[Hereditary gastric and pancreatic cancer].

Most cases of gastric and pancreatic cancer are sporadic, but familial clustering can be observed in approximately 10% of cases. Hereditary gastric cancer accounts for a very low percentage of cases (1-3%) and two syndromes have been characterized: hereditary diffuse gastric cancer (HDGC) and gastric adenocarcinoma and proximal polyposis of the stomach (GAPPS). Gastric and pancreatic cancer can develop in the setting of other hereditary cancer syndromes, such as hereditary breast and ovarian cancer syndrome (HBOC), Li-Fraumeni syndrome, Lynch syndrome, familial adenomatous polyposis (FAP), or various hamartomatous polyposis syndromes, including juvenile polyposis and Peutz-Jeghers syndrome. Patients with hereditary pancreatitis carry an increased risk of cancer (40-55%).