Implementation of the Targeted Axillary Dissection Procedure in Clinically Node-Positive Breast Cancer: A Retrospective Analysis.

BACKGROUND: The targeted axillary dissection (TAD) procedure is used in clinically positive lymph node (cN+) breast cancer to assess whether pathological complete response (pCR) is achieved after neoadjuvant systemic therapy (NST) to decide on de-escalation of axillary lymph node dissection (ALND). In this study, we review the implementation of the TAD procedure in a large regional breast cancer center. METHODS: All TAD procedures between 2016 and 2022 were reviewed. The TAD procedure consists of marking pre-NST the largest suspected metastatic lymph node(s) using a radioactive I-125 seed. During surgery, the marked node was excised together with a sentinel node procedure. Axillary therapy (ALND, axillary radiotherapy, or nothing) recommendations were based on the amount of suspected positive axillary lymph nodes (ALNs < 4 or ≥ 4) pre-NST and if pCR was achieved after NST. RESULTS: A total of 312 TAD procedures were successfully performed in 309 patients. In 134 (43%) cases, pCR of the TAD lymph nodes were achieved. Per treatment protocol, 43 cases (14%) did not receive any axillary treatment, 218 cases (70%) received adjuvant axillary radiotherapy, and 51 cases (16%) underwent an ALND. During a median follow-up of 2.8 years, 46 patients (14%) developed recurrence, of which 11 patients (3.5%) had axillary recurrence. CONCLUSIONS: Introduction of the TAD procedure has resulted in a reduction of 84% of previously indicated ALNDs. Moreover, 18% of cases did not receive adjuvant axillary radiotherapy. These data show that implementation of de-escalation axillary treatment with the TAD procedure appeared to be successful.