Abstract PS1-43: Axillary surgery after neoadjuvant chemotherapy in patients treated for an operable breast cancer with a proven initially positive axillary node: Preliminary results of identification and removal of the initially positive axillary node

Abstract

Abstract BackgroundAlmost half of the patient with initially metastatic axillary node, treated with neoadjuvantchemotherapy (NAC) for a large operable breast cancer, has no axillary lymph node involvementat the time of surgery after NAC. Sentinel lymph node detection (SLND), performed after NAC,has a high false negative rate (FNR) when compared to FNR after primary surgery. GANEA 3 isa French prospective multi institutional ongoing trial, aimed at assessing the impact of targeting,before NAC, the initially positive node and removing it after NAC. The main objective of GANEA3 trial is the accuracy of this initially positive node to predict pathological status of the otheraxillary nodes after NAC. A total of 385 patients are required.ObjectiveThe current abstract assessed preliminary results of the detection rate of the clipped node and thedifferent methods to find it during axillary surgery based on the first 41 patients.Patients and MethodThis study is part of GANEA 3 Trial validated by scientific national board (clinicialtrials.gov:NCT03630913).Inclusion criteria: TNM stage T1-T3 N1 infiltrating breast carcinoma, indication of NAC, andsigned consent form,Exclusion criteria: more than 5 suspicious axillary nodes, inflammatory cancer, local relapse,mental disorder, pregnancy or no contraceptive method, contra-indication to NAC, NACinterrupted due to progressive disease.Design: Patients treated for an early breast cancer with NAC, axillary sonography with fine needlecytology before NAC to select patients with a proven lymph node involvement. Initially positive node identification warranted, for example with a clip. After NAC patients underwent the removalof the clipped node, a SLN detection with the combined method (patent blue and technetium) andan axillary lymph node dissection (ALND). In order to find the clipped node, during surgery thesurgeon attempted to find it with palpation and sonography. Each surgical specimen was then x-rayed before pathological examination.Studied parameters were clipped node and SLND detection rate, and the methods used to find theclipped node.ResultsFrom January 2019, to November 2019, 41 patients were enrolled, from 13 institutions, withinitially positive axillary node clipped, NAC courses and surgery after NAC.Median age was 53 (31-75), pathological subtype infiltrative ductal carcinoma (n=40) andinfiltrative lobular carcinoma (n=1), a median of 7 courses of NAC (1-16).SLN detection rate was 90% (37/41). A median number of 2 sentinel nodes were removed (1-7).The clipped node was removed in 100% of cases. The clipped node was identified by thesurgeon palpation (n=11), an axillary wire (n=13), per operative axillary sonography (n=4),surgical specimen radiography (n=11), the pathologist (n=2).The clipped node was part of SLN in 29 cases (70%). It was part of axillary lymphadenectomyspecimen in 6 cases (14.5%) and was find alone as an isolated node in 6 cases (14.5%).ConclusionThe clipped node was always found after NAC. It was mostly always part of SLN or ALNDspecimens. Further studies are needed in order to help the surgeon to remove only the clippednode. Citation Format: Celine Renaudeau, Roman Rouzier, Pierre Gimbergues, Marian Gutowski, Eva Jouve, Philippe Rauch, Charles Coutant, Christelle Faure, Catherine Uzan, Pierre-François Dupré, Vivien Ceccato, Charlotte N'go, Augustin Reynard, Isabelle Doutriaux, Loic Campion, Jean-Marc Classe. Axillary surgery after neoadjuvant chemotherapy in patients treated for an operable breast cancer with a proven initially positive axillary node: Preliminary results of identification and removal of the initially positive axillary node [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-43.