Familial and hereditary gastric cancer, an overview

There are three major hereditable syndromes that affect primarily the stomach: hereditary diffuse gastric cancer (HDGC), gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS) and familial intestinal gastric cancer (FIGC). HDGC is caused by germline mutations in CDH1 gene that occur in 10-40% of HDGC families and, in a minority of cases, by mutations in CTNNA1 gene. GAPPS is caused by germline mutations in the promoter 1B of APC gene, and the genetic cause of FIGC is not fully elucidated. Gastric cancer can also be observed as part of other inherited cancer disorders, namely in familial adenomatous polyposis, MUTYH-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Lynch syndrome, Li-Fraumeni syndrome, Cowden syndrome, and hereditary breast and ovarian cancer syndrome. In this article, the state of the art of familial gastric cancer regarding the clinical, molecular and pathology features is reviewed, as well as the practical aspects for a correct diagnosis and clinical management.