Surgery (resection) can be an option when there is a likelihood that cancer can be removed completely. If tumors are widespread throughout the body, surgery may not be the best choice. It may mean risk and pain that does not help, and may delay chemotherapy or other treatments that can extend life and improve quality.
- Surgery to remove the primary tumor may or may not be the first step in treating stage IV colon or rectal cancer, particularly if disease has spread beyond the colon or rectum to more than one organ and it appears that the metastases (tumors in distant organs) are not surgically resectable. Research shows that removing the primary tumor may not be necessary to prevent bowel blockage or perforation.
- If metastases are resectable, the tumor in the colon or rectum may be removed at the same time as the metastases, or at a different time. FOLFOX chemotherapy before and after surgery for liver metastases has been shown to improve long-term survival.
- Surgery to remove liver metastases can result in long-term remission or cure for carefully chosen patients. Indications for liver resection include:
- Metastasis is only in the liver and has not spread anywhere else where it cannot be removed surgically.
- After surgery, there will be an adequate amount of healthy liver remaining. Most surgeons now stress that it is the amount of remaining liver that is critical in decision-making rather than the number of tumors.
- Tumors are not located too close to vital anatomical structures.
- If liver tumors cannot be removed initially, conversion chemotherapy can sometimes reduce the size of the metastases and make successful surgery possible. Close collaboration between surgical and medical oncologists is critical to decide the best time for surgery after tumors begin to shrink.
- After liver surgery, chemotherapy is often given to prevent the cancer from coming back (recurring). Systemic (intravenous) chemotherapy is the most common form of chemotherapy used. Sometimes delivering chemotherapy directly to the liver via hepatic arterial infusion (HAI) is chosen. Hepatic arterial infusion involves placing a small pump in the abdomen during surgery that delivers chemotherapy to the cancerous area of the liver.
- Surgery to remove additional metastases in the lungs, abdomen, and other sites may increase survival time and decrease difficult symptoms. When all visible cancer tissue can be removed, long-term remissions or cures are sometimes possible, especially when followed up with chemotherapy.
- Surgery to remove cancer on surfaces in the abdominal cavity (peritoneal carcinomatosis) can also result in long-term remissions and cure in carefully selected patients. Surgical oncologists have developed a Consensus Statement on the best approach to surgery and chemotherapy for patients with peritoneal metastases, including how to evaluate which patients will benefit from the rigorous surgery.
- If a tumor blocks the flow of feces through the colon or rectum but removal of the tumor is not possible, surgeons may create a diverting colostomy to let feces move around the tumor. Another technique is to insert a plastic or metal stent to keep the bowel open.