Eduard-Alexandru Bonci

PURPOSE: Surgical axillary staging in patients with node-positive breast cancer (BC) who converted to clinical node negativity through neoadjuvant chemotherapy (NACT) has changed significantly in recent years. Targeted axillary dissection (TAD) and target lymph node (TLN) biopsy (TLNB) became increasingly popular. However, data comparing marking techniques for the TLN are limited. Here, we evaluate marking techniques in the largest prospective cohort worldwide. MATERIALS AND METHODS: Among patients from the ongoing prospective multicenter AXSANA (EUBREAST-03) study who received TLN marking and TAD/TLNB, we evaluated different marking methods with respect to detection and removal rates and clinical performance. RESULTS: Until January 6, 2025, 6,129 patients from 26 countries were enrolled. Of these patients, 2,596 had ≥1 TLN marked before NACT and completed surgery; 13.3% of the patients had ≥4 suspicious nodes at diagnosis. Pre-NACT TLN marking used a clip in 2,003 patients (77.2%), magnetic seed in 287 (11.1%), carbon ink in 192 (7.4%), radar marker in 119 (4.6%), radioactive seed in 18 (0.7%), radiofrequency identification device (RFID) in 12 (0.5%), or other methods in two (0.1%). One TLN was marked in 2,427 patients (93.5%), two TLNs in 138 (5.3%), and ≥3 in 27 patients (1%). Targeted removal of the TLN was planned in 2,100 patients (80.9%; TAD in 2,076 [80.0%] and TLNB in 24 [0.9%]). The TLN was detected and removed by TAD/TLNB in 1,915 patients (91.2%). TLN detection rate was the highest in patients whose TLNs were marked pre-NACT with markers suitable for probe-guided detection (96.6%; radioactive seed: 100%, magnetic seed: 96.9%, radar marker: 96.1%, RFID: 90%), followed by carbon ink (94.9%) and clip (89.6%; P < .001). CONCLUSION: This large prospective analysis of patients with initially clinically node-positive BC receiving NACT demonstrates that probe-guided detection markers used to mark metastatic nodes before NACT provide superior detection rates.

Background: Completion axillary lymph node dissection (cALND) is often recommended for patients with isolated tumour cells (ITCs) or micrometastases in the sentinel lymph node (SLN) or target lymph node (TLN) to assess the definite nodal tumour burden after neoadjuvant chemotherapy (NACT). The aim of this study was to investigate the upgrade of N stage by cALND in patients with low-volume metastases in the SLN/TLN after NACT from the prospective, international, multicentre AXSANA cohort study. Methods: NACT-treated patients that converted from a positive to a negative clinical lymph node status and underwent cALND based on low-volume SLN/TLN involvement were included. The association between the final N stage, the pathological tumour response in the breast, and the clinical impact of cALND on post-NACT treatment decisions was determined. Results: Among 5329 patients recruited between June 2020 and March 2024, 2194 were scheduled for SLN biopsy (SLNB), targeted axillary dissection (TAD), or TLN biopsy (TLNB). Among 16 patients with ypN0i+(SLN/TLN), one patient was upgraded to ypN1a by cALND, while five of the 71 patients with ypN1mi(SLN/TLN) were upstaged to ypN2 and one of the 71 patients with ypN1mi(SLN/TLN) was upstaged to ypN3. None of these patients had a pCR in the breast and thus nodal upstaging had no impact on post-NACT treatment decisions. Conclusion: Despite substantial additional nodal involvement in low-volume SLN/TLN disease, cALND does not provide clinically meaningful information for post-NACT systemic treatment modifications and should not be encouraged for diagnostic purposes alone.