A study published in the April issue of the Journal of Clinical Lipidology downplayed the risk of cancer from taking ezetimibe, the cholesterol-lowering drug sold as Zetia and also a component of Vytorin. The study was based on an analysis of adverse events reports filed with the Food and Drug Administration.

Researchers Richard Karas and Alawi Alsheikh-Ali tabulated all adverse event reports listing "cancer" or "malignancy" filed with the FDA from July 2004 to March 2008 of patients taking ezetimibe or ezetimibe/simvastatin, and compared those to reports of patients taking three statin drugs. There were 2.9 and 1.3 cancer-related adverse event reports per million ezetimibe or ezetimibe/simvastatin prescriptions, respectively, as compared to a range of 3.1 to 5.1 cancer-related adverse event reports per million prescriptions for the statin drugs.

The researchers also compared cancer reports as a proportion of all reported adverse events for each medication, with similar results. Karas, who disclosed that he earned speaking and/or consulting fees from ezetimibe marketers Merck and Schering-Plough, and his co-author concluded that their study "does not support that ezetimibe or [ezetimibe/simvastatin] increase the risk of cancer." However, as pointed out by cardiologist James Stein in an interview with heartwire, this is a case where "'lack of proof' should not be construed as 'proof of lack.'"

As previously reported on GoozNews, the SEAS trial found that among patients treated with the ezetimibe/simvastatin combination, there were significantly more cancer cases and cancer deaths compared to patients treated with placebo.

Unfortunately, cancer is a common diagnosis and few doctors or patients would connect a new case of cancer with a cholesterol-lowering drug. The adverse event reporting system is better at detecting rare adverse events, or adverse events where the patient develops an obvious symptom while on a drug that goes away when the drug is discontinued.

In addition, it is difficult to see how any particular case of cancer could be definitively connected to ezetimibe even if it turns out that ezetimibe causes cancer or increases the risk of cancer death. Bottom line: if you are worried about cancer signal in SEAS, this study is unlikely to provide you any comfort.

-- Marilyn Mann