High-sensitivity epidermal growth factor receptor immunostaining for colorectal carcinomas, compared with EGFR PharmDx™: a study of diagnostic accuracy.

摘要: Immunostaining for epidermal growth factor receptor (EGFR) is important in the contemporary therapeutic strategy of colorectal carcinomas. We tried to increase detection sensitivity, and compared high-sensitivity EGFR immunostaining with a worldwide standard, PharmDx™ (Dako). In order pursue detection, deparaffinized sections were pressure-cooked 1 mM EDTA solution, pH 8.0. Two mouse monoclonal antibodies against EGFR, clone EGFR2.5 DAK-H1-WT, six kinds secondary reagents, including biotin-free catalyzed signal amplification (CSA II), Simple Stain MAX-PO, PolyVue, Novolink, EnVision™ FLEX+, MACH3, evaluated compare results those PharmDx™, employing combination 2-18-C9 as primary antibody reagent. Furthermore, we replaced kit CSAII. sensitivity was higher DAK-H1-WT than EGFR2.5, among strongest signals observed Novolink. All 30 carcinomas showed distinct expression our immunostaining, while only 16 (53%) gave focal positivity PharmDx™. When by CSA II, strong seen all cases, pattern comparable sequence. Non-neoplastic crypt epithelial cells often weakly standard but consistently revealed membrane staining two sequences. frequently false negativity. Importantly, sensitively detected when polymer simply II.