A Prospective, Multicenter Registry Study to Evaluate the Clinical Feasibility of Targeted Axillary Dissection (TAD) in Node-positive Breast Cancer Patients

Objective This study aimed to investigate the feasibility and accuracy of non-radioactive target lymph node (TLN) biopsy and targeted axillary dissection (TAD) in routine clinical practice. Background data TAD involves TLN biopsy (TLNB) and sentinel lymph node biopsy (SLNB) and was recently introduced as a new standard for less invasive axillary staging in breast cancer (BC) patients undergoing neoadjuvant systemic therapy (NST); however, clinical evidence is limited. Methods The SenTa study is a prospective registry study conducted at 50 centers. Patients with invasive BC who underwent clip insertion into the most suspicious axillary lymph node (LN) were eligible. Axillary surgery was performed with or without SLNB, TLNB, and/or axillary lymph node dissection (ALND). Main endpoints were the detection rate (DR) and false-negative rate (FNR) of TLNB and TAD after NST. Results Between 2017 and 2018, 548 consecutive BC patients underwent clip placement into biopsy-confirmed positive LNs. After NST (n = 473), the clipped TLN was intraoperatively resected in 329 of 423 patients (77.8%, 95% confidence interval [CI]: 74.0 to 82.0). TAD was successful in 199 of 229 patients (DR: 86.9%, 95% CI: 81.8 to 91.0), the SLN and TLN were identical in 129 patient (64.8%). FNRs were 7.2% (8 of 111, 95% CI: 3.1 to 13.6) for TLNB followed by ALND (n = 203) and 4.3% (2 of 46, 95% CI: 0.5 to 14.8) for TAD followed by ALND (n = 77). Conclusions The SenTa study demonstrates the feasibility of TAD in a real-world cohort of BC patients. Our findings are of great importance for de-escalation of surgical strategies.