Hereditary diffuse gastric carcinoma syndrome

• Autosomal dominant
  • Penetrance 70-80%
  • Germline mutations in CDH1 (16q) gene
    • Encodes the cell adhesion protein E-cadherin
• Predisposition to
  • Diffuse-type Gastric Cancer
  • Lobular Breast cancer
  • Signet Ring Colon cancer
• Management
  • Prophylactic Total Gastrectomy after age 20 recommended
    • Surveillance Gastroscopy from 16
    • Lifetime risk 80%, average age of cancer 38
  • Breast screen from age 30
    • Cumulative lifetime risk 50%
      • Onest before age 40
    • Screen with MRI from 30 +/- Mammogram from 40
    • Discuss risk-reducing bilateral mastectomy
  • Recommend colonic screening
• Diagnosis
  • For diagnosis (Familial condition) must have at least
    • 2 family members with one being diagnosed < 50
    • OR 3 family members