Calcium channel blockers and cancer: a risk analysis using the UK Clinical Practice Research Datalink (CPRD)

OBJECTIVE: The evidence of an association between calcium channel blockers (CCBs) and cancer is conflicting. The objective of the present study was to evaluate the risk of cancer (all, breast, prostate and colon cancers) in association with exposure to CCB. METHODS: This is a population-based cohort study in patients exposed to CCBs from across the UK, using two comparison cohorts: (1) patients with no exposure to CCB (non-CCB) matched on age and gender and (2) unmatched patients unexposed to CCB and at least one other antihypertensive (AHT) prescription. Cancer incidence rates computed in the exposed and the two unexposed groups were compared using HRs and 95% CIs obtained from multivariate Cox regression analyses. RESULTS: Overall, 150 750, 557 931 and 156 966 patients were included, respectively, in the CCB, non-CCB and AHT cohorts. Crude cancer incidence rates per 1000 person-years were 16.51, 15.75 and 10.62 for the three cohorts, respectively. Adjusted HRs (CI) for all cancers comparing CCB, non-CCB and AHT cohorts were 0.88 (0.86 to 0.89) and 1.01 (0.98 to 1.04), respectively. Compared to the AHT cohort, adjusted HRs (CI) for breast, prostate and colon cancer for the CCB cohort were 0.95 (0.87 to 1.04), 1.07 (0.98 to 1.16) and 0.89 (0.81 to 0.98), respectively. Analyses by duration of exposure to CCB did not show excess risk. CONCLUSIONS: This large population-based study provides strong evidence that CCB use is not associated with an increased risk of cancer. The analyses yielded robust results across all types of cancer and different durations of exposure to CCBs.