Aspirin Or NSAIDs Won't Prevent Colorectal Cancer

This is the first time the Task Force has made a recommendation related to taking medicines to prevent colorectal cancer. After reviewing the latest evidence on the topic, the Task Force found that the potential harms of taking more than 300 mg per day of aspirin or NSAIDs--which can include increased risks for stroke, intestinal bleeding or kidney failure--outweigh the potential benefits of colorectal cancer prevention.

Meanwhile, patients taking aspirin to prevent other conditions such as heart disease should continue to discuss the benefits with their clinicians, according to Task Force Chair Ned Calonge, M.D., who is also Chief Medical Officer and State Epidemiologist for the Colorado Department of Public Health and Information. The Task Force found good evidence that taking low doses of aspirin (usually less than 100 mg) can reduce risk for heart disease but does not reduce the rate of colorectal cancer. In 2002, the Task Force strongly recommended that clinicians discuss the use of aspirin as a preventive medication with adults who are at increased risk for heart disease and that those discussions should address the potential benefits and harms of aspirin therapy.

Colorectal cancer is the third most common type of cancer in men and women and is the second-leading cause of cancer-related deaths in the United States. About 56,000 Americans die from colorectal cancer and 150,000 new cases are diagnosed each year. Between 5 percent and 6 percent of people develop colorectal cancer in their lifetime, and the majority of those diagnosed are over the age of 50.

Twenty percent of individuals diagnosed with colorectal cancer have a first- or second-degree relative with the disease, and African Americans have the highest rate of colorectal cancer compared with other races.

In recent years, some progress has been made to detect and treat colorectal cancer earlier through screening and early removal of polyps. In 2002, the Task Force strongly recommended that clinicians screen men and women age 50 and older for colorectal cancer.

Task Force leaders stress the evidence on the merits of screening but urge caution on taking preventive medicine for colorectal cancer. “Individuals taking high doses of aspirin or NSAIDs to prevent colorectal cancer should be aware of the potential harms and discuss them with their clinician,” said Dr. Calonge.

The U.S. Preventive Services Task Force is an independent panel of experts in prevention and primary care. The Task Force conducts rigorous, impartial assessments of the scientific evidence for the effectiveness of a broad range of clinical preventive services, including screening, counseling and preventive medications. Its recommendations are considered the gold standard for clinical preventive services. AHRQ provides technical and administrative support, but the recommendations of the panel are its own.

The Task Force based its conclusions on a report from a research team led by David Moher, M.D., at AHRQ's Evidence-based Practice Center at the University of Ottawa in Canada.

The Task Force grades the strength of the evidence as “A” (strongly recommends), “B” (recommends), “C” (no recommendation for or against), “D” (recommends against) or “I” (insufficient evidence to recommend for or against screening). The Task Force recommends against the routine use of aspirin and NSAIDs to prevent colorectal cancer in individuals at average risk for the disease (a “D” recommendation). The recommendation is published in the  Annals of Internal Medicine.