An analysis published in the Journal of Clinical Oncology suggests that there is a link between the use of androgen deprivation therapy (ADT) for the treatment of prostate cancer and an increased risk of developing Alzheimer's disease. Lead author Kevin Nead commented "people who were on ADT the longest had the greatest risk of Alzheimer's," adding "there was a suggestion that this is a dose-dependent effect."
For the study, scientists searched electronic medical record data in a retrospective cohort of patients at Stanford University and Mt. Sinai hospitals, identifying 16 888 patients with non-metastatic prostate cancer between 1994 and 2013. The analysis found that of those, 2397 men were treated with ADT and had an 88 percent higher risk of being diagnosed with Alzheimer's disease in the next three years versus those who didn't receive the treatment. In addition, a subset of patients who received the therapy for longer than 12 months had more than twice the risk.
The authors noted that although men treated with ADT tend to be older and sicker than those who have surgery or radiation for prostate cancer, they adjusted for such factors in the analysis. The researchers added that while the study is the first to link ADT to Alzheimer's disease, testosterone has been shown to aid the growth of brain cells and modulate the accumulation of B-amyloid protein, the main component of amyloid plaques seen in people with Alzheimer's disease.
Nead suggested that ADT might also affect the health of a person's blood vessels or other important systems, which in turn could affect their brain function. However, Nead cautioned that the observational study cannot prove a direct cause-and-effect link between ADT and Alzheimer's disease, while another unknown variable might have influenced the results. "Given that it's a first-time association in a retrospective analysis, this study helps inform future research but it's not appropriate at this point to make treatment decisions off of it," Nead remarked.
