DEAR MAYO CLINIC:

I have just been diagnosed with early stage rectal cancer and I'm only 40 years old. Am I going to have to wear a colostomy bag for the rest of my life? What are the statistics for this cancer?

ANSWER:

Rectal cancer, a form of colon cancer, is relatively common. More than 40,000 cases of rectal cancer are diagnosed in the United States each year.

The outlook for people with rectal cancer varies, depending on how advanced the cancer is and whether it has spread outside the rectum. Rectal cancer that's confined to the rectal wall and doesn't involve any lymph nodes has a cure rate of more than 90 percent. If the cancer has spread to nearby lymph nodes, the cure rate is approximately 60 percent. Although specific treatment for each patient is based on the location and stage of the cancer, most patients with rectal cancer do not need a colostomy.

The colon, also called the large bowel, is approximately five feet long, and the rectum is the last 10 inches of colon. The rectum ends at the anus. The majority of rectal cancers are in the middle to upper portion of the rectum. In these cases, the section of rectum with the cancer can be removed and the two ends of bowel spliced together; a permanent colostomy is not needed. Sometimes the surgeon will place a temporary stoma -- a surgically-created opening from your intestine to the surface of your abdomen for the passage of stool out of your body into a special bag. Typically, a temporary stoma is removed about three months after rectal surgery. Or if you have chemotherapy, the stoma may be closed after you finish your course of chemotherapy.

When rectal cancer is near the anus, however, it may be impossible to remove the cancer without removing the anus as well.

In these cases, a permanent colostomy is necessary. But only about 10 percent of patients with rectal cancer require a permanent colostomy.

Rectal cancer differs from other forms of colon cancer in that rectal cancer is more likely to come back near the original site of the cancer (local recurrence), whereas other types of colon cancer, if they come back, are more likely to affect other organs, such as the liver or lungs (distant recurrence). Because local recurrence is a concern, rectal cancer requires a different course of treatment than other colon cancers.

If rectal cancer is detected early, before it spreads beyond the rectal wall (stage 0 or I), it can be treated with surgery alone. If it has spread through the rectal wall into the surrounding tissue, or if any lymph nodes are involved (stage II or III), then chemotherapy and radiation therapy are recommended before surgery to prevent local recurrence and increase cure rates.

A family history of colon or rectal cancer can increase your risk of developing these types of cancer. Most people with rectal cancer are older than 50. The fact that you've been diagnosed at age 40 could indicate that you may have an inherited genetic predisposition to the disease. You may want to investigate this further with a medical genetics counselor. Your doctor can recommend an appropriate genetics expert in your area.

The earlier rectal cancer is diagnosed, the better the cure rate. Any signs or symptoms of rectal cancer should be evaluated by a physician right away. The most common sign of rectal cancer is rectal bleeding or bloody stool. Changes in bowel habits, including diarrhea, constipation or a change in stool consistency for more than two weeks, can also be signs of rectal cancer.

Rectal cancer can be diagnosed using flexible sigmoidoscopy.

During this test, which can be done in your doctor's office with minimal discomfort, the doctor passes a flexible, slender, lighted tube attached to a video monitor into the rectum and sigmoid -- approximately the last two feet of the colon.

Or, depending on your age, symptoms and medical history, a colonoscopy may be recommended instead. Colonoscopy is similar to flexible sigmoidoscopy, but the instrument used, a colonoscope, is longer and allows the doctor to view the entire colon.

When identified in its early stages, rectal cancer can often be successfully treated.

-- Richard Devine, M.D., Colon and Rectal Surgery, Mayo Clinic, Rochester, Minn.

(Medical Edge from Mayo Clinic is an educational resource and doesn't replace regular medical care. E-mail a question to medicaledge@mayo.edu , or write: Medical Edge from Mayo Clinic, c/o TMS, 2225 Kenmore Ave., Suite 114, Buffalo, N.Y., 14207. For more information, visit www.mayoclinic.org.)

(c) 2009 Mayo Foundation for Medical Education and Research. Distributed by Tribune Media Services Inc. All Rights Reserved.

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