Pretreatment Body Composition Parameters and HALP Score in Relation to Pathological Complete Response in HER2-Positive Breast Cancer Receiving Neoadjuvant Systemic Therapy

Background/Objectives: Pathological complete response (pCR) is an important early endpoint in HER2-positive breast cancer treated with neoadjuvant therapy. Although tumor biology is a major determinant of response, the potential contribution of host-related factors such as body composition and systemic inflammatory-nutritional status remains uncertain. This study evaluated the associations of pretreatment skeletal muscle index (SMI), myosteatosis, an imaging-defined low-SMI obesity phenotype, and hemoglobin-albumin-lymphocyte-platelet (HALP) score with pCR.