Is there an immunohistochemical technique definitively valid in epidermal growth factor receptor assessment

摘要: Immunohistochemistry (IHC) is required for the selection of patients a monoclonal antibody based targeted treatment with C225 (Erbitux). To validate usefulness IHC, confirmation assays and scoring systems are mandatory. In an attempt to standardize immunohistochemical detection epidermal growth factor receptor (EGFR), we retrospectively evaluated three commercially available EGFR kits or antibodies analyzed discrepancies between tests in terms percentage positive cells, intensity, cut-off value fixatives. We extracted 232 paraffin-embedded samples from metastatic colorectal cancer clinical trial. For all cases, expression was assessed FDA approved Dako pharmaDx kit, Zymed kit Ventana 3C6 antibody. Different values were tested, intensity scored 0, 1+, 2+, 3+ following Dako's recommendations. The cases varied 93 75% 1% 80 61% 5% cells 72% 48% 10%. Both more sensitive than test (Ventana >Dako; p Dako; p=2.10(-6)). No difference noted (p=0.75). A high concordance observed 3 evaluation intensities. use system combining not useful as staining correlated cells: (p<10(-6)) (p<10(-5)). interaction identified any fixatives, nature received (i.e. slides vs blocks, biopsies surgical specimens). Our data showed higher detected by tests, whatever positivity. showed, date, its accuracy, studies have be conducted response cetuximab, possibly correlation FISH amplification carcinoma.