Intraoperative Sentinel Node Fine-Needle Aspiration Biopsy as a Substitute for Whole Sentinel Node Excisional Biopsy in Breast Cancer Patients. Initial Report

Abstract

IntroductionSentinel Node Biopsy (SNB) is the choice procedure for axillary staging in Breast Cancer. Following the ACOSOG Z11 trial, axillary dissection is advised only in patients with more than 2 positive SNs. We aimed at exploring palpation-guided, intraoperative fine-needle aspiration biopsy of the SN as a replacement for whole SN excision in node-negative BC patients to minimize side-effects. Patients and MethodsWe included 80 patients with BC undergoing SNB between December 2020 and May 2022. After identification of the SN, the breast surgeon performed SN-FNAB. Results were compared with definitive pathological assessment. ResultsDiagnostic yield was 80%, including a “learning curve.” 58 of 64 patients with suitable samples tested negative. In this group, the Negative Predictive Value was 77.6% (IC 64.7%-87.5 %). If micro metastasis is disregarded, the NPV would increase to 86.2% (IC 74.6%-93.9%). If we accept the Z11 criterion for axillary dissection, the NPV would rise to 100%. Six patients had a positive SN-FNAB. They were all confirmed as having macro metastatic-positive SNs at the final pathological assessment, and 3 of them also displayed extra nodal extension (ENE). ConclusionWe believe that intraoperative SN-FNAB is highly accurate for swiftly depicting both low axillary tumor burden/negative cases, in whom axillary dissection is to be omitted, as well as high axillary tumor burden cases.