The role of pre-operative axillary ultrasound in assessment of axillary tumor burden in breast cancer patients: a systematic review and meta-analysis

Abstract

Background: Recent studies have suggested that a significant proportion of patients with axillary nodal metastases diagnosed by pre-operative axillary ultrasound (AUS) guided needle biopsy was overtreated with axillary lymph node dissection (ALND). The role of routine AUS and needle biopsy in early breast cancer was questioned. This review aims to determine if pre-operative AUS could predict the extent of axillary tumor burden and the need for ALND. Methods: PubMed and Embase literature databases were searched systematically for abnormal AUS characteristics and axillary nodal burden. Studies were eligible if they correlated the sonographic abnormalities in AUS with the resultant axillary nodal burden in ALND according to the ACOSOG Z0011 criteria. Result: Eleven retrospective studies and one prospective study with 1658 patients were included. Sixty-five percent of patients with one abnormal lymph node in AUS and 56% of those with two had a low axillary nodal burden. Using one abnormal lymph node as the cut-off, the pooled sensitivity and specificity in prediction of axillary nodal burden were 66% (95% CI 63-69%) and 73% (95% CI 70-76%), respectively. Across the six studies that evaluated suspicious nodal characteristics, the increased nodal cortical thickness may be associated with high axillary nodal burden. Conclusions: More than half of the patients with pre-operative positive AUS and biopsy-proven axillary nodal metastases were over-treated by ALND. Quantification of suspicious nodes and extent of cortical morphological changes in AUS may help identify suitable patients for sentinel lymph node biopsy.