037); however, this significance level is
 

above the 0.025 level required for significance by the Bonferroni
 

inequality criterion.
 

In each of the 95% confidence intervals, shown in the tables, the
 

value of one is included, indicating the absence of significant
 

positive results. It should also be noted that each of the
 

intervals has an upper limit greater than one, indicating the
 

theoretical possibility of the induction of tumors by
 

pyrazinamide, which could not be detected under the conditions of
 

this test.
 

22
 
IV. RESULTS - MICE
 

A. Body Weights and Clinical Signs (Mice)
 

Mean body weights of the treated male mice were higher than those
 

of the matched controls from about week 25 to the end of the
 

study (figure 3). Mean body weights of the high-dose females
 

were generally equal to or higher than those of the matched
 

controls, while the low-dose females had lower body weights after
 

the feeding of pyrazinamide was completed. Fluctuations in the
 

growth curve may be due to mortality; as the size of the group
 

diminishes, the mean body weight may be subject to wide
 

variation. Difficult breathing and progressive weight loss were
 

noted in individual animals in all groups. No signs of chemical-


related toxicity in the mice were recorded.
 

To control respiratory disease in the mouse colony, all animals
 

were treated with oxytetracycline in the drinking water at, doses
 

of 0.6 mg/ml for 5 days during week 67 and 0.3 mg/ml for the
 

following 5 days during week 68; also, rooms housing the mice
 

were treated with propylene glycol vapor for about 2 months,
 

beginning at week 67.
 

B. Survival (Mice)
 

The Kaplan and Meier curves estimating the probabilities of
 

23
 
(9 

I 30­

UJ 

5 

Q 

O 

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:

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an 

3 ADD

DD

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P 

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MALE MICE 

D MATCHED CONTROL 

O LOW DOSE 

A HIGH DOSE 

20 30 40 SO 80 70 

TIME ON STUDY (WEEKS) 

80 90 100 110 

A A A 

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O 

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o 

o 

16 I FEMALE MICE 

D MATCHED CONTROL 

O LOW DOSE 

A HIGH DOSE 

20 30 40 SO 60 70 

TIME ON STUDY (WEEKS) 

100 110 

Figure 3. Growth Curves For Mice Fed Pyrazinamide In The Diet 

24 
survival for male and female mice fed pyrazinamide in the diet at
 

the doses of this experiment, together with those of the matched
 

controls, are shown in figure 4.
 

In male mice, the Tarone test result for positive dose-related
 

trend in mortality over the period is not significant, with 29/35
 

(83%) of the high-dose group, 33/35 (94%) of the low-dose group,
 

and 9/15 (60%) of the matched controls living beyond week 52 on
 

study. In female mice, the Tarone test is significant (P =
 

0.016), but in the negative direction, with 31/35 (89%) of the
 

high-dose group, 24/35 (69%) of the low-dose group, and 9/15
 

(60%) of the matched controls living beyond week 52 on study. In
 

the female low-dose group, eight animals were reported missing:
 

two at week 10, one at week 31, and five at week 39.
 

C. Pathology (Mice)
 

Histopathologic findings on neoplasms in mice are summarized in
 

Appendix B, tables Bl and B2; findings on nonneoplastic lesions
 

are summarized in Appendix D, tables Dl and D2.
 

A variety of neoplasms occurred in both the control and treated
 

groups. Some types of neoplasms occurred only, or with a greater
 

frequency, in mice of the treated groups when compared with the
 

controls. These lesions, however, are not uncommon in this
 

strain of mouse independent of any chemical administration.
 

25
 
PROBABILITY OF SUR

PROBABILITY OF SURVIVAL 

i 

5

3 3 3 > f> f» !3 f3 • F > ?3 3 1 3 3 

i \>s i J j . 1 !s ;3 S i5 ii S a; £S 1» !5 3 sI 

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g-' 
In addition to the neoplastic lesions, a number of degenerative,
 

proliferative, and inflammatory changes were also encountered in
 

animals of the treated and control groups (Appendix D). These
 

nonneoplastic lesions are commonly seen in aged mice; however,
 

the suppurative lesions involving the heart, trachea, and lungs
 

were associated with increased deaths.
 

Suppurative bronchopneumonias accompanied by suppurative
 

tracheitis occurred in 7/12 (58%) control males, 17/31 (55%)
 

low-dose males, and 17/33 (52%) high-dose males. Similar lesions
 

occurred in 5/13 (38%) control females, 12/24 (50%) low-dose
 

females, and 12/29 (41%) high-dose females. Interstitial and
 

suppurative myocarditis occurred in 10/31 (32%) low-dose males
 

and 13/33 (39%) high-dose males in contrast to 1/24 (4%) low-dose
 

females and 1/29 (3%) high-dose females. None of the control
 

mice had myocarditis. The heart lesions resembled those
 

associated with bacterial infections. In two high-dose male
 

mice, a vegetative valvular endocarditis with large bacterial
 

colonies was observed. The respiratory infections appeared to
 

have resulted from intercurrent disease, whereas the myocarditis
 

appeared to be sex and chemical related.
 

Although this bioassay was complicated by intercurrent disease,
 

pyrazinamide appeared, in the judgment of the pathologists, to
 

27
 
have little or no carcinogenic activity when fed to B6C3F1 mice
 

under the conditions of this study.
 

D. Statistical Analyses of Results (Mice)
 

Tables Fl and F2 in Appendix F contain the statistical analyses
 

of the incidences of those primary tumors that occurred in at
 

least two animals in one group and with an incidence of at least
 

5% in one or more than one group.
 

In male mice, the results of the Cochran-Armitage test for dose-


related trend and of the Fisher exact test for direct comparison
 

of the incidences of tumors in the treated groups with those in
 

the matched-control group are not significant.
 

In female mice, the result of the Cochran-Armitage test for the
 

incidence of lymphoma is significant (P = 0.037), but the results
 

of the Fisher exact test are not significant and the survival of
 

the female controls was less than that of the treated groups.
 

In each of the 95% confidence intervals, shown in the tables, the
 

value of one is included, indicating the absence of significant
 

results. It should also be noted that each of the intervals has
 

an upper limit greater than one, indicating the theoretical
 

possibility of induction of tumors by pyrazinamide, which could
 

not be detected under the conditions of this test.
 

28
 
V. DISCUSSION
 

Administration of pyrazinamide did not appreciably affect the
 

Fischer 344 rats in this bioassay. Mean body weights of the
 

dosed males were only slightly lower than those of the matched
 

controls; those of the dosed females were more nearly comparable
 

to those of the controls; and survival of all groups was high.
 

Mean body weights of the dosed male and female mice were equal to
 

or higher than those of the matched controls throughout most of
 

the study; however, mortality was high among the controls.
 

A sufficient number of each group of rats was at risk to
 

termination of the study for the development of late-appearing
 

tumors. However, survival of the dosed and control mice was too
 

low for meaningful analyses of incidences of tumors appearing
 

after week 52; interstitial and suppurative myocarditis in the
 

dosed mice and suppurative bronchopneumonias in both dosed and
 

matched-control groups of both sexes were associated with these
 

early deaths.
 

In male rats, no tumor appeared in the dosed groups at an
 

incidence significantly different from that in the control
 

groups. In female rats, the incidence of chromophobe adenoma or
 

carcinoma of the pituitary in the low-dose group 14/30 (47%)
 

compared with the matched controls 2/14 (14%) had a probability
 

29
 
level of 0.037; however, this level is above that required for
 

significance by the Bonferroni inequality criterion. The
 

historical incidence of this tumor in female Fischer 344 rats in
 

the bioassay program at this laboratory was 53/235 (23%), which
 

is higher than the incidence in the low-dose group. In addition,
 

the incidence in the high-dose group was not significant in any
 

tests, and the tumor cannot be associated with administration of
 

the chemical.
 

In mice, interstitial and suppurative myocarditis in the dosed
 

animals and suppurative bronchopneumonias in both dosed and
 

matched control mice of both sexes were associated with increased
 

deaths. In female mice, a significant dose-related trend (P =
 

0.037) occurred in the incidence of lymphoma (matched controls
 

0/13, low-dose 2/25, high-dose 6/29); however, the incidences in
 

the dosed groups were not statistically significant when compared
 

with that in the matched controls. In addition, the survival of
 

these controls was less than that of the dosed animals. The
 

incidence in the high-dose group is higher than that of the
 

historical incidence of lymphoma in female mice at this
 

laboratory 42/538 (8%). Thus, the association of lymphoma with
 

administration of the chemical in female mice is not clear and
 

cannot be fully evaluted, due to the small size of the group and
 

30
 
poor survival among the female controls. In male mice, no tumors
 

occurred in a significant incidence.
 

No long-term studies of the toxicity of pyrazinamide in
 

laboratory animals have been reported in the literature. In a
 

7-month study in which pyrazinamide was fed at a concentration of
 

30,000 ppm to 10 female mice of strain dd, pulmonary adenomas
 

occurred in six animals (Mori et al., 1960). Pulmonary tumors
 

were not observed at significant incidences in dosed rats or mice
 

in the present bioassay.
 

