Prognostic Importance of Axillary Lymph Node Response to Neoadjuvant Systemic Therapy on Axillary Surgery in Breast Cancer—A Single Center Experience

Abstract

Neoadjuvant systemic treatment (NST) is the standard treatment for HER2+, triple-negative (TN), and highly proliferative luminal HER2− early breast cancer. Pathologic complete response (pCR) after NST is associated with improved outcomes. We evaluated the predictive factors for axillary-pCR (AXpCR) and its impact on the extent of axillary node surgery. This retrospective study included 92 patients (median age of 50.4 years) with an initially node-positive disease. Patients were treated with molecular subtype-specific NST (4.3% were luminal A-like, 28.3% luminal HER2−, 26.1% luminal HER2+, 18.5% HER2+ non-luminal, and 22.8% TN). Axillary-, breast- and total-pCR were achieved in 52.2%, 48.9%, and 38% of patients, respectively. In a binary logistic regression model for the whole population, the only independent factor significantly associated with AXpCR was breast-pCR (OR 7.4; 95% CI 2.6–20.9; p < 0.001). In patients who achieved breast-pCR, aggressive subtypes (HER2+ and TN; OR 11.24) and clinical tumor stage (OR 0.10) had a significant impact on achieving AXpCR. Axillary lymph node dissection was avoided in 53.3% of patients. In conclusion, in node-positive patients with HER2+ and TN subtypes, who achieved breast-pCR after NST, de-escalation of axillary surgery could be considered in most cases.