Validity of sentinel lymph nodes biopsy after neoadjuvant chemotherapy in case of complete pathological response of axillary lymph nodes

Aim
To determine the validity of sentinel lymph node (SLN) biopsy after neoadjuvant chemotherapy (NAC) in case of complete pathological response of axillary lymph node.
Patients and methods
This is a prospective study that included female patients with cancer breast who became clinically and radiologically node negative (cN0) after receiving NAC during the period of March 2016 to October 2018 in Alexandria Medical Research Institute, Alexandria, Egypt. Dual technique was used to identify the SLN followed by standard axillary lymph node dissection (ALND). Analysis of the pathological reports was used to determine the false-negative rate (FNR) of SLN.
Results
Of the 86 patients who completed the NAC and showed cN0, SLN could be identified in 76 (88.4%) patients. ALND was completed for the 76 patients, and SLNs showed false-negative results in nine (11.8%) patients. Patients in whom three or more (10.3%) SLNs could be identified showed better FNR compared with patients with two SLNs or less (16.7%).
Conclusions
SLN biopsy after NAC for patients with cN0 seems to be a reliable technique to replace ALND if certain precautions are applied. The use of a dual technique for SLN identification and determination of at least three SLNs to be the minimum number accepted is an essential requirement to be applied in this selective approach to ensure FNR within accepted range. In addition, patients should be counseled regarding benefits of the SLN biopsy technique and the possibility of failure to identify the SLN or being false negative.