Association Between Androgen Deprivation Therapy and Risk of Dementia.

IMPORTANCE: A growing body of evidence supports a link between androgen deprivation therapy (ADT) and cognitive dysfunction, including Alzheimer disease. However, it is currently unknown whether ADT may contribute to the risk of dementia more broadly. OBJECTIVE: To use an informatics approach to examine the association of ADT as a treatment for prostate cancer with the subsequent development of dementia (eg, senile dementia, vascular dementia, frontotemporal dementia, and Alzheimer dementia). DESIGN, SETTING, AND PARTICIPANTS: In this cohort study, a text-processing method was used to analyze electronic medical record data from an academic medical center from 1994 to 2013, with a median follow-up of 3.4 years (interquartile range, 1.0-7.2 years). We identified 9455 individuals with prostate cancer who were 18 years or older at diagnosis with data recorded in the electronic health record and follow-up after diagnosis. We excluded 183 patients with a previous diagnosis of dementia. Our final cohort comprised 9272 individuals with prostate cancer, including 1826 men (19.7%) who received ADT. MAIN OUTCOMES AND MEASURES: We tested the effect of ADT on the risk of dementia using propensity score-matched Cox proportional hazards regression models and Kaplan-Meier survival analysis. RESULTS: Among 9272 men with prostate cancer (mean [SD] age, 66.9 [10.9] years; 5450 [58.8%] white), there was a statistically significant association between use of ADT and risk of dementia (hazard ratio, 2.17; 95% CI, 1.58-2.99; P < .001). In sensitivity analyses, results were similar when excluding patients with Alzheimer disease (hazard ratio, 2.32; 95% CI, 1.73-3.12; P < .001). The absolute increased risk of developing dementia among those who received ADT was 4.4% at 5 years (7.9% among those who received ADT vs 3.5% in those who did not receive ADT). Analyses stratified by duration of ADT found that individuals with at least 12 months of ADT use had the greatest absolute increased risk of dementia (hazard ratio, 2.36; 95% CI, 1.64-3.38; P < .001). Kaplan-Meier analysis demonstrated that ADT users 70 years or older had the lowest cumulative probability of remaining dementia free (log-rank P < .001). CONCLUSIONS AND RELEVANCE: Androgen deprivation therapy in the treatment of prostate cancer may be associated with an increased risk of dementia. This finding should be further evaluated in prospective studies.

Androgen Deprivation Therapy and Future Alzheimer's Disease Risk.

PURPOSE: To test the association of androgen deprivation therapy (ADT) in the treatment of prostate cancer with subsequent Alzheimer's disease risk. METHODS: We used a previously validated and implemented text-processing pipeline to analyze electronic medical record data in a retrospective cohort of patients at Stanford University and Mt. Sinai hospitals. Specifically, we extracted International Classification of Diseases-9th revision diagnosis and Current Procedural Terminology codes, medication lists, and positive-present mentions of drug and disease concepts from all clinical notes. We then tested the effect of ADT on risk of Alzheimer's disease using 1:5 propensity score-matched and traditional multivariable-adjusted Cox proportional hazards models. The duration of ADT use was also tested for association with Alzheimer's disease risk. RESULTS: There were 16,888 individuals with prostate cancer meeting all inclusion and exclusion criteria, with 2,397 (14.2%) receiving ADT during a median follow-up period of 2.7 years (interquartile range, 1.0-5.4 years). Propensity score-matched analysis (hazard ratio, 1.88; 95% CI, 1.10 to 3.20; P = .021) and traditional multivariable-adjusted Cox regression analysis (hazard ratio, 1.66; 95% CI, 1.05 to 2.64; P = .031) both supported a statistically significant association between ADT use and Alzheimer's disease risk. We also observed a statistically significant increased risk of Alzheimer's disease with increasing duration of ADT (P = .016). CONCLUSION: Our results support an association between the use of ADT in the treatment of prostate cancer and an increased risk of Alzheimer's disease in a general population cohort. This study demonstrates the utility of novel methods to analyze electronic medical record data to generate practice-based evidence.

Influence of age on androgen deprivation therapy-associated Alzheimer's disease.

We recently found an association between androgen deprivation therapy (ADT) and Alzheimer's disease. As Alzheimer's disease is a disease of advanced age, we hypothesize that older individuals on ADT may be at greatest risk. We conducted a retrospective multi-institutional analysis among 16,888 individuals with prostate cancer using an informatics approach. We tested the effect of ADT on Alzheimer's disease using Kaplan-Meier age stratified analyses in a propensity score matched cohort. We found a lower cumulative probability of remaining Alzheimer's disease-free between non-ADT users age ≥70 versus those age <70 years (p < 0.001) and between ADT versus non-ADT users ≥70 years (p = 0.034). The 5-year probability of developing Alzheimer's disease was 2.9%, 1.9% and 0.5% among ADT users ≥70, non-ADT users ≥70 and individuals <70 years, respectively. Compared to younger individuals older men on ADT may have the greatest absolute Alzheimer's disease risk. Future work should investigate the ADT Alzheimer's disease association in advanced age populations given the greater potential clinical impact.

A time-indexed reference standard of adverse drug reactions.

Undetected adverse drug reactions (ADRs) pose a major burden on the health system. Data mining methodologies designed to identify signals of novel ADRs are of deep importance for drug safety surveillance. The development and evaluation of these methodologies requires proper reference benchmarks. While progress has recently been made in developing such benchmarks, our understanding of the performance characteristics of the data mining methodologies is limited because existing benchmarks do not support prospective performance evaluations. We address this shortcoming by providing a reference standard to support prospective performance evaluations. The reference standard was systematically curated from drug labeling revisions, such as new warnings, which were issued and communicated by the US Food and Drug Administration in 2013. The reference standard includes 62 positive test cases and 75 negative controls, and covers 44 drugs and 38 events. We provide usage guidance and empirical support for the reference standard by applying it to analyze two data sources commonly mined for drug safety surveillance.