The role of ultrasound guided core biopsy of axillary nodes in predicting macrometastases and avoiding overtreatment outside ACOSOG Z0011 parameters

Background Z0011 study suggests patients with minimal disease do not require axillary clearance. Exclusions include T3 tumours, mastectomy or neoadjuvant treatment. This study assessed the utility of pre-operative US-guided core biopsy of axillary nodes and its correlation with nodal macrometastases. Methods 247 women with breast cancer outside Z0011 criteria were reviewed retrospectively. Sensitivity and specificity of pre-operative axillary ultrasound and core biopsy compared to final histology was assessed by contingency tables. Results 75/247 patients had macrometastases. Ultrasound-axilla was 72% sensitive and 77% specific in predicting macrometastasis. The positive (PPV) and negative predictive value (NPV) was 58% and 86.4% respectively. Core-biopsy of axilla node, was 92.6% sensitive and 66.7% specific in detecting macrometastasis. PPV and NPV 79.4% and 86.7% respectively. Conclusion Positive pre-operative ultrasound-guided core biopsy accurately predicts macroscopic involvement of axillary nodes. Selected patients outside Z0011 parameters can proceed to axillary clearance without sentinel node biopsy or risking overtreatment.