Calcium channel blocking agents and risk of cancer in patients with coronary heart disease

Objectives. This analysis sought to estimate the risk ratio for cancer incidence and cancer-related mortality associated with the use of calcium channel blocking agents (CCBs) in a large group of patients with chronic coronary heart disease (CHD). Background. Recent publications contend that the use of short-acting CCBs may double the risk of cancer incidence and possibly increase mortality in hypertensive patients. Methods. Cancer incidence data were obtained for 11,575 patients screened for the Bezafibrate Infarction Prevention (BIP) study, one-half of whom were treated at the time of screening with CCBs, over a mean follow-up period of 2.8 years. Cause- specific mortality was available through September 1996 (mean follow-up 5.2 years). The statistical power of detecting an odds ratio ≤1.5 (given the cancer incidence rate of 2.1 in the nonusers of CCBs) was 0.91. The power declined to 0.77, 0.54 and 0.41, with declining odds ratios of 1.4, 1.3 and 1.25, respectively. Results. Of 246 incident cancer cases, 129 occurred among the users (2.3%) and 117 among nonusers of CCBs (2.1%). After adjustment for age, gender and smoking, the odds ratio estimates for all cancers combined was 1.07 (95% confidence interval [CI] 0.83 to 1.37) for CCB users relative to nonusers. The adjusted risk ratio for all-cause mortality for age, gender and smoking and pertinent prognostic clinical characteristics was estimated at 0.94 (95% CI 0.85 to 1.04). The adjusted risk ratio for cancer-related mortality was 1.03 (95% CI 0.75 to 1.41). Conclusions. Patients with CHD treated with CCBs exhibited a similar risk of cancer incidence and total and cancer-related mortality compared with nonusers of CCBs. This analysis provides a certain assurance that CCB use in middle-aged and elderly patients with CHD is not associated with a meaningful difference in cancer incidence and related mortality.