Confocal Endoscopic Microscopy for Detection of Early Stage Gastric Cancer in Subjects With Hereditary Diffuse Gastric Cancer Syndrome

Background: Hereditary Diffuse Gastric Cancer (HDGC) syndrome is caused by a germline mutation in the Cadherin 1 (CDH1) gene. Carriers of this mutation have a 56-70% lifetime risk of developing gastric adenocarcinoma. Current international guidelines recommend endoscopic screening of CDH1 mutation carriers that consists of systematic biopsies of an otherwise normal appearing stomach. However, this approach lacks sufficient sensitivity for detecting intramucosal foci of signet ring cells (SRC), which are pathognomonic of HDGC syndrome. The goal of the current study is to utilize confocal endoscopic microscopy (CEM) for screening the gastric mucosa in this high-risk population. Objective: Determine if confocal endoscopic microscopy (CEM) will afford greater sensitivity for detection of signet ring cells (SRC) foci in CDH1 germline mutation carriers. Eligibility: CDH1 germline mutation carriers, or those who meet clinical criteria for HDGC testing but have tested negative for a CDH1 gene mutation or those who have other germline mutations suspected to be, or reported to be, associated with HDGC (e.g. Catenin Alpha 1 (CTNNA1). Design: Phase II, single-institution study of CEM for detection of intramucosal SRC foci compared to current systematic gastric mapping procedure.