Routine use of aspirin or nonsteroidal anti-inflammatory drugs should not be recommended as preventive therapy for colorectal cancer in patients at average risk for the disease, according to a statement released by the U.S. Preventive Services Task Force.
The caution against prophylactic use of these agents applies to asymptomatic adults, including those with a family history of colon cancer, but not to patients with a personal history of colon cancer or polyps, familial adenomatous polyposis, or hereditary nonpolyposis colon cancer syndromes, the statement specified (Ann. Intern. Med. 2007;146:361–4).
The USPSTF issued its recommendation based on literature reviews conducted by the Agency for Healthcare Research and Quality (AHRQ). These reviews evaluated the role of aspirin, NSAIDs, and cyclo-oxygenase-2 (COX-2) inhibitors for the primary prevention of colorectal cancer and colorectal adenoma. On the basis of the relevant literature published between 1996 and 2006, the USPSTF determined that “the harms outweigh the benefits of aspirin and NSAID use for the prevention of colorectal cancer.”
The literature reviews showed that aspirin, COX-2 inhibitors, and NSAIDs reduce the incidence of colonic adenomas and that aspirin and NSAIDs reduce the incidence of colorectal cancer. However, these drugs were associated with adverse gastrointestinal outcomes and, in the case of COX-2 inhibitors, with important cardiovascular events.
But the USPSTF also said that clinicians should continue to discuss aspirin chemoprophylaxis in patients who are at increased risk for coronary heart disease, because there is “good evidence” that low-dose (less than 100 mg) aspirin therapy can reduce the risk of heart disease.