Purpose: A growing body of literature suggests that statins may have chemopreventive potential against cancer. Our aim was to examine the strength of this association through a detailed meta-analysis and meta-regression analysis of randomized controlled trials (RCTs).
Methods: A comprehensive search for trials published up to 2005 was performed, reviews of each study were conducted, and data were abstracted. Before meta-analysis, the studies were evaluated for publication bias and heterogeneity. Pooled relative risk (RR) estimates and 95% CIs were calculated using the random- and fixed-effects models. Subgroup, sensitivity, and meta-regression analyses were also conducted.
Results: Thirty-five RCTs of statins for cardiovascular outcomes contributed to the analysis (n = 109,143). The degree of variability between trials was consistent with what would be expected to occur by chance alone. Statin use was not associated with a substantially increased or decreased overall risk of cancer (RR = 0.99; 95% CI, 0.94 to 1.04). Similarly, statin use did not significantly affect respiratory cancer risk (RR = 0.95; 95% CI, 0.83 to 1.09). However, the meta-regression analysis indicated that age of study participants modified the association between statin use and cancer risk (P = .003).
Conclusion: Our findings do not support a protective effect of statins against cancer. However, this conclusion is limited by the relatively short follow-up periods (4.5 years on average) of the studies analyzed. Thus, it is important to continue monitoring the long-term safety profiles of statins. Until then, physicians need to be vigilant in ensuring that statin use remains restricted to the approved indications.