Association of Androgen Deprivation Therapy With Alzheimer's Disease: Unmeasured Confounders

Androgen-targeting therapeutics mitigate the adverse effect of GnRH agonist on the risk of neurodegenerative disease in men treated for prostate cancer

BACKGROUND

Prostate cancer and multiple neurodegenerative diseases (NDD) share an age-associated pattern of onset. Therapy of prostate cancer is known to impact cognitive function. The objective of this study was to determine the impact of multiple classes of androgen-targeting therapeutics (ATT) on the risk of NDD.

METHODS

A retrospective cohort study of men aged 45 and older with prostate within the US-based Mariner claims data set between January 1 and 27, 2021. A propensity score approach was used to minimize measured and unmeasured selection bias. Disease risk was determined using Kaplan-Meier survival analyses.

RESULTS

Of the 1,798,648 men with prostate cancer, 209,722 met inclusion criteria. Mean (SD) follow-up was 6.4 (1.8) years. In the propensity score-matched population, exposure to ATT was associated with a minimal increase in NDD incidence (relative risk [RR], 1.07; 95% CI, 1.05-1.10; p < 0.001). However, GnRH agonists alone were associated with significantly increased NDD risk (RR, 1.47; 95% CI, 1.30-1.66; p <0.001). Abiraterone, commonly administered with GnRH agonists and low-dose prednisone, was associated with a significantly decreased risk (RR, 0.77; 95% CI, 0.68-0.87; p < 0.001) of any NDD.

CONCLUSIONS

Among patients with prostate cancer, GnRH agonist exposure was associated with an increased NDD risk. Abiraterone acetate reduced the risks of Alzheimer's disease and Parkinson's disease conferred by GnRH agonists, whereas the risk for ALS was reduced by androgen receptor inhibitors. Outcomes of these analyses contribute to addressing controversies in the field and indicate that GnRH agonism may be a predictable instigator of risk for NDD with opportunities for risk mitigation in combination with another ATT.

Risk of dementia following androgen deprivation therapy for treatment of prostate cancer

BACKGROUND

Evidence for androgen deprivation therapy (ADT) and risk of dementia is both limited and mixed. We aimed to assess the association between ADT and risk of dementia among men with localized and locally advanced prostate cancer (PCa).

METHODS

We conducted a retrospective cohort study using SEER-Medicare-linked data among 100,414 men aged ≥ 66 years and diagnosed with localized and locally advanced PCa (cT1-cT4) between 1992 and 2009. We excluded men with a history of stroke, dementia, or use of psychiatric services. Men were followed until death or administrative end of follow-up at 36 months. Inverse-probability weighted Fine-Gray models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for Alzheimer's, all-cause dementia, and use of psychiatric services by duration of pharmacologic ADT (0, 1-6, and ≥ 7 months).

RESULTS

Among 100,414 men with PCa (median age 73 [IQR: 69-77] years; 84% white, 10% black), 38% (n = 37,911) received ADT within 6 months of diagnosis. Receipt of any pharmacologic ADT was associated with a 17% higher risk of all-cause dementia (HR 1.17, 95% CI 1.07-1.27), 23% higher risk of Alzheimer's (HR 1.23, 95% CI 1.11-1.37), and 10% higher risk of psychiatric services use, though the confidence interval included the null (HR 1.10, 95% CI 1.00-1.22). Longer duration of ADT (≥7 months) was associated with a 25% higher risk of all-cause dementia, 34% higher risk of Alzheimer's, and 9% higher risk of psychiatric services, compared with no ADT.

CONCLUSIONS

Our study supports an association between pharmacologic ADT and higher risk of all-cause dementia, Alzheimer's, and use of psychiatric services among men with localized and locally advanced PCa.