A comparison of the yield from endoscopic surveillance in detecting early gastric cancer in CDH1+ve versus CDH1-ve HDGC families
Session type: Poster / e-Poster / Silent Theatre session
Theme: Epidemiology and prevention
Germline CDH1 (E-cadherin) mutation is present in 40% of individuals fulfilling the criteria for Hereditary Diffuse Gastric Cancer (HDGC) and confers 80% lifetime risk of gastric cancer. Current guidelines advise prophylactic gastrectomy for CDH1-positive individuals but endoscopic surveillance is recommended for patients delaying gastrectomy, due to comorbidity or psychosocial reasons, and for individuals from CDH1-negative families fulfilling HDGC criteria (van der Post et al J Med Genet 2015). This study aimed to determine the endoscopic yield of signet ring cell foci (SRCF) according to CDH1 mutation status.
A prospective cohort study of 54 CDH1+ve and 31 CDH1-ve patients fulfilling HDGC criteria undergoing 175 endoscopies (CDH1+ve: 103; CDH1-ve: 72) according to the Cambridge HDGC protocol (van der Post et al 2015). The median (IQR) follow up, in months, was 16.0 (3.5-39.0) (CDH1+ve: 11.0 (3.0-28.3); CDH1-ve: 27.0 (7.0-48.0)). Data on patient age, gender, ethnicity, H. pylori status and PPI use was collected. The outcome was time to detection of SRCF from first endoscopy. Kaplan-Meier analysis with log rank test and Cox regression on CDH1 status, age and ethnicity were performed.
Between the CDH1+ve and –ve group, there was no significant difference in gender (p=0.637), H. pylori status (p=0.094) or PPI use (p=0.810), but there was a significant difference in median age (34.5 vs 45, p=0.026) and ethnicity (18.5% vs 0% Asian, p=0.012). CDH1+ve patients had significantly higher progression to endoscopic detection of SRCF (p=0.000) than CDH1-ve patients, with over 12-fold increased risk of SRCF on endoscopy (HR 12.2, 95% Cl 2.8-52.8, p=0.001). On Cox regression, age (p=0.811) and ethnicity (p=0.733) were not associated with risk of SRCF. In the CDH1-ve group, only 2 related individuals ever had SRCF detected.
There is very low endoscopic yield of SRCF in CDH1-ve patients. The value and frequency of surveillance in this group should be reconsidered.