Treatment
Dual-tracer
RESIDUAL DISEASE, DISEASE, MINOR
The TAS procedure was defined by palpation-guided selective removal of clipped and biopsy proven nodes, SLNs, and removal of all palpably suspicious findings. The sequence of the individual steps, however, was left to the discretion of the surgeon. TAS was designed to turn a clinically node-positive axilla into a clinically negative axilla by removing all palpably obvious disease. TAS could not reflect a procedure as standardized as ALND, because it was designed to de-escalate axillary surgery in a personalized fashion. Therefore, we expected that the pragmatic concept of TAS would result in some degree of intersurgeon variability. During the SLN procedure that was performed according to local standard practice, all nodes that were either blue (blue dye), hot (technetium Tc 99m), fluorescent (indocyanine green), or magnetic (superparamagnetic iron oxide particles) were removed. Dual-tracer mapping was recommended. Patients in the control group of the TAXIS trial underwent TAS followed by back-up ALND after intraoperative randomization in the upfront surgery setting or in case of residual nodal disease when confirmed by intraoperative frozen section analysis. In case of late confirmation of residual disease on final histopathology, randomization was delayed accordingly for a few days. ALND was performed at the discretion of the treating surgeon according to the pragmatic TAXIS trial design and typically cleared levels I and II. A full level III dissection above and medial to the pectoralis minor muscle was only recommended when there was gross nodal disease detected by palpation or imaging. In the experimental arm, patients received TAS followed by axillary radiotherapy (ART). All patients underwent adjuvant whole-breast irradiation after breast-conserving surgery and chest-wall irradiation after mastectomy. While patients in the ALND group received regional nodal irradiation excluding the dissected axilla as a target volume, patients in the ART group received regional nodal irradiation including the axilla.