194P - Body mass index as a prognostic factor in operable breast cancer patients treated with adjuvant anthracyclines with or without taxanes

Abstract

Breast cancer is the most frequent invasive tumor in women. Obesity is a risk factor for several types of cancer, including breast cancer. Obesity is an unfavorable prognostic factor in breast cancer regardless of menopausal status and treatment protocol. The aim of the study was to assess the effect of obesity on prognosis in operable breast cancer patients according to pathologic subtypes. A retrospective analysis of 500 operable breast cancer patients received adjuvant anthracyclines with or without taxanes enrolled in the period between Sep 2011 and Sep 2013, the primary end point was to assess the prognostic effect of body mass index (BMI) on disease recurrence, breast cancer mortality (BCM), and overall mortality (OM). The secondary end point was to detect the difference by breast cancer pathologic subtypes (ER, PR positive/HER2 positive, ER, PR positive/HER2 negative, ER, PR negative/HER2 positive, and triple negative) Analyses were adjusted for age, tumor size, grade, nodal status, menopausal status, hormone receptors and HER2 receptor status, surgery and chemotherapy regimen. Obese patients (BMI = 30-39.9 kg/m2) had similar prognosis as that of normal weight patients (BMI <25 kg/m2) (control group) in terms of recurrence (HR 1.07 95% CI 0.8-1.32 P= 0.42), BCM (HR 1.04; 95% CI 0.84-1.28; P= 0.84) and OM (HR 0.96; 95% CI 0.79-1.18; P= 0.73). Patients with severe obesity BMI ≥40 kg/m2 had a significantly increased risk of recurrence (HR 1.25; 95% CI 1.1-1.59; P= 0.05), BCM (HR 1.3; 95% CI 1.1-1.74; P= 0.05) and OM (HR 1.3; 95% CI 1.05-1.72; P= 0.02) compared to the control group. The prognostic effect of severe obesity showed no remarkable variation among pathologic subtypes. Severely obese breast cancer patients with a BMI ≥40 kg/m2 treated with anthracyclines with or without taxanes had a worse prognosis in terms of recurrence, BCM & OM than patients with a BMI <25 kg/m2. The risk was not altered in different pathologic subtypes.