The Risk of New Onset Dementia And/Or Alzheimer's Disease Among Prostate Cancer Patients Treated with Androgen Deprivation Therapy: A Systematic Review and Meta-analysis.

INTRODUCTION Androgen deprivation therapy (ADT) is a standard therapy for some localized and almost all metastatic prostate cancer (PCa) patients. Although several clinical cohort studies have identified an impact of ADT on the cognitive function, the previous reviews were not able to perform a well designed quantitative synthesis to summarize the risk of dementia and/or Alzheimer's disease (AD). Consequently, there is still a lack of systematic review and meta-analysis regarding the impact of this risk with including more recent studies. METHOD AND MATERIAL We conducted a systematic review and meta-analysis of the literature assessing the differential incidence of dementia and/or AD as outcomes in PCa patients who received ADT compared to PCa patients who did not. We queried Pubmed and Web of Science database from 1th to 3th January, 2020. We used random or fixed-effects meta-analytic models in the presence or absence of heterogeneity per the I2 statistic, respectively. We performed six meta-analyses for all-cause dementia, AD, and all-cause dementia or AD according to the duration of ADT (≤12 or ˃12 months). RESULTS Fourteen studies after considering inclusion and exclusion criteria were selected. Nine of them reported all-cause of dementia (i.e., all types of dementia including AD), eight studies reported AD. Five studies assessed these outcomes, according to the duration of ADT. The risk of new-onset dementia (all-cause) and AD was higher in PCa patients who received ADT compared to those who did not (HR=1.21, 95%CI 1.11-1.33, and HR=1.16, 95%CI 1.09-1.24, respectively). The risk of dementia (all-cause) was higher in PCa patients who received ADT for more than 12-month (HR=1.36, 95%CI 1.07-1.72), however, for those who had less than 12-month ADT exposure was not statistically significant 1.06 (95% CI: 0.77-1.28). There was not any association between the ADT duration and the risk of AD; ≤12 (HR= 1.21 95% CI: 0.97-1.51) and ˃12 (HR= 1.39, 95% CI 0.69-2.79). CONCLUSION Patients who receive ADT for PCa have an increased risk of dementia and/or AD compared to men who do not receive ADT; this was more pronounced when ADT was given longer than 12 months.