Patients and Methods
tumor malignancy, breast cancer
DISEASE, NODE-POSITIVE BREAST CANCER, BREAST CANCER
This prospective study was preplanned within the randomized controlled international phase-III TAXIS trial (OPBC-03/SAKK 23/16/IBCSG 57-18/ABCSG-53/GBG 101; ClinicalTrials.gov Identifier: NCT03513614). Patients ≥ 18 years of age with histologically or cytologically proven node-positive breast cancer and adequate condition for breast cancer surgery were included. Node-positive disease was detected by palpation or imaging at the time of initial diagnosis. Clip placement in the biopsy-proven positive lymph node was required. Patients were included in both the upfront surgery setting and after NACT in case of residual nodal disease, which was confirmed by either intraoperative frozen section analysis or final histopathology. Patients with stage IV, cN3c or cN2b breast cancer, contralateral or other tumor malignancy within 3 years, prior axillary surgery (except SLN procedure), or prior axillary radiotherapy were considered ineligible. Furthermore, patients with nodal pCR, absence of clip in the specimen radiography, palpable disease left behind in the axilla after TAS, or no SLN identified in the axilla were excluded from randomization. This study was pre-planned after 500 patients were randomized (one-third of the total sample size) in the TAXIS trial. It was planned to gain relevant insight into the impact of IGL on performance of the pragmatic concept of TAS. Patients were treated from August 2018 to June 2022. Data extraction was performed after data cleaning on 30 September 2022.This study was approved by the local ethics committees and performed in accordance with the requirements of the national regulatory authorities. Written informed consent was obtained from all patients. The study is reported according to the STROBE guidelines (Supplementary Table 