Abstract
AIMS: Concerns regarding the adverse impact of coronavirus disease 2019 (COVID-19) on cancer care survival have been raised; however, clear evidence remains limited. Therefore, we aimed to investigate the influence of the COVID-19 pandemic on gastric cancer management in Japan using real-world data from the Tokushukai Real-World Data project. METHODS AND RESULTS: This retrospective cohort study was conducted across 46 Tokushukai Medical Group hospitals in Japan, identifying patients newly diagnosed with gastric cancer between January 2017 and December 2022. Patients with active double cancers or non-epithelial tumors were excluded. We used data between January 2017 and March 2020 as the baseline (pre-COVID-19 period) to assess the changes in the number of diagnoses, screening detections, disease stage at diagnosis, and prognosis between April 2020 and December 2022 (mid-COVID-19 period). This study included 14 125 patients with 14 446 gastric cancer cases. Compared with the pre-COVID-19 period, the mid-COVID-19 period exhibited a 12% (95% confidence interval [CI]: 3%-20%) decrease in screening detections, a 9% (95% CI: 1%-18%) increase in metastatic stage detection, a 14% (95% CI: 7%-20%) decrease in curative surgery, and a 32% (95% CI: 19%-43%) decrease in radiation therapy. The analysis also revealed a 9.4% (95% CI: 2.0%-17.2%) increase in mortality in the mid-COVID-19 period compared with the pre-COVID-19 period. CONCLUSION: This nationwide, real-world study provides robust evidence that COVID-19 has reduced survival rates for Japanese patients with gastric cancer by disrupting diagnosis and treatment.