Efficacy of Ultrasound-Guided Core Needle Biopsy in Detecting Metastatic Axillary Lymph Nodes in Breast Cancer

Purpose: Axillary lymph node status is an important prognostic factor in breast cancer. Axillary lymph nodes can be evaluated using fine-needle aspiration cytology (FNAC) or core needle biopsy (CNB) before surgery. This study compared the accuracy and false-negative rates between FNAC and CNB in patients with breast cancer who either did or did not receive neoadjuvant chemotherapy (NAC). Methods: The clinicopathological factors of the patients were analyzed retrospectively, and the sensitivity, specificity, positive and negative predictive values, false-positive and false-negative rates, and accuracy of FNAC (n = 27) and CNB (n = 23) were compared. Results: Regardless of whether or not NAC was performed, the CNB evaluation of the metastatic axillary lymph nodes had a 100.0% sensitivity, specificity, negative predictive value, and accuracy, except for one case with an inadequate sample. In the FNAC group, the false-negative rate was higher in patients with breast cancer who received NAC before evaluating the lymph nodes (9.1% vs. 7.7%). Moreover, ultrasound imaging was the most sensitive imaging modality that can detect the suspicious axillary lymph node. Conclusion: CNB was more effective in evaluating the axillary lymph nodes in breast cancer than FNAC and was performed without major complications.