Radiation therapy is often used with surgery and chemotherapy to treat cancers of the colon, rectum and anus. Treatment involves focused radiation to the bowel and pelvis to treat cancer cells in the area. Surrounding healthy tissue can be affected, but normal cells are often better able to heal from radiation injury than are cancer cells.
Frequently, the goal of treatment is “organ-preservation”. With organ- preservation, the part of your body that controls your bowel movements, the anus, is not removed. Radiation therapy is often used in organ-preserving approaches, with the result that you will continue to be able to have bowel movements through your anus. If the anus does have to be removed, you would wear a bag on the outside of your abdomen to collect and store your bowel movements.
Radiation therapy may be used:
- For colon cancer, depending on the location and stage of your cancer, radiation therapy can lower the chance of recurrence.
- For some rectal cancers, radiation therapy is given before surgery, with or without chemotherapy, to make the tumor smaller so it can be removed more easily. In some cases, radiation and chemotherapy are given after surgery instead of before surgery.
- Anal cancer can often be treated with radiation therapy and chemotherapy, as an “organ-preserving” approach that avoids the need for surgery.