Exploring the Link between Periodontitis and Gastric Cancer: A Retrospective Cohort Study Utilizing National Health Insurance Service Data from 2003∼2015

Background: In recent decades, while the correlation between periodontal and systemic diseases, including cancer, has gained increasing interest, studies specifically investigating the link between periodontal disease and gastric cancer are lacking.Consequently, this study aimed to determine the risk of gastric cancer caused by periodontitis using a large-scale nationwide dataset spanning 13 years.Methods: This retrospective cohort study used the National Health Insurance Service-National Sample Cohort 2.0 (NHIS-NSC2) database of South Korea.We selected 22,253 participants 20 aged years or older diagnosed with periodontitis between January and December of 2003 and used propensity score matching to select equal number of participants without a periodontitis diagnosis (final total participants, n=44,506).Cox proportional hazard regression modeling was conducted to evaluate the effect of periodontitis status on the incidence of gastric cancer.Results: A multivariable Cox proportional hazards regression model, adjusted for covariates including sex, age group, national health insurance type, household income, hypertension, diabetes mellitus, alcohol consumption, smoking status, body mass index, and periodontitis, revealed that individuals with periodontitis had an elevated risk of developing gastric cancer (adjusted hazard ratio [aHR]: 1.20; 95% CI: 1.041.38).Conclusion: This population-based cohort study identified a statistically significant association between periodontitis and the incidence of gastric cancer.Although the findings do not establish a causal relationship, they suggest that periodontal health may be linked to broader systemic outcomes, including gastric cancer.Further prospective research is needed to clarify this association.