1044 Background: Obesity represents a well-known risk factor for the development of breast cancer and an adverse prognostic factor in early disease. Overweight is associated with reduced efficacy of aromatase inhibitors in adjuvant setting. Few data have been reported about the potential relationship of overweight and outcome in advanced breast cancer (ABC). Methods: We retrospectively evaluated body mass index (BMI) in a consecutive series of 400 ABC patients treated at our institution. BMI was calculated at baseline of diagnosis of ABC. We evaluated association of BMI and other prognostic and predictive markers with Progression Free Survival (PFS) and Overall Survival (OS). We evaluated PFS at first and subsequent lines of chemotherapy (CT) and endocrine therapy (ET). Overweight patients were defined as having BMI > 25. Results: Overweight patients were 52%. Median age of the population was 58 years. Median OS was 33.7 months. Overall, 76% of patients presented with ER+ and 17.7% with HER2+ ABC.Overweight was associated with increased age at diagnosis, menopausal status and luminal B or triple negative immunophenotype. At multivariate analysis, BMI > 25 was associated with better PFS at first-line ET (HR= 0.68, 95% CI 0.46-0.99). BMI was not associated with OS. Conclusions: BMI at baseline does not seem to be an adverse prognostic factor for ABC patients. Overweight may be associated with better PFS in endocrine responsive ABC treated with ET, especially in first-line setting. The role of BMI in ABC deserves to be further investigated.
Clinical benefit of fulvestrant in postmenopausal women with advanced breast cancer according to body mass index