Diagnostic Accuracy of Axillary Ultrasound in Early-Stage Breast Cancer

Abstract

Sentinel lymph node biopsy is the standard application for evaluating the axilla in patients with breast cancer. The Z0011 trial conducted by The American College of Surgeons Oncology Group (ACOSOG) revealed that axillary dissection may be redundant in selected patients with positive sentinel node. This raises questions regarding the application of this result to ultrasound-positive patients. This research therefore aimed to evaluate how accurate an ultrasound scan is for axillary node status in early-stage breast carcinoma. The study included 156 newly diagnosed clinical T1-T2, N0 breast cancer patients attending our breast clinic between January 2010 and February 2016. Sentinel lymph node biopsy and axillary lymph node clearance in the presence of sentinel lymph node metastasis was performed on all the breast cancer patients. Axillary ultrasound reports were reviewed retrospectively and the results compared with surgical pathology results. The sensitivity and specificity of axillary ultrasound for detecting axillary lymph node disease was 69.2% and 98%, respectively, with a negative predictive value of 86.4% and positive predictive value of 94.7%. Given the high sensitivity and specificity, and high positive predictive value and negative predictive value demonstrated in the present study, axillary ultrasound represents a potential alternative to sentinel lymph node biopsy for staging of the axilla in early breast cancer. Subsequent trials (SOUND) comparing axillary ultrasound alone with sentinel lymph node biopsy in early breast cancer patients will provide additional information about the subject.