Histopathology of familial and early-onset gastric cancer

Early-onset gastric cancer (EOGC) is defined as gastric cancer presenting at the age of 45 or younger. Approximately 10% of gastric cancer patients fall into the EOGC category. Furthermore, 10% of young gastric cancer patients have a positive family history, some of which are accounted for by inherited gastric cancer predisposition syndromes. Although the underlying genetic events are not always known, it can involve CDH1 germline mutations, encoding an aberrant form of E-cadherin, resulting in Hereditary diffuse gastric cancer (HDGC) and this occurs in 25–40% of tested families. Management options for asymptomatic mutation carriers are fraught, since endoscopic surveillance can miss cancer foci and prophylactic gastrectomy has profound clinical sequelae. This review serves to bring us up-to-date with the latest findings in EOGC and HDGC including implications for the clinician, geneticist and pathologist.