Meta-analysis concludes statins have no effect on cancer risk

A recent meta-analysis published in the Journal of the American Medical Association (JAMA) found that statins have no effect on cancer risk. The finding is in contrast with at least 7 retrospective analyses that suggest that statins reduce the risk of developing cancer.

"There have been a number of observational studies both supporting and refuting a statin's beneficial effects on cancer," said study co-author Craig I. Coleman, PharmD, assistant professor of pharmacy practice at the University of Connecticut School of Pharmacy, and director of the Pharmacoeconomics and Outcomes Studies Group at Hartford Hospital, Hartford, Conn. "Our meta-analysis supports the latter conclusion."

Dr Coleman and colleagues from the University of Connecticut performed a meta-analysis of 26 randomized, controlled trials of statins in which the incidence of either cancer diagnosis or cancer death was reported. The total number of patients exceeded 86,000, and the duration of follow-up ranged from 1.9 to 10.4 years. A range of statins was studied, with pravastatin being the most common.

No significant difference versus controls was found in analyses of individual statins, statins with low or high lipophilicity, or natural or synthetic statins.

Similarly, when restricting the analysis to only the randomized, double-blind, placebo-controlled trials, no significant difference in cancer incidence was observed between statin and placebo (OR=1.05; 95% CI, 0.99–1.12).

Three previous meta-analyses have generated similar results, with no differences in the incidence of cancer between statins and controls, the authors noted.

Three previous case-control studies also found that statins did not reduce the incidence of cancer. Neither the dose nor the intensity of statin treatment was found to affect cancer incidence.

Most of the studies in the meta-analysis had follow-ups of 3 to 5 years, a sufficient duration to detect a potentially favorable effect of statins on cancer risk, stated Dr Coleman.

A study's ability to detect a difference between 2 groups is dependent on both event rate and sample size, and although the event rate (cancer incidence and cancer death) was low, "10s of thousands of patients were included in these statin studies, and thus our meta-analysis was well-powered to detect differences in cancer rates/death if they existed," Dr Coleman said.

SOURCE: Dale KM, Coleman CI, Henyan NN, Kluger J, White CM. Statins and cancer risk: A meta-analysis. JAMA. 2006;295:74-80.