Clinical feasibility and oncological safety of non-radioactive targeted axillary dissection after neoadjuvant chemotherapy in biopsy-proven node-positive breast cancer: a prospective diagnostic and prognostic study

Background: Targeted axillary dissection (TAD) includes biopsy of clipped lymph node and sentinel lymph nodes. However, clinical evidence regarding clinical feasibility and oncological safety of non-radioactive TAD in a real-world cohort remains limited. Methods: In this prospective registry study, patients routinely underwent clip insertion into biopsy-confirmed lymph node. Eligible patients received neoadjuvant chemotherapy (NACT) followed by axillary surgery. Main endpoints included the false-negative rate (FNR) of TAD and nodal recurrence rate. Results: Data from 353 eligible patients were analyzed. After completion of NACT, 85 patients directly proceeded to axillary lymph node dissection (ALND), furthermore, TAD with or without ALND was performed in 152 and 85 patients, respectively. Overall detection rate of clipped node was 94.9% (95%CI, 91.3%-97.4%) and FNR of TAD was 12.2% (95%CI, 6.0%-21.3%) in our study, with FNR decreasing to 6.0% (95%CI, 1.7%-14.6%) in initially cN1 patients. During a median follow-up of 36.6 months, 3 nodal recurrences occurred (3/237 with ALND; 0/85 with TAD alone), with a three-year freedom-from-nodal-recurrence rate of 100.0% among the TAD-only patients and 98.7% among the ALND patients with axillary pathologic complete response (P=0.29). Conclusions: TAD is feasible in initially cN1 breast cancer patients with biopsy-confirmed nodal metastases. ALND can safely be foregone in patients with negativity or a low volume of nodal positivity on TAD, with a low nodal failure rate and no compromise of three-year recurrence-free survival.