It is concluded that under the conditions of this bioassay, the
 

early deaths and small size of the control group precluded a
 

conclusion regarding the carcinogenicity of pyrazinamide in
 

female B6C3F1 mice. Pyrazinamide was not carcinogenic for
 

Fischer 344 rats or for male B6C3F1 mice.
 

31
 

VI. BIBLIOGRAPHY
 

Armitage, P., Statistical Methods in Medical Research, John Wiley
 

& Sons, Inc., New York, 1971, pp. 362-365.
 

Berenblum, I., ed., Carcinogenicity Testing; A. Report of the
 

Panel on Carcinogenicity of the Cancer Research Commission
 

of the UICC, Vol. 2^, International Union Against Cancer,
 

Geneva, 1969.
 

Cox, D. R., Regression models and life tables. J. R. Statist.
 

Soc. B;187-220. 1972, pp. 48-52.
 

Cox, D. R., Analysis of Binary Data, Methuen & Co., Ltd., London,
 

1970.
 

Gart, J. J., The comparison of proportions: a review of
 

significance tests, confidence limits and adjustments for
 

stratification. Rev. Int. Stat. Inst. 39;148-169. 1971.
 

Kaplan, E. L. and Meier, P., Nonparametric estimation from
 

incomplete observations. J. Amer. Statist. Assoc.
 

J>3:457-481, 1958.
 

Linhart, M. S., Cooper, J. A., Martin, R. L., Page, N. P., and
 

Peters, J. A., Carcinogenesis bioassay data system. Comp.
 

and Biomed. Res. _7:230-248, 1974.
 

Miller, R. G., Jr., Simultaneous Statistical Inference,
 

McGraw-Hill Book Co., New York, 1966, pp. 6-10.
 

Mori, K., Yasuno, A., and Matsumoto, K., Induction of pulmonary
 

tumors in mice with isonicotinic acid hydrazid. Gann
 

11:83-89, 1960.
 

Pratt, W. B., The chemotherapy of tuberculosis. In: Fundamentals
 

of Chemotherapy, Oxford University Press, New York, 1973,
 

pp. 19-23.
 

Saffiotti, U., Montesano, R., Sellakumar, A. R., Cefis, F., and
 

Kaufman, D. G., Respiratory tract carcinogenesis in hamsters
 

induced by different numbers of administrations of benzo (a)
 

pyrene and ferric oxide. Cancer Res. 32;1073-1081. 1972.
 

33
 
Smith H., Chemotherapy of tuberculosis. In: Antibiotics in
 

Clinical Practice, University Park Press, Baltimore, Md.,
 

1977, pp. 289-291 and 306-309.
 

Tarone, R. E., Tests for trend in life table analysis. Biometrika
 

.62:679-682, 1975.
 

Weinstein, L., Antimicrobial agents, drugs used in the
 

chemotherapy of tuberculosis and leprosy. In: The
 

Pharmacological Basis of Therapeutics, Goodman, L. S. and
 

Gilman, A., eds., Macmillan Publishing Co., Inc., New York,
 

1975, pp. 1100-1101 and 1212-1213.
 

34
 
APPENDIX A
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

RATS FED PYRAZINAMIDE IN THE DIET
 

35
 

TABLE A1. 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE RATS 

FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE HIGH DOSE 

ANIMALS INITIALLY IN STUDY

ANIMALS NECROPSIEC

ANIHALS EXAMINED HISTOFATHOLOGICALLY

 15

 14

 14

 35

 35

 35

 36 

 36 

 36 

INTEGUMENTARY SYSTEM 

*SUECUT TISSUE

SARCOMA, NOS

FIBFOMA

FIBEOSAEC.OMA

 (14) (35)

 1 (3%) 

1 (3%) 

1 (3X) 

 (36) 

EESFIBAICBY SYSTEM 

#LUNG

FIBBOSARCOMA, METASTATIC

 (14) (35)

 1 (3X) 

 (36) 

HEMATOPCItTIC SYSTEM 

*flULTIPL E CEGAN S

UNCIFFERENTTATE D LEUKEMI A

 (14 )

 2 (14»)

 (35)

 2 (655) 

 (36 ) 

CISCULATOEY SYSTEM 

NONE 

DIGESTIVE SYSTEM 

NONE 

URINAR Y SYSTEM 

NONE 

ENECCaiN E SYSTEM 

#FITUITARY (10) (32)

CHBCMOFHOBE_ ADENOMA l_jd 

* NUMEEE OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

* SUMEEE OF ANIMALS NECROESIED 

 (30) 

37
 
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

CHRONOEHOBE CABCINOMA 1 (3X)
 

tADRENAL (14) (35) (36)
 

PHECCHRCBOCYTCMA 1 OX) 1 (3X)
 

#THYROID (35) (32)
 

FOLLICULAR-CELL CARCINOMA 1 (7X) 1 (3X)
 

C-CELL ADENOMA 2 (14X) 1 <3X) 3 (9S)
 

C-CELL CARCINOMA 3 (9X)
 

tEANCREATIC ISLETS (14) (35) (36)
 

ISIET-CE1L ADENOMA 1 (7%) 3 (9X)
 

EEEfiODOCTIVE SYSTEM
 

*MAMBARY GIAND (14) (35) (36)
 

ADENOCAECINOMA, NOS 1 (3%)
 

#TES1IS (14) (35) (36)
 

INTERSTITIAL-CE1L TUMCR 13 (93X) 30 (86X) 29 (81X)
 

NEBVOU S SYSTEM
 

#E3AIN (13) (34) (36)
 

ASTROCYTOMA 1 (3%)
 

SEECIAL SENSE OEGANS
 

*EAR CANAI (14) (35) (36)
 

SQUAMOOS CEI1 PAPILLOKA 1 (3X)
 

SQUAMODS CELL CARCINOMA 1 (3%)
 

KUSCULCSKEIETAL SYSTEM
 

NONE
 

EOCY CAVI1IES
 

*EERITONEUM (14) (35) (36)
 

MESOTHELIOMA^NOS
 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 * NUMBER OF ANIMALS NECBOESIED
 

38
 
TABLE A1. MALE RATS: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

*ELEUR A (1") (35) (36) 

FIEROSAKCOMA , HETASTATIC 1 (3X) 

A ll CIHER SYSTEMS
 

NONE
 

AMHAl DISPOSITION SUMMARY
 

ANIMALS INITIALLY IN STUDY 15 35 36
 

NATURAL DEATHS
 

MORIBUND SACRIFICE
 

SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE 11 29 30
 

ANIMAL HISSING
 

3 INCLUDES AUTOLYZED ANIMALS
 

1UH08 SUMMARY
 

TOTAL ANIMALS HITH PRIMARY TUMORS* 13 3U 30
 

TOTAL PRIMARY TUMORS 20 51 37
 

TOTAL ANIMALS HITH BENIGN TUHORS 13 32 30
 

TOTAL BENIGN TUMORS 17 HI 33
 

TOTAL ANIMALS WITH MALIGNANT TUMOKS 3 9 2
 

TOTAL MALIGNANT TUMORS 3 10 2
 

TOTAL ANIMALS WITH SECONDARY TUMORSt 1
 

TOTAL SECONDARY TUMORS 2
 

TOTAL ANIMALS HITH TUMORS UNCERTAIH­ EENIGN OR MALIGNANT 2
 

TOTAL UNCERTAIN TUMORS 2
 

TOTAL ANIMALS HITH TUHORS ONCERTAINERIMARY OR METASTATIC
 

TOTAL UNCERTAIN TUMORS
 

* PRIMARY TUMORS: ALL TUHOHS EXCEPT SECONDARY TDBOBS
 

t SECONDARY TUMORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 

39
 
TABLE A2. 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN FEMALE RATS 

FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE HIGH DOSE 

ANIHALS INITIALLY IN STUDY

ANIMALS NECBCFSIEC

ANIMALS EXAMINED HISTOPATHOLOGICALLY

 15

 15

 15

 35

 3U

 3U

 34 

 34 

 3U 

INTEGUMENTARY SYSTEM 

*SUBCUT TISSUE

BASAL-CELL CARCINOMA

 (15) (3U)

 1 (3%) 

 (3U) 

BESPIfiATOfiY SYSTEM 

#LUNG

ALVEOLAR/BRONCHIOLAR ADENOMA

 (15) (33) (3U) 

1 (3S) 

HEKATOPCIETIC SYSTEM 

*MULTIPLE ORGANS

MALIGNANT LYBPHOMA, HIXED TYPE

UNDIFFERENTIATED LEUKEMIA

#SPLEEN

ADENOCARCINOHA, NOS, METASTATIC

 (15)

 2 (13%)

 (15)

 (3U)

 1 (3X) 

2 (6X)

 (3U)

 (3U) 

2 (6X) 

 (3U) 

1 (3S) 

CIRCULATORY SYSTEM 

NONE 

DIGESTIVE SYSTEM 

NOME 

UEINABY SYSTEM 

tURINABY BLADDER

TRANSITIONAL-CELL PAPILLOH*

 (15) (34)

 !_I3_Ji 

 (33) 

