Surgical MArker Localization OR clip and wire application for targeted axillary dissection in node-positive breast cancer patients – Results from the randomized superiority MALLORCA-trial

BACKGROUND: In node-positive breast cancer patients undergoing neoadjuvant therapy (NAT), targeted axillary dissection (TAD) combining sentinel lymph node (SLN) biopsy and removal of a pretherapeutically marked metastatic node is increasingly used to adequately stage the axilla, thereby omitting axillary lymph node dissection (ALND). Reliable localization of the clipped node is critical, however no prospective randomized comparisons of available marking systems have been published. METHODS: In this prospective randomized multicenter trial, 42 patients with biopsy-proven axillary metastases received NAT and were randomly assigned to either application of a gel-embedded clip (HydroMARK™; arm A) or a magnetic surgical marker (Pintuition®; arm B) marking. After NAT, TAD was performed. Primary endpoint was efficacy (success rate, procedure time). Secondary outcomes included safety, marking reliability, and surgical handling. Marker-to-SLN concordance and axillary pathological complete response (pCR) were also observed. RESULTS: Marker localization during surgery was successful in 36/42 cases. Magnetic surgical markers resulted in higher reliability, significantly shorter procedure duration (12.7 min vs. 19.3 min) and higher surgeon satisfaction (mean 9.1 vs. 6.8 out of 10; p < 0.01). Intraoperative clip loss occurred in 3 cases (all arm A), with additional dislocations in 3 others (2 in arm A, 1 in arm B). No significant differences were found regarding adverse events or SLN concordance (64 % overall). Axillary pCR was observed in 55 % of patients. CONCLUSION: Magnetic surgical markers showed clear advantages for TAD after NAT in procedural efficiency, reliability, and intraoperative handling compared to gel-embedded clips. Marker selection should consider technical, procedural, and imaging-related factors.