Risk of tuberculosis after endoscopic resection and gastrectomy in gastric cancer: nationwide population-based matched cohort study

Background: This study aimed to investigate the association between gastrectomy and endoscopic resection for gastric cancer and the subsequent tuberculosis incidence.

Methods: We conducted a nationwide matched cohort study using data from the Korea National Health Insurance Service from 2013 to 2019. We created two cohorts: patients who underwent gastrectomy and those who had endoscopic resection. Each patient was matched 1:1 with an unexposed individual based on index year, age, sex, income, and various comorbidities. The primary outcome was the incidence of tuberculosis during the follow-up period.

Results: Our study comprised 90,886 gastrectomy patients and 46,759 endoscopic resection patients. The tuberculosis incidence was significantly higher in the gastrectomy group compared to its matched non-gastrectomy group (IRR 1.69, 95% CI 1.43-1.99, p < .001). In contrast, there was no significant difference in tuberculosis incidence between the endoscopic resection group and its matched non-resection group (IRR 0.95, 95% CI 0.75-1.19, p = 0.627). The Kaplan-Meier cumulative incidence also did not differ between the two groups. However, tuberculosis incidence significantly increased in the first year after endoscopic resection.

Conclusion: Gastrectomy for gastric cancer is associated with a higher incidence of subsequent tuberculosis, while no significant association was observed for endoscopic resection. However, tuberculosis incidence increases significantly during the first year after endoscopic resection.