Colorectal Cancer Prevention

You can radically reduce the threat of death from this common disease.

"Getting screened for colon cancer should be considered as essential as getting your blood pressure checked if you're over age 50--it's that effective," says Gabriel Feldman, M.D., head of colon-cancer screening and research at the American Cancer Society. And researchers have identified a number of other steps that may further reduce your risk of the disease. "Most people who get screened and take the other recommended steps can essentially eliminate their chance of dying of colon cancer," Feldman says.

Screening for colon cancer has recently become more convenient, since people can now choose one of three screening options. Here's a rundown on the options and the other colon-protecting steps.

Some 90 percent of colon cancers can be cured if they're detected early--and screening is generally the only way to spot them early. Once the disease has spread, survival drops to less than 50 percent.

More important, screening also saves lives by preventing colon cancer. That's because the tests detect not only cancers but also intestinal polyps--tiny, mushroom-shaped growths that often turn cancerous but can be easily removed. Overall, screening can reduce the average person's risk of colon cancer by a conservatively estimated two-thirds and the risk of colon-cancer death by at least that much.

Most adults should start being screened for colon cancer at age 50; high-risk individuals should generally start sooner.

The American Cancer Society, the American College of Gastroenterology, and other major groups have endorsed several screening, options, each offering comparable protection. The choice generally depends on personal preference--yours and your doctor's--and on your insurance coverage.

Stool test plus sigmoidoscopy

Doctors have long had two screening tests for spotting early signs of colon cancer: the fecal occult-blood test, which can detect invisible traces of blood oozing from a suspicious growth into the stool; and sigmoidoscopy, the use of a flexible, lighted tube to directly inspect the lower (sigmoid) part of the colon, where roughly half of all colon cancers arise. But both tests have limitations.

Many cancers and polyps bleed only intermittently, sometimes not at all; as a result, the blood test alone misses about one-fourth of the cancers and probably more of the polyps. Some evidence suggests the blood test is particularly likely to miss growths low in the colon. Sigmoidoscopy spots those effectively--but the scope is too short to reach the upper parts of the colon, where 40 to 50 percent of the cancers and polyps lurk.

So most experts now recommend that, starting at age 50, individuals undergo the cheap and simple stool test every year, and sigmoidoscopy every five years. Studies suggest that the stool test alone cuts mortality by about one-third, sigmoidoscopy alone by about one-third, and the combination by about two-thirds.

The stool test involves taking home several cards from your doctor and, on different days, using a small stick to place a small sample of stool on the cards. You then return the cards to the doctor's office, where they're tested for invisible blood. Don't rely on over-the-counter fecal-blood kits; some are inaccurate, and even the accurate ones need to be interpreted by a physician. To help avoid a false-positive result--one that wrongly suggests polyps or cancer--take these steps.

Last updated Nov 26/06