# NUMBER OF ANIMALS HITH TISSUE EXAMINED MICROSCOPICALLY 

* NUMBER OF ANIMALS NECROPSIED 

40
 
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED) 

ENECCBINE SYSTEM
 

tPITUITARY
 

CHBOMOEHOBE ADENOMA
 

CHEOMOPHOBE CARCINOMA
 

ttTHYBOID
 

FOLLICULAR-CELL ADENOMA
 

C-CELL ADtNOMA
 

C-CELL CARCINOMA
 

REPRODUCTIVE SYSTEM
 

*MAMMAH Y GLAND
 

PAPILLARY ADENOMA
 

FIBROADENOMA
 

((UTERUS
 

ADENOCARCINOMA, NOS
 

SARCOMA, NOS
 

LEICMYOMA
 

ENDOMETEIAL STROMAL POLYP
 

ftCVARY
 

CYSTADENOMA, NOS
 

NERVOUS SYSTEM
 

#ERAIN
 

OLIGODENDROGLIOMA
 

SPECIAL SENSE ORGANS
 

*EAR CANA L
 

SQUAMOUS CELL CARCINOMA
 

KERATOACANTHOMA
 

HUSCULOSKELITAL	 SYSTEM
 

NONE
 

# NUMBE R OF ANIMAL S MITH TISSUE

* NUMBE R CF ANIMAL S NECEOPSIED 

CONTROL LOW DOSE 

(11*) (30) 

2 (14%) 13 (43%) 

1 (3X) 

(15) (33) 

1 (7%) 

1 (1%) 1 (3%) 

(15)	 (34)
 

1 (3X)
 

4 (21%) 5 (15*)
 

(15)	 (3tt)
 

1 17%)	 1 (3»)
 

2 (6%)
 

1 (3%)
 

3 (20%)	 5 (15%)
 

(15)	 (34)
 

(15)	 (33)
 

1 (7*)
 

(15)	 <3U)
 

1 (7%)
 

 EXAMINE D MICROSCOPICALLY 

41 

HIGH DOSE 

(24)
 

7 (29%)
 

(32)
 

1 (3%)
 

(34)
 

4 (12%)
 

(34)
 

1 (3%)
 

5 (15%)
 

(34)
 

1 (3%)
 

(34)
 

(34)
 

1 (3%)
 
TABLE A2. FEMALE RATS: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

ECCY CAVITIES
 

*PERITONEUM (15) (34) (34)
 

ADENOCARCINOMA, NOS, METASTATIC 1 (3%)
 

All OTHER SYSTEMS
 

NONE
 

ANIMA I DISPOSITION SUMMARY
 

ANIHALS INITIA11Y IN STUDY 15 35
 

NATURAL DEATHS 4
 

MORIBUND SACRIFICE 10
 

SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE 13 21 29
 

ANIMA L MISSING
 

a INCLUDES AU10LYZED ANIMALS
 

TUMOR SUMMAR Y
 

TOTAL ANIMALS WITH PRIMARY TUMORS* 11 26 19
 

TOTAL PRIMARY TUMORS 16 35 23
 

TOTAL ANIMALS WITH BENIGN TUMOES 9 22 15
 

TOTAL BENIGN TUMORS 12 27 18
 

TOTAL ANIMALS WITH KALIGNAN 4 T TUMORS 8 5
 

TOTAL MALIGNANT TUMORS 4 8 5
 

TOTAL ANIMALS WITH SECONDARY TUMOESf 1
 

TOTAL SECONDARY TUMORS 2
 

TOTAL ANIMALS WITH TUMORS UNCERTAIN­ EENIGN OR MALIGNANT
 

TOTAL UNCERTAIN TUMORS
 

TOTAL ANIMALS WITH TUMORS UNCERTAIN­ PRIMARY CR METASTATIC
 

TOTAL UNCERTAIN TUMORS
 

* PRIMARY TUMORS: ALL TUHCRS EXCEPT SECONDARY TUMORS
 

# SECONDARY TUMORS: MiTASTATIC TUMORS OR TUMORS INVASIVE IKTO AN ADJACENT ORGAN
 

42
 
APPENDIX B
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN
 

MICE FED PYRAZINAMIDE IN THE DIET
 

43
 

TABLE B1. 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN MALE 

MICE FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE


ANIMALS INITIALLY IN STUDY 15 35


ANIMALS MISSING 1
 

ANIMALS NECEOESIED 12 31
 ANIMALS EXAMINED HISTOPATHOLOGICALLY 12 31


INTEGUMENTARY SYSTEM
 

NCNE
 

BESEIBATORY SYSTEM
 

NONE
 

HEMATOPCIETIC SYSTEM
 

'MULTIPLE OBGANS (12) (31)


MALIG.LYMPHOMA, LYBPHOCYTIC TYPE 1 (3X)
 

MALIG.LYMPHOMA, HISTIOCYTIC TYPE 2 (6X)


ISPLEEN (12) (31)


MALIGNANT LYMPHOMA, MIXED TYPE 1 (8%)
 

CIRCULATORY SYSTEM
 

NONE
 

DIGESTIVE SYSTEM
 

KLIVER (12) (31)


HEPATOCELLULAE ADENOMA


HEPATOCELLULAR CABCIBOBA 1 (8X)


URINARY SYSTEM
 

NONE
 

ENDOCRINE SYSTEM
 

NONE
 

* NUHBEB OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 * DUMBER OF ANIMALS NECROPSIED
 

 HIGH DOSE
 

 35
 

 33
 

 33
 

 (33)
 

1 (3X)
 

 (33)
 

 (33)
 

2 (6%)
 

1 (3%)
 

45
 
TABLE B1. MALE MICE: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE
 

F.EEEQDUCTIVI SYSTIB
 

*MAHMARY GLAND (12) (31) (33)
 

ADtNOMA, NOS 1 (3%)
 

#TESTIS (12) (31) (32)
 

INTERSTITIAL-CELL TUMOR 1 (3%)
 

NERVOUS SYSTEM
 

"TRIGEMINAL GANGLION (12) (31) (33)
 

NEURILEMOMA, MALIGNANT 1 (3%)
 

SEHCIAL SEKSE OEGANS
 

*HARDERIAN GLAND (12) (31) (33)
 

ADENOMA, NOS 1 (3%)
 

MUSCUIOSKELETAL SYSTEM
 

NONE
 

BOEY CAVITIES
 

NONE
 

AIL OTHER SYSTEMS
 

NONE
 

ANIMAL DISPOSITION SUBHARY
 

ANIBALS INITIALLY IN STUDY 15 35 35
 

NATURAL DEATHS 11 13
 

HORIBOND SACRIFICE 21 22
 

SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERMINAL SACRIFICE
 

ANIMAL HISSING
 

i NUMBER OF ANIMALS HUH TISSUE EXAMINED MICROSCOPICALLY
 * BOMBER OF ANIMALS NECBOFSIED
 

46
 
TABLE B1. MALE MICE: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE
 

TUMOR SUMMABY
 

TOTAL ANIMALS WITH PRIMARY TUHOES* 2 5 6
 

TOTAL PRIMARY TUMORS 2 5 6
 

TOTAL ANIMALS WITH BENIGN TUMORS 1 H
 

TOTAL BENIGN TUMORS 1 H
 

TOTAL ANIMALS WITH MALIGNANT TUMORS 2 4 2
 

TOTAL MALIGNANT TUMORS 2 4 2
 

TOTAL ANIMALS HITH SECONDARY TUMORS#
 

TOTAL SECONDARY TUMORS
 

TOTAL ANIMALS WITH TUMOBS UNCERTAIN­ EENIGN OR MALIGNANT
 

TOTAL UNCERTAIN TUHORS
 

TOTAL ANIMALS HITH TUHORS UNCERTAINERIHABY OP METASTATIC
 

TOTAL UNCERTAIN TUHORS
 

* PRIMARY TUMORS: ALL TUMORS EXCEPT SECONDARY TUHORS
 

# SECONDARY TUMORS: METASTATIC TUHORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 
TABLE B2.
 

SUMMARY OF THE INCIDENCE OF NEOPLASMS IN 

FEMALE MICE FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE HIGH DOSE
 

ANIMALS INITIALLY IN STUDY 15 35 35
 

ANIMALS MISSING 8
 

ANIMALS NECROPSIED 13 25 29
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY 13 25 29
 

INTEGUMENTARY SYSTEM
 

NONE
 

EESEIBATORY SYSTEM
 

#LUNG (13) (2«) (29)
 

ALVEOLAR/BRONCHIOLAR CARCINOMA 1 (8%) 1 (3X)
 

HEBATOPOIETIC SYSTEM
 

*MULTIPLE ORGANS (13) (25) (29)
 

MALIG.LYHPHOMA. LYMPHOCYTIC TYPE 1 (4X)
 

MALIG.LYBPHOHA, HISTIOCYTIC TYPE U (1««)
 

MALIGNANT LYHPHOMA, MIXED TYPE 1 (H%) 2 (7X)
 

CISCUIATOEY SYSTEM
 

NONE
 

DIGESTIVE SYSTEM
 

#LIVER (13) (25) (28)
 

