Breast cancer mortality among users of cholesterol-lowering drugs.

Abstract

1514 Background: Breast cancer is a common malignancy and cause of cancer death. Recent studies have suggested that statins, an established cholesterol-lowering drug group used in the prevention of cardiovascular mortality, could have beneficial effects against recurrence and progression of breast cancer. We evaluated breast cancer-specific mortality among users of statins and other cholesterol-lowering drugs (fibrates and bile-acid binding resins) in a cohort of breast cancer patients. Methods: Our study cohort included all newly diagnosed breast cancer patients in Finland during 1995-2003 (31,236 cases), identified from the Finnish Cancer Registry. Information on cholesterol-lowering medication use was obtained from a national prescription database.We used Cox proportional hazards regression method to estimate mortality among medication users. Results: A total of 4,169 participants had used statins, while 313 had used fibrates or resins. Despite similar median age, tumor and treatment characteristics, only statin use was associated with decreased breast cancer mortality (participants with localized tumors: HR 0.33, 95% CI 0.24-0.42; metastatic tumors: HR 0.52, 95% CI 0.31-0.86). Fibrate and resin use were associated with increased overall mortality (HR 1.70, 95% CI 0.96-2.99 for participants with localized disease, HR 2.65, 95% CI 1.18-5.96 for participants with metastatic disease). Conclusions: Decreased breast cancer mortality among users of statins, but not other cholesterol-lowering drugs despite similar population characteristics suggests that this drug group may have benefit in prevention of cancer progression. Clinical trials testing statins’ efficacy in breast cancer patients are warranted.