Colorectal Cancer: Prevention Is

By Dr. David A. Rothenberger

Colorectal cancer is the No. 2 cancer killer in the United States, causing about 55,000 deaths a year. Only lung cancer kills more people. What makes this figure especially tragic is that 35,000 to 40,000 of these deaths are preventable using tests and treatments available now.

In most cases, colorectal cancer is preventable because the disease develops slowly, allowing time for effective intervention. Generally, the risk of this cancer can be eliminated by removing pre-cancerous polyps from the colon and rectum. Even when cancer develops, it is often possible to remove it using a standard surgical procedure without chemotherapy or radiation. The key is to identify the cancer early before it spreads; this means screening before symptoms develop.

The symptoms of colorectal cancer include:

• Blood in the stool or bleeding from the rectum
• Abdominal pain and/or discomfort or pain with a bowel movement
• Unexplained weight loss
• Sensing that your bowel does not empty completely

Factors that increase your risk for colorectal cancer include obesity, lack of exercise, smoking, a high-fat, low-fiber diet, and alcohol consumption. Individuals with a family history of colorectal cancer or who suffer from inflammatory bowel disease are also at greater risk for the disease. But, the most important risk factor is age. That's why everyone over age 50 should be screened regularly.

Although the medical community accepts several screening methods for those at average risk for colorectal cancer, the method I generally recommend is colonoscopy, a procedure in which a flexible scope is used to examine the entire length of the colon. The two other methods include a yearly Hemoccult(TM) test to detect the presence of blood in a patient's stool and sigmoidoscopy, a procedure involving a scope that examines the rectum and lower colon. A sigmoidoscopy should be done every five years.

Why do I recommend colonoscopy? There are a number of reasons. Hemoccult(TM) testing relies on the patient to collect his or her own stool sample at home for later examination, and compliance is generally poor. As for sigmoidoscopy, a recent large-scale study of almost 1,500 patients, conducted at the University of Minnesota and at several other cancer centers around the country, discovered that for women, sigmoidoscopy is not highly effective in detecting advanced, pre-cancerous polyps. Removing this type of polyp prevents the vast majority of colorectal cancer. In fact, our study revealed that, because women tend to develop polyps higher in the colon than men, sigmoidoscopy has a success rate of only 30 percent for women, less than half the success rate for men.

There are other reasons I prefer colonoscopy. For one, if your test is normal, you don't need another one for 10 years unless you develop symptoms. Secondly, a colonoscopy makes it possible to detect and remove pre-cancerous polyps immediately, thus eliminating the long-term danger they pose to your health.

Some evidence suggests non-steroidal anti-inflammatory medicines such as ibubrofen, as well as dietary supplements such as calcium and folic acid, might reduce the risk of colorectal cancer. But, without question, the best way to treat colorectal cancer is through prevention. If you're over 50, or have a medical history that includes family members under the age of 50 who have been diagnosed with the disease, or any of the risk factors mentioned above, call your doctor today and schedule a screening test. Delaying that call could prove a deadly mistake.

This column is an educational service of the University of Minnesota. Advice presented should not take the place of an examination by a health-care professional. For more health-related information, go to http://www.healthtalk.umn.edu.