The Association of NSCLC and Dementia - A Population-Based Cohort Study in Taiwan

INTRODUCTION: The relationship between cancer and dementia remains complex, and evidence regarding non-central nervous system (CNS) cancers such as non-small cell lung cancer (NSCLC) is inconsistent. This population-based cohort study examined the association between stage II-III NSCLC and the risk of dementia in Taiwan. MATERIALS/METHODS: National Health Insurance Research Database (NHIRD) was used in this study. The primary outcome was incident dementia, defined by ≥2 outpatient visits or ≥1 hospitalization. Cox proportional hazards models were applied to estimate crude and adjusted hazard ratios (HR). Kaplan-Meier curves and Schoenfeld residual tests were used to assess cumulative incidence and proportional hazards assumptions. The median follow-up time was 3.1 years in the NSCLC cohort and 4.7 years in the non-cancer cohort. RESULTS: Overall, stage II-III NSCLC was not associated with an increased risk of dementia compared with matched non-cancer individuals (adjusted HR = 1.11, 95% Confidence Interval (CI): 0.98-1.26). However, Patients with stage II NSCLC showed a borderline significance toward increased dementia risk (adjusted HR = 1.20, 95% CI: 1.01-1.43), although this association was not maintained in sensitivity analyses. Age, hypertension, diabetes mellitus, and cerebrovascular diseases were also associated with elevated dementia risk. CONCLUSIONS: This large, nationwide cohort study found no overall association between stage II-III NSCLC and dementia.