The task force recommendation against the routine use of NSAIDs for colorectal cancer chemoprevention emerged from two systematic risk-benefit analyses carried out by Catherine Dubé, M.D., of the University of Calgary in Alberta, and colleagues. The task force's NSAID-colorectal cancer guidelines and the Canadian review results appeared in the March 6 issue of the Annals of Internal Medicine. Dr. Dubé and colleagues conducted a systematic review of randomized controlled trials, case-control studies, and cohort studies of aspirin chemoprophylaxis.

"Cyclo-oxygenase-2 inhibitors and NSAIDs reduce the incidence of colonic adenomas," the Canadian group concluded. "Nonsteroidal anti-inflammatory drugs also reduce the incidence of colorectal cancer. However, these agents are associated with important cardiovascular events and gastrointestinal harms. The balance of benefits to risk does not favor chemoprevention in average-risk individuals."