Discussion
palpable disease
DISEASE, NODE-POSITIVE BREAST CANCER, MAXILLARY TUMOR
This is the first prospective study investigating the role of IGL in TAS for clinically node-positive breast cancer in patients undergoing upfront surgery or NACT with residual nodal disease. While IGL was frequently used, it had no impact on the number of positive or negative lymph nodes removed and residual nodal disease after TAS, with two-thirds of patients having at least one additional positive lymph node. Without use of IGL, the number of nodes removed during TAS decreased over the study period, suggesting that surgeons went through a learning curve and sampled fewer nodes at later time points. The study was, however, not designed to assess whether this small difference in number of nodes removed over time was clinically relevant. However, due to the limited impact of IGL on all other performance characteristics of TAS, we conclude that IGL is not a key element of TAS.TAS consists of palpation-guided selective removal of obvious nodal disease, thereby tailoring the extent of axillary surgery to the extent of axillary disease. It further includes the SLN procedure to reduce the volume of microscopic disease, while IGL of clipped or suspicious nodes is optional.In the adjuvant setting, the main difference between TAS and the SLN procedure is that TAS allows IGL of nodes, and that the selective removal of palpably suspicious disease is a regular key component. Currently, since palpable disease is the main contraindication to the SLN procedure when used for staging purposes, it is rarely encountered. In the neoadjuvant setting, the main difference between the therapeutic concept of TAS, which serves as final surgical treatment of residual nodal disease, and the diagnostic concept of TAD is that the latter by definition requires IGL and is routinely followed by ALND in case of residual nodal disease.When planning this study, we were interested to see how the pragmatic concept of TAS would be translated into clinical practice at the participating TAXIS study sites. Therefore, we extensively documented key aspects of TAS including details on preoperative workup (e.g., type of clips and imaging) and the intervention (e.g., number of lymph nodes removed, SLN- and localization techniques). Indeed, significant variation by country was observed. In Switzerland, for example, IGL was omitted in one-quarter of patients, whereas in Austria, Germany, and Hungary, IGL was used in almost all cases (Table To the authors’ knowledge, TAXIS is the only RCT addressing the omission of ALND in patients with palpable disease who undergo upfront surgery to date. However, several authors questioned the justification for ALND in this setting by showing low axillary tumor load in many of these patients, and a prospective observational study is currently investigating the selective use of ALND.In the neoadjuvant setting, the only RCT besides TAXIS to investigate omission of ALND for residual nodal disease after NACT is the Alliance A011202 trial (NCT01901094). While we eagerly await the primary analysis of this trial, ALND remains standard care, apart from, perhaps, the lowest volume of residual nodal disease, where ART may be considered on an individual basis.