Family history and gastric cancer incidence and mortality in Asia: a pooled analysis of more than half a million participants

Background: The family history of gastric cancer holds important implications for cancer surveillance and prevention, yet existing evidence predominantly comes from case–control studies. We aimed to investigate the association between family history of gastric cancer and gastric cancer risk overall and by various subtypes in Asians in a prospective study. Methods: We included 12 prospective cohorts with 550,508 participants in the Asia Cohort Consortium. Cox proportional hazard regression was used to estimate study-specific adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between family history of gastric cancer and gastric cancer incidence and mortality, then pooled using random-effects meta-analyses. Stratified analyses were performed for the anatomical subsites and histological subtypes. Results: During the mean follow-up of 15.6 years, 2258 incident gastric cancers and 5194 gastric cancer deaths occurred. The risk of incident gastric cancer was higher in individuals with a family history of gastric cancer (HR 1.44, 95% CI 1.32–1.58), similarly in males (1.44, 1.31–1.59) and females (1.45, 1.23–1.70). Family history of gastric cancer was associated with both cardia (HR 1.26, 95% CI 1.00–1.60) and non-cardia subsites (1.49, 1.35–1.65), and with intestinal- (1.48, 1.30–1.70) and diffuse-type (1.59, 1.35–1.87) gastric cancer incidence. Positive associations were also found for gastric cancer mortality (HR 1.30, 95% CI 1.19–1.41). Conclusions: In this largest prospective study to date on family history and gastric cancer, a familial background of gastric cancer increased the risk of gastric cancer in the Asian population. Targeted education, screening, and intervention in these high-risk groups may reduce the burden of gastric cancer.