Comparison of Diagnostic Sensitivity and Procedure-Related Pain of Concurrent Ultrasound-guided Fine-needle Aspiration and Core-needle Biopsy of Axillary Lymph Nodes in Patients with Suspected or Known Breast Cancer.

Objective: Conflicting data exist on the diagnostic sensitivity of core-needle biopsy (CNB) compared to fine-needle aspiration (FNA) in the evaluation of axillary lymph node metastasis from breast cancer. Our purpose was to evaluate the sensitivity of CNB and FNA using subsequent axillary surgery as the gold standard and to compare the patients' subjective pain levels for each biopsy method.

Methods: This IRB-approved prospective study enrolled 140 patients from February 2014 to May 2019 with known or suspected breast cancer. Patients underwent both US-guided FNA and 14-gauge CNB of the same node with clip placement and rated their pain level using a verbal numerical rating scale of 0 to 10. The diagnostic sensitivities were determined by pathology of the surgically excised lymph node using the McNemar test of correlated proportions. Changes in pain scores for CNB and FNA were determined using the Wilcoxon rank sum test.

Results: A total of 94 patients had confirmatory excision of the biopsied node with nodal metastasis detected in 71.3% (67/94). The sensitivity of CNB for detection of nodal metastasis was 95.5% (64/67), while the sensitivity of FNA was 67.2% (45/67) (P < 0.05). Overall pain score ratings for CNB increased by 0.6 from baseline on an 11-point numerical rating scale, while overall pain score rating for FNA decreased by 0.2 from baseline (P < 0.05).

Conclusion: Our study demonstrates that 14-gauge CNB has superior sensitivity for detection of axillary nodal metastases and mildly increased pain compared with 25-gauge FNA in patients with breast cancer.