At its earliest stage (stage 0), colon cancer is limited to the inner lining of your colon. As colon cancer progresses, it can grow through your colon and extend to nearby structures. The most advanced stage of colon cancer (stage IV) indicates cancer has spread to other areas of the body, such as the liver or lungs.
The stage refers to the extent of the cancer and how far it has spread. Staging colon cancer is essential to determine the best treatment approach. Colon cancer is typically staged based on a system established by the American Joint Committee on Cancer called the TNM staging system. The system considers the following factors:
It helps determine how serious the cancer is and how best to treat it. Doctors also use a cancer’s stage when talking about survival statistics. The earliest stage colorectal cancers are called stage 0 (a very early cancer), and then range from stages I (1) through IV (4). As a rule, the lower the number, the less the cancer has spread.