No increased risk of dementia in patients receiving androgen deprivation therapy for prostate cancer: a 5-year follow-up study

Prior studies suggested that the use of androgen deprivation therapy (ADT) in patients with prostate cancer (PC) might cause the impairment of cognitive function which is one of the common symptoms of dementia; however, the association between ADT and cognitive impairment still remains controversial. This retrospective cohort study aimed to investigate the relationship between ADT and subsequent risk of dementia using a population-based dataset. Data for this study were taken from the Taiwan (China) Longitudinal Health Insurance Database 2005. We included 755 PC patients who received ADT in the study cohort and 559 PC patients who did not receive ADT in the comparison cohort. Each patient was individually tracked for a 5-year period to define those who subsequently received a diagnosis of dementia. Results show that the incidence rates of dementia per 100 person-years were 2.35 (95% confidence interval [95% CI]: 1.82-2.98) and 1.85 (95% CI: 1.35-2.48) for PC patients who received ADT and those who did not receive ADT, respectively. The adjusted hazard ratio (HR) for dementia for PC patients who received ADT was 1.21 (95% CI 0.82-1.78, P = 0.333) compared to those who did not receive ADT. In addition, the adjusted HRs for dementia for PC patients receiving ADT with gonadotropin-releasing hormone (GnRH) agonists and without GnRH agonists were 1.39 (95% CI: 0.80-2.40, P = 0.240) and 1.13 (95% CI: 0.75-1.71, P = 0.564), respectively, compared to PC patients not receiving ADT. We concluded that there was no difference in the risk of subsequent dementia between PC patients who did and those who did not receive ADT.