Key Points
                    - After lip and oral cavity cancer has been diagnosed, tests are done to find out if cancer cells have spread within the lip and oral cavity or to other parts of the body.     - There are three ways that cancer spreads in the body.    - Cancer may spread from where it began to other parts of the body.    - The following stages are used for lip and oral cavity cancer:         - Stage 0 (Carcinoma in Situ)     - Stage I     - Stage II     - Stage III     - Stage IV
                
                
                    After lip and oral cavity cancer has been diagnosed, tests are done to find out if cancer cells have spread within the lip and oral cavity or to other parts of the body.
                    The process used to find out if cancer has spread within the lip and oral cavity or to other parts of the body is called staging. The information gathered from the staging process determines the stage of the disease. It is important to know the stage in order to plan treatment. The results of the tests used to diagnose lip and oral cavity cancer are also used to stage the disease. (See the General Information section.)
                
                
                    There are three ways that cancer spreads in the body.
                    Cancer can spread through tissue, the lymph system, and the blood:         - Tissue. The cancer spreads from where it began by growing into nearby areas.     - Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.     - Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
                
                
                    Cancer may spread from where it began to other parts of the body.
                    When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.         - Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.    - Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.        The metastatic tumor is the same type of cancer as the primary tumor. For example, if lip cancer spreads to the lung, the cancer cells in the lung are actually lip cancer cells. The disease is metastatic lip cancer, not lung cancer.
                
                
                    The following stages are used for lip and oral cavity cancer:
                    Stage 0 (Carcinoma in Situ)    In stage 0, abnormal cells are found in the lining of the lips and oral cavity. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.        Stage I    In stage I, cancer has formed and the tumor is 2 centimeters or smaller. Cancer has not spread to the lymph nodes.        Stage II    In stage II, the tumor is larger than 2 centimeters but not larger than 4 centimeters, and cancer has not spread to the lymph nodes.       Stage III    In stage III, the tumor:            - may be any size and has spread to one lymph node that is 3 centimeters or smaller, on the same side of the neck as the tumor; or     - is larger than 4 centimeters.              Stage IV     Stage IV is divided into stages IVA, IVB, and IVC.            - In stage IVA, the tumor:                  - has spread through tissue in the lip or oral cavity into nearby tissue and/or bone (jaw, tongue, floor of mouth, maxillary sinus, or skin on the chin or nose); cancer may have spread to one lymph node that is 3 centimeters or smaller, on the same side of the neck as the tumor; or       -  is any size or has spread through tissue in the lip or oral cavity into nearby tissue and/or bone (jaw, tongue, floor of mouth, maxillary sinus, or skin on the chin or nose), and cancer has spread:                           -  to one lymph node on the same side of the neck as the tumor and the lymph node is larger than 3 centimeters but not larger than 6 centimeters; or          - to more than one lymph node on the same side of the neck as the tumor and the lymph nodes are not larger than 6 centimeters; or          - to lymph nodes on the opposite side of the neck as the tumor or on both sides of the neck, and the lymph nodes are not larger than 6 centimeters.                                  - In stage IVB, the tumor:                  - may be any size and has spread to one or more lymph nodes that are larger than 6 centimeters; or       - has spread further into the muscles or bones in the oral cavity, or to the base of the skull and/or the carotid artery. Cancer may have spread to one or more lymph nodes anywhere in the neck.                 - In stage IVC, the tumor has spread beyond the lip or oral cavity to distant parts of the body, such as the lungs. The tumor may be any size and may have spread to the lymph nodes.