Do statins cause cancer? A meta-analysis of large randomized clinical trials

Although the short-term safety and tolerability of statins has been well established, their potential carcinogenicity in the long term is still debated. The goal of this study was to determine whether long-term treatment with statins is associated with an increased risk of fatal and nonfatal cancers.

We searched the Medline database between January 1966 and December 1999 for randomized, controlled trials of human subjects in which monotherapy with a statin was compared with placebo. No language restrictions were applied. Only trials with a minimum treatment duration of 4 years and a minimum of 1,000 subjects were included. Studies that did not provide information on fatal or nonfatal cancers were excluded. Data on fatal and nonfatal cancers and all-cause mortality were extracted by a single nonblinded reviewer. Overall crude estimates of risk difference were computed by summing the numerators and denominators of trial-specific risk estimates.

Five trials met the inclusion criteria. The estimated differences in absolute risk between treatment and placebo were as follows (negative risks indicate that treatment was safer than placebo): all nonfatal cancers, 0.0% (95% confidence interval [CI]: -0.8% to 0.8%); all fatal cancers, -0.1% (95% CI: -0.7% to 0.4%); all fatal and nonfatal cancers combined, -0.1% (95% CI: -1.0% to 0.7%); and all-cause mortality, -1.5% (95% CI: 2.8% to 0.2%).

This study demonstrates no association between statin use over a 5-year period and the risk of fatal and nonfatal cancers. This conclusion is limited by the relatively short follow-up of the studies analyzed. Similar analyses of data from studies with longer follow-up periods would be valuable.