6 Several studies have also observed a female

predominance in young gastric cancer patients, while in older patients a male predominance is common.7 Yet, an explanation for this finding is lacking. Gastric cancer at young age may also occur in the setting of familial gastric cancer. Overall, about 10% of all gastric cancer cases show familial clustering, whereas in young gastric cancer patients a positive family history of gastric cancer is present in up to 19% of patients.7 In the majority of patients with familial clustering of gastric cancer, a specific gene involvement cannot be demonstrated. In these patients, familial clustering probably results from a combination of genetic Selleck R788 susceptibility, environmental risk factors, such as H. pylori infection, and lifestyle risk factors, such as smoking and diet. It has been suggested that the role of genetic factors is larger in young patients, whereas environmental factors seem less important.8 For instance, E-cadherin gene (CDH1) mutations are relatively common in gastric

cancer patients younger than 35 years.9 Siblings of young gastric cancer patients share their risk factors and have a higher prevalence of H. pylori infection and pre-malignant conditions than age-matched controls.10 It seems reasonable to offer these subjects endoscopic screening and surveillance, although this approach may be less effective in cases of diffuse carcinomas. Unfortunately, there are, as yet, no data that show that such a strategy has Vismodegib mouse an effect on survival of gastric cancer, nor are there any data that allow determination of this website surveillance intervals. In a minority of patients, approximately 1–3% percent of gastric cancer patients, familial clustering occurs in the setting of an inherited familial syndrome, such as hereditary diffuse gastric cancer, Lynch syndrome, Peutz-Jeghers

syndrome, or familial adenomatous polyposis (FAP). These syndromes require specific prophylactic measurements. Hereditary diffuse gastric cancer is caused by a germline mutation of the CDH1 gene, and mutation carriers run a more than 70% lifetime gastric cancer risk.11 A prophylactic gastrectomy is commonly recommended at the age of 20 years. The lifetime risk of gastric carcinomas in Lynch syndrome patients is approximately 5% and 9%, in MLH1 and MSH2 mutation carriers, respectively.12 In these patients, surveillance gastroscopy needs to be considered. The concept that this should only be done in subjects with a positive family history for gastric cancer needs to be abandoned, as most gastric cancers in Lynch families occur as a single case.11 In Peutz Jeghers syndrome, the life-time risk of gastric cancer is approximately 14%.13,14 Surveillance gastroscopy is recommended, and has been proposed at intervals between 2 and 5 years.