HEPSTOCELLULAR CARCINOMA 1
 

URINARY SYSTEM
 

NONE
 

ENDOCRIN E SYSTEM 

((PITUITARY (8) (18) (20)
 

CJBOBOPJiOBE_ADENOHA_­ 1 (5X1
 

* NUMBER OF ANIMALS KITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECBOPSIED
 

48
 
TABLE B2. FEMALE MICE: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

#EANCRZATIC ISIETS (13) (25) (29)
 

ISLET-CELL ADENOHA 1 (3X) 

6EEEOEUCTIVE SYSTEM
 

*MAMMARY GLAND (13) (25) (29)
 

ADENOMA, NOS 1 («*)
 

SiEVCUS SYSTEM
 

*TRIGEMINAl GANGLION (13) (25) (29)
 

NEURILEMOMA, MALIGNANT 1 (H%)
 

SEECIAL SENSE ORGANS
 

NONE
 

MUSCULOSKELETAL SYSTEM
 

*EONE (13) (25) (29)
 

CSTEOSAKCCMA 1 (4%)
 

EOCY CAVITIES
 

NCNE
 

ALL OTHER SYSTEMS
 

*M'JLTIPLE OEGANS (13) (25) (29)
 

OSTEQSARCOMAX_MET ASTATIC l_li%)
 

* NUMBER OF ANIMALS HITH .TISSUE EXAMINED MICEOSCOPICALLY
 * NUMBER OF ANIMALS NECROPSIED
 

49
 
TABLE B2. FEMALE MICE: NEOPLASMS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE
 

ANIMAL DISPOSITION SUMMARY
 

ANIHALS INITIALLY IN STUDY 15 35 35
 

NATURAL DEATHS 6 2 9
 

MORIBUND SACRIFICE 6 13 10
 

SCHEDULED SACRIFICE
 

ACCIDENTALLY KILLED
 

TERHINAL SACRIFICE 3 12 16
 

ANIMAL HISSING 8
 

3 INCLUDES AUTOLYZED ANIMALS
 

TUKOR SUMMARY
 

TOTAL ANIMAIS WITH PRIMARY TUMORS* 1 5 9
 

TOTAL PRIMARY TUMORS 1 5 10
 

TOTAL ANIMALS WITH BENIGN TUMORS 1 2
 

TOTAL BENIGN TUMORS 1 2
 

TOTAL ANIMALS WITH MALIGNANT TUMORS 1 U 8
 

TOTAL MALIGNANT TUMORS 1 U 6
 

TOTAL ANIMALS WITH SECONDARY TUMORS* 1
 

TOTAL SECONDARY TUMORS 1
 

TOTAL ANIMALS WITH TUMORS UNCERTAIN­ EENIGN OR MALIGNANT
 

TOTAL UNCERTAIN TUMORS
 

TOTAL ANIMALS WITH TUMORS UNCERTAIN­ PRIMARY OR METASTATIC
 

TOTAL UNCERTAIN TUMORS
 

* PBIHARY TUMORS: ALL TUMORS EXCEPT SECONDARY TUMORS
 

# SECONDARY TUMORS: METASTATIC TUMORS OR TUMORS INVASIVE INTO AN ADJACENT ORGAN
 

50
 
APPENDIX C
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS
 

IN RATS FED PYRAZINAMIDE IN THE DIET
 

51
 

TABLE C1. 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN MALE 

RATS FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE
 

ANIMALS INITIALLY IN STUDY 15 35
 

ANIMALS NECBOPSIED 14 35
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY 14 35
 

INTEGUMENTARY SYSTEM
 

*SKIN (14) (35)
 

INFLAMMATION, CHRONIC FOCAL
 

*SUBCUT TISSUE (14) (35)
 

EPIDERMAL INCLUSION CYST 1 (3X)
 

HEMORRHAGE
 

RESEIRATOBY SYSTEM
 

#TRACHEA (14) (35)
 

LYMPHOCYTIC INFLAMMATORY INFILTR 1 (3X)
 

INFLAMMATION, SUPPURATIVE 8 (57*) 16 (46%)
 

PLASMA-CELL INFILTRATE 1 (3X)
 

INFLAMMATION, CHRONIC SUPPURATIV
 

#LUNG (14) (35)
 

EMPHYSEMA, NOS
 

ERONCHOPNEUMONIA SOPPURATIVE 2 (14%) 2 (6*)
 

ABSCESS, NOS
 

BRONCHOPNEUKONIA CHRONIC SUPPUHA 1 <3X)
 

CALCIFICATION, METASTATIC
 

HYPEPPLASIA, ALVEOLAR EPITHELIUM
 

HEMATOPOIETIC SYSTEM
 

#EONE MARROW (1U) (35)
 

ATROPHY, NOS 5 (36%) 14 (40%)
 

#SPLEEN (1<*) (35)
 

HEMATOPOIESIS 3 (9%)
 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMA1S NECROPSIED
 

HIGH DOSE
 

36
 

36
 

36
 

(36)
 

1 (3%)
 

(36)
 

1 (3%)
 

(36)
 

1 (3*)
 

7 (19*)
 

1 (3X)
 

(36)
 

1 (3*)
 

1 (3*)
 

1 (3X)
 

1 (3X)
 

1 (3*)
 

1 (3*)
 

(35)
 

11 (31*)
 

(36)
 

.1 13 Si.
 

53
 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

CIBCU1ATOBY SYSTEM
 

#HEART (14) (35) (36)
 

THROHBUS, MURAL 1 (3*)
 

#MYOCABDIUM (14) (35) (36)
 

INFLAMMATION, INTERSTITIAL 1 (3%) 1 (3*)
 PERIARTERITIS 1 (3%)
 

*AORTA (14) (35) (36)
 PERIARTERITIS 1 (3%)
 

DIGESTIVE SYSTEM
 

KLIVER (14) (35) (36)
 

HEMORRHAGE 1 (3%)
 

HYPERFLASIA, NODULAE 2 (6%) 2 (6%)
 

HEMATOPOIESIS 1 (3%)
 

#PANCREATIC ACINUS d<») . (35) (36)
 

ATROPHY, NOS 2 (14%) 3 (9%)
 

ATROPHY, FOCAL 2 (6%)
 

#STOMACH (14) (35) (36)
 

ULCER, FOCAL 1 (7%)
 

4CUODENUM (14) (35) (36)
 

ULCER, FOCAL 1 (7%)
 

#COLON d<») (35) (36)
 

ULCER, NOS 1 (3%)
 

OEINAR Y SYSTEM
 

(tKIDNEY (14) (35) (36)
 

INFLAMMATION, CHRONIC 13 (93%) 34 (97%) 34 (94%)
 

ENtCCRINE SYSTEM
 

tADRENAL (14) (35) (36)
 

ANGIECTASIS .L13J1.
 

* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROESIED
 

54
 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

I1HYBOID
 

CYSTIC FOLLICLES
 

HYPERPLASIA, C-CELL
 

HYPEEPLASIA, FOLLICULAR-CELL
 

tPARATHYROID
 

HYPEEPLASIA, NOS
 

REPRODUCTIVE SYS-TEM
 

*PBEPOTIAL GLAND


INFLAMMATION, CHRONIC SUPPURATIV
 

HYPERPLASIA, EPITHELIAL
 

#PROSTATE


INFLAMMATION, SUPPURATIVE


#TESTIS


INFLAMMATION, NECBOTIZING
 

ATROPHY, NOS
 

NIBVOUS SYSTEM
 

IERAIN
 

HEMORRHAGE
 

MALACIA
 

SPECIAL SENSE ORGANS
 

*EYE
 

SYNECHIA, ANTERIOR
 

*EYE/CRYSTALLINE LENS
 

MINERALIZATION
 

MUSCOLOSKELETAt SYSTEH
 

NONE
 

EOEY CAVITIES
 

*P«RITONEDH
 

CONTROL LOW DOSE HIGH DOSE 

(14) (35) (32) 

1 (3%) 

1 (3X) 

1 (7%) 

(7) 122) (19) 

<5X) <5X) 

 (14) (35) (36) 

1 (3X) 

1 (3X) 

 (14) (35) (36) 

2 (14X) 2 (6X) 

 (14) (35) (36) 

1 

1 (3X) 

(13) (34) (36) 

1 (8X) 

1 (8X) 

(14) (35) (36) 

1 (3X) 

d«) (35) 

1 (3X) 

(36) 

(14) (35) (36)
 

* NUMBER OF ANIMALS HITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECEOPSIED
 

55
 
TABLE C1. MALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

All OTHER SYSTEMS
 

NONE
 

SPECIAL MCBEHOLOGY EOMHARY
 

AUTOLYSIS/NO NECROPSY
 

# NUMBEfi OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 * NUMBER OF ANIMALS NECROPSIED
 

56
 
TABLE C2.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN FEMALE 

RATS FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE HIGH DOSE
 

ANIMALS INITIALLY IN STUDY 15 35 34
 

ANIMALS NECROPSIED 15 34 34
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY 15 34 34
 

