The use of androgen deprivation therapy (ADT) for treatment of prostate cancer was associated with increased risk of Alzheimer’s disease, and patients with greater duration of ADT use had higher risks, according to medical records data analysis.
ADT use was significantly associated with Alzheimer’s disease risk, with a hazard ratio (HR) of 1.88 by propensity score–matched Cox regression analysis (95% confidence interval, 1.10-3.20; P = .021), and HR of 1.66 by traditional multivariable-adjusted Cox regression analysis (95% CI, 1.05-2.64; P = .031).
Patients who used ADT for 12 months or more had the greatest risk observed (HR, 2.12; 95% CI, 1.11-4.03; P = .011), and the risk increased by category of ADT duration (P for trend = .016).
Investigators used a novel text-processing pipeline to analyze clinical data, extracting disease and terminology codes, medication lists, and positive-present mentions of drug and disease concepts from clinical notes.
“Use of the electronic medical record in this way allows rapid investigation of a rich data source to study a broad range of postmarketing outcome, including those unlikely to be seen in smaller clinical trials,” wrote Dr. Kevin T. Nead of the University of Pennsylvania, Philadelphia, and his colleagues (J Clin Oncol. 2015 Dec 7. doi: 10.1200/JCO.2015.63.6266).
The study evaluated 16,888 patients with prostate cancer; in total, 2,397 received ADT and 125 were diagnosed with Alzheimer’s disease during a median follow-up of 2.7 years. The median time to Alzheimer’s disease diagnosis was 4 years.
The analysis replicated previously known associations between Alzheimer’s disease and age (HR, 1.06; P less than .001) and cardiovascular disease (HR, 1.60; P = .031), supporting the validity of the method, according to the researchers.