A study published in JAMA Oncology stated that androgen deprivation therapy (ADT), a standard treatment for men with prostate cancer, may raise the risk of dementia. The use of ADT has increased dramatically in the last few decades with as many as 500,000 men currently receiving ADT in the United States.
“ADT has a demonstrated survival benefit in some patients with prostate cancer. However, it also has been linked to several adverse health effects”, wrote study authors led by Dr. Kevin T. Nead of Stanford University School of Medicine in California. “A growing body of evidence supports a link between ADT and cognitive dysfunction, including Alzheimer disease.”
The study authors analyzed medical records of prostate cancer patients treated between 1994 and 2013. The final study included 9,272 men with prostate cancer who had not previously been diagnosed with dementia. Of that group, 1,826 patients received treatment including ADT. Over half of the men were white with a mean age of 66.9. After a follow-up of 3.4 years, 314 cases of dementia were diagnosed. The study revealed a statistically significant link between ADT use and risk of dementia.
The median time for the dementia diagnosis was four years. The risk of developing dementia at five years in men treated with ADT was 7.9 percent compared with 3.5 percent in those who did not undergo ADT, according to cancernetwork.com.
Men with the greatest risk of dementia were those who received ADT for at least 12 months. When patients who received chemotherapy were excluded, results were similar. “We show a dose response effect between greater duration of use of ADT and increased risk of dementia. Finally, we find that use of ADT increases the risk of dementia, regardless of age, but that older men receiving ADT were the least likely to remain dementia free,” the authors wrote. Patients treated with ADT who were 70 or older had the lowest cumulative probability of remaining dementia-free, according to Kaplan-Meier analysis.
Androgens appear to have a role in the health and viability of neurons in the central nervous system and testosterone analogs have been shown to have a neuroprotective function, revealing a potential mechanism of how ADT may have an influence on the development of dementia.