Sigmoid Colon Resection

When the sigmoid colon has a polyp which is cancerous, a sigmoid colon resection is required. Cancer of the colon can be anywhere in the large bowel. This includes the ascending colon, the transverse colon, the descending colon or the sigmoid colon. Many colon polyps that result in colon cancer come out of the sigmoid colon, which is the last part of the colon before the stool reaches the rectum and is eliminated.

Depending on how advanced the cancer is, a portion of the sigmoid colon may need to be resected or the entire sigmoid colon resection may need to be performed. Doctors look for nearby lymph nodes and check them for cancer as well. If lymph nodes are involved, treatment that includes radiation or chemotherapy may be needed.

Stages of Sigmoid Colon Cancer

Like other colon cancers, sigmoid colon cancer comes in different stages. The different stages determine whether or not a sigmoid colon resection is necessary or just a polypectomy is performed:

• In stage 0 cancer: This is called carcinoma in situ and refers to cancer that is still in the epithelial tissue of the polyp. A polypectomy is often just what's needed.
• In stage 1 colon cancer of the sigmoid colon: The colon cancer has traveled through the epithelium and is in the middle layers of the colon. Sometimes a sigmoid colon resection is done in these cases.
• In stage 2 sigmoid colon cancer: The cancer has moved beyond the middle layers of the colon and may actually extend to nearby organs. A sigmoid colon resection and lymph node dissection is necessary.
• In stage 3 sigmoid colon cancer: Colon cancer is found in at least three lymph nodes. A sigmoid colon resection is required along with removal of all nearby lymph nodes. Radiation is sometimes used as is chemotherapy.
• In stage 4 sigmoid colon cancer: Colon cancer is the most advanced and has spread to other parts of the body, most commonly the liver and the lungs. A sigmoid colon resection is required to remove the main body of tumor. Chemotherapy and radiation are used to try and kill remaining colon cancer cells or those that have traveled to other body areas. The colon cancer survival rate is 8-15 percent after five years with stage 4 colon cancer.

Detection and Removal of Polyps

Colon cancer of the sigmoid colon arises out of hyperplastic polyps of the sigmoid colon. There are three ways to detect and remove the colon polyps. The first is via a flexible sigmoidoscopy, a shorter tube that has a camera at the end of the tube. It reaches about 60 centimeters in length and can find most polyps in the lower colon. Usually a polyp cannot be removed via flexible sigmoidoscopy and a colonoscopy must be done to actually get a biopsy.

A colonoscopy can travel the length of the colon and can detect and remove all polyps it sees. It has a 95 percent success rate in determining whether or not polyps exist. A colonoscope is put into the rectum and a camera looks for polyps. If any polyps are found, it is determined if they can be removed via the colonoscope. Polyps are then removed and tested for cancer. If a polyp is found to be cancerous in the sigmoid colon, a sigmoid resection and lymph node dissection will be done.

Another way to detect polyps that might be cancerous is to do a virtual colonoscopy. This is a CT scan of the abdomen after inserting air into the colon. The CT scan can visualize any colon polyps as contrasted by the air. If any are found, a colonoscopy is done to remove the polyps. If these are positive for cancer, then a sigmoid colon resection is done in order to remove all traces of the cancer.

Written by Christine Traxler

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