INTEGUMENTAPY SYSTEM
 

*SKIN (15) (34) (34)
 

INFLAMMATION, CHRONIC SUPPURATIV 1 (3%)
 

*SUBCOT TISSUE (15) (34) (34)
 

INFLAMMATION, CHRONIC SUPPURATIV 1 (3%)
 

RESPIRATORY SYSTEM
 

• TRACHEA (15) (34) (33)
 

INFLAMMATION, SUPPURATIVE 8 (53%) 13 (38%) 7 (21%)
 

PLASMA-CELL INFILTRATE 2 (6%)
 

• LUNG	 (15) (33) (34)
 

BBONCHOFNEUMONIA SUPPUBATIVE 1 (3%)
 

PNEUMONIA INTERSTITIAL CHRONIC 1 (3%)
 

HYPERPLASIA, LYMPHOID 1 (3%)
 

HEBATOPOIETIC SYSTEM
 

•BONE	 HARRO W (15) (34) (33)
 

ATROPHY, NOS 9 (60%) 18 (53%) 16 (48%)
 

• SPLEEN	 (15) (34) (34)
 

HYPERPLASIA, LYHPHOID 1 (3%)
 

HEHATOPOIESIS 2 (13%) 4 (12%) 3 (9%)
 

•RENAL	 LYMPH NODE (9) (21) (17)
 

HYPERPLASIA, PLASHA CEIL 1 (11%)
 

CIBCULATORY SYSTEM
 

t SOMBER OF ANIHALS HITH TISSUE EXAMINED MICROSCOPICALLY
 

* SOMBER OF ANIHALS NECBOPSIED
 

57
 
TABLE C2. FEMALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE 

CIGESTIVE SYSTEM
 

#LIVEB (15) (34)
 

NECEOSIS, COAGULATIVE
 

CYTOPLASMIC VACUOLIZATION
 

CYTOLOGIC DEGENERATION 1 (3*)
 

HEBATOPOIESIS 1 d%)
 

#PANCREATIC ACINDS (15) (34)
 

ATROPHY, NOS 1 (7X)
 

fSBALL INTESTINE (15) (34)
 

INFLAMMATION, CHRONIC NECROTIZIN
 

URINAR Y SYSTEM
 

#KIDNEY (15) (34) 

INFLAMMATION, NOS 1 (3%) 

INFLAMMATION, CHRONIC 10 (67X) 22 (65X) 

ENCOCRINE SYSTEM
 

fACRENAL (15) (34)
 

ANGIECTASIS 1 (7X)
 

#THYROID (15) (33)
 

HYPERPLASIA, C-CELL
 

REPRODUCTIVE SYSTEM
 

*HAMMARY GLAND (15) (34)
 

CYST, NOS 1 (7X) 1 (3*)
 

*PREPUTIAL GLAND (15) (34)
 

INFLAMMATION, CHRONIC FOCAL 1 (7X)
 

•UTERUS	 (15) (3«)
 

METAPLASIA, SQUAMOOS
 

DECIDOAL ALTERATION, NOS 1 (7X) 1 (3X)
 

tUTEBUS/ENDOMETRIUM (15) (34)
 

INFLAMMATION. SUPPORATIVE * 4122XL 8 (24X)
 

« NOMBEB OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

* NUMBE R OF ANIMALS NECROESIED 

58 

HIGH DOSE 

(34)
 

1 <3X)
 

1 (3X)
 

2 (6X)
 

(34)
 

(34)
 

1 (3X)
 

(34)
 

13 (38%)
 

(34)
 

(32)
 

1 (3X)
 

(34)
 

3 <9X)
 

(34)
 

(34)
 

1 (3X)
 

(34)
 

7 (2 1X1
 
TABLE C2. FEMALE RATS: NONNEOPLASTIC

INFLAMMATION, CHRONIC


INFLAMMATION, CHRONIC SUPPUHATIV


INFLAMMATION, CHRONIC NECROTIZIN


HYPERPLASIA, CYSTIC


tCVARY/OVIDUCT


INFLAMMATION, SUPPURATIVE


ttOVAH Y

CYST, NOS

INFLAMMATION , SUPPURATIV E

NEFVOU S SYSTEM 

NON E 

SPECIAL SENSE ORGANS
 

*EYE


SYNECHIA, ANTERIOR


*EYE/CCRNEA


INFLAMMATION, CHRONIC


*HARDERIAN GLAND


INFLAMMATION, GF. ANDLOK ATO US


MUSCDLOSKELETAL SYSTEM
 

NCNE
 

BOEY CAVITIES
 

*FERITONEUM


INFLAMMATION, CHRONIC


PEBIAR1ERITIS


*MESENTERY


STEATITIS


ALL CTHER SYSTEMS
 

NONE
 

 LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE
 

1 (3%)
 

1 (3X) 1 (3X)
 

1 (1%)
 

3 (9X)
 

 (15)	 (34) (34)
 

3 (20%) 3 (9%) 1 (3%)
 

 (15) (34) (34) 

4 (27%) 6 (18%) 11 (3251 

1 (7X) 1 (3%) 

 (15)	 (34) (34)
 

1 (3%)
 

 (15)	 (34) (34)
 

1 (3*)
 

 (15)	 (34) (34)
 

1 (3%)
 

 (15) (34)	 (34)
 

1 (3S)
 

1 (1%)
 

 (15)	 (34) (34)
 

1 (3%) 1 (3%)
 

*	 NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROESIED
 

59
 
TABLE C2. FEMALE RATS: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE
 

SPECIAL MORPHOLOGY SUMMARY
 

NO LESION REPORTED
 

AUTOLYSIS/NC NECROPSY
 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 * NUMBER OF ANIMALS NECROESIED
 

60
 
APPENDIX D
 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS
 

IN MICE FED PYRAZINAMIDE IN THE DIET
 

61
 

TABLE 01.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS 

IN MALE MICE FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE
 

ANIMALS INITIALLY IN STUDY 15 35
 

ANIMALS MISSING 1
 

ANIMALS NECROPSIED 12 31
 

ANIMALS EXAMINED HISTOF ATHOLOGICALLY 12 31
 

INTEGUHENTAEY SYSTEM
 

*SKIN (12) (31)
 

INFLAMMATION, NOS 1 (3*)
 

*SUBCUT TISSUE (12) (31)
 

HEMORRHAGE 1 (3*)
 

EESFIBATOBY SYSTEM
 

IIRACHEA (12) (31)
 

INFLAMMATION, SUPPURATIVE 2 (17*) 10 (32*)
 

#LUNG/BRONCHOS (12) (31)
 

INFLAMMATION, SUPPURATIVE
 

HYPERPL&SIA, PLASHA CELL 1 (3*)
 

tLUNG (12) (31)
 

INFLAMMATION, SUPPUBATIVE
 

BRONCHOPNEUMONIA SUPPURATIVE 7 (58*) 17 (55*)
 

HYPERPLASIA, ALVEOLAR EPITHELIUM 1 (8%) 1 (3*)
 

HYPERPLASIA, PLASHA CELL 3 (25*) 5 (16*)
 

HEMATOPOIETIC SYSTEM
 

IEONE HARROW (11) (30)
 

ATROPHY. SOS
 

tSPLEEN (12) <31)
 

ATROPHY, NOS 1 (3*)
 

HEBATOPOIESIS 2 (17*) 5 (16*)
 

IHEDIASTINAL L.NODE (3) (22)
 

HlfEBPLASILi PLASMA CELL , -., _„_, ...._„-„-.
 1.<5X) ,


* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 

HIGH DOSE
 

35
 

33
 

33
 

(33)
 

(33)
 

2 (6*)
 

(33)
 

9 (27*)
 

(33)
 

3 (9*)
 

(33)
 

1 (3*)
 

17 (52*)
 

on
 

1 (3*)
 

(33)
 

H (12*)
 

(12)
 

63
 
TABLE D1. MALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

HIGH DOSE
 

(12)
 

(33)
 

1 (3X)
 

(33)
 

a (12*
 

9 (27J
 

1 (3X)
 

(33)
 

1 (3X)
 

2 (6X)
 

(33)
 

2 (6X)
 

(33)
 

1 (3X)
 

2 (6X)
 

2 (6X)
 

(33)
 

1 (3X)
 

(33)
 

1 J3XJ
 

#BESENTEBIC I. NODE
 

CONGESTION, NOS
 

INFLAMMATION, CHRONIC NECROTIZIN
 

ATROPHY, NOS
 

HYPERPLASIA, RETICULUM CELL
 

#THYMUS
 

HYPERPLASIA, PLASMA CELL
 

CIRCULATORY SYSTEM
 

tMYOCARDIOM
 

INFLAMMATION, INTERSTITIAL
 

INFLAMMATION, SUPPURATIVE
 

INFLAMMATION, NECROTIZING
 

•ENDOCARDIUM
 

INFLAMMATION, SUPPURATIVE
 

INFLAMMATION, ACUTE/CHRONIC
 

*AORTA
 

INFLAMMATION, NECROTIZING
 

DIGESTIVE SYSTEM
 

tLIVER
 

HEMORRHAGE
 

INFLAMMATION, NECEOTIZING
 

INFLAMMATION, CHRONIC
 

NECBOSIS, COAGOLATIVE
 

HYPERPLASIA, NODULAR
 

HYPERPLASIA, RETICULOH CELL
 

HEMATOPOIESIS
 

#LIVER/CENTRILOBULAR
 

CYTOPLASMIC VACUOLIZATION
 

URINARY SYSTEM
 

tKIDNEY
 

INFLAMMATION, CHRONIC
 

CONTROL
 

(3)
 

