Comparative Molecular Analyses of Esophageal Squamous Cell Carcinoma, Esophageal Adenocarcinoma, and Gastric Adenocarcinoma

AbstractBackground.Gastroesophageal cancers are often grouped together even though cancers that originate in the esophagus often exhibit different histological features, geographical distribution, risk factors, and clinical characteristics than those originating in the stomach. Herein, we aimed to compare the molecular characteristics of three different gastroesophageal cancer types: esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), and gastric adenocarcinoma (GAC).Subjects, Materials, and Methods.In total, 3,342 gastroesophageal cancers were examined. Next‐generation sequencing was performed on genomic DNA isolated from formalin‐fixed paraffin‐embedded tumor samples using the NextSeq platform. Tumor mutational burden was measured by counting all nonsynonymous missense mutations, and microsatellite instability was examined at over 7,000 target microsatellite loci. Immunohistochemistry and in situ hybridization techniques were also performed.Results.When compared with EAC and GAC, ESCC showed significantly lower mutational rates within APC, ARID1A, CDH1, KRAS, PTEN, and SMAD4, whereas more frequent mutations were observed in BAP1, CDKN2A, FOXO3, KMT2D, MSH6, NOTCH1, RB1, and SETD2. Human epidermal growth receptor 2 (HER2) overexpression was observed in 13% of EAC compared with 6% of GAC and 1% of ESCC (p 
Source: The Oncologist - Category: Cancer & Oncology Authors: Tags: Precision Medicine, Gastrointestinal Cancer Source Type: research