Antihypertensive medication and their impact on cancer incidence: a mixed treatment comparison meta-analysis of randomized controlled trials

Objective The aim of this article is to determine the association between commonly used antihypertensive agents and the incidence of cancer. Methods We conducted a mixed treatment comparison meta-analysis of randomized, controlled ( placebo, active, or untreated control) trials of antihypertensive drugs. A systematic literature search was conducted through June 2007. The primary outcome measure assessed was the incidence of cancer. Mixed treatment comparison meta-analysis was used to combine direct, within-trial, and between-drug comparisons with indirect evidence from the other trials. The indirect comparisons, which safeguard within-trial randomized findings, were constructed from trials with one treatment in common. Results are reported as odds ratios with 95% credible intervals. Results In total, 27 studies ( 56 treatment arms, 126 137 patients enrolled, and 5868 cancers identified during follow-up) were included in the base-case analysis. They were hypertension, prehypertension, heart failure, coronary artery disease, or renal disease trials and patients were randomized to one of the five major antihypertensive drug classes or to placebo/untreated control. With the placebo/untreated control group as the referent comparison, the odds for developing cancer were 0.99 (0.80 - 1.24) for angiotensin-converting enzyme inhibitors; 1.12 (0.87 - 1.47) for angiotensin receptor blockers; 1.00 (0.78 - 1.32) for beta-adrenergic blockers; 0.94 (0.73 - 1.19) for diuretics and 0.95 (0.79 - 1.13) for calcium channel blockers. In sensitivity analyses, the results were not altered to any noteworthy extent including exclusion of studies under 3 years duration. Conclusion Based on the totality of the clinical trial literature, commonly used antihypertensive drugs are not associated with increased odds of developing cancer.