Calcium channel blockers, ACE inhibitors, and the risk of cancer in hypertensive patients: a report from the Department of Health Hypertension Care Computing Project (DHCCP)

Objective: Recent studies have shown inconsistent results on the risk of ca ncer in hypertensive patients using calcium channel blockers (CCBs) and ang iotensin-converting enzyme (ACE) inhibitors. We investigated a large number of patients from the Department of Health Hypertension Care Computing Proj ect (DHCCP) observational database treated with these drugs for hypertensio n to see whether the use of CCBs for hypertension is associated with an inc reased risk of cancer mortality and the use of ACE inhibitors with a reduct ion. Design: Matched case-control study and a longitudinal study of survival fro m 1 year after presentation. Patients: A total of 11 663 patients treated for hypertension from 1971 thr ough 1987. They were recruited on presentation to one of the hospital hyper tension clinics or general practices involved. Main outcome measures: Death with any mention of cancer on the death certif icate in patients treated with an Index drug group; CCBs, ACE inhibitors, b eta adrenergic blocking drugs (BBs), or receiving a diuretic. The treatment groups were mutually exclusive. Results: A total of 391 cases of cancer were matched with 1050 controls, in this case-control study the adjusted relative risk estimate in comparison to diuretic treatment for CCBs was 0.79 (95% CI 0.37 to 1.69), and for CCBs plus a diuretic, 1.05 (0.65 to 1.69). Non-significant results were also ob served for ACE inhibitors (1.48 (0.43 to 5.1), and 1.40 (0.56 to 3.50) with a diuretic), and also for the BE and methyldopa groups. In the longitudina l survival study, the adjusted relative risk estimate for CCBs was 1.1 (0.6 0 to 1.94) and 1.0 (0.53 to 1.86) for CCBs plus a diuretic, and for ACE inh ibitors 1.33 (0.37 to 4.76) and 1.47 (0.67 to 3.23), respectively. Conclusions: In this population there was no increased cancer mortality wit h the use of CCBs and a relative risk greater than 1.7 to 2.0 was excluded with 95% confidence. The suggestion that ACE inhibitors reduce cancer morta lity was not supported with best estimates of relative risk of 1.3 to 1.5 a nd exclusion of values less than 0.4 to 0.7.