Sentinel node staging for breast cancer: intraoperative molecular pathology overcomes conventional histologic sampling errors

Background: When sentinel node dissection reveals breast cancer metastasis, completion axillary lymph node dissection is ideally performed during the same operation. Intraoperative histologic techniques have low and variable sensitivity.. A new intraoperative molecular assay (GeneSearch BLN Assay; Veridex, LLC, WarTen, NJ) was evaluated to determine its efficiency in identifying significant sentinel lymph node metastases (>.2 mm). Methods: Positive or negative BLN Assay results generated from fresh 2-mm node slabs were compared with results from conventional histologic evaluation of adjacent fixed tissue slabs. Results: In a prospective study of 416 patients at 11 clinical sites, the assay detected 98% of metastases > 2 mm and 88% of metastasis greater >.2 mm, results superior to frozen section. Micrometastases were less frequently detected (57%) and assay positive results in nodes found negative by histology were rare (4%). Conclusions: The BLN Assay is properly calibrated for use as a stand alone intraoperative molecular test. (c) 2007 Excerpta Medica Inc. All rights reserved.