Colon Cancer

The colon and rectum are parts of the body's digestive system and together form a long, muscular tube called the large intestine. The colon is the first 6 feet of the large intestine and the rectum is the last 8-10 inches. Treatment approaches differ between cancers of the colon or rectum and are, therefore, discussed separately. A separate section has been created for Rectal Cancer.

Adenocarcinoma refers to cancer that begins in the cells that line the colon or large intestine and accounts for over 90%-95% of cancers originating in the colon. Other cancers, including carcinoid tumors and leiomyosarcoma, also originate in the colon, but are not referred to as colon cancer. This treatment overview deals only with adenocarcinoma of the colon, which will be referred to as colon cancer.

The treatment of colon cancer typically consists of surgery and/or chemotherapy and may involve several physicians, including a gastroenterologist, a surgeon, a medical oncologist and other specialists. Care must be carefully coordinated between the various treating physicians involved in managing the cancer.

Colon cancer begins in cells that line the colon. As the cells increase in number, they spread circumferentially around the colon like a "napkin ring." If detected early, cancer cells may only be found in the colon. If not detected early, the cancer may invade adjacent organs and spread through the lymph and blood systems throughout the body to the liver, lungs and other organs.

Surgery
Upon completion of the clinical staging evaluation, surgery is performed to remove the cancer along with part of the normal adjacent colon and determine the level of spread within the colon and abdomen. Surgery is performed through an abdominal incision or through a laparoscope. Laparoscopic surgery is less invasive and involves the insertion of surgical instruments through very small incisions in the abdomen. Patients experience faster healing times compared with traditional abdominal surgery, and their outcomes with regard to cancer recurrence and survival have been shown in some trials to be similar. It is important for patients to discuss the risks and benefits of the two techniques with their doctor, as laparoscopic surgery is not yet the standard of care, but is still considered investigational.