DNA Mismatch Repair Proteins and BRAF V600E Detection by Immunohistochemistry in Colorectal Cancer Demonstrates Concordance with Next Generation Sequencing

Background and Aims: Multiple laboratory methods are used to screen patients with colorectal cancer (CRC) for mismatch repair (MMR) protein deficiency identify possible Lynch syndrome patients. The goal of this study was compare the agreement between ready-to-use immunohistochemistry (IHC) assays MLH-1, PMS-2, MSH-2, MSH-6, mutated BRAF at V600E molecular in CRC cases. inclusion mutation testing is important identification sporadic CRC, as very rarely observed tumors. Methods: cases were analyzed by ColoSeqTM tumor sequencing assay VENTANA MMR IHC Panel that included anti-MLH1, anti-PMS2, anti-MSH2, anti-MSH6, anti-BRAF antibodies. Additionally, MLH1 loss evaluated promoter hypermethylation. Results: One hundred eighteen analyzed. overall percent (OPA) each marker status compared next-generation (NGS) exceeded 96%. Twenty-three positive NGS, twenty showed Samples expression demonstrated genetic and/or epigenetic alterations consistent patterns. Conclusions: results indicate can correctly proteins presence protein, supporting utility an aid stratify vs. potential syndrome.