Clinical use of an intra-operative RT-PCR assay for the detection of metastases in sentinel lymph nodes of breast cancer patients at the Institut Jules Bordet

11100 Background: A molecular assay (GeneSearch™ BLN Assay, Veridex, LLC), CE marked and approved by the FDA, has been in clinical use at our institution for over 18 months to intra-operatively detect metastases ≥0.2 mm in the sentinel lymph nodes (SLNs) in breast cancer patients. After a small validation study (N=78, sensitivity = 92.3%, specificity = 96.9%) the assay was adopted as the only intra-operative SLN test used at the Institut Jules Bordet. This is the first report of the post-market assay performance. Methods: One SLN per patient is cut into approximately 2 mm sections. Alternating sections are processed fresh in the BLN assay. The assay detects mRNA expression of mammaglobin and CK19. Predetermined cutoffs are set to detect metastases ≥0.2 mm. The BLN Assay results are used to make intra-operative decisions for same surgery axillary lymph node dissections (ALND). The remaining alternating sections of the SLN are examined later by permanent section H&E. Results: Since August 2006, the BLN Assa...