Dr. Kirkpatrick - Colorectal Awareness Month

 ”Value of colonoscopy in asymptomatic, low-risk patients is unclear”
By Dr. Donald Kirkpatrick
Daily News, March 10, 2008

The era of aggressive colon cancer screening for patients with no symptoms and no identifiable risk factors began when Katie Couric underwent a colonoscopy on national television in 2000. Television commercials portrayed polyps being chased by police, advertising campaigns trumpeted “Get the test, get the cure,” and the population over age 50 started to feel guilty if their large intestine had yet to be inspected by anything less than a complete colonoscopy.

Enthusiasm for the concept of “find polyps, remove them, prevent colon cancer” was fostered by the National Polyp Study published in 1993 where a population having colon polyps removed demonstrated a lower incidence of colon cancer over a five year period than expected. Unfortunately, multiple subsequent studies involving more than five times as many patients have not reproduced this effect. Surprisingly, cancer rates for patients having polyps removed in these larger studies have been nearly equal to the control groups not having a colonoscopy.

In 2007, a more concerning study involving over 3,000 participants showed patients found to have polyps, even if removed, had a higher incidence of developing colon cancer compared to expected population rates. Reviewers of this study are concluding the value of a colonoscopy relates to identifying patients who don’t have polyps because they are less likely to develop cancer, but the overall lack of protective benefit of having polyps removed remains unexplained.

While medical organizations attempt to sort out why the expected decrease in colon cancer incidence has not occurred despite aggressive screening strategies in university based studies, the average health care consumer needs to be apprised of just where things stand at the moment. There is currently no compelling evidence that screening colonoscopy in an asymptomatic patient with no risk factors for colon cancer is the best strategy. Instead, the 20 percent protective benefit of annual fecal sample testing for microscopic blood available from your doctor’s office may be the best screening investment in 21st century medicine.

When television personalities and advertising campaigns touting expensive technologies influence the practice of medicine, the results are predictable: soaring health care costs, high expectations for favorable results, and eventually, the realization that what sound too good to be true, is too good to be true.

Dr. Donald Kirkpatrick of Longview is a gastroenterologist practicing at Pacific Surgical Institute and St. John Medical Center.