BackgroundThree randomized trials have concluded at non inferiority of omission of complementary axillary lymph node dissection (cALND) for patients with involved sentinel node (SN). However, we can outline strong limitations of these trials to validate this attitude with a high scientific level. We designed the SERC randomized trial (ClinicalTrials.gov, number NCT01717131) to compare outcomes in patients with SN involvement treated with ALND or no further axillary treatment. The aim of this study was to analyze results of the first 1000 patients included.MethodsSERC trial is a multicenter non-inferiority phase 3 trial. Multivariate logistic regression analysis was used to identify independent factors associated with adjuvant chemotherapy administration and non-sentinel node (NSN) involvement.ResultsOf the 963 patients included in the analysis set, 478 were randomized to receive cALND and 485 SLNB alone. All patient demographics and tumor characteristics were balanced between the two arms. SN ITC was present in 6.3% patients (57/903), micro metastases in 33.0% (298), macro metastases in 60.7% (548) and 289 (34.2%) were non eligible to Z0011 trial criteria.Whole breast or chest wall irradiation was delivered in 95.9% (896/934) of patients, adjuvant chemotherapy in 69.5% (644/926), endocrine therapy in 89.6% (673/751) and the proportions were similar in the two arms. The overall rate of positive NSN was 19% (84/442) for patients with cALND. Crude rates of positive NSN according to SN status were 4.5% for ITC (1/22), 9.5% for micro metastases (13/137), 23.9% for macro metastases (61/255) and were respectively 29.36% (64/218), 9.33% (7/75) and 7.94% (10/126) when chemotherapy was administered after cALND, before cALND and for patients without chemotherapy.ConclusionThe main objective of SERC trial is to demonstrate non inferiority of cALND omission. A strong interaction between timing of cALND and chemotherapy with positive NSN rate was observed.Trial registrationThis study is registered with ClinicalTrials.gov, number NCT01717131 October 19, 2012.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-5053-7) contains supplementary material, which is available to authorized users.

Based on results of clinical trials, completion ALND (cALND) is frequently not performed for patients with breast conservation therapy and one or two involved sentinel nodes (SN) by micro- or macro-metastases. However, there were limitations despite a conclusion of non-inferiority for cALND omission. No trial had included patients with SN macro-metastases and total mastectomy or with >2 SN macro-metastases. The aim of the study was too analyze treatment delivered and pathologic results of patients included in SERC trial. SERC trial is a multicenter randomized non-inferiority phase-3 trial comparing no cALND with cALND in cT0-1-2, cN0 patients with SN ITC (isolated tumor cells) or micro-metastases or macro-metastases, mastectomy or breast conservative surgery. We randomized 1855 patients, 929 to receive cALND and 926 SLNB alone. No significant differences in patient’s and tumor characteristics, type of surgery, and adjuvant chemotherapy (AC) were observed between the two arms. Rates of involved SN nodes by ITC, micro-metastases, and macro-metastases were 5.91%, 28.12%, and 65.97%, respectively, without significant difference between two arms for all criteria. In multivariate analysis, two factors were associated with higher positive non-SN rate: no AC versus AC administered after ALND (OR = 3.32, p < 0.0001) and >2 involved SN versus ≤2 (OR = 3.45, p = 0.0258). Crude rates of positive NSN were 17.62% (74/420) and 26.45% (73/276) for patient’s eligible and non-eligible to ACOSOG-Z0011 trial. No significant differences in patient’s and tumor characteristics and treatment delivered were observed between the two arms. Higher positive-NSN rate was observed for patients with AC performed after ALND (17.65% for SN micro-metastases, 35.22% for SN macro-metastases) in comparison with AC administered before ALND.

Many trials confirmed the safety of omitting axillary dissection in the selected patients treated for early breast cancer. The external validity of these trials is questionable. Our study aimed to evaluate the accuracy of the French population representativity in the SERC trial and the differences between these two populations as well as comparing the French and the Swedish populations (the SENOMIC trial population and the Swedish National Breast Cancer Registry (NKBC) cohort) of patients with sentinel node (SN) micro-metastasis. A higher rate of smaller tumors and grade 1 tumors was observed in the French cohort when compared to the SERC population. Our findings conclude that both French populations show similar characteristics. Positive non-sentinel node (NSN) rates at completion axillary lymph node dissection (ALND) were 10.28 % and 11.3 % in the SERC trial and French cohort, respectively (p = 0.5). The rate of grade 1 tumors was lower in the SENOMIC trial (16.2%) and in the NKBC cohort (17.4%) compared to the SERC trial population (27.3%) and the French cohort (34.4%). Our findings in addition to the previously demonstrated concordance between the SENOMIC trial and the NKBC populations imply that the results of both the SERC and the SENOMIC trials can be applied to both French and Swedish real populations.

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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.