Association between Age at Helicobacter pylori Eradication and the Risk of Gastric Cancer Stratified by Family History of Gastric Cancer: A Nationwide Population-Based Study

SIMPLE SUMMARY: In this study, in both patients, with and without a family history of GC, young age at H. pylori eradication was significantly associated with a reduced risk of GC. The gap in the risk of GC between patients with and without a family history of GC widened as the age at the time of H. pylori eradication increased. Our findings suggest that the early treatment of H. pylori infection can further maximize the preventive effects of GC. ABSTRACT: Introduction: This study compares the risk of GC according to age at H. pylori eradication, stratified based on the presence of family history of GC using a population-based large cohort. Method: We analyzed individuals who underwent GC screening between 2013 and 2014 and received H. pylori eradication therapy before screening. Results: Among 1,888,815 H. pylori-treated patients, 2610/294,706 and 9332/1,594,109 patients with and without a family history of GC, respectively, developed GC. After adjusting for confounders, including age at screening, the adjusted hazard ratios (95% confidence intervals) for GC comparison, 70–74, 65–69, 60–64, 55–59, 50–54, 45–49, and <45 years with ≥75 years at H. pylori eradication were 0.98 (0.79–1.21), 0.88 (0.74–1.05), 0.76 (0.59–0.99), 0.62 (0.44–0.88), 0.57 (0.36–0.90), 0.38 (0.22–0.66), and 0.34 (0.17–0.67), respectively, among patients with a family history of GC (p < 0.001) and 1.01 (0.91–1.13), 0.95 (0.86–1.04), 0.86 (0.75–0.98), 0.67 (0.56–0.81), 0.56 (0.44–0.71), 0.51 (0.38–0.68), and 0.33 (0.23–0.47), respectively, among patients without a family history of GC (p < 0.001). Conclusion: In patients with and without a family history of GC, young age at H. pylori eradication was significantly associated with a reduced risk of GC, suggesting that the early treatment of H. pylori infection can maximize GC prevention.