1 (33X)
 

(11)
 

(12)
 

(12)
 

(12)
 

(12)
 

1 (8X)
 

1 (8X)
 

(12)
 

(12)
 

1 (8X)
 

LOW DOSE
 

(22)
 

1 (5X)
 

1 (5X)
 

1 (5X)
 

1 (5X)
 

(31)
 

(31)
 

6 (19X)
 

H (13X)
 

(31)
 

(31)
 

(31)
 

1 (3X)
 

2 (6X)
 

1 (3X)
 

1 (3X)
 

(31)
 

1 (3X)
 

(31)
 _ _ __.. ._
 

* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* 'NOHBEB OF ANIMALS NECROPSIED
 

64
 
TABLE D1. MALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

#URIS4EY BLADDER (10) (30) (31) 

ULCER, FOCAL 1 (3%) 

ENECCRINE SYSTEM
 

NONE
 

EEEEOEOCTIV E SYSTEM 

*MABBARY GLAND (12) (31) (33)
 

METAPLASIA, SQOABOUS 1 (3*)
 

KEBVCDS SYSTEM
 

NONE
 

SEtCIAL SENSE ORGANS
 

*EAE CANAL (12) (31) (33)
 

INFLAMMATION, CHRONIC SUPPURATIV 1 (3X)
 

MUSCULOSKELETAL SYSTEM
 

NONE
 

EOEY CAVI1IIS
 

•PERITONEUM	 (12) (31) (33)
 

INFLAMMATION, CHRONIC FOCAL 1 (3X;
 

INFLAMMATION, CHRONIC NECROTIZIN 1 (3»)
 

*PLEURA (12) (31) (33)
 

INFLAMMATION, SUPPUEATIVE 1 (3%;
 

*EPICAHDIUB (12) (31) (33)
 

INFLAMMATION, SUPPURATIVE 1 (3%;
 

*M£SENTERY	 (12) (31) (33)
 

HEMORRHAGE I
 

* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 

65
 
TABLE D1. MALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

All OTHEE SYSTEMS
 

NONE
 

SFICIAL MORPHOLOGY SUMMARY
 

NO LESION REPORTED 1 1
 

ANIMAL MISSING/NO NECROPSY 1
 

N C NECROPSY PERFORMED 2 1 2
 

AUTOLYSIS/NO NECROPSY 1 2
 

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER CF ANIMALS NECEOESIED
 

66
 
TABLE 02.

 

SUMMARY OF THE INCIDENCE OF NONNEOPLASTIC LESIONS IN FEMALE 

MICE FED PYRAZINAMIDE IN THE DIET 

CONTROL LOW DOSE HIGH DOSE
 

ANIMALS INITIALLY IN STUDY 15 35 35
 

ANIMALS MISSING 8
 

ANIMALS NECROPSIED 13 25 29
 

ANIMALS EXAMINED HISTOPATHOLOGICALLY 13 25 29
 

INTEGUMENTARY SYSTEM
 

NONE
 

RESPIRATOEY SYSTEM
 

#TRACHEA (13) (25) (29)
 

INFLAMMATION, SUPPURATIVE 1 (8X) 6 (24X) 6 (21X)
 

ILUNG (13) (24) (29)
 

BRONCHOENEUMONIA SUPPURATIVE 5 (38X) 12 (50X) 12 (41X)
 

BRONCHOENEUMONIA CHRONIC SUPPUBA 1 (8X)
 

INFLAMMATION, FOCAL GPANULOMATOU 1 (3X)
 

HYFERPLASIA, PLASMA CELL 3 (23%) 3 (13X) 2 (7%)
 

HEMATOPOIITIC SYSTEM
 

*EONE MARROW (13) (24) (29)
 

ATROPHY, NOS 1 (3%)
 

tSPLEEN (13) (25) (29)
 

FIBROSIS, FOCAL 1 (3X)
 

ATROPHY, NOS 1 (3X)
 

ANGIECTASIS 1 (3X)
 

HYPERPLASIA, RETICULUM CELL 1 (3X)
 

HEMATOEOIESIS 2 (7X)
 

#MANDIBULAR L. NODE (7) (12) (23)
 

HYPERPIASIA, PLASMA CELL 1 (4%)
 

#ERONCHIAL LYMPH NODE (7) (12) (23)
 

HYEERPLASIA, LYBPHOID 1 (14%)
 

#MEDIASTINAL L.NCDE (7) (12) (23)
 

HYPER£Ift.SIAi_PLASMA_CELL
 

* NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 * NUMBER OF ANIMALS NECEOPSIED
 

67 
TABLE 02. FEMALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE
 

#EANCBJATIC L.NOCE (7) (12)
 

INFLAMMATION, CHRONIC
 

#MESENTERIC L. NODE (7) (12)
 

CONGESTION, NOS 1 (8X)
 

ATBCPHY, NOS 1 (8X)
 

tINGOINAL LYMPH NODE (7) (12)
 

HYPERPLASIA, IYMPHOID 1 (1<»X)
 

#THYMUS (13) (25)
 

HYPERPLASIA, PLASMA CELL 1 (<*«)
 

CIFCULATORY SYSTEM
 

IMYOCARDIUM (13) (2<»)
 

INFLAMMATION, INTERSTITIAL 1 (OX)
 

INFLAMMATION, SOPPORATIVE
 

EIGISTIVE SYSTEM
 

#LIVER (13) (25)
 

CYTOPLASMIC VACUOLIZATION
 

HYPERPLASIA, NODULAR 1 (4%)
 

ANGIECTASIS
 

#PANCREATIC ACINUS (13) (25)
 

ATROPHY, NOS
 

#SIOMACH (13) (25)
 

ULCER, FOCAL 1 («X)
 

SFEYERS PATCH (13) (25)
 

HYPERE1ASIA, LYBPHCID
 

KEUCDBNUM (13) (25)
 

ULCER, FOCAL
 

URINABY SYSTEM
 

NONE,
 

I NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY
 

* NUMBER OF ANIMALS NECROPSIED
 

HIGH DOSE
 

(23)
 

1 (*»«)
 

(23)
 

(23)
 

(29)
 

(29)
 

1 (3X)
 

(28)
 

« (1«X)
 

2 (7X)
 

1 (<IX)
 

(29)
 

1 (3%)
 

(29)
 

(29)
 

1 (3X)
 

(29)
 

1 (3X)
 

68
 
TABLE 02. FEMALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE
 

ENECCRINE SYSTEM
 

#EITUITARY (8) (18)
 

HYPERPLASIA, CHBOMCEHCBE-CELL
 

REPRODUCTIVE SYSTEM
 

*MAMMARY GLAND (13) (25)
 

METAPLASIA, SQUAMOUS 1 (4X)
 

#UTERUS (13) (24)
 

THROMBOSIS, NOS 1 (4X)
 

#UTERUS/ENDOMETRIUM (13) (24)
 

INFLAMMATION, SUPPUBATIVE 3 (13X)
 

INFLAMMATION, CHRONIC SUPPURATIV 2 (8X)
 

HYPERPLASIA, CYSTIC 5 (38X) 14 (58X)
 

#OVARY (13) (23)
 

CYST, NOS 4 (17X)
 

HEMORRHAGE
 

INFLAMMATION, SUPPURATIVE 1 (4X)
 

INFLAMMATION, CHBONIC SUPPURATIV 1 (4X)
 

NERVOUS SYSTEM
 

NONE
 

SEECIAL SENSE ORGANS
 

*MIDELE EAR (13) (25) 

INFLAMMATION, CHRONIC SUPPURATIV 1 (4X) 

HDSCUIOSKE1ETAL SYSTEM 

NON E 

EOEY CAVITIES 

*PERITONEUM (13) (25) 

IHZMHBATIQNx_CHROMIC_I2CAi_ 1 «**> 

* NUMBER OF ANIMALS HITH TISSUE EXAMINED MICROSCOPICALLY
 

* BOBBER OF ANIMALS NECROPSIED
 

69
 

HIGH DOSE
 

(20)
 

1 (5X)
 

(29)
 

(29)
 

(29)
 

3 (10X)
 

23 (79X)
 

(28)
 

2 (7X)
 

1 (4X)
 

(29) 

1 (3X) 

(29)
 
TABLE 02. FEMALE MICE: NONNEOPLASTIC LESIONS (CONTINUED) 

CONTROL LOW DOSE HIGH DOSE 

NECROSIS, FAT 1 (3X) 

A LL CTHER SYSTEMS 

*MULTIPLE ORGANS

HYFEHFLASIA, PLASMA CELL

ADIPOSE TISSUE 

INFLAMMATION, GRANOLOMATOOS

 (13) (25) (29) 

2 

1 

SPECIAL MCKEHOLOGY SUMMARY 

NO LESION REPORTED U 1 

ANIMAL MISSING/NO NECROPSY 8 

NO NECROPSY PERFORMED 1 1

AUTOLYSIS/NO NECROPSY 1 1

# NUMBER OF ANIMALS WITH TISSUE EXAMINED MICROSCOPICALLY 

* NUMBER OF ANIMALS NECROESIED 

H 

2 

70
 
APPENDIX E
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS IN RATS
 

FED PYRAZINAMIDE IN THE DIET
 

71
 

__ 

Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Pyrazinamide in the Diet3
 

Matched Low High
 

Topography; Morphology Control Dose Dose
 

Subcutaneous Tissue:
 

Sarcoma, NOS (not otherwise specified),
 

or Fibrosarcomab 0/L4 (0) 2/35 (6) 0/36 (0)
 

P Values0«d N.S. N.S. N.S.
 

