Comparing Methods for Targeted Axillary Dissection in Breast Cancer Patients: A Nationwide, Retrospective Study

Area of Science:

• Oncology
• Surgical Oncology
• Breast Cancer Research

Background:

• Targeted axillary dissection (TAD) is used post-neoadjuvant chemotherapy to remove sentinel nodes and marked metastatic lymph nodes (LNs).
• Two-step TAD involves initial coil-marking of metastatic LNs followed by intraoperative re-marking.
• Successful TAD is critical, as non-detection of marked lymph nodes (MLNs) necessitates axillary clearance, particularly when patients achieve pathological complete response (ax-pCR).

Purpose of the Study:

• To compare the effectiveness of various two-step TAD methods in a Danish national cohort.
• To evaluate the impact of different re-marking techniques on lymph node identification rates.
• To assess the overall success rate of complete TAD.

Main Methods:

• A retrospective analysis of 543 patients who underwent two-step TAD between January 1, 2016, and August 31, 2021.
• Data extracted from the Danish Breast Cancer Group database and patient medical files.
• Comparison of hook-wire, iodine seeds, and ink marking for secondary re-marking.

Main Results:

• Preoperative ultrasound-guided re-marking was successful in 79.4% of patients.
• Non-identification of the coil-marked LN was more common in patients with ax-pCR.
• The marked lymph node (MLN) identification rate was 91% and sentinel node (SN) identification rate was 95% following successful secondary marking.
• Iodine seed marking demonstrated significantly higher success rates (OR 5.34) compared to ink marking.
• The overall success rate for complete TAD (removal of MLN and SN) was 82.3%.

Conclusions:

• Two-step TAD frequently results in non-identification of the coiled LN, particularly in patients with ax-pCR.
• Despite successful re-marking, the intraoperative identification rate of the MLN is lower compared to one-step TAD.
• Iodine seed marking is a more effective secondary marking technique than skin ink marking.