Statin use and the risk of colorectal adenoma: A meta-analysis

Background: Although statin use has been reported to reduce the risk of colorectal cancer beyond its cholesterol-lowering effects, the benefit of statins against colorectal adenoma has not been fully clarified. We aimed to investigate the association between statin use and the risk of colorectal adenoma. Methods: We conducted a systematic literature search on MEDLINE, EMBASE, and the Cochrane Library using the primary keywords "adenoma," "polyp," "colorectal," "colon," "rectal," "rectum," "neoplasia," "neoplasm," "statin," "3-hydroxy-3-methylglutarylcoenzyme A," and "HMG-CoA." Studies were included if they evaluated the association between statin use and adenoma and reported relative risks (RRs) or odds ratios or provided data for estimation. Pooled estimates were calculated using the random-effects model. Results: Six studies including 13 239 patients were analyzed. The median proportion of patients with any adenoma was 29.7% (range, 20.9-38.4%) in patients taking statins and 31.2% (range, 19.6-63.4%) in patients not taking statins across included studies. The median proportion of patients with advanced adenoma in those taking statins was 7.7% (range, 3.1-27.2%), whereas that in patients not taking statins was 11.3% (range, 3.5-32.4%). On meta-analysis, statin use did not significantly affect the risk of any adenoma (pooled RR = 0.901; 95% confidence interval [CI], 0.735-1.104); however, it was associated with a lower risk of advanced adenoma (pooled RR = 0.833; 95% CI, 0.750-0.925). Conclusions: Statin use seems to be associated with a reduced risk of advanced adenoma, but not any adenoma. Statins may prevent neoplastic progression of adenomas rather than the development of adenomas