Major Forms of Cancer - Colon-rectum cancer

Cancer of the colon (large intestine) and rectum is the second leading cause of cancer death in the United States. Each year it claims an estimated 55,000 lives, and produces about 150,000 new cases—more than any other kind of cancer except skin cancer. It afflicts men and women about equally. The five-year survival rate from this form of cancer, usually after surgery, is 60 to 70 percent where the cancer was localized and 30 to 40 percent where there was regional involvement. However, authorities now believe that this rate could be upped substantially through early diagnosis and prompt treatment.

Symptoms

It is important, then, to be alert to the early symptoms of these cancers. Cancers of the colon often produce changes in bowel habits that persist longer than normal. The change may be constipation or diarrhea, or even both alternating. Cancers of the colon also often produce large quantities of gas, which cause abdominal discomfort ranging from a feeling of overfullness to pain, intermittent at first and then coming as regular cramps.

Both colon cancer and rectal cancer may also cause bleeding. Sometimes such bleeding is evidenced in the stool or on the tissue (the most frequent first sign of rectal cancer); but if the bleeding is slight and occurs high enough up the colon, it may not be visible at all. After a period of weeks, however, the persistent bleeding causes anemia in the patient.

All such symptoms should be investigated promptly. Unfortunately, many persons tend to ignore them. Chronic constipation, for example, or gas, is easy to dismiss for the nuisance that it usually is. Even rectal bleeding, which demands immediate medical consultation, is often ignored by hemorrhoid sufferers, who fail to realize that hemorrhoids and cancer, though unrelated, can and sometimes do exist in the same persons at the same time.

Detection

For these reasons, the key to successful and early diagnosis of colon and rectum cancer lies in making a proctoscopy part of the regular annual health checkup. In this procedure, performed in a physician's office, a lighted tube called a proctoscope is passed into the rectum. Through it, the physician can examine the walls visually for signs of tumor. If the physician thinks it advisable to check the sigmoid colon also, the procedure is called a proctosigmoidoscopy , and a similar instrument called a sigmoidoscope is used. The American Cancer Society now recommends that everyone over age 40 have a proctoscopy or proctosigmoidoscopy in routine annual checkups.

Therapy

The indicated treatment for colon-rectum cancer is surgical removal of the affected part of the bowel. Adjacent portions and related lymph nodes may also be removed, and if the surgeon sees that the cancer is widespread, he may have to perform extensive surgery. This may require that he create a colostomy —a temporary or permanent opening in the abdominal wall through which solid wastes may pass. Although this method of voiding the bowels is somewhat inconvenient at first, most colostomy patients adjust to it very easily and lead perfectly normal, active, and healthy lives. The wall of prudish silence that used to surround the disease and the colostomy is fortunately crumbling. An organization for colostomy patients called the United Ostomy Association keeps up with current information on diet, colostomy equipment, and other problems the members have in common.

Radiotherapy is sometimes used before the operation (occasionally to make surgery possible) and sometimes afterward to treat recurrence of the cancer. Various chemical agents have been found useful in treating colon-rectum cancer that has spread to the lymph nodes or more widely.