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

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 (p < 0.001). ROM limitation (38.3% vs. 20.0%), reduced daily-activity performance (41.1% vs. 23.1%), AWS (13.9% vs. 7.0%), and lymphedema (16.1% vs. 4.2%) were all more frequent after ALND (p ≤ 0.002). Pain intensity was higher (2.28 ± 2.82 vs. 1.31 ± 2.11; p < 0.001). In multivariable analysis, ALND (β = 1.18, p < 0.001), higher BMI (β = 0.27, p = 0.001), and depressive disorders (β = 0.31, p < 0.001) independently predicted worse shoulder function; age and physiotherapy timing were not significant. Functional deficits persisted across lumpectomy and mastectomy subgroups. CONCLUSIONS: ALND is associated with greater long-term shoulder dysfunction compared with SLNB. Obesity and depressive symptoms exacerbate morbidity, highlighting the importance of comprehensive survivorship rehabilitation. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT05950685.