Colon Cancer Screening: Any Test Better Than No Test at All
Nov. 29, 2000 -- When his stomach problems first started several years ago, Edward Leigh's family doctor chalked it up to stress. By the time his colon cancer -- or colorectal cancer -- was finally diagnosed in August 1999, Leigh, 42, was experiencing regular bouts of severe bleeding. His symptoms were attributed, at various times, to irritable bowel syndrome, food poisoning, and hemorrhoids.
"Even with all my symptoms, I never thought of colon cancer," Leigh tells WebMD. "When I first started having symptoms, there just wasn't any public awareness about colon cancer. It wasn't that I denied the possibility of cancer, it just never crossed my mind."
Because of the delay in getting diagnosed, Leigh's cancer was found at an advanced stage and required aggressive chemotherapy. The motivational speaker now devotes much of his time to raising public awareness about colon cancer, and urging people to get tested -- early and often.
Now a long-term follow-up study from the University of Minnesota in Minneapolis suggests that the simplest and cheapest test available for detecting colon cancer can actually prevent the disease. Moreover, experts are using the findings to try to shift the public focus from the debate over which screening tool to use and how often, to getting screened early and often, no matter what method is used.
Writing in the Nov. 30, 2000 issue of The New England Journal of Medicine, researchers involved in the Minnesota Colon Cancer Control Study reported a 20% reduction in the incidence of colon cancer among those with no symptoms who received either yearly or twice yearly fecal occult-blood screenings. The study included over 46,000 people between the ages of 50 and 80 who were followed for 18 years.
Fecal occult-blood screening is a stool test that looks for microscopic amounts of blood too small to be seen with the naked eye. The advantage of the test is that it is much cheaper and less invasive than other testing methods like flexible sigmoidoscopy and colonoscopy. The disadvantage of the test is that it is not very accurate. Blood in the stool could be due to many factors, including ulcers and hemorrhoids. And because many tumors do not bleed, negative results are possible in people that actually have cancer.
The findings confirm the long held belief that identifying and removing the polyps known to often lead to colon cancer actually prevents the disease. In the study, all patients with abnormal fecal occult blood tests were advised to undergo more extensive testing and have all detected polyps removed.
"For the first time, we are able to show that this screening procedure for colorectal cancer not only reduces [the death rate], but also reduces the incidence of the disease," lead researcher Jack S. Mandel, PhD, of the scientific consulting firm Exponent in Menlo Park, Calif., tells WebMD. "We have shown that routine screening of [people without symptoms] at average risk for colon cancer significantly reduces incidence."