Statin use and the risk of prostate cancer: A metaanalysis of 6 randomized clinical trials and 13 observational studies.

Statins have been suggested to prevent prostate cancer. Our aim was to examine statin use in relation to both total prostate cancer and the more clinically important advanced prostate cancer, through a detailed metaanalysis of the epidemiologic studies published on the subject in peer-reviewed literature. A comprehensive search for articles published up to November 2007 was performed, reviews of each study were conducted and data were abstracted. Prior to metaanalysis, the studies were evaluated for publication bias and heterogeneity. Pooled relative risk (RR) estimates and 95% confidence intervals (CIs) were calculated using the random-effects model. Subgroup and sensitivity analyses were also performed. Nineteen studies [6 randomized clinical trials (RCTs), 6 cohort and 7 case-control studies] contributed to the analysis. There was no evidence of an association between statin use and total prostate cancer among either RCTs (RR = 1.06, 95% CI: 0.93-1.20) or the observational studies (RR = 0.89, 95% CI: 0.65-1.24). However, high heterogeneity was detected among the observational studies. Moreover, long-term statin use did not significantly affect the risk of total prostate cancer (RR = 0.93, 95% CI: 0.77-1.13). In contrast, synthesis of the available reports that had specifically examined statin use in relation to advanced prostate cancer indicated a protective association (RR = 0.77, 95% CI: 0.64-0.93). Our results do not support the hypothesis that statins reduce the risk of total prostate cancer. However, further research is required to investigate whether the particular association of statin use with lower risk of advanced prostate cancer is indeed causal.