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.