Development and Validation of an Easy‐to‐Implement, Practical Algorithm for the Identification of Molecular Subtypes of Gastric Cancer: Prognostic and Therapeutic Implications

AbstractBackground.Gastric cancer (GC) is a heterogeneous disease, and substantial efforts have been made to develop a molecular biology‐based classification system for GC. Analysis of the genomic signature is not always feasible, and thus, we aimed to (i) develop and validate a practical immunohistochemistry (IHC)‐ and polymerase chain reaction (PCR)‐based molecular classification of GC and (ii) to assess HER2 status according to this classification.Materials and Methods.A total of 894 consecutive patients with GC from two individual cohorts (training, n = 507; validation, n = 387) were classified using Epstein‐Barr virus (EBV) in situ hybridization, microsatellite instability (MSI) testing, and IHC for E‐cadherin and p53.Results.We were able to classify patients into five groups in the training cohort: group 1 (MSI+), group 2 (EBV−, MSI−, non‐epithelial‐mesenchymal transition [non‐EMT]‐like, p53−), group 3 (EBV+), group 4 (EBV−, MSI−, non‐EMT‐like, p53+), and group 5 (EBV−, MSI−, EMT‐like). In the training cohort, each group showed different overall survival (OS) after gastrectomy (p
Source: The Oncologist - Category: Cancer & Oncology Authors: Tags: Cancer Diagnostics and Molecular Pathology, Gastrointestinal Cancer Source Type: research