Evaluating Axillary Lymph Node Yield After Neoadjuvant Chemotherapy

Introduction: The benefits that neoadjuvant chemotherapy (NAC) provides in treating patients with breast cancer are well known. However, its effects on axillary lymph nodes and lymph node yield (LNY) following axillary lymph node dissection (ALND) remain unclear. Given the importance of LNY for accurate axillary staging in patients with breast cancer, we retrospectively reviewed a large national cancer database to determine if NAC has an effect on LNY following axillary surgery. Methods: A retrospective review of the National Cancer Database was performed. Patients diagnosed from 2010 to 2015 with T0–T4, clinical N0–3, and M0 breast cancer who underwent ALND were included. Patients were categorized by NAC and primary surgery (PS). A descriptive analysis of patient and tumor characteristics, as well as extrinsic factors, was performed. A univariate analysis using Student’s t-test was performed to evaluate LNY between the two groups. Results: A total of 118,108 patients were included in our study. We found that 29,066 (24.6%) patients underwent NAC, and 89,042 (75.4%) had surgery as initial treatment (PS group). The median LNY by ALND in the NAC group was 11 (Q1, Q3: 6, 16). The median LNY in the PS group was 11 (Q1, Q3: 6, 17), p < 0.001. Conclusion: Despite differences in patient characteristics and external factors, we found no difference in LNY following ALND between patients who underwent NAC and those who had initial surgery. Efforts should be made to achieve equivalent LNY whether or not patients receive NAC.