Outcomes of screening gastroscopy in first-degree relatives of patients fulfilling hereditary diffuse gastric cancer criteria

Background and Aims: The aim of this study was to determine the yield of endoscopic screening in first-degree relatives (FDRs) of CDH1-negative hereditary diffuse-type gastric cancer (HDGC) patients. Methods: In this retrospective observational cohort study, in 2 expert centers in the Netherlands data were collected on FDRs from families fulfilling the international HDGC criteria that underwent endoscopic screening. Extensive inspection of the stomach was performed by gastroscopy, taking random and/or targeted stomach biopsy specimens to identify diffuse-type gastric cancer. Results: Between 2004 and 2016, 90 persons (40% men; mean age, 48 years) from 40 families were offered endoscopic screening. The mean number of endoscopies per person was 3. The mean follow-up time was 46 months and mean endoscopic interval 20 months. Signet ring cell carcinoma foci restricted to the mucosa (pT1a) were identified in 4 persons (4%) from 1 family, which afterward was diagnosed with a germline CTNNA1 mutation. Advanced poorly cohesive gastric carcinoma was diagnosed in 1 person from another family. Intestinal metaplasia was diagnosed in 38 persons (42%) and low-grade dysplasia in 4 persons (4%). Additionally, in 40 persons (44%) scar tissue was observed in the gastric mucosa, which can hinder the endoscopic detection of small white lesions typical for HDGC. Conclusions: Endoscopic screening in HDGC families without a pathogenic CDH1 mutation may be reasonable, as we detected signet ring cell carcinomas in 6% of persons screened. However, the criteria and frequency of screening may have to be reconsidered