The effect of statins on overall survival of breast cancer.

Abstract

34 Background: Observational studies have raised the possibility that use of statins may reduce the incidence and overall risk of cancer. In contrast, some randomized trials have consistently shown no effect of statins at cancer incidence or mortality. However, data about the potential effect of statins on overall survival of breast cancer are limited. We intend to examine the role of statins at overall survival of women diagnosed with breast cancer. Methods: A retrospective observational study was conducted from 1993 to 2007, using data from McLaren Regional Medical Center in Flint, Michigan on women diagnosed with breast cancer. Patient's characteristics including age at diagnosis, race, stage and use of statin with dosage were recorded. Patients with coronary artery disease were excluded to eliminate the confounding effect. The three-year overall survival was considered the primary outcome. Results:s A total of 392 women diagnosed with breast cancer were identified. 146 patients were on statins therapy prior to diagnosis (group 1), and 246 patients were not on statins (group 2). African American percentage was 7%. Mean age at diagnosis was 65 for both groups. Atorvastatin was the most used treatment with a dose of 20 mg daily. Patients were classified according to the TNM staging system of breast cancer as stage I, II, III, IV (58%, 31%, 8%, 3%) for group 1, and (62%, 32%, 4%, 2%) for group 2 respectively. The 3-year stage-specific survivals were calculated and compared between the two groups using Fisher's exact test (Table). Overall survival was not statistically significant between the two groups. Conclusions: Our study did show that statins do not affect the three-year overall survival of breast cancer at early stages, but it may improve the outcome at advanced stages. A larger national data review is warranted. [Table: see text]