Purpose: To evaluate the accuracy of preoperative ultrasonography (US) and US-guided fine-needle aspiration (US-FNA) for detecting axillary lymph node (ALN) metastasis.
Patients and methods: We retrospectively reviewed 382 breast cancer patients with clinically negative ALN who underwent US and/or US-FNA for ALN. US-FNA of ALN was performed in 121 patients with suspicious findings on US. The diagnostic performance of US alone or with the addition of US-FNA for detecting ALN metastasis was calculated on the basis of final pathologic reports of ALN surgery.
Results: Among a total of 382 patients, 129 had metastatic ALNs while 253 exhibited no signs of axillary metastasis on final pathology. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of axillary US alone were 56.6% (73/129), 81.0% (205/253), 60.3% (73/121), and 78.5% (205/261), respectively. Addition of US-FNA resulted in sensitivity, specificity, PPV, and NPV of 39.5% (51/129), 95.7% (242/253), 82.3% (51/62), and 75.6% (242/320), respectively. Excluding complete responders to neoadjuvant chemotherapy, specificity and PPV after adding US-FNA were increased to 99.6% (242/243) and 98.1% (51/52), respectively. The sensitivity and specificity of ALN metastasis were similar between the palpable and nonpalpable breast cancer groups; however, after adding US-FNA, NPV was increased in the nonpalpable breast cancer group compared with the palpable breast cancer group (p = 0.0398). By including preoperative axillary US and US-FNA, 16.2% (62/382) of all breast cancer patients were able to avoid unnecessary sentinel lymph node biopsy (SLNB).
Conclusions: The combination of axillary US and US-FNA is useful in preoperative work-up of breast cancer patients and provides valuable information for planning proper breast cancer management.