This is a genotype with recommended actions if clinically confirmed. In brief:
- Hereditary diffuse gastric cancer (HDGC) associated with CDH1 mutations is characterized by the development of diffuse (singlet ring cell) gastric cancer.
- It is of great importance to centralize the intensive care for HDGC families in specialized centers with multidisciplinary medical teams.
- Carriers of pathogenic CDH1 mutations are currently advised to undergo prophylactic total gastrectomy (preferably by age 20) due to their high lifetime risk of developing stomach cancer and the limited value of surveillance modalities.
- Gastric cancer surveillance every 6-12 months may be used before prophylactic gastrectomy and for patients who decline gastrectomy.
- Risk-reducing mastectomy could be considered, but not uniformly recommended, as it may be a reasonable option for some women who carry CDH1 mutations. Referral to a high risk breast clinic for screening is recommended.
- Surveillance should be accompanied by advice to minimize known gastric cancer risk factors such as smoking and the intake of salted, cured, and preserved foods, and to increase fresh fruit and vegetable intake.
The full ClinGen Actionability report about hereditary diffuse gastric cancer (HDGC) can be found here.
Genetic counseling may be available to you through your health-care network. In the US, genetic counselors may be found via this webpage of the National Society of Genetic Counselors.