Long‐Term Shoulder Dysfunction After Breast and Axillary Surgery: Impact of Surgical Extent and Predictors of Function

ABSTRACT Purpose To evaluate long‐term shoulder outcomes after sentinel lymph‐node biopsy (SLNB) versus axillary lymph‐node dissection (ALND) and identify predictors of chronic shoulder dysfunction. Material and Methods This prospective multicenter study enrolled 1111 women (≥ 18 years) undergoing breast cancer surgery with SLNB ( n  = 931) or ALND ( n  = 180) across five tertiary hospitals between October 2022 and June 2024. Functional outcomes were assessed using QuickDASH, range‐of‐motion (ROM), daily‐activity limitations, pain, axillary web syndrome (AWS), and lymphedema. Multivariable regression identified independent predictors of poor shoulder function. Results ALND was associated with consistently greater morbidity. Mean QuickDASH scores were 17.1 ± 10.5 after ALND versus 11.5 ± 9.8 after SLNB (