Abstract P3-01-08: Sentinel lymph node biopsy alone after neoadjuvant chemotherapy in patients with cytologically proven node-positive breast cancer

Abstract

Abstract Background The purpose of this study was to identify the feasibility and accuracy of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) in patients with axillary lymph node (ALN) metastasis at diagnosis. Methods This is a retrospective study of 332 patients who were diagnosed with invasive breast cancer and ALN metastasis and treated with NAC followed by curative surgery at Samsung Medical Center between January 2007 and December 2013. Patients were classified into five groups according to surgical procedure for the ALNs and pathologic results; group 1, patients with negative SLN status and no further dissection was performed; group 2, patients with negative SLN status undergoing further axillary lymph node dissection (ALND); group 3, patients with positive or undetected SLNs undergoing further ALND; group 4, patients without residual axillary metastasis undergoing complete ALND; and group 5, patients with pathologic nodal positive disease undergoing ALND. Results Sentinel lymph nodes identification rate after NAC was 99.1% and false negative rate was 24.1%. The median number of retrieved SLNs was 4 (range, 1–10). There was no difference in the overall survival among the groups (p=0.06). There was no significant difference in the disease-free survival rate between the SLNB only and complete ALN dissection groups who revealed a pathologic complete node response (79.6% versus 80.5%) and the rate of axillary recurrence demonstrated no significant differences among the groups. (p=0.225) There was a statistical difference of recurrence between group 1 versus 2, and group 1 versus 4 in hormone receptor-negative patients. (p=0.027) Conclusion SLNB after NAC in breast cancer patients with initial ALN metastasis may help identify downstaging to negative nodal status and thereby reduce the surgical morbidity by avoiding standard ALN dissection. Citation Format: Park S, Ryu JM, Paik H-J, Yi HW, Bae SY, Lee SK, Kil WH, Kim SW, Lee JE, Nam SJ. Sentinel lymph node biopsy alone after neoadjuvant chemotherapy in patients with cytologically proven node-positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-08.