Colon cancer is preventable, but screening is key.

Byline: GUEST VIEWPOINT By Craig Chamberlain, William Wu and Dee Tvedt For The Register-Guard

Most of us have been, or will be, touched by colon cancer, the second leading cause of cancer deaths in the United States. It affects an estimated 145,000 men and women in the United States every year, resulting in 58,000 deaths. It is tragic that appropriate screening could prevent most of these deaths.

In 1999, the U.S. Senate designated March as National Colorectal Cancer Awareness Month. Each March brings an opportunity to highlight this lethal cancer and to emphasize the importance of screening for it, because it is a very curable cancer if detected early. However, if it is not detected early and spreads outside the colon, the prognosis for lengthy survival is poor. Symptoms such as pain, rectal bleeding or a change in bowel pattern are unreliable indicators. They may not be present until the cancer is more advanced.

Virtually all colorectal cancers begin as po- lyps, small growths arising from the lining of the colon. Most polyps are benign, but many have malignant potential. These precancerous polyps can grow, mutate and develop into a cancer. It typically takes from five to 10 years for this to occur, which allows a window of opportunity to find and remove these growths before they turn into a malignancy. Since most colon cancers occur in people older than 50, the American Cancer Society recommends that screening begin at that age. People who are at higher risk (such as those who have a family history of colon cancer) may need to be screened earlier.

Several options exist for colon cancer screening: fecal occult blood tests (which checks for hidden blood in the stool), flexible sigmoidoscopy (which uses a short flexible scope to examine the lower portion of the colon and rectum), barium enema (an X-ray of the colon), virtual colonoscopy (a more specialized X-ray using CAT scan technology) and colonoscopy (which uses a long flexible scope to examine the entire colon).

Colonoscopy is the only test that not only diagnoses abnormalities but also removes polyps or early cancer and biopsies abnormal tissue at the time of the procedure.

The American Cancer Society states that colonoscopy "is regarded as the gold standard because this procedure is the most highly sensitive compared to other tests; examines the entire colon; and allows for screening, diagnosis and removal of polyps in a single visit.' It is covered by Medicare and by most insurance plans.

Performed under sedation, colonoscopy is generally more comfortable than flexible sigmoidoscopy or barium enemas. The risk of complications is slight, but the value is clear. All other tests may need to be followed by colonoscopy if abnormal or questionable results are obtained.

Colonoscopy is the most expensive of all the tests, but it is also the most cost-effective. A review prepared for the U.S. Preventive Services Task Force in 2002 found that all types of colon cancer screening (including a colonoscopy performed every 10 years) are effective in reducing premature deaths and can be done at an acceptable cost to society.

The cost of preventing each colon cancer death (or the cost per year of life saved) compares favorably with such widely accepted interventions as Pap smears or mammograms.

The National Cancer Institute reports that approximately half of Americans age 50 and older are being screened for colon cancer. People avoid screening for many reasons: lack of time, modesty, fear and denial.

A number of celebrities have raised awareness of colon cancer and the importance of screening. Katie Couric, Heidi Klum, Eric Davis and The Register-Guard's own Bob Welch have spoken about the subject. As Couric testified before the U.S. Senate Select Committee on Aging in March 2000, `A lot of people don't want to talk about it. Colons. Rectums. Bowels. Not exactly the stuff of cocktail party conversation. ...

`But if you recall, not long ago people felt uncomfortable talking about breast cancer ... and men rarely discussed their prostates. Now, these cancers are routinely discussed with family, friends, and most importantly doctors. We have to do the same for colon cancer.'

It is important for us as a society to put aside our squeamishness. Maintaining good health involves many things, and for everyone who is 50 or older, screening for colon cancer should be among them. We need to spread the word: colon cancer is preventable; screening saves lives; colonoscopy is the gold standard for screening.

Craig Chamberlain, M.D., and William Wu, M.D., are two of eight physician partners of the Eugene Gastroenterology Consultants. Dee Tvedt, a certified gastrointestinal registered nurse, is the education coordinator at the Oregon Endoscopy Center.