Relative Risk (Matched Control)f Infinite
 

Lower Limit 0.125
 

Upper Limit Infinite —
 

—
 

CO
 Weeks to First Observed Tumor 95
 ., i- . ...
 

Hematopoietic System: Leukemia** 2/14 (14) 2/35 (6) 0/36 (0)
 

P Valuesc»d P " 0.037(N) N.S. N.S.
 

Relative Risk (Matched Control)f 0.400 0.000
 

Lower Limit 0.033 0.000
 

Upper Limit 5.172 1.291
 

Weeks to First Observed Tumor 89 104
 
Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Pyrazinamide in the Diet3
 

(continued) 

Matched Low High 

Topography ; Morphology Control Dose Dose 

Pituitary: Chromophobe Carcinomab 0/10 (0) 0/32 (0) 1/30 (3) 

P Values0 » d N.S. N.S. N.S. 

__ 

Relative Risk (Matched Control)f Infinite 

Lower Limit 0.019 

Upper Limit — Infinite — __ 

Weeks to First Observed Tumor 104 

Pituitary: Chromophobe Adenoma
 

or Carcinomab 1/10 (10) 4/32 (13) 1/30 (3)
 

P Valuesc»d N.S. N.S. N.S.
 

Relative Risk (Matched Control)f 1.250 0.333
 

Lower Limit 0.152 0.005
 

Upper Limit 59.496 25.331
 

Weeks to First Observed Tumor 105 87 104
 
Table El. Analyses of the Incidence of

Fed Pyrazinamide in

(continued) 

Matched
 

Topography: Morphology Control
 

Thyroid: C-cell Carcinoma0

 0/14 (0)
 

P Valuesc»d N.S.
 

Relative Risk (Matched Control)*
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

^i Thyroid: C-cell Adenoma
 01

 or Carcinomab 2/14 (14)
 

P Valuesc»d N.S.
 

Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor 105
 

 Primary Tumors in Male Rats 

 the Diet3 

Low
 

Dose
 

3/35 (9)
 

N.S.
 

Infinite
 

0.258
 

Infinite
 

101
 

4/35 (11)
 

N.S.
 

0.800
 

0.135
 

8.252
 

101
 

High
 

Dose
 

0/32 (0)
 

N.S.
 

«...
 

—
 

-.«.
 

3/32 (9)
 

N.S.
 

0.656
 

0.088
 

7.314
 

104 
Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Pyrazinamide in the Diet3
 

(continued)
 

Topography : Morphology


Testis: Interstitial-cell Tumorb


P Valuesc»d


Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor


Ear Canal: Squamous-cell
 

Papilloma or Carcinoma13


P Valuesc>d


Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor


Matched
 

 Control
 

 13/14 (93)
 

 N.S.
 

 89
 

 0/14 (0)
 

 N.S.
 

—
 

Low High 

Dose Dose 

30/35 (86) 29/36 (81) 

N.S. N.S. 

0.923 0.868 

0.831 0.780 

1.259 1.226 

93 85 

2/35 (6) 0/36 (0) 

N.S. N.S. 

__ 

Infinite 

0.125 

Infinite — 

— 

88 —— 
Table El. Analyses of the Incidence of Primary Tumors in Male Rats
 

Fed Pyrazinamide in the Diet3
 

(continued)
 

a

Treated groups received doses of 5,000 or 10,000 ppm in feed.
 

^Number of tumor-bearing animals /number of animals examined at site (percent).
 

c

Beneath the incidence of tumors in the control group is the probability level for the Cochran-


Armitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the
 

incidence of tumors in a treated group is the probability level for the Fisher exact test for
 

the comparison of that treated group with the matched-control group when P < 0.05; otherwise,
 

not significant (N.S.) is indicated.
 

d

A negative trend (N) indicates a lower incidence in a treated group than in the control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

95% confidence interval of the relative risk between each treated group and the control
 

group .
 
Table E2.


Topography: Morphology


Hematopoietic System:
 

Lymphoma or Leukemia*5


P Valuesc»d


 Analyses of the Incidence of Primary Tumors in Female Rats
 

Fed Pyrazinamide in the Diet3
 

Matched Low High
 

 Control Dose Dose
 

 2/15 (13) 3/34 (9) 2/34 (6)
 

 N.S. N.S. N.S.
 

Relative Risk (Matched Control)f 

Lower Limit 

Upper Limit 

0.662 

0.087 

7.410 

0.441 

0.036 

5.706 

Weeks to First Observed Tumor 105 97 98 

oo Pituitary: Chromophobe Carcinomab

 0/14 (0) 1/30 (3) 0/24 (0) 

P Valuesc » d N.S. N.S. N.S. 

Relative Risk (Matched Control)f 

Lower Limit 

Upper Limit 

Infinite 

0.026 

Infinite 

__ 

— 

— 

Weeks to First Observed Tumor 97 —_ 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

(continued)
 

Topography; Morphology


Pituitary: Chromophobe Adenoma
 

or Carcinomab


P Values0 »d


Departure from Linear Trend6


Relative Risk (Matched Control)*
 

Lower Limit
 

Upper Limit
 

vo Weeks to First Observed Tumor


Thyroid: C-cell Carcinomab


P Valuesc»d


Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor
 

Fed Pyrazinamide in the Diet3 

Matched Low High 

 Control Dose Dose 

 2/14 (14) 14/30 (47) 7/24 (29) 

 N.S. P ­ 0.037 N.S. 

P * 0.033 

3.267 2.042 

0.927 0.474 

26.414 18.084 

 105 79 96 

 0/15 (0) 0/33 (0) 1/32 (3) 

 N.S. N.S. N.S. __ 

Infinite 

0.026 —­ Infinite — 

—. 104 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

(continued)
 

Topography: Morphology


Thyroid: C-cell Adenoma
 

or Carcinomab


P Valuesc«d


Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor


oo
 

o Mammary Gland: Fibroadenoiaa*5


P Valuesc»d


Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor


Fed Pyrazinamide in the Dieta 

Matched Low High 

 Control Dose Dose 

 1/15 (7) 1/33 (3) 1/32 (3) 

 N.S. N.S. N.S. 

0.455 0.469 

0.006 0.006 

34.631 35.679 

 105 105 104 

 4/15 (27) 5/34 (15) 4/34 (12) 

 N.S. N.S. N.S. 

0.551 0.441 

0.145 0.099 

2.468 2.121 

 105 105 98 
__ 

Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

Fed Pyrazinamide in the Diet3
 

(continued)
 

Matched Low High
 

Topography: Morphology Control Dose Dose
 

Uterus: Endometrial Stromal
 

Polypb 3/15 (20) 5/34 (15) 5/34 (15)
 

P Values0 »d N.S. N.S. N.S.
 

Relative Risk (Matched Control)^ 0.735 0.735
 

Lower Limit 0.172 0.172
 

Upper Limit 4.323 4.323
 

Weeks to First Observed Tumor 105 88 96
 

oo
 Uterus: Sarcoma, NOSb

 0/15 (0) 2/34 (6) 0/34 (0)
 

P Values0 »d N.S. N.S. N.S.
 

Relative Risk (Matched Control)f Infinite
 

Lower Limit 0.138
 

Upper Limit Infinite
 —
 

—
 

Weeks to First Observed Tumor — 88
 ——
 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

(continued)
 

Topography: Morphology


Uterus: Adenocarcinoma, NOSb


P Valuesc»d


Relative Risk (Matched Control.)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor


Ear Canal: Keratoacanthoma
 

oo
 to or Squamous-cell Carcinoma*'


P Values0 »d


Relative Risk (Matched Control)f
 

Lower Limit
 

Upper Limit
 

Weeks to First Observed Tumor


Fed Pyrazinamide in the Diet3 

Matched Low High 

 Control Dose Dose 

 1/15 (7) 1/34 (3) 1/34 (3) 

 N.S. N.S. N.S. 

0.441 0.441 

0.006 0.006 

33.649 33.649 

 101 105 96 

 1/15 (7) 0/34 (0) 1/34 (3) 

 N.S. N.S. N.S. 

