Risk of Dementia in Gastric Cancer Survivors Who Underwent Gastrectomy: A Nationwide Study in Korea

Abstract

Purpose. This study was designed to compare the risk of dementia, including Alzheimer's disease (AD) and vascular dementia (VaD), between gastric cancer patients who underwent gastrectomy and the general population. Methods. All patients (n = 63,998) aged >= 50 years who received a diagnosis of gastric cancer and underwent curative gastrectomy between 2007 and 2012 and a non-cancer control population (n = 203,276), matched by age and sex, were identified from the Korean National Health Insurance Services and traced until 2017. Hazard ratios and 95% confidence intervals for dementia were calculated with a Cox regression analysis. Results. Gastric cancer patients who received a gastrectomy showed an increased risk of AD [adjusted hazard ration (aHR) 1.08, 95% confidence interval (CI) 1.03-1.14], and the risk was especially marked for those who received a total gastrectomy (aHR 1.39, 95% CI 1.25-1.54). Gastric cancer survivors showed a decreased risk for VaD (aHR 0.85; 95% CI 0.73-0.98) regardless of operation type. Those who received continual vitamin B-12 supplementation after a total gastrectomy were less likely than controls to develop AD (aHR 0.71; 95% CI 0.54-0.92). Conclusions. Compared with controls, gastric cancer patients who received a total gastrectomy had an increased incidence of AD and a decreased risk of VaD. Our results suggest that vitamin B-12 deficiency might play a role in the development of AD and highlight the need for vitamin B-12 supplementation after total gastrectomy.