Calcium channel blockers and the risk of cancer

Context. - Recent epidemiologic studies have raised the concern that calcium channel blocker use may increase the risk of cancer overall and of several specific cancers. Objective. - To assess whether calcium channel blocker use increases the risk of cancer overall and of specific cancers. Design. - Case-control drug surveillance study based on data collected from 1983 to 1996. Setting. - Hospitals in Baltimore, Md, New York, NY, and Philadelphia, Pa. Patients. - A total of 9513 patients aged 40 to 69 years with incident cancer of various sites and 6492 controls aged 40 to 69 years admitted for nonmalignant conditions. Main Outcome Measures. - Incident cancer overall and 23 specific cancers. Results. - Calcium channel blocker use was unrelated to the risk of cancer overall (relative risk [RR], 1.1; 95% confidence interval [Cl], 0.9-1.3). Use was not significantly associated with increased risks of individual cancers, including those previously implicated, except cancer of the kidney (RR, 1.8; 95% Cl, 1.1-2.7). Recent use, use for 5 or more years, and use of individual calcium channel blocker drugs were also not associated with cancer incidence. Use of β-blockers and angiotensin- converting enzyme inhibitors was generally unrelated to cancer overall or individual cancers, but both were associated with kidney cancer (RR, 1.8; 95% Cl, 1.3-2.5; and RR, 1.9; 95% Cl, 1.2-3.0, respectively). Conclusions. - The present study suggests that the use of calcium channel blockers is unrelated to an increase in the overall risk of cancer or of individual cancers, except kidney cancer, which has been associated with hypertension or drugs to treat hypertension in previous studies.