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.