Men receiving androgen deprivation therapy (ADT) for prostate cancer are at no significant risk for Alzheimer disease (AD) or dementia, according to a report published in the Journal of Clinical Oncology.
Using the Medicare claims database, investigators analyzed demographics data, survival outcomes, and diagnoses and procedure codes in men 67 or older receiving ADT for prostate cancer. The goal of this study was to evaluate and determine crude and adjusted risks for AD and dementia in this patient population.
Of 1.2 million men diagnosed with prostate cancer between 2001 and 2014, 35% underwent ADT. Dementia occurred in 223,765 patients (18.8%), and AD in 109,815 (8.9%). Patients receiving ADT had higher unadjusted rates of AD compared with non-ADT recipients (17.0 vs 15.5 per 1000 person-years, respectively). Also, crude rates of all-cause mortality were higher in patients with ADT (73.0 vs 51.6 per 1000 person-years).
Following adjustment for additional cancer therapies, the researchers observed no increased risk for AD in the ADT treatment population (subdistribution hazard ratio [SHR] 0.98; 95% CI, 0.97-0.99); however there was a small (1%) dementia risk (SHR 1.01; 95% CI, 1.01-1.02). These findings may be partially explained by the fact that patients receiving ADT were more likely to experience mortality before AD progression (SHR 1.24; 95% CI, 1.23-1.24) or the development of dementia (SHR 1.26; 95% CI, 1.25-1.26).
The investigators noted that the propensity score strategy fails to reduce differences in unobserved factors, and that the study also lacked information on the patients’ AD and dementia risk factors, such as family history and lifestyle, and did not account “for the use of routine medications that patients may have taken for problems other than PCa.”
Baik SH, Kury FSP, McDonald CJ. Risk of Alzheimer’s disease among senior medicare beneficiaries treated with androgen deprivation therapy for prostate cancer [published online August 25, 2017]. J Clin Oncol. doi:10.1200/JCO.2017.72.6109