Advancing the Evaluation and Management of CDH1-Associated Gastric Cancer.

Gastric cancer is a significant global health concern, with CDH1-associated gastric cancer representing a small but important subset of cases. Historically, individuals with CDH1 pathogenic germline variants were advised to undergo prophylactic total gastrectomy due to the high reported risk of gastric cancer and the limited sensitivity of upper endoscopy in detecting signet ring cell carcinoma (SRCC). However, emerging data suggest that the cumulative lifetime risk of advanced gastric cancer among CDH1 germline pathogenic variant carriers is lower than previously thought, and early-stage SRCC detected on endoscopy does not necessarily indicate imminent-or even eventual-progression to advanced cancer. The near-universal presence of T1a SRCC in gastrectomy specimens from asymptomatic CDH1 pathogenic variant carriers calls into question the reflexive recommendation for gastrectomy, including upon detection of SRCC during surveillance. Furthermore, the morbidity and quality-of-life impact associated with total gastrectomy require careful consideration. Active endoscopic surveillance has shown promise as an alternative management strategy for gastrectomy in patients lacking indicators of >T1a SRCC, though current data are limited by short follow-up periods and selection bias. This review synthesizes recent findings on the natural history of CDH1-associated gastric cancer and evaluates the risks and benefits of gastrectomy versus active endoscopic surveillance, with the goal of helping clinicians provide personalized and evidence-based recommendations for patients with CDH1 pathogenic variants.