Meta-Analysis Shows Aspirin Can Reduce Recurrence of Colon Polyps

Multiple lines of evidence, including data from randomized clinical trials, suggest that aspirin may reduce the risk of colon adenomas and perhaps cancer. A quantitative summary of the clinical data – and a more precise estimate of the magnitude of the benefit associated with aspirin use – has been missing.

In the current study, Bernard F. Cole, Ph.D., of the University of Vermont in Burlington, and colleagues performed a meta-analysis of all available randomized clinical trials that examined adenoma formation in participants assigned to regular aspirin use or placebo.

Among 2,698 participants who underwent colonoscopic follow-up after randomization, 37% of the participants assigned to placebo developed adenomas compared with 33% of those assigned to aspirin. Moreover 12% of the participants assigned to placebo developed advanced adenomas compared with 9% of the participants assigned to aspirin. The pooled analysis indicated that regular aspirin use resulted in an absolute risk reduction of 6.7% for developing adenomas relative to placebo.

"The substantial size of the relative reduction in risk seen in our analysis (28% for advanced adenomas) and seen in clinical trials that evaluated the effect of aspirin on colorectal cancer risk (26% reduction) indicates the potentially important health benefits of aspirin use," the authors write. "Of course, these benefits need to be considered in the context of all of the health effects of aspirin, positive and negative."

This research was recently published in the Journal of the National Cancer Institute.