If a polyp is found to be a cancer, treatment depends on whether the cancer is likely to have spread. The risk of spread is determined by microscopic examination of the polyp by a pathologist. If the risk is low, no further treatment is necessary. If the risk is high, particularly if the cancer has invaded beyond the superficial layers of the polyp, the affected segment of the large intestine may need to be removed surgically. Removal of colorectal polyps does prevent a cancer from developing at that one location, but the patient may be at risk to develop polyps at other locations. Close follow-up is indicated for these patients. When a person has a polyp removed, the entire large intestine and rectum are examined by colonoscopy at regular intervals as determined by the number and type of polyps identified.
Treatment for colorectal cancer is most effective when the cancer is found early. Colorectal cancer treatment may include surgery, radiation, chemotherapy or any combination of these. Surgery is the first line of defense against colorectal cancer. Some patients may have radiation and/or chemotherapy prior to surgery. Others might have one or both afterwards, and some will not have either.