Doctors need to know what stage your oral cancer is in to help decide what treatment to recommend. The stage is based on the size and extent of your tumor, the number of lymph nodes involved, and whether the cancer has spread. Your oncologist will get this information from performing various tests.
The TNM System is a standard system for describing the extent of a cancer's growth. It was developed by the International Union Against Cancer and the American Joint Committee on Cancer. Here's what the letters stand for in the TNM System:
T refers to the size of the primary tumor.
N refers to whether the lymph nodes in the neck area have become cancerous.
M refers to whether the cancer has spread to distant organs in the body (metastasized), such as your lungs, bones, or liver.
Your oncologist assigns an X, or numerical values from 0 to 4, to your T, N, and M stages. These letter and number combinations are called stage groupings. They're used to determine your overall disease stage.
The most commonly used system to stage cancer is called the American Joint Committee on Cancer TNM classification. This system defines cancers by Roman numerals 0 through IV. The lower the number, the less the cancer has spread. The higher the number, the more the cancer has spread. These are the stages of oral cancer and their definitions. Be sure to ask your doctor to help explain your cancer's stage to you. Each TNM category, with its assigned X or numerical value from 0 to 4, falls into one of these stages. X means that the T, N, or M cannot be determined:
Stage 0. In this stage, cancer is only in the layer of cells lining your oral cavity or oropharynx. The cancer is very tiny. It has not spread or gone deeper. Cancer at this stage is also called carcinoma in situ. You might hear the terms Tis, N0, or M0 used to describe a stage 0 tumor. Treatment may include surgery, radiation, or a combination of both.
Stage I. In this stage, there is cancer in your mouth, but it is 2 centimeters (cm) (about .75 inch) or less in size. The cancer has not spread to the lymph nodes or to other places in your body. Cancer at this stage offers a very good chance of survival. You might hear the terms T1, N0, and M0 used to describe a stage I tumor. Treatment may include surgery, radiation, or a combination of both.
Stage II. In this stage, the cancer is between 2 and 4 cm (about 1.5 inches) in size. The cancer has not spread to the lymph nodes or other places in your body. The chance of survival is very good at this stage. You may hear your doctor use these the terms T2, N0, and M0 to describe a stage II tumor. Treatment may include surgery, radiation, or a combination of both.
Stage III. In this stage, the tumor is larger than 4 cm (about 2 inches) and has not spread to the lymph nodes or to other places in your body. Or the cancer is any size and has spread to nearby lymph nodes, but not to other places in your body. You may hear several TNM terms to describe a stage III tumor: T3, N0, M0; T1, N1, M0; T2, N1, M0; and T3, N1, M0. Surgery or radiation or both are likely. Chemotherapy may be suggested to destroy any cancer that has spread, and other options include targeted treatments which target specific cancer cells in oral cancer called epidermal growth factor receptor (EGFR). The drug cetuximab specifically targets EGFR cells.
Stage IV. In this stage, the tumor can be any size, but the cancer has spread to the lymph nodes or other parts of your body. You may hear a TNM description that includes any T number (1 to 4), any N number (0 to 3), and either M0 or M1. Surgery to remove the tumor is likely. You may also have radiation or chemotherapy, targeted treatments, or a combination.
Recurrent. Recurrent cancer is cancer that has come back after it was treated. When cancer occurs again, the staging process is also begun again. You'll probably have tests similar to those you had the first time to determine the extent of the cancer.