Antihypertensive medications and cancer patient survival: A populationbased retrospective cohort study

Abstract

Rationale: The relationship between antihypertensive medications and cancer development has been widely studied. There is extensive in vitro evidence for a beneficial effect for beta-blocker drugs in particular. Population-based research has until recently focused on the associations between antihypertensive use and cancer incidence, and there is a need for further study of the influence of these drugs on cancer patient survival. Hypotheses: Antihypertensive use was expected to be associated with increased mortality relative to nonuse. Beta-blockers were expected to provide a survival benefit relative to other classes of antihypertensive. Methods: Patient information from the Manitoba Cancer Registry was linked with prescription information from Manitoba’s Drug Product Information Network for patients diagnosed between 2004 and 2008 with new lung (n = 4241), colorectal (n = 3967), breast (n = 4019), prostate (n = 3355) and liver (n = 244) cancer primaries. Cox proportional-hazards regression analysis was used to evaluate all-cause mortality for users of four classes of medication (betablockers, calcium channel blockers, diuretics, and ACE inhibitors / ARBs) relative to nonusers. A separate set of analyses was then conducted on single drug category users to permit direct comparison between beta-blockers and other classes of antihypertensive. Results: Antihypertensive medication use was associated with increased cancer mortality. There is no significant evidence that beta-blocker use results in improved survival relative to other classes of antihypertensive. There is a significant association between calcium channel blocker use and improved lung cancer survival relative to beta-blocker users (HR = 0.79, 95% CI = 0.64, 0.98), warranting further study.