ASPIRIN AND NONSTEROIDAL ANTIINFLAMMATORY AGENTS AND RISK FOR COLORECTAL ADENOMAS

Background & Aims: Aspirin and nonsteroidal antiinflammatory drugs hav e been reported to protect against the development of colorectal cance r. Because adenomas are precursors to most colorectal cancers, the aim of this study was to examine the relationship of these medications to the risk for colorectal adenomas in a colonoscopy-based case-control study. Methods: Study participants were drawn from patients who underw ent colonoscopy at the University of North Carolina Hospitals. Medicat ion use was assessed by telephone using a comprehensive list of prescr iption and nonprescription drugs as well as questions about dietary an d lifestyle factors that might be relevant for adenoma development. Re sults: There were 210 patients with adenomas and 169 adenoma-free cont rols. After adjusting for potential confounders, regular users were ha lf as likely to currently have adenomas compared with nonusers (adjust ed odds ratio, 0.56; 95% confidence interval, 0.34-0.92). Regular user s who stopped medication at least 1 year before colonoscopy were still protected (adjusted odds ratio, 0.59; 95% confidence interval, 0.21-1 .67), although small numbers make this conclusion tentative. The prote ctive effects of aspirin and the nonaspirin nonsteroidal anti-inflamma tory drugs were similar. Conclusions: The results suggest that aspirin and nonsteroidal anti-inflammatory drugs cause early disruption of th e adenoma-carcinoma sequence. The challenge for the future will be to learn more about dose, duration, and mechanism of action.