Multi-institutional evaluation of sentinel lymph node (SLN) examination by one-step nucleic acid amplification (OSNA) assay in breast cancer: Performance of metastases detection and prediction of additional non-sentinel lymph node (non-SLN) involvement.

Abstract

1040 Background: Although sentinel lymph node biopsy (SLNB) is a common procedure in treatment of early stage breast cancer, SLN examination protocols have not been standardized. OSNA assay is a semi-automated lymph node examination method using molecular biological technique and has been valued as a tool for the intraoperative SLN examination with potential for standardization. Also, OSNA assay is quite unique in providing semi-quantitative result (++/+) reflecting volume of metastatic foci by measuring the amount of CK19mRNA in a lymph node. This study evaluated clinical utility of OSNA assay in the clinical setting at 10 institutes in Japan. Methods: 415 clinically node negative breast cancer patients scheduled for SLNB were enrolled. Each surgically-obtained SLN was applied to both postoperative pathological examination and OSNA assay; a central slice of each SLN with 1 mm thickness was applied to pathological examination for one section H&E staining, and the residual portion was applied to OSNA assay...