HDCN Article Review/Hyperlink

Pahor M, Guralnik JM, Ferrucci L, Corti M-C, Salive ME, Cerhan JR, Wallace RB, Havlik RJ

Calcium channel blockade and the incidence of cancer in aged populations

Lancet (Aug) 348:494-498 1996

It seems to be open season on calcium chanel blockers. With case control studies suggesting that short-acting dihydropyridine CCBs increase the risk of death (Furberg et al), and another study suggesting an increased incidence of GI bleeding with CCBs (Pahor et al), this new study (by the same Pahor et al who did the GI bleeding study) suggests that the risk of cancer may be increased in patients taking short acting CCBs. There were 451 elderly patients taking CCBs and 4601 who were not. Patients using CCBs had a 70% increased risk of developing cancer over a 5 year follow up period, and the risk appeared to rise with higher doses of the CCBs.

Comment: This is an observational study, and such studies are notorious for coming up with conclusions not found in subsequent studies. For example, the Furberg study, which was a meta-analysis that claimed to demonstrate increased mortality with CCBs, the relationship apparently could not be confirmed when the original data were reanalyzed by Messerli et al. Also, a large Israeli study by Braun et al also found no increased risk of death with CCBs.

At the same time Pahor's latest study was being announced, Dr. Shimon Braun issued a press release stating that in his as yet unpublished data, which involved a large number of patients, and analyzed previously with regard to mortality, he could find no association between cancer and CCBs (as reported in the New York Times 8/22/96).

Comment: It seems that the limitations of case-control and observational studies of many kinds have not been sufficiently appreciated. This is not to say that the results of the present study are wrong. There is at least a proposed biologic mechanism: CCBs in certain vitro models can block apoptosis. But data from such papers should be used only to generate hypotheses, and not to infer causality. This is always stated by the article authors, but then promptly forgotten in the brouhaha which follows the article's release. (John T. Daugirdas, M.D., University of Illinois at Chicago)

The full text of an editorial describing the Pahor study is available at the Lancet site (the abstract is not available). The first time you access the Lancet site, you will need to register to get a login ID and password. Click on the links below after you have registered. Lancet Press Release-- Editorial.