Targeted axillary dissection in breast cancer: current evidence and ongoing trials

In breast cancer patients with clinically positive lymph nodes who achieve a complete pathological nodal response after neoadjuvant systemic therapy, axillary lymph node dissection (ALND) may not always be required. As less invasive approaches are explored, targeted axillary dissection (TAD) has emerged as a promising technique that could spare patients the morbidity of axillary lymph node dissection. First described in 2016, TAD combines sentinel lymph node biopsy with removal of the metastatic lymph node(s) that were marked before starting neoadjuvant therapy. The procedure involves identifying and marking the initially involved node, referred to as the target lymph node (TLN), and removing it along with the sentinel lymph node. There is no international consensus for surgical axillary staging of patients with lymph node involvement undergoing neoadjuvant systemic therapy. This paper overviews the literature since the conception of TAD to assess current evidence regarding the diagnostic accuracy and oncologic safety of TAD. TAD has an identification rate of 82.6-100 %, a false-negative rate of 2-12.2 %, and a negative predictive value of 87.5-100 %. Intraoperatively visible markers demonstrate superior performance, with reduced false-negative rates. Complication rates remain consistently low, with gradual improvement through the learning curve. The 3- and 5-year disease-free survival are preserved in patients with complete response to neoadjuvant therapy, but long-term outcomes are lacking. Prospective randomised trials remain essential to establish definitive evidence for omitting axillary lymph node dissection after TAD.