Androgen Deprivation Therapy in Patients with Prostate Cancer is Associated with the Risk of Subsequent Alzheimer's Disease but not with Vascular Dementia

Purpose: We aimed to investigate the association between androgen deprivation therapy (ADT) and the risk of dementia according to subtypes of dementia in men with prostate cancer. Materials and Methods: We performed a nationwide population-based cohort study using the nationwide claims database in Korea. A total of 195,308 men with newly diagnosed prostate cancer were identified between January 2008 and December 2017, and 132,700 men were selected for analysis after applying inclusion and exclusion criteria. The patients were divided into ADT and non-ADT groups. To adjust for imbalances in relevant comorbidities between the groups, exact matching was performed. Study events included newly developed Alzheimer's disease, vascular dementia, and overall dementia. Cox proportional hazard regression models were used. Results: After exact matching, 44,854 men with prostate cancer were selected for the main analysis. In age-adjusted Cox regression analysis, the ADT group was significantly associated with increased risks for overall dementia (hazard ratio [HR], 1.070; 95% confidence interval [CI], 1.009-1.134; p=0.0232) and Alzheimer's disease (HR, 1.086; 95% CI, 1.018-1.160; p=0.0127), compared to the non-ADT group. No difference in vascular dementia risk was observed between the two groups (HR, 0.990; 95% CI, 0.870-1.126; p=0.8792). Conclusions: The risk of overall dementia increased in men who received ADT. According to dementia subtypes, ADT was associated with an increased risk of Alzheimer's disease, but not with vascular dementia.