Long-term use of nonsteroidal anti inflammatory drugs and the risk of colorectal adenomas

Aims: Previous studies have suggested that the regular use of NSAIDs reduces the risk of colorectal adenomas. The aim of this study was to examine this association while taking possible confounding factors into account. Methods: The intake of drugs including NSAID intake during the last 20 years was assessed by means of a case-control study in 184 cases and matched hospital and community controls. Results: Overall, there were few individuals with a relevant drug intake for more than 5 years. NSAID intake for more than five years was associated with decreased risk in comparison with both control groups. The RR was 0.20 (0.04-1.04) compared with hospital and 0.21 (0.04-0.99) compared with population controls, the latter association being statistically significant. Subgroup analysis by type of drug revealed a significant protective effect only for long-term aspirin intake in relation to hospital controls, the RR being 0.09 (0.01-0.82). Conclusion: Our data support the hypothesis that there is a protective effect of NSAID intake of more than 5 years against the development of colorectal polyps.