Sentinel Lymph Node Biopsy after Neoadjuvant Chemotherapy is Accurate and Reduces the Need for Axillary Dissection in Breast Cancer
Kelly K Hunt, *Min Yi, *Elizabeth A. Mittendorf, *Cynthia Guerrero, *Gildy V. Babiera, *Isabelle Bedrosian, *Rosa F. Hwang, *Henry M. Kuerer, Merrick I. Ross, *Funda Meric-Bernstam
The University of Texas M. D. Anderson Cancer Center, Houston, TX
OBJECTIVE - Sentinel lymph node (SLN) biopsy is widely used for nodal staging in early-stage breast cancer. This study was performed to evaluate the accuracy of SLN biopsy for patients undergoing neoadjuvant chemotherapy versus patients undergoing surgery first.
METHODS - 3,746 patients with clinically node negative T1 to T3 breast cancer underwent SLN biopsy from March 1994-2007. Clinicopathologic data and details regarding the SLN biopsy procedure were reviewed and comparisons made between patients receiving neoadjuvant chemotherapy and those undergoing surgery first.
RESULTS - 575 (15.3%) patients underwent SLN biopsy after chemotherapy and 3,171 (84.7%) underwent surgery first. Neoadjuvant patients were younger (51 vs 57 yrs, p<0.0001) and more likely to have clinical stage T2-T3 tumors (87.3% vs 18.8%, p<0.0001) at diagnosis. SLN identification rates were 97.4% in the neoadjuvant and 98.7% in the surgery first groups, respectively (p=0.017). False-negative rates were similar between groups (5 of 84=5.9% in neoadjuvant vs 23 of 542=4.2% in the surgery first group, p=0.48). Analyzed by presenting T stage, there were fewer positive SLNs in the neoadjuvant group (T1: 12.7% vs 19.0%, p=0.2; T2: 20.5% vs 36.5%, p<0.0001; T3: 30.4% vs 51.4%, p=0.04). After adjusting for clinical stage, there were no differences in local-regional recurrences, disease-free or overall survival between groups.
CONCLUSIONS - In patients with clinically negative nodes at presentation, SLN biopsy after chemotherapy is as accurate for axillary staging as doing SLN biopsy prior to chemotherapy. Using SLN biopsy after chemotherapy results in fewer positive SLNs and spares patients unnecessary axillary dissections.