Shortcomings of ultrasound-guided fine needle aspiration in the axillary management of women with breast cancer

Background: Ultrasound, along with ultrasound-guided fine needle aspiration, is currently used for the axillary evaluation of breast cancer patients in order to identify candidates for axillary lymph node dissection. The aim of this study is to evaluate the accuracy of this tool in correctly identifying patients who may or may not benefit from axillary clearance in light of the ACOSOG Z0011 trial recommendations. Methods: One hundred one patients (65 with positive US-FNA with corresponding axillary lymph node dissection (ALND), and 36 with negative US-FNA with corresponding ALND/sentinel lymph node biopsy) were studied for the number of involved axillary lymph nodes, tumor clinicopathologic features, and axillary radiologic findings. Results: From the positive US-FNA group, 43% of patients had two or fewer positive lymph nodes upon ALND pathologic examination. In the US-FNA negative group, the negative predictive value for detecting axillary disease was 72.7%. With both groups combined, the sensitivity, specificity, PPV, and NPV of US-FNA for selecting patients based on axillary disease burden were 86%, 51.7%, 57%, and 83.3%, respectively. Conclusion: Based on Z0011 guidelines, US-FNA is not a reliable tool in triaging patients in need for ALND and leads to overtreatment of 43% patients when positive, while depriving a small but significant percentage of patients from necessary therapy, when negative.