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Overview 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. The last part of the rectum contains the rectal sphincter or anus. The rectal sphincter is the muscle that controls the defecation. Preservation of the rectal sphincter during surgery for rectal cancer is necessary for the preservation of control of bowel function. Treatment approaches differ between cancers of the colon or rectum, and are therefore discussed separately. A separate section has been created for Colon Cancer. Adenocarcinoma is the most common type of cancer that originates in the cells that line the rectum or large intestine. It accounts for over 90-95% of cancers originating in the rectum. Other types of cancer including carcinoid and leiomyosarcoma also originate in the rectum, but are not referred to as rectal cancer. This treatment overview deals only with adenocarcinoma of the rectum which will be referred to as rectal cancer. The treatment of rectal cancer may involve several physicians, including a gastroenterologist, a surgeon, a medical oncologist, a radiation oncologist, and/or other specialists. Care must be carefully coordinated between the various treating physicians involved in management of your cancer. In order to understand the best treatment options available for treatment of rectal cancer, you must first determine where the cancer has spread in the body. The initial spread of rectal cancer occurs circumferentially around the rectum and laterally into the adjacent fat and muscles. Rectal cancer can then invade nearby organs and spread through the lymph and blood systems. Rectal cancer cells may spread via the blood throughout the body to the liver, lungs and other organs. Determining the extent of the spread or the stage of the cancer requires a number of tests and is ultimately confirmed by surgical removal of the cancer and exploration of the abdominal cavity. Computerized Tomography and Magnetic Resonance Imagery scans of the chest, abdomen, and pelvis are used to determine where the cancer has spread. Additional cancers of the colon or rectum are present in 3-5% of patients. A colonoscopy may be used to identify whether a second cancer is present in the colon or rectum prior to surgery. Endorectal ultrasound (EUS) is a special probe that is inserted into the rectum that can help determine the thickness of the cancer. EUS can help determine the stage, which is effected by the thickness of the cancer. Hepatic artery and liver blood flow studies may also help determine which patients need chemotherapy after surgery for rectal cancer. Upon completion of the clinical "staging evaluation", surgery is performed to remove the cancer with part of the normal adjacent rectum and to further determine the level of spread within the rectal wall and abdomen. The type of surgery performed depends on the size and the location of the cancer. Surgery is commonly performed through an abdominal incision. In some cases, the rectal cancer is located close to the anus, and the anus is removed with the cancer. Large rectal cancers close to the anus that cannot be removed without damaging anal function are sometimes treated with chemotherapy to help shrink the cancer before surgery. This is referred to as neoadjuvant chemotherapy. If there is enough shrinkage of the cancer, surgery may be performed that spares anal function. However, in some cases, the cancer is too close to the anus and the anus is removed with the cancer. In other instances, the cancer may be localized, but too large to remove surgically. In these cases, administration of chemotherapy and/or radiation before surgery may shrink the cancer and allow complete surgical removal. For more information, go to Surgical Management of Rectal Cancer. Following surgical removal of rectal cancer, a final "pathologic" stage will be given. This is based on extent of spread of cancer after looking at the removal of tissue under a microscope. This may be a letter or a number as several different staging systems are used to describe rectal cancer. All new treatment information concerning rectal cancer is categorized and discussed by the stage. In order to learn more about the most recent information available concerning the treatment of rectal cancer, click on the stage for which you are interested. Stage I (A-B1): Cancer is confined to the lining of the rectum. Stage II (B2-3): Cancer may penetrate the wall of the rectum into the surrounding fat or muscles or other adjacent organs but does not invade any local lymph nodes. Stage III (C1-3): Cancer invades one or more of the local lymph nodes but has not spread to other distant organs. Stage IV (D): Cancer has spread to distant locations in the body which may include the liver, lungs, bones, or other sites. Recurrent/Relapsed: The rectal cancer has progressed or returned (recurred/relapsed) following an initial treatment.
USED WITH PERMISSION OF CANCERCONSULTANTS.COM copyright® 1998, last updated 01/01, CancerConsultants.com - All Rights Reserved. "The information contained above is general in nature and is not intended as a guide to self-medication by consumers or meant to substitute for advice provided by your own physician or other medical professional. The reader is advised to consult with a physician or other medical professional and to check product information (including packaging inserts) for changes and new information regarding dosage, precautions, and contra indication before administering any drug, herb, supplement, compound, therapy or treatment discussed herein. Neither the editors nor the publisher accepts any responsibility for the accuracy of the information or consequences from the use or misuse of the information contained herein." |
