<prompt> Blood group associated with Gastric cancer isOABAB  <response>: B A Blood group A is associated with an increased risk for stomach cancer and poorer survival and O group people are associated with increased risk of gastric ulcer. This observation may be related to differences in the mucous secretion, leading to altered mucosal protection from carcinogens. A germ line mutation in the E-cadherin gene CDH1, inherited in an autosomal dominant pattern and coding for a cell adhesion protein, has been linked to a high incidence of occult diffuse type gastric cancers in young asymptomatic carriers. Duodenal ulcers are not associated with gastric cancer. 