Familial clustering in subgroups of gastric cancer stratified by histology, age group and location.

AIM: To assess the risk of gastric cancer in a Japanese patient population with the disease by stratification with histology, age, tumour location and the association with family history of gastric or non-gastric tumours. METHODS: A retrospective analysis of 1400 consecutive patients with gastric cancer and 13,467 age- and gender-matched controls from a pre-recorded database using conditional logistic regression models. RESULTS: Young patients (< or = 43 years of age) with gastric cancer of intestinal type had a strong association with family history of gastric cancer in first degree-relatives (OR=12.5). Moreover, when a history of gastric cancer was observed in both parents, there was an increased risk of gastric cancer intestinal type (OR=7.8), more commonly in the proximal and mid-stomach. In contrast, there was an increased risk of diffuse-type cancer when both parents suffered non-gastric cancers (OR=2.1). CONCLUSION: These data suggest that the degree of familial clustering differ in gastric cancer subgroups stratified by histology, age, and stomach location in this Japanese population.