126TiP Tailored axillary surgery with or without axillary lymph node dissection followed by radiotherapy in patients with clinically node-positive breast cancer (SAKK 23/16 / IBCSG 57-18 / ABCSG-53 / GBG 101 - TAXIS): A multicenter randomized phase III trial

Complete lymph node removal through conventional axillary lymph node dissection (ALND) has been standard treatment for breast cancer patients for almost a century. However, ALND came under increasing scrutiny due to its association with significant patient morbidity. Several studies have since provided evidence to suggest omission of ALND, often in favor of axillary radiation, in selected clinically node-negative sentinel lymph node (SLN)-positive patients. Clinically node-positive patients, by contrast, continue to undergo ALND in many cases. There is a need for a clinical trial to evaluate the optimal treatment for clinically node-positive breast cancer patients in terms of surgery and radiotherapy. The TAXIS trial is designed to examine the value of tailored axillary surgery (TAS), a new technique for selectively removing positive lymph nodes. In this international, multi-center, phase-III, non-inferiority randomized controlled trial, including 32 study sites from five countries, we plan to randomize 1500 patients to either receive TAS followed by ALND and regional nodal irradiation excluding the dissected axilla, or receive TAS followed by regional nodal irradiation including the full axilla. All patients undergo adjuvant whole-breast irradiation after breast conserving surgery and chest wall irradiation after mastectomy. Inclusion of internal mammary nodes is recommended irrespective of treatment arm. The main objective of the trial is to test the hypothesis that treatment with TAS and axillary radiotherapy is non-inferior to ALND in terms of disease-free survival of clinically node-positive breast cancer patients. Secondary objective is to test if quality of life is significantly better with TAS. The trial was activated on 31 July 2018 and the first patient was randomized on 07 August 2018. As of 24 January 2020, 186 patients have been randomized. Accrual is planned until end of 2023, with a total study duration until the primary endpoint of 11 years. NCT03513614. SAKK, GBG, ABCSG, IBCSG. Krebsliga Beider Basel, Fond'Action contre le cancer, Rising Tide Foundation for Clinical Cancer Research, Swiss Cancer Research, Claudia von Schilling Foundation for Breast Cancer Research, Agendia.