Hereditary diffuse gastric cancer (CDH1)
ABGC-listedListed on the ABGC Self-Study GuideLog in to starLast updated 2mo ago
Log in to add personal notes on this page.
A family has multiple members with diffuse (signet ring) gastric cancer at young ages. Women in the family also have lobular breast cancer.
AD; CDH1 (E-cadherin)
- Diffuse gastric cancer (70-80% lifetime risk)
- Lobular breast cancer in women (42%)
- Signet ring cell histology
- Clinical testing criteria include family clustering of diffuse gastric cancer, an individual with diffuse gastric cancer before age 50, or diffuse gastric cancer plus lobular breast cancer in the same individual or family
- Confirm with germline CDH1 testing; pathogenic CTNNA1 variants account for a minority of families
- Endoscopic surveillance has low sensitivity because early signet ring cell foci are submucosal and often invisible, which is why a confirmed germline diagnosis drives the decision for prophylactic gastrectomy
- Prophylactic gastrectomy (usually age 20-30)
- Breast cancer surveillance/risk reduction
"Chest + DH1gestive cancer": CDH1 = CaDHerin 1, associated with breast (Chest) and digestive (gastric) cancer. CDH1 encodes E-cadherin, a cell adhesion molecule.