The Critical Role of Axillary Ultrasound and Aspiration Biopsy in the Management of Breast Cancer Patients with Clinically Negative Axilla

Background Sonographic evaluation of the axilla can predict node status in a significant proportion of clinically node-negative patients. This review focuses on the value of ultrasound followed by ultrasound-guided cytology in assessing the need for sentinel node mapping and conservative versus complete axillary dissections. Design Breast primaries from 168 sentinel node candidates were prospectively assessed for clinicopathologic variables associated with increased incidence of axillary metastases. Patients were classified accordingly, and those at a higher risk underwent ultrasound of their axillae, followed by aspiration biopsy if needed. Sentinel node mapping was performed in all low-risk patients, and in high-risk patients with normal axillary ultrasounds or negative cytology. Final axillary status was compared in terms of nodal stage, number of positive nodes, and size of metastasis. Results 112 patients were at high risk for nodal disease (67%), with a statistically significant lower probability for remaining node-negative and a statistical significantly higher risk for having more than one positive node. All patients with more than three positive nodes were detected by ultrasound-guided cytology. High-risk patients with final positive axillae missed by ultrasound or ultrasound guided cytology had tumor deposits measuring ≤5 mm. Conclusion Extent of axillary dissections can be decided based on the risk for axillary metastases: sentinel node mapping for low-risk patients; less-aggressive axillary dissections for high-risk patients with negative ultrasound and/or negative cytology; and a standard dissection for high-risk patients with positive cytology.