Upper extremity morbidity after neoadjuvant systemic therapy in initially node-positive breast cancer: SLNB versus ALND

Objective This study aimed to evaluate the effect of axillary surgery type on upper-extremity morbidity in patients with clinically node-positive breast cancer at diagnosis who received neoadjuvant systemic therapy and adjuvant radiotherapy. Methods This retrospective study included patients treated between February 2022 and April 2025. Patients were grouped according to axillary surgery as sentinel lymph node biopsy (SLNB) or axillary lymph node dissection (ALND). Upper-extremity morbidity was evaluated for lymphedema, shoulder flexion and abduction limitation, pain, neurosensory symptoms, daily activity limitation, and axillary web syndrome. In the SLNB group, outcomes were also analyzed according to removed SLN count. Results A total of 134 patients were included: 64 in the SLNB group and 70 in the ALND group. Baseline characteristics were generally comparable. Lymphedema was more frequent after ALND than after SLNB (32.9% vs. 10.9%, p = 0.002). Flexion limitation (14.3% vs. 3.1%, p = 0.033), abduction limitation (28.6% vs. 9.4%, p = 0.005), pain (42.9% vs. 15.6%, p = 0.001), neurosensory symptoms (47.1% vs. 9.4%, p < 0.001), and daily activity limitation (18.6% vs. 4.7%, p = 0.016) were also more common after ALND. Axillary web syndrome was observed only in the ALND group. Removed SLN count (≤ 3 vs. >3) was not significantly associated with upper-extremity morbidity. Conclusion In initially clinically node-positive breast cancer patients treated with neoadjuvant systemic therapy and adjuvant radiotherapy, ALND was associated with greater upper-extremity morbidity than SLNB. These findings suggest that limiting the extent of axillary surgery may reduce upper-extremity morbidity in appropriately selected patients. Clinical trial number Not applicable.