Surgical Treatment of Colorectal Cancer

Thomas P. Wright , M.D. Colon & Rectal Surgery General Surgery

Q: What does staging of colorectal cancer mean?
Staging of colorectal cancer indicates if the cancer of the colon or rectum has progressed and how far. Staging does not describe the size of the tumor, but how deeply the tumor has invaded the wall of the colon or rectum and whether it has spread to the lymph nodes or other body tissues.

Q: How is the staging of colorectal cancer defined?
Three different staging systems are used for colorectal cancer. These include the Dukes, Astler-Coller and the AJCC/TNM systems. The stages of colorectal cancer can be denoted as A, B, C, or A, B1, B2, B3, C1, C2, C3, D, or I, II, III, or IV, depending on the system used. For all three systems, the higher the number or letter the greater the depth of penetration of the tumor through the wall of the bowel, the greater the spread of the colorectal cancer to other body tissues, and the worse the prognosis.

Q: What are the sites of metastases for colorectal cancer?
The colorectal cancer can spread to the lymph nodes, and to other organs and tissues such as the liver, lung, peritoneum, and ovary.

Q: What is the usual treatment for colorectal cancer?
The primary treatment for all stages of colorectal cancer is surgery. Tumors that have grown through the wall of the bowel will also require chemotherapy and/or radiation therapy.

Q: What types of surgery are performed for colorectal cancer?
The type of surgery depends on the location and extent of the cancer growth. An early stage of colorectal cancer may only require a local excision (tumor is removed without cutting into the abdominal wall) or polypectomy (removal of polyp).

More advanced stages of colon cancer require a bowel or colon resection, usually called a segmental resection or partial colectomy. The surgeon removes the cancer and a length of the healthy tissue on either side as well as the nearby lymph nodes. The two ends of colon are then reattached (anastamosis). Rarely, if an anastomosis is not feasible, a colostomy is necessary. A colostomy is an opening (stoma) on the outside of the abdomen for elimination of wastes, and an ostomy bag is worn to collect waste. Sometimes a temporary colostomy may be necessary in order for the bowel to heal. In order to prevent blockage in the flow of feces, a diverting colostomy may be necessary.

Several surgical procedures are used for rectal cancer. Stage I rectal cancers can sometimes be managed by a local or transanal resection. This procedure does not require an abdominal incision but can be performed through the anus. This procedure is only performed when complete removal of the cancer can be achieved. Many Stage I and most Stage II and III rectal cancers are removed by either a low anterior or abdominoperineal resection (the latter requires a permanent colostomy due to the cancer being located very low in the rectum). Some Stage IV rectal cancers may require a diverting colostomy as described.

Surgery may also be indicated for metastatic colorectal cancer. When there are only a small number of metastases in the liver, lungs, or other abdominal tissue, these can sometimes be surgically removed.

Resources
Follow Up Evaluation After Surgery For Colorectal Cancer