Pretreatment Body Composition and Its Association with Pathologic Complete Response and Survival in Breast Cancer Patients Undergoing Neoadjuvant Chemotherapy: A Retrospective Cohort Study

Background and Objectives: We investigated how pretreatment body-composition parameters relate to pathologic complete response (pCR), disease-free survival (DFS), and overall survival (OS) in women with non-metastatic breast cancer who received neoadjuvant chemotherapy (NAC). Materials and Methods: We retrospectively analyzed 278 women treated with NAC at a single institution between January 2010 and December 2022. On computed tomography (CT) or PET-CT, visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT), skeletal muscle mass (SMM), and skeletal muscle density (SMD) were measured at the third lumbar vertebra (L3) with a semi-automated technique. Receiver operating characteristic (ROC) analysis was used to define optimal SMM cut-offs, and survival was examined by Kaplan-Meier estimation and Cox proportional-hazards regression.