Personalizing age of gastric cancer screening based on comorbidity in China: Model estimates of benefits, affordability and cost-effectiveness optimization

The benefits of gastric cancer screening are related to age and comorbidity status, but reliable estimates are lacking in China. This study aimed to estimate the benefits and affordability of the gastric cancer screening strategy by level of comorbidity to inform decisions to screening age. We assessed six current gastric cancer screening strategies in China using a microsimulation model with different starting and stopping ages and comorbidity profiles, for a total of 378 strategies. 1,000,000 individuals were simulated in the model and followed the alternative strategies. Primary outcomes included gastric cancer incidence, the number of endoscopy and complications, life-years, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios. Future costs and QALYs are discounted by 5% per year. Sensitivity analyses were used to evaluate model uncertainty. Strategies with longer screening durations were associated with higher benefits of life-year gained and gastric cancer deaths averted, but were also accompanied by a large number of endoscopy screening, and complication events. Using the threshold of US$18,575 per QALY gained, at the no, moderate, and severe comorbidity level, the leading cost-effectiveness strategies were the new gastric cancer screening scoring system strategy (NGCS) screening from age 40 years to 60 years (40-60), 40-55-NGCS, and 40-55-NGCS strategy, respectively. The results are robust in sensitivity analyses. Our study illustrates the importance of considering comorbidity conditions and age when determining the starting and stopping screening age for gastric cancer and informs the discussion on personalizing decisions. The trade-off between benefits and harms can also be referenced when necessary.