0.000 0.441 

0.000 0.006 

8.176 33.649 

 105 — —— 
Table E2. Analyses of the Incidence of Primary Tumors in Female Rats
 

Fed Pyrazinamide in the Diet3
 

(continued)
 

a

Treated groups received doses of 5,000 or 10,000 ppm.
 

^Number of tumor-bearing animals/number of animals examined at site (percent).
 

c

Beneath the incidence of tumors in the control group is the probability level for the Cochran-


Armitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the
 

incidence of tumors in a treated group is the probability level for the Fisher exact test for
 

the comparison of that treated group with the matched-control group when P < 0.05; otherwise,
 

not significant (N.S.) is indicated.
 

d

A negative trend (N) indicates a lower incidence in a treated group than in the control group.
 

ou eThe probability level for departure from linear trend is given when P < 0.05 for any comparison.
 u>
 

^The 95% confidence interval of the relative risk between each treated group and the control
 

group.
 

APPENDIX F
 

ANALYSES OF THE INCIDENCE OF PRIMARY TUMORS IN MICE
 

FED PYRAZINAMIDE IN THE DIET
 

85
 

Table Fl. Analyses of the Incidence of Primary Tumors in Male Mice
 

Fed Pyrazinamide in the Diet3
 

Matched Low High
 

Topography; Morphology Control Dose Dose
 

Hematopoietic System: Lymphoma" 1/12 (8) 3/31 (10) 1/33 (3)
 

P Values0 »d N.S. N.S. N.S.
 

Relative Risk (Matched Control)^ 1.161 0.364
 

Lower Limit 0.109 0.005
 

Upper Limit 58.909 27.718
 

Weeks to First Observed Tumor 104 67 86
 

Liver: Hepatocellular Carcinoma" 1/12 (8) 0/31 (0) 1/33 (3)
 oo
 

--4
 

P Values0>d N.S. N.S. N.S.
 

Relative Risk (Matched Control)^ 0.000 0.364
 

Lower Limit 0.000 0.005
 

Upper Limit 7.160 27.718
 

Weeks to First Observed Tumor 69 90
 —
 
Table Fl. Analyses of the Incidence of Primary Tumors in Male Mice
 

Fed Pyrazinamide in the Dieta
 

(continued) 

Matched Low High 

Topography; Morphology Control Dose Dose 

Liver: Hepatocellular
 

Adenoma or Carcinoma*5 1/12 (8) 0/31 (0) 3/33 (9)
 

P Valuesc»d N.S. N.S. N.S.
 

Relative Risk (Matched Control)f 0.000 1.091
 

Lower Limit 0.000 0.103
 

Upper Limit 7.160 55.481
 

Weeks to First Observed Tumor 69 82
 —
 a

Treated groups received doses of 5,000 or 10,000 ppm.
 

^Number of tumor-bearing animals/number of animals examined at site (percent).
 

c

Beneath the incidence of tumors in the control group is the probability level for the Cochran-


Armitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the
 

incidence of tumors in a treated group is the probability level for the Fisher exact test for
 

the comparison of that treated group with the matched-control group when P < 0.05; otherwise,
 

not significant (N.S.) is indicated.
 

^A negative trend (N) indicates a lower incidence in a treated group than in the control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

95% confidence interval of the relative risk between each treated group and the control
 

group.
 
Table F2. Analyses of the Incidence of Primary Tumors in Female Mice
 

Fed Pyrazinamide in the Diet3
 

Matched Low High
 

Topography; Morphology Control Dose Dose
 

Heinatopoietic System: Lymphoma'5 0/13 (0) 2/25 (8) 6/29 (21)
 

P Values0>d P = 0.037 N.S. N.S.
 

Relative Risk (Matched Control)* Infinite Infinite
 

Lower Limit 0.166 0.779
 

Upper Limit Infinite Infinite
 

Weeks to First Observed Tumor 92 81
 —
 a

Treated groups received doses of 5,000 or 10,000 ppm.
 oo
 

^Number of tumor-bearing animals/number of animals examined at site (percent).
 

c

Beneath the incidence of tumors in the control group is the probability level for the Cochran-


Arraitage test when P < 0.05; otherwise, not significant (N.S.) is indicated. Beneath the
 

incidence of tumors in a treated group is the probability level for the Fisher exact test for
 

the comparison of that treated group with the matched-control group when P < 0.05; otherwise,
 

not significant (N.S.) is indicated.
 

^A negative trend (N) indicates a lower incidence in a treated group than in the control group.
 

e

The probability level for departure from linear trend is given when P < 0.05 for any comparison.
 

95% confidence interval of the relative risk between each treated group and the control
 

group.
 

Review of the Bioassay of Pyrazinamide* for Carcinogenicity
 

by the Data Evaluation/Risk Assessment Subgroup of the
 

Clearinghouse on Environmental Carcinogens
 

January 18, 1978
 

The Clearinghouse on Environmental Carcinogens was
 

established in May, 1976 under the authority of the National
 

Cancer Act of 1971 (P.L. 92-218). The purpose of the Clear­ inghouse is to advise on the National Cancer Institute's
 

bioassay program to identify and evaluate chemical carcino­ gens in the environment to which humans may be exposed. The
 

members of the Clearinghouse have been drawn from academia,
 industry, organized labor, public interest groups, State
 

health officials, and quasi-public health and research
 

organizations. Members have been selected on the basis of
 

their experience in carcinogenesis or related fields and,
 collectively, provide expertise in organic chemistry, bio­ chemistry, biostatistics, toxicology, pathology, and epide­ miology. Representatives of various Governmental agencies
 

participate as ad hoc members. The Data Evaluation/Risk
 

Assessment Subgroup of the Clearinghouse is charged with the
 

responsibility of providing a peer review of NCI bioassay
 

reports on chemicals studied for carcinogenicity. In this
 

context, below is the edited excerpt from the minutes of the
 

Subgroup's meeting at which Pyrazinamide was reviewed.
 

The primary reviewer noted the relatively high incidence
 

of myocarditis, particularly in the treated male mice, which
 

resulted in a shorter survival time among the animals. She
 

expressed reservations regarding the conclusion drawn in
 

the report to the effect that an evaluation of the treated
 

female mice cannot be made due to mortality and small size
 

of the matched control groups. She said that the data
 

suggest a possible relationship between treatment and an
 

increased incidence of lymphomas in the female mice. She
 

urged that the results be compared with historical control
 

animals to determine their statistical significance and
 

latent period. In regard to the male mice, the primary
 

reviewer said that the animals did not survive long enough
 

to be able to evaluate the carcinogenicity of Pyrazinamide.
 With respect to the rat portion of the study, she agreed
 

with the conclusion given in the report that Pyrazinamide
 

was not carcinogenic, under the conditions of test.
 

The secondary reviewer agreed with the conclusions
 

in the report that Pyrazinamide was not carcinogenic in
 

91
 
either the rats or mice, under the conditions of test.
 

However, he said that the small number of control animals
 

made it difficult to exclude the possibility that the lymphomas
 

in the female mice were not a result of treatment. He pointed
 

out the treatment-related incidence of myocarditis in the
 

male mice and the possible relationship of bronchial
 

pneumonia to this condition. The secondary reviewer concluded
 

that a possibility existed that the lymphomas in the female
 

mice were induced by Pyrazinamide. In regard to human risk,
 

he pointed out that the dose levels administered were 15 to
 

30 times the dosages used in man and were administered for
 

the lifetime of the animals as opposed to a 1 or 2-year
 

treatment period in humans. The secondary reviewer concluded
 

that, if a retest of the mouse study is recommended, it should
 

be given low priority.
 

A discussion ensued on the need of using historical
 

control data. In some instances the decision is based on
 

the adequacy of the bioassay study and whether a repeat
 

bioassay should be undertaken.
 

It was moved that the staff's conclusion be accepted
 

with respect to the rat portion of the study. In regard
 

to the mouse portion, i't was further moved that the data
 

were inadequate for evaluating the carcinogenicity of
 

Pyrazinamide, although the elevated incidence of lymphomas
 

in the female mice requires special notice. It was
 

recommended that the drug be considered by the Chemical
 

Selection Working Group- for possible retest in mice. The
 

motion was seconded and approved by all the Subgroup members
 

except Mr. Garfinkel, who opposed.
 

Members Present Were:
 

Arnold Brown (Acting Chairman), Mayo Clinic
 

Lawrence Garfinkel, American Cancer Society
 

Joseph Highland, Environmental Defense Fund
 

Charles Kensler, Arthur D. Little Company
 

Verald K. Rowe, Dow Chemical, U.S.A.
 

Sheldon Samuels, Industrial Union Department, AFL-CIO
 

Louise Strong, University of Texas Health Sciences Center
 

Sidney Wolfe, Health Research Group
 

Subsequent to this review, changes may have been made
 

in the bioassay report either as a result of the review
 

or other reasons. Thus, certain comments and criticisms
 

reflected in the review may no longer be appropriate.
 

92
 4 U. S. GOVERNMENT PRINTING OFFICE : 1978 260-899/3040 

DHEW Publication No. (NIH) 78-848