Predictive Value Of Ultra-High Esr1 Mrna Expression In Early Breast Cancer.

e12045Background: Ultrahigh ESR1 mRNA expression in luminal breast tumors is predictive for benefit from adjuvant tamoxifen compared to placebo treatment in NSABP B14, while protein determination by IHC or LBA is not (Kim et al JCO 2011).The predictive cut-off value at ER score 10 by Oncotype is significantly higher than the diagnostic cut-off at 6.5. Here we tested wether the ultrahigh expression of ESR1 mRNA determined by MammaTyper is predictive for survival after NAC treatment of advanced PBC. Methods: Pretreatment biopsies from n = 54 patients with PBC treated within a randomized NAC phase II trial were examined (2). RNA was extracted from FFPE sections using the RNXtract kit and ESR1 mRNA from each section was measured with the MammaTyper kit (BioNTech Diagnostics GmbH). ESR1 mRNA values by Oncotype DX and MammaTyper from n = 113 surgical samples were compared. Statistical analysis were performed using the SAS JMP 9.0.0 software. Results: Quantification of ESR1 mRNA expression in luminal tumors (n =...