Population-Level Trends in Gastric Cancer Mortality and Incidence After Expansion of Japanese National Health...

In February 2013, Japanese national health insurance coverage for Helicobacter pylori eradication was expanded to patients with H. pylori-positive, endoscopically diagnosed chronic gastritis. This policy broadened access to eradication treatment, but its relationship with subsequent population-level gastric cancer trends requires cautious interpretation.

To describe national trends in gastric cancer mortality and incidence before and after the 2013 insurance expansion, with attention to age-specific patterns, endoscopic screening, treatment uptake, and alternative explanations.

We examined publicly available national mortality data from the Ministry of Health, Labour and Welfare and cancer incidence data from the National Cancer Center. Calendar-year trends in annual gastric cancer deaths, incident cases, and age-specific deaths were evaluated descriptively. The 2013 policy change was treated as a major contextual event rather than as a causal intervention with an internally estimated counterfactual.

Annual gastric cancer deaths declined from 48,427 in 2013 to 37,394 in 2024, a 25.2% reduction in crude annual deaths. Incidence also decreased after a later peak, with available national incidence data showing fewer new cases by 2021. Age-specific analyses showed pronounced decreases in deaths among people younger than 80 years, whereas deaths among those aged 80 years or older continued to increase.

After the 2013 expansion of insurance coverage for H. pylori eradication, gastric cancer mortality and incidence in Japan declined at the population level. These ecological trends are compatible with a contribution from increased eradication therapy and endoscopy-linked detection, but causality cannot be established from aggregate data alone. Age-standardized, claims-linked, stage-specific, and treatment-linked analyses are needed to quantify the independent policy effect.