Prediction of Axillary Lymph Node Stages According to Sentinel Lymph Nodes Involvement and Luminal Subtypes in Patients Receiving Neoadjuvant Chemotherapy

Abstract

Abstract Background: Sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND) for assessing axillary lymph node status in clinically node-negative breast cancer patients. However, the approach to axillary surgery after neoadjuvant treatment is still controversial. In this present study, our objective is to predict the pathological nodal stage based on the SLNB results and the clinicopathological characteristics of patients who initially presented with clinical N1 positivity but converted to clinical N0 status after neaoadjuvant chemotherapy (NAC). Materials and Methods: After NAC, clinically node-negative150 patients were included The relationship between clinicopathologic parameters, the number of positive lymph nodes in SLNB and ALND was assessed through binary/multivariate logistic regression analysis. Results: Among 150 patients, 78 patients had negative SLNB and 72 patients had positive SLNB. No additional nodes positive at ALND ((y)pN1) varied among patients with SLNB 1+, 2+, and 3+ was 80.8%, 41.7%, and 13.6%, respectively. Following the detection of SLNB 1+ positivity, the rates of complete lymph node response ((y)pN1) were 75%, 100%, and 100%, in luminal A/B, HER-2 positive, and triple-negative subtypes, respectively. Lower T stage (T1-3 vs. T4), having fewer than 4 clinical nodes before NAC (<4 vs. ≥4), post-operative Ki-67 decrease (<10% vs. stable/increase), and being in the triple-negative or HER2-positive subgroup compared to Luminal A/B (Luminal A/B vs. HER2-positive/triple-negative) were found to be predictive parameters for (y)pN1 in both univariate and multivariate analyses. Conclussion: The number of SLNB-positive nodes and tumor-related parameters as well as the response to treatment, may predict no additional nodes positive at ALND ((y)pN1).