SENTinel Node Biopsy before or after NeoAdjuvant Systemic Treatment – The German SENTINA Trial.

Abstract

Background: For patients with breast cancer undergoing neoadjuvant systemic treatment (NST) the optimal timing of sentinel node biopsy (SLNB) is unclear. While adequate axillary staging prior to NST could allow for a-priori tailoring of systemic treatment, SLNB after NST could spare those patients from complete axillary dissection (AD), who are free of metastases in the axilla or convert from a positive (Npos) to a negative (Nneg) axillary status following NST. For these patients, however, the reliability of SLNB to predict the axillary status remains yet to be prospectively confirmed.Material and Methods: The German SENTINA protocol, as a substudy of the German Geparquinto neoadjuvant trial of the AGO and the German Breast Group (GBG), is a 4-arm prospective multicenter case control study designed to examine the role of SLN in patients undergoing NST.Study design:Arm A before NST: clinically Nneg + negative SLN --> no add. Axillary surgery Arm B before NST: clinically Nneg + positive SLN --> sentinel-node-guided AD after NST Arm C before NST: clinically Npos, after NST: clinically Nneg --> sentinel-node-guided AD after NST Arm D before NST: clinically Npos, after NST: clinically Npos --> ADStudy objectives:1. to compare the detection rate of SLNB before and after NST2. to evaluate the number of patients with involved nodes despite being clinically Nneg before NST3. to determine the number of patients who convert from clinically Npos to histologically Nneg after NST4. to evaluate the false-negative rate of SNB for patients who convert from clinically Npos to histologically SNneg after NST5. to determine lymphatic pathway configuration, detection rate and false-negative rate of SLNB after prior SLNB6. to determine the false negative rate of intraoperative frozen section before and after NSTResults: Until now 366 patients from 30 institutions have been enrolled in this trial. 230 patients have completed primary systemic and surgical treatment. A total of 1508 patients were calculated as adequate to have the one-sided confidence interval of 95 % for the false negative rate of SLNB in the arms B and C not exceeding 10% (196 pts each). 82 pts entered arm A. Fifty-eight, 76 and 24 pts were recruited for the arms B, C and D respectively.Conclusion: To our knowledge the SENTINA trial is the first prospective multicenter study to evaluate the role of SLNB in the neoadjuvant setting. The SENTINA protocol will allow for a direct comparison of the feasibility and reproducibility of a standardized SLNB-procedure before and after NST. The study will provide reliable data on the predictive value of SLNB before and after NST in patients converting from a clinically positive to a negative axillary status and offer insights into the biology of axillary response to NST. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1008.

Neoadjuvant (Preoperative) Therapy in Breast Cancer

“…There is a current SNB trial looking at SNB before and after neoadjuvant systemic therapy in Germany called SENTINA (Kuehn et al, 2009). This is a four arm study.…”

Evidence-Based De-Escalation in Axillary Management—Is Less Really More?

“…The landmark Sentinel Neoadjuvant (SENTINA) study and the American College of Surgeons Oncology Group (ACOSOG) Z1071 trial evaluated the accuracy of post-NST SLNB in cN+ disease and found false-negative rates (FNRs) of 14.6% and 12.6%, respectively, raising questions about the safety of SLNB in this population. 1,2 In the ACOSOG Z1071 trial, dual-agent mapping and excision of the clipped node reduced the FNR to 10.8% and 6.8%, respectively. 3 Caudle et al 4 formalized the practice of targeted axillary dissection (TAD), which includes removal of the clipped node with SLNB and demonstrated an FNR of 2%.…”