Abstract P6-14-03: Statin and aspirin use is not associated with a reduced risk of VTE's in breast cancer patients

Abstract

Introduction: Statins and aspirin have been shown to reduce the risk of venous thromboembolic events (VTE's) in the general population in randomized trials. Aim: To assess whether statins and aspirin reduce the incidence of deep vein thrombosis and pulmonary embolism in patients diagnosed with breast cancer. Methods: The Breast Cancer in Northern Israel Study (BCINIS) is an on-going population-based case-control study of consecutive breast cancer cases and matched controls diagnosed in the northern part of Israel since 2000. Only cases insured by the Clalit Health Services (64%) were included in this analysis. Data on medication use and VTE were extracted from the computerized database. Patients taking Warfarin or LMWH were excluded. Statistical analysis was performed using SPSS (v 18). Use of medications was analyzed as a time dependent covariate in a Cox Regression model. Results: Of 3552 patients 261 (7.3%) had a VTE during a median follow up of 4.7 years. In a multivariate analysis age (HR 1.03, 95% CI 1.02–1.04), BMI (HR 2.12, 95% CI 1.43–3.14 for BMI >30), chemotherapy (HR 3.87, 95% CI 2.50–5.98) and metastatic disease (HR 2.27, 95% CI 1.10–6.53) were associated with an increased risk for VTE's. Statins, mainly simvastatin and pravastatin, were used by 55.7% of the patients, and 45.7% used aspirin. Neither statins nor aspirin were associated with a significantly reduced risk for a VTE. After controlling for age, BMI, stage, chemotherapy and tamoxifen use the HR for statins was 0.80, CI 0.56–1.13, p = 0.2, and the HR for aspirin was 1.004, CI 0.74–1.76, p = 0.98. Conclusion: In contrast to the findings in the general population, statin and aspirin use were not associated with a reduced risk for VTE's in our cohort of breast cancer patients. Our results might be explained by an alternate mechanism of VTE formation in breast cancer and the use of low potency statins (simvastatin and pravastatin) in this cohort. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-14-03.