Intraoperative ultrasound-guided wire(IOUS-wire) localization biopsy versus preoperative fine needle aspiration cytology(FNAC) for early breast cancer with clinically positive nodes, a retrospective cohort study.

Background: The false-negative rate (FNR) of fine needle aspiration (FNA) for clinically positive (suspicious) lymph nodes (LNs) remains excessively high.

Methods: We compared the feasibility and diagnostic efficiency of using a novel procedure to FNA for the assessment of clinically positive nodes in patients with early breast cancer. Between 1 January 2015 and 30 September 2023, 198 consecutive patients who consented to undergo axillary biopsy were referred to either the intraoperative ultrasound-guided wire localization group (IOUS-wire) or the ultrasound-guided fine needle aspiration group (US-FNAC). The primary endpoint was the false-negative rate (FNR) and accuracy rates of the two methods. One hundred patients were in the IOUS-wire group, whereas the other 98 patients were in the US-FNAC group.

Results: The FNR of clinically positive lymph node biopsies was lower in the IOUS-wire localization group than in the US-FNAC group (16.1% versus 87.5%, p < 0.001). Among the 32 successfully identified metastatic lymph nodes, 26 (81.3%) were detected in the IOUS-wire group. In the US-FNAC group, 42 additional lymph node metastases were identified via SLNB among patients initially classified as FNAC-negative. The accuracy rates for IOUS-wire and US-FNAC were 95% and 57.1%, respectively (p < 0.001). No significant differences were observed in complications or median SLNs harvested between groups.

Conclusion: IOUS-wire localization with frozen sections demonstrated superior diagnostic performance compared to preoperative US-FNAC in patients with clinically node-positive early breast cancer. This novel method should be further pursued as a potential biopsy method for evaluating axillary node status, particularly in settings where rapid intraoperative decision-making is prioritized.