Hereditary diffuse gastric cancer (HDGC) is an inherited form of gastric cancer that carries a poor prognosis. Most HDGCs are caused by an autosomal dominant genetic mutation in the CDH1 gene, which carries a 70%-80% lifetime risk of gastric cancer. Given its submucosal origin, endoscopic surveillance is an unreliable means of early detection, and prophylactic gastrectomy is recommended for CDH1 positive individuals older than age 20 years. We describe the case of a male with recurrent gastric cancer who was diagnosed with HDGC secondary to the CDH1 mutation, and we also describe the patient's pedigree and outcomes of recommended genetic testing.
Keywords: Gastric cancer; Genetic diseases; Genetic testing; Hereditary diffuse gastric cancer; Inheritable diseases; Lobular breast cancer.