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Management of the axilla for high-risk early breast cancer (EBC) before and after neoadjuvant chemotherapy (NACT): an analysis of the multicentre GeparOcto trial
Gerber B.1, Schneeweiss A.2, Möbus V.3, Golatta M.4, Tesch H.5, Krug D.6, Denkert C.7, Lübbe K.8, Heil J.4, Ataseven B.9, Klare P.10, Untch M.11, Kast K.12, Jackisch C.13, Seither F.14, Nekljudova V.14, Loibl S.14, Kühn T.15
1University of Rostock, Department of Obstetrics and Gynaecology, Rostock, Deutschland, 2Nationales Centrum für Tumorerkrankungen, Heidelberg, Deutschland, 3University of Frankfurt, Frankfurt, Deutschland, 4Universitätsklinikum Heidelberg, Heidelberg, Deutschland, 5Bethanien Krankenhaus Frankfurt, Frankfurt, Deutschland, 6Universitätsklinikum Schleswig-Holstein Kiel, Klinik für Strahlentherapie, Kiel, Deutschland, 7Universitätsklinikum Marburg, Institut für Pathologie UKGM, Marburg, Deutschland, 8Diakovere Henriettenstiftung Hannover, Hannover, Deutschland, 9Kliniken Essen Mitte, Essen, Deutschland, 10Praxisklinik Krebsheilkunde für Frauen, Berlin, Deutschland, 11HELIOS Clinic Berlin-Buch, Berlin, Deutschland, 12Universitätsklinikum Carl Gustav Carus Dresden, Dresden, Deutschland, 13Sana-Clinic Offenbach, Offenbach, Deutschland, 14GBG, Neu-Isenburg, Deutschland, 15Klinikum Esslingen, Esslingen, Deutschland

Background: pCR in breast after NACT for patients with EBC correlates with initial lymph node status. We investigated the axilla management of patients with pN+ at presentation.
Methods: Between 12/2014 and 06/2016, the neoadjuvant GeparOcto trial (Schneeweiss et al. EJC 2018) enrolled 961 patients. Sentinel lymph node biopsy (SLNB) in cN0 patients at baseline was not encouraged because of its impairing on pCR results.
Results: At baseline 117/501 (23.4%) of cN0 patients were diagnosed as pN1(sn) before NACT. 59/431 (13.7%) cN+ patients were pN1(sn). In 233/431 (54.1%) patients, cN+ was confirmed as pN+ by core biopsy as recommended. Overall, 443 were pN+ at baseline, 182 by SLNB (59 initially cN+, 117 initially cN0; 6 cN missing), 242 by biopsy, 19 by ALND. Of those 242 patients with pN+ confirmed by biopsy before NACT, 132 (54.5%) were ycN0 after NACT (5.4% received SLNB, 94.6% ALND) and 77 (31.8%) were ycN+ (9.1% received SLNB, 90.9% ALND), 33 had no examination. In addition to 95.6% of patients with pN0 at baseline, 35.2% of patients with pN+ at baseline diagnosed by SLNB did not undergo axillary surgery.
Conclusions: SLNB at baseline was performed in cN0 and cN+ (which is not recommended) impairing pCR evaluation. 35% of patients with pN+ by SLNB before NACT did not receive any further surgical procedure. All patients with pN+ by biopsy before NACT underwent axillary surgery as recommended. Axillary procedures in neoadjuvant treated patients are very variable and do not always adhere to guidelines.