Long-Term Follow-Up of Node-Negative Breast Cancer Patients Evaluated via Sentinel Node Biopsy After Neoadjuvant Chemotherapy

The purpose of this study was to assess the usefulness of sentinel node biopsy (SNB) after neoadjuvant chemotherapy (NAC) in patients with clinically node-negative breast cancer. SNB after NAC was as accurate as SNB without NAC. Axillary recurrence-free survival rates were excellent regardless of whether NAC was performed before SNB. Sentinel node biopsy (SNB) is used to accurately assess axillary lymph node status in patients with node-negative breast cancer. However, its use after neoadjuvant chemotherapy (NAC) is controversial. We retrospectively assessed the usefulness of SNB after NAC by comparing axillary recurrence rates and other parameters in patients with clinically node-negative breast cancer who underwent SNB after NAC or without NAC. At our hospital, 1179 patients with clinically node-negative breast cancer underwent SNB from April 2007 to December 2013. The clinicopathological and survival data of patients who underwent SNB after NAC (the NAC group) and those who underwent SNB without NAC (the control group) were compared. Patients with a metastatic sentinel node underwent axillary lymph node dissection. The number of patients in the NAC and control groups was 183 (15.5%) and 996 (84.5%), respectively. At diagnosis, tumors were significantly larger in the NAC group (P < .0001). Sentinel nodes were identified in almost all patients in both groups (99.5% in the NAC group vs. 99.8% in the control group). They were nonmetastatic in 147 (80.8%) patients in the NAC group and 849 (85.5%) patients in the control group. At the median follow-up time of 51.1 months, 6 patients (0.6%) in the control group had axillary lymph node recurrence compared with no patients in the NAC group. SNB after NAC was as accurate as SNB without NAC in patients with clinically node-negative breast cancer. Axillary recurrence-free survival rates were excellent regardless of whether NAC was performed before SNB.