Axillary Management After Neoadjuvant Chemotherapy

The standard treatment for locally advanced and node-positive breast cancer is surgery following neoadjuvant chemotherapy (NAC). Using NAC in advanced-stage tumors and biologically aggressive subtypes can lead to de-escalation in surgical treatment for the breast and axilla. Previously, NAC was believed to alter lymphatic drainage due to fibrosis and tumor emboli in lymphatic channels. However, the theAmerican College of Surgeons Oncology Group (ACOSOG) Z1071 and Sentinel-lymph-node biopsy in patients with breast cancer before and after neoadjuvant chemotherapy (SENTINA) trials investigated the performance of sentinel lymph node biopsy (SLNB) after NAC in patients with proven axillary lymph node involvement at the initial biopsy. In contemporary breast cancer management, particularly in the axillary approach, less invasive techniques are becoming increasingly common. This raises the question of whether there might be a patient group where SLNB could be avoided. In this study, the investigators sought a new method to evaluate the axilla after NAC in patients with known axillary involvement previously. For this purpose, the investigators performed an ultrasound-guided needle biopsy on the clipped axillary lymph node with known metastasis before the planned surgery, aiming to assess the axilla without performing SLNB after treatment. Additionally, the investigators investigated which patient group might benefit more from this predictability based on molecular subtypes and clinical-pathological features.