Abstract PO4-19-04: AXSANA – EUBREAST-3: An international prospective multicenter cohort study to evaluate different surgical methods of axillary staging in clinically node-positive breast cancer patients treated with neoadjuvant chemotherapy

Abstract

Abstract Background The optimal surgical staging procedure of the axilla in patients who convert from a clinically positive (cN+) to a clinically negative node status (ycN0) through neoadjuvant chemotherapy is still controversial. Widely diverse techniques such as full Axillary Lymph Node Dissection (ALND), Targeted Axillary Dissection (TAD), Targeted Lymph Node Biopsy (TLNB) and Sentinel Lymph Node Biopsy (SLNB) alone are given preference in different international guidelines. So far, no comparative data on the oncological outcome or the morbidity of the different procedures are available. Further research is needed to safely de-escalate the extent of axillary surgery in this patient group. Trial design The AXSANA study is an international prospective cohort study including cN+ patients converting to ycN0 status and treated with different axillary staging techniques according to the standard at their treating institution. The study was initiated by the EUBREAST network. The trial includes patients with cT1-4c tumors, who present initially with axillary lymph node metastasis scheduled for neoadjuvant chemotherapy. According to an amendment in 2020 the inclusion of patients with highly suspicious nodes without confirmation using a minimally invasive biopsy is allowed. All patients converting to ycN0 status undergo follow-up for 5 years irrespectively of the ypN status. Primary endpoints: Invasive disease-free survival, axillary recurrence rate and health-related quality of life (HRQoL). HRQoL are evaluated using four standardized questionnaires (EORTC QLQ-C 30, EORTC QLQ-BR 23, Lymph ICF and SOC-13) at baseline and after 1, 3 and 5 years after surgery. Secondary endpoints are the feasibility and performance of different axillary staging techniques (detection rate, number of removed lymph nodes and association with complications, arm morbidity and quality of life, operating time and use of clinical and economic resources); impact of learning curve, and the detailed mapping of surgical and oncological treatment standards in different countries. The impact on different regional treatment strategies (radiotherapy, ALND) in patients with ypN0(i+), ypN1(mi) and ypN1 is assessed. Current status of the study: 4336 patients from 284 study sites and 26 countries were enrolled in the study between June 2020 and June 2023. Among 3722 patients with a defined surgical concept 1631 women were scheduled for TAD, 1483 for ALND, 469 for SLNB, 25 for TLNB and 109 for other procedures. A target lymph node was marked in 2309 patients, most frequently using clips/coils (1850, 80.1%), followed by magnetic seeds (219, 9.5%), carbon ink (171, 7.4%), radar marker (80, 3.5%), radioactive seeds (4, 0.2%) and other techniques (24, 1.0%). Funding: AGO-B, GBG, Claudia-von Schilling Foundation, Ehmann Foundation, Eugen und Irmgard Hahn Foundation, AWOgyn, Merit Medical, Endomagnetics, Mammotome Contact information: Prof. Dr. Thorsten Kühn Department of Gynecology and Obstetrics University of Ulm, Germany Baumreute 37 D-73730 Esslingen Germany E-Mail: kuehn.thorsten@t-online.de Citation Format: Thorsten Kühn, Steffi Hartmann, Elmar Stickeler, Jana de Boniface, Oreste Davide Gentilini, Sarah Fröhlich, Franziska Ruf, Marc Thill, Michael Hauptmann, Guldeniz Karadeniz Cakmak, Isabel Rubio, Maria Luisa Gasparri, Michalis Kontos, Eduard-Alexandru Bonci, Laura Niinikoski, Bilge Aktas Sezen, Rosa Di Micco, Dawid Murawa, Geeta Kadayaprath, David Pinto, Florentia Peintinger, Matilda Appelgren, Janine M. Simons, Marjolein Smidt, Ellen Schlichting, Lukas Dostalek, Elisabeth Thiemann, Markus Hahn, Michael Schrauder, Semra Gunay, Gunay Gurleyik, Nina Helidon, Hagigat Valiyeva, Ashutosh Kothari, Marian Vanhoeij, Andraz Perhavec, Tsvetomir Ivanov, Dov Zippel, Lia Rebaza, Sarun Thongvitokomarn, Sibylle Loibl, Maggie Banys-Paluchowski. AXSANA – EUBREAST-3: An international prospective multicenter cohort study to evaluate different surgical methods of axillary staging in clinically node-positive breast cancer patients treated with neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-19-04.