CALCIUM-CHANNEL BLOCKERS AND THE RISK OF CANCER

Context.-Recent epidemiologic studies have raised the concern that cal cium channel blocker use may increase the risk of cancer overall and o f several specific cancers. Objective.-To assess whether calcium chann el blocker use increases the risk of cancer overall and of specific ca ncers, Design,-Case-control drug surveillance study based on data coll ected 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 a ged 40 to 69 years admitted for nonmalignant conditions. Main Outcome Measures.-Incident cancer overall and 23 specific cancers, Results.-Ca lcium channel blocker use was unrelated to the risk of cancer overall (relative risk [RR], 1.1; 95% confidence interval [CI], 0.9-1.3). Use was not significantly associated with increased risks of individual ca ncers, including those previously implicated, except cancer of the kid ney (RR, 1.8; 95% CI, 1.1-2.7). Recent use, use for 5 or more years, a nd use of individual calcium channel blocker drugs were also not assoc iated with cancer incidence, Use of beta-blockers and angiotensin-conv erting enzyme inhibitors was generally unrelated to cancer overall or individual cancers, but both were associated with kidney cancer (RR, 1 .8; 95% CI, 1.3-2.5; and RR, 1.9, 95% CI, 1.2-3.0, respectively). Conc lusions.-The present study suggests that the use of calcium channel bl ockers is unrelated to an increase in the overall risk of cancer or of individual cancers, except kidney cancer, which has been associated w ith hypertension or drugs to treat hypertension in previous studies.