Statins and primary liver cancer: a meta-analysis of observational studies
Statins are among the most commonly prescribed drugs used to manage dyslipidemia. Hepatocellular carcinoma is the third leading cause of cancer mortality and its rates have recently been increasing in central and northern Europe and USA. To quantify the association between statin use and risk for HCC, we performed a meta-analysis of published studies. We conducted a MEDLINE search for observational studies reporting the association between exposure to statins and risk for incident liver cancer until March 2012. Fixed-effect and random-effect models were used to estimate summary relative risks (RR) and the corresponding 95% confidence intervals (CIs). Moreover, between-study heterogeneity and publication bias were assessed using adequate statistical tests. Five observational studies (two case-control and three cohort studies) based on 2574 cases of HCC were included. Statin treatment, compared with no treatment, was inversely related to HCC (summary RR=0.58; 95% CI 0.46-0.74). Between-study heterogeneity was significant (P<0.001) and numerically relevant (I2=65%). When only longest statin use was considered, the RR was 0.66 (95% CI 0.55-0.80). Influence analysis on the overall estimate showed that heterogeneity was largely because of one study; when omitting it, the I2 dropped to 27% (P=0.240), whereas the summary RR was only marginally modified (RR=0.52; 95% CI 0.44-0.62). There was no evidence of publication bias. This meta-analysis suggests a favorable effect of statins on HCC, in the absence, however, of a duration-risk relationship.