Andrew Pieri

Abstract P2-01-14: Pre-operative axillary staging results in over-treatment in some breast cancer patients

Introduction Following a diagnosis of breast cancer, pre-operative ultrasound staging of the axilla is recommended. Patients found to have metastatic disease on biopsy or FNA can proceed directly to axillary clearance (ALNC) at the time of their breast tumour excision. However, although ultrasound staging is a sensitive test to detect axillary disease, it does not differentiate between low and high volume nodal metastasis. Recent evidence suggests that, in selected patients with low volume axillary disease following SLNB, completion ALNC may be safely omitted. This has been reflected in the recently updated ASCO guidelines. In light of this current trend towards axillary conservation, some patients undergoing ALNC after positive axillary staging may be over-treated. The aims of this study is to establish the nodal burden of patients undergoing ALNC following positive axillary staging and to compare the nodal burden of those patients with those undergoing completion ALNC after a positive SLNB. Methods Data was collected prospectively over 12 months from nine hospitals within the North of England Cancer Network. Age, tumour characteristics, breast operation, axillary staging results, axillary operation(s) and nodal results were recorded. Results A total of 1010 patients with breast cancer underwent pre-operative axillary staging. 215 patients (21%) had an ALNC. Of these, 115 (53%) cases underwent a primary ALNC after positive staging. The remaining 100 (47%) patients had a completion ALNC following a positive SLNB. The nodal burden for patients undergoing ALNC is shown in the table below: Analysis of the data revealed that tumour size was a significant predictor of low volume axillary disease (i.e. Conclusion In this study, 46% of patients undergoing ALNC after positive staging had low volume disease (2 or less positive nodes). In the context of recent evidence if these patients had undergone a SLNB following the positive pre-operative staging they may have avoided a completion ALNC. This study demonstrates tumour size to be a significant predictor of low volume axillary disease and thus may be an important factor to consider alongside pre-operative staging when selecting patients who may be better managed by a SLNB rather than proceeding directly to ALNC. Citation Format: Andrew Pieri, Henry Cain, Sebastian Aspinall. Pre-operative axillary staging results in over-treatment in some breast cancer patients [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P2-01-14.