Impact of clinicopathological factors on sensitivity of axillary ultrasonography in the detection of axillary nodal metastases in patients with breast cancer

Background: Ultrasonography and fine-needle aspiration (FNA) are used to evaluate the breast and regional nodes in breast cancer patients. We sought to identify factors influencing the sensitivity of ultrasonography for detection of nodal metastasis. Methods: Patients with a clinically negative axilla who underwent axillary ultrasonography and sentinel lymph node biopsy were included. Results: Of 208 patients, axillary ultrasonography was negative in 180 (86%) and suspicious or indeterminate in 28 (14%). FNA was performed in 22 patients whose findings were indeterminate or suspicious, and 3 were positive for malignancy. Final pathological examinations revealed positive nodes in 53 patients: 39 (22%) of 180 with negative ultrasonographic findings and 14 (50%) of 28 with indeterminate or suspicious ultrasonographic findings (P = .001). Excisional biopsy was more common for patients with indeterminate or suspicious findings on preoperative ultrasonography (P = .038). There were no significant differences in tumor size, histological features, size of nodal metastasis, or number of positive nodes between patients whose ultrasonography findings were negative and those whose findings were indeterminate or suspicious. Conclusions: Ultrasonographically suggested nodal metastasis is associated with the finding of nodal disease on final pathological examination. No significant clinicopathologic criteria were found to impact sensitivity of ultrasonography; however, excisional biopsy for diagnosis may be a confounding variable in subsequent axillary ultrasonography.