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 TLN biopsy and TAD in routine clinical practice. BACKGROUND DATA: TAD involves TLN biopsy (TLNB) and sentinel lymph node biopsy and was recently introduced as a new standard for less invasive axillary staging in 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 nderwent clip insertion into the most suspicious axillary lymph node were eligible. Axillary surgery was performed with or without sentinel lymph node biopsy, TLNB, and/or axillary lymph node dissection (ALND). Main endpoints were the detection rate and FNR of TLNB and TAD after NST. RESULTS: Between 2017 and 2018, 548 consecutive BC patients underwent clip placement into biopsy-confirmed positive lymph nodes. After NST (n = 473), the clipped TLN was intraoperatively resected in 329 of 423 patients [77.8%, 95% confidence interval (CI): 74.0-82.0]. TAD was successful in 199 of 229 patients (detection rate: 86.9%, 95% CI: 81.8-91.0), the SLN and TLN were identical in 129 patient (64.8%). FNRs were 7.2% (8 of 111, 95% CI: 3.1-13.6) for TLNB followed by ALND (n = 203) and 4.3% (2 of 46, 95% CI: 0.5-14.8) 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.

Prospective, Multicenter, Randomized Phase III Trial Evaluating the Impact of Lymphoscintigraphy as Part of Sentinel Node Biopsy in Early Breast Cancer: SenSzi (GBG80) Trial.

PURPOSE: The aim of the current work was to clarify whether a preoperative lymphoscintigraphy (LSG) enhances staging accuracy of sentinel lymph node biopsy (SLNB). PATIENTS AND METHODS: In a prospective, multicenter, randomized phase III trial, patients with cN0 early breast cancer or extensive/high-grade ductal carcinoma in situ planned for standard radioactive-labeled colloid LSG with subsequent SLNB were randomly assigned 1:1 to receive SLNB either with knowledge of the LSG findings or without. As the false-negative rate of SLNB correlates with the number of resected sentinel lymph nodes (SLNs), our primary end point was the mean number of histologically detected SLNs per patient. One thousand one hundred two evaluable patients were necessary to demonstrate noninferiority of SLNB without LSG. Stratified one-sided 95% CI for the difference (without LSG - with LSG) in the mean number of histologically detected SLNs had to be greater than -0.27 (10% noninferiority margin). Stratification was performed according to tumor focality and trial site. Additional predefined secondary end points (rates of node-positive patients and of completion axillary lymph node dissection) were analyzed to rule out differences in the reliable detection of nodal metastases. RESULTS: Between May 2014 and October 2015, 1,198 patients were randomly assigned in 23 German and Swiss breast centers. Modified intention-to-treat analysis (n = 1,163) showed a mean number of histologically detected SLNs of 2.21 with LSG and 2.26 without LSG (difference 0.05; stratified 95% CI, -0.18 to infinity), thus establishing noninferiority of omitting preoperative LSG. Secondary end points displayed no statistically significant differences. CONCLUSION: We show that SLNB is equally effective irrespective of the surgeon's knowledge of preoperative LSG results. SLNB without LSG will speed up the preoperative workflow and reduce cost.