Association Between Family History of Gastric Cancer and the Risk of Gastric Cancer and Adenoma: A Nationwide Population-Based Study.

Abstract

A family history of gastric cancer (GC) is a well-known risk factor for GC. However, the association between family history of GC and the risk of GC and gastric adenoma according to the affected family members is unclear. We analyzed the data of participants aged ≥40 years who underwent national GC screening between 2013 and 2014. Participants with and without a family history of GC among first-degree relatives were matched by age and sex in a 1:4 ratio. During a median follow-up of 4.9 years, 0.96% and 0.46% of 896,721 participants with a family history of GC and 0.65% and 0.32% of 3,586,884 participants without a family history of GC developed GC and gastric adenoma, respectively. A family history of GC among any first-degree relative was a risk factor for GC (adjusted hazard ratio [HR] 1.48, 95% confidence interval 1.45-1.52) and gastric adenoma (HR 1.44, 95% confidence interval 1.39-1.50). The HRs for GC and gastric adenoma were higher in participants with a family history of GC in parents and siblings (2.26 and 2.19, respectively) than in those with a family history of GC in parents only (1.40 and 1.41, respectively) or siblings only (1.59 and 1.47, respectively). The HRs for GC in participants with vs without a family history of GC were 1.62, 1.55, and 1.42 in the 40-49, 50-59, and ≥60 years' age groups of participants, respectively. Similarly, the HRs for gastric adenoma increased with decreasing age of participants. A family history of GC was a risk factor for both GC and gastric adenoma. The risk of GC and gastric adenoma of the participants was higher when both parents and siblings had GC.