Pre-Operative Axillary Nodal Staging by Ultrasonography and Fine-Needle Cytology Reduces the Number of Unnecessary Sentinel Node Biopsies in Breast Cancer Patients.

Abstract

Abstract Aims: The role of pre-operative axillary ultrasound for nodal staging in early breast cancer patients is evolving. In this study, we evaluated the role of axillary ultrasound (AUS) and fine-needle aspiration cytology (FNAC) to stage the axilla pre-operatively in a large series of operable breast cancer patients including its role in the detection of nodal micrometastases. A second objective was to ascertain whether a significant learning curve is associated with this technique.Methods: Between October 2006 and March 2009, all patients diagnosed with invasive breast cancer in our unit had an AUS pre-operatively. Patients with suspicious nodes on ultrasound underwent FNAC. Cytology positive patients proceeded directly to axillary clearance, while others underwent sentinel lymph node biopsy. Data from this retrospective study was analyzed using appropriate statistical techniques to evaluate the efficacy of this technique to detect nodal metastases pre-operatively.Results: 495 patients scheduled to undergo surgery for invasive breast cancer were included in this study. 7 patients had bilateral malignancies and, therefore, a total of 502 axillae were examined using ultrasound. The median age of patients in our study was 61 years (range 32-91). 137 patients (27.3%) had proven nodal metastases on final histology. 39 of 137 (28.5%) node positive patients were accurately identified by pre-operative AUS and FNAC and, therefore, spared an unnecessary sentinel node biopsy. The combined technique of AUS and FNAC had an overall accuracy of 80.5% (95% CI: 76.8-83.7), sensitivity of 28.5% (95% CI: 21.6-36.5), specificity of 100% (95% CI: 99-100), positive predictive value of 100% (95% CI: 91-100), and negative predictive value of 78.8% (95% CI: 74.9-82.3). Pre-operative AUS and FNAC was normal in all patients with nodal micrometastases (n=15) and isolated tumour cells (n=11) on histopathology. No significant learning curve was demonstrated for this technique in our study. Overall, 28.5% of node positive patients and 7.9% of all breast cancer patients avoided an unnecessary sentinel node biopsy due to this procedure.Conclusions: Pre-operative AUS and FNAC is an inexpensive, minimally-invasive outpatient procedure with an accuracy of more than 80% that can avoid unnecessary sentinel lymph node biopsy in 28.7% of node positive patients. It has no role in the detection of nodal micrometastases and there is no demonstrable learning curve seen with this technique. Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 1018.