Abstract S2-07: Sentinel node detection after neoadjuvant chemotherapy in patient without previous axillary node involvement (GANEA 2 trial): Follow-up of a prospective multi-institutional cohort

Abstract

Abstract Background Half of the patient treated with neoadjuvant chemotherapy (NAC) for a large operable breast cancer has no axillary lymph node involvement at the time of surgery. Sentinel lymph node detection (SLND), after NAC, is aimed to select patient who should be safely spared of an axillary lymphadenectomy (ALND).GANEA 2 is a French prospective multi institutional trial, aimed to assess SLND after NAC. Objective To assess the risk of relapse for patients without previous axillary node involvement treated with NAC followed with a SLND without a systematic lymphadenectomy. Patients and Method Inclusion: FIGO stage T1-T3 infiltrating breast carcinoma, indication of NAC. Exclusion: inflammatory cancer, local relapse, contra-indication to NAC, NAC interrupted due to progressive disease. Design: indication to plan a NAC, axillary sonography with fine needle cytology before NAC to select patients without lymph node involvement, SLND after NAC. ALND was mandatory in case of SLN involvement (macro or micro-metastasis) or SLND failure. Follow-up was scheduled with a medical visit / 6 months with axillary assessment and a mammography each year. Follow-up results are updated every 6 months. Pathological analysis were carried out according to standard methods and classified according to the last American Joint Committee staging system. Studied parameters were SLND detection rate, pathological results on breast specimen and nodes, rate of relapse (axilla, breast, metastasis), and survival. Results From July 2010 to February 2014, 587 patients were enrolled, from 17 institutions, and experienced breast tumor surgery and a SLND after NAC. Each patient experienced breast surgery. A breast tumour pathological complete response was found in 21.3% (125/587). SLND rate was 97% (570/587), with a median number of 2 sentinel nodes (1-9). Patients with a sentinel detection failure (n=17) experienced a systematic lymphadenectomy, without any involvement (n=13), a micro-metastasis (n=2) and a macro-metastasis (n=2). A total of 140 patients had at least one sentinel node involved: macro-metastasis (n=86), micro-metastasis (n=54). A lymphadenectomy was performed in 128 cases: metastasis free (n=100), macro-metastasis (n=17), micro-metastasis (n=11). A total of 430 patients had a SLN metastasis free (75% ;430/570). A not mandatory lymphadenectomy was performed (n=14): metastasis free (n=11), macro-metastasis (n=2) and micro-metastasis (n=1). 17 patients were lost to follow-up. A total of 399 patients without sentinel node involvement were followed 2.3 years (from 0.5 to 5.6 yrs). At 3 years overall survival was 97.8% [94.9-99.1], disease free survival was 94.8% [91.0-97.1%]. Six patients died. Fifteen patients experienced a relapse: 8 metastasis, 4 homolateral breast, 2 controlateral breast, 1 homolateral axillary relapse. Conclusion This is the most important series of patients followed 2.3 years after SLND without axillary lymphadenectomy after NAC for an advanced breast cancer, showing acceptable results. The current series validate the safety of this conservative strategies avoiding systematic lymphadenectomy to patients without initially involved axillary node treated with NAC. Citation Format: Classe J-M, Loaec C, Alran S, Paillocher N, Tunon-Lara C, Gimbergues P, Faure-Virelizier C, Chauvet M-P, Lasry S, Dupre P-F, Verhaeghe J-L, De Blaye P, Gutowski M, Barranger E, Lecuru F, Lefevre Lacoeuille C, Loussert L, Lambaudie E, Ferron G, Campion L. Sentinel node detection after neoadjuvant chemotherapy in patient without previous axillary node involvement (GANEA 2 trial): Follow-up of a prospective multi-institutional cohort [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S2-07.