If your care team diagnoses you with rectal cancer, the next step is finding out the stage of the cancer, or how advanced it is. Staging helps us design a plan that treats you in the most effective way possible. So your care team can determine the stage of the cancer, you will have diagnostic tests to find out:
- how deeply the cancer has grown in the wall of the rectum
- whether the cancer has spread to other parts of the body
The stage of cancer helps determine the typical treatment and outlook for people with cancer at that same point. However, each person’s cancer experience is unique.
There are five stages of rectal cancer, starting at zero and going up to four. They are often written with the Roman numerals I, II, III, and IV. In general, the lower the number, the less the cancer has spread and easier it is to treat.
Stage 0 rectal cancer is found only in the innermost lining of the rectum wall, called the mucosa.
Stage I rectal cancer means that the tumor has spread beyond the inner lining but remains within the rectum wall and has not spread to the lymph nodes. Lymph nodes are small organs that are part of the immune system and act like filters.
Stage II rectal cancer extends through the thick outer muscle layer of the rectum but has not spread to the lymph nodes.
Stage III rectal cancer has spread outside the rectum to one or more lymph nodes.
Stage IV rectal cancer has spread to other parts of the body, such as the liver or lungs. The cancer may be in the lymph nodes.