Feasibility of sentinel lymph node biopsy in patients who had conversion of axillary lymph nodes from clinically positive to negative following neoadjuvant chemotherapy

Abstract

Purpose : Complete remission of axillary lymph node after neoadjuvant chemotherapy (NAC) can be commonly observed. However, the use of sentinel lymph node biopsy (SLNB) following NAC in patients presenting with clinically positive lymph nodes remains controversial. This study evaluated the feasibility of SLNB in patients who had conversion of axillary nodes from clinically positive to negative following NAC. Method : We reviewed the records of 26 patients who had breast cancer with clinically axillary lymph node-positive status and negative conversion after NAC, between 2010 and 2016. Of these, 11 patients underwent axillary lymph node dissection (ALND) without SLNB, and 15 patients underwent ALND following SLNB, regardless of its results. SLB was performed using both blue dye and a radiolabeled colloid mapping agent. Result : Complete disease regression of axillary lymph nodes in 65.4% (17 of 26 patients). The sentinel lymph node (SLN) identification rate was 86.7%(13 of 15 patients). The median number of retrieved SLNs was 1 (range, 1-3). Of 13 patients, 8 had negative SLNs on frozen section analysis and had no additional metastasis in lymph nodes removed by ALND. The false negative rate of SLNB after NAC was 0%. Conclusions : SLNB may be feasible in patients who had conversion of axillary nodes from clinically positive to negative following NAC, regardless of number of retrieved SLNs and may help reduce surgical morbidity by avoiding the need for standard axillary lymph node dissection in these patients.