Random biopsies in patients harboring a CDH1 mutation: time to change the approach?

hereditary diffuse gastric cancer (HDGC) can be caused by a CDH1 mutation. It often presents as multiple foci of signet ring cell carcinoma (SRCC) that is rarely detected by gastroscopy. Prophylactic total gastrectomy is recommended at a young age. The aim of this study was to determine the adequacy of gastroscopy according to the Cambridge protocol in patients with a CDH1 mutation. patients with a CDH1 mutation admitted to our department between September 2016 and October 2018 were evaluated. All patients underwent a baseline gastroscopy according to the Cambridge protocol, followed by a recommended total gastrectomy. Endoscopic findings, the number of biopsies and histological evaluation of biopsy samples were registered. Postoperative histopathological assessment was compared with endoscopic findings in patients that underwent a total gastrectomy (n = 13). twenty-five patients were included and 35 gastroscopies performed. On these, 996 gastric biopsies were performed, which included 952 random and 44 targeted. Only three patients had SRCC foci in random biopsies and one also had SRCC lesions in two targeted biopsies. In our cohort, 332 random and 22 targeted biopsies were needed to identify a single SRCC focus. Total gastrectomy was performed in 13 patients and SRCC foci were identified in 12 surgical specimens, the remaining specimen had a precursor lesion of HDGC. gastroscopy has a poor sensitivity to detect SRCC. Even with Cambridge protocol, gastroscopy has a very limited role in the surveillance of patients with a CDH1 mutation and prophylactic total gastrectomy is the most advisable option. Nevertheless, endoscopic protocols should be optimized to favor targeted biopsies over a high number of random biopsies.