Prevalence of inherited and acquired risk factors for venous thromboembolic (VTE) disease among women with breast cancer taking adjuvant tamoxifen (TAM)

Abstract

802 Background: Information dealing with the association between TAM and risk of developing VTE mainly rely on women included in clinical trials of chemoprevention or adjuvant breast cancer therapy. However, the prevalence of inherited risk factors for VTE and their correlation with acquired ones was never evaluated in detail in women receiving adjuvant TAM in the setting of clinical practice. Methods: Before starting TAM therapy we evaluated the prevalence of either acquired (i.e., hypertension, diabetes, hyperlidemia, previous angina and smoking status) or inherited (i.e., VTE familial history, factor V Leiden and prothrombin G20210A mutations) risk factors for VTE in 48 consecutive operable and estrogen (ER) and/or progesterone (PR) receptor-positive breast cancer women. Median age was 55 years (range, 29–77) and 29 (60.4%) were in postmenopausa. TAM was the sole therapy in 11 out of 48 (22.9%) while it was given after an adjuvant chemotherapy consisting of CMF or antracycline-based regimen to the remaining 37 (77.0%). Results: The factor V Leiden mutation was detected in 3 out of 48 (6.2%) women and the prothrombin G20210A mutation in 4 (8.3%), while no homozygote was observed. When comparison was performed with 181 age- and sex-matched healthy control women used for statistical comparison no difference in the prevalence of either V Leiden (P=0.374) or prothrombin G20210A (P=0.107) mutation was found. Patients carrying V Leiden or prothrombin mutations displayed a trend towards an increase of VTE episodes among first-degree family members (P=0.07), the same did not apply for the patient's thrombotic history (P=0.316). No association was found between V Leiden or prothrombin mutations and the presence of diabetes (P=0.206), hypertension (P=0.560), hyperlipidemia (P=0.280) and smoking status (P=0.652). Conclusions: In conclusion, before starting with TAM screening for inherited VTE risk factors should be offered to women with personal or familial thrombotic history. Asymptomatic patients with heterozigous factor V Leiden or prothrombin mutations should be shifted to aromatase inhibitors. No significant financial relationships to disclose.