The association between body mass index and pathological complete response in neoadjuvant-treated breast cancer patients

Background: Obesity seems to be associated with a poorer response to adjuvant chemotherapy in breast cancer (BC); however, associations in the neoadjuvant chemotherapy (NACT) setting and according to menopausal status are less studied. This study aims to investigate the association between pretreatment body mass index (BMI) and pathological complete response (pCR) following NACT in BC according to menopausal and estrogen receptor (ER) status. Material and Methods: The study cohort consisted of 491 patients receiving NACT in 2005–2019. Based on pre-NACT patient and tumor characteristics, the association between BMI and achieving pCR was analyzed using logistic regression models (crude and adjusted models (age, tumor size, and node status)) with stratification by menopausal and ER status. Results: In the overall cohort, being overweight (BMI ≥25) compared by being normal-weight (BMI