Androgen Deprivation Therapy May Double Risk of Dementia for Men With Prostate Cancer

Men with prostate cancer being treated with a common hormone therapy may be doubling their risk of dementia, according to a study conducted by researchers at the University of Pennsylvania.

This is the first study to show a significant association between dementia and androgen deprivation therapy (ADT) used in men. The patients with the highest risk were those who were on ADT for the longest period of time.

“Currently there is a lot of discussion about how we treat patients with prostate cancer, how we screen prostate cancer and whether we potentially give some patients more treatment than they may benefit from,” said lead author Kevin Nead, M.D., a resident in the department of Radiation Oncology at the Perelman School of Medicine at the University of Pennsylvania, in an interview with CURE. “I think in that environment, the findings about side effects from that treatment are very important because they might change the conversation a little bit.”

The study, published in JAMA Oncology, included 9,272 individuals with prostate cancer, and of those, 1,826 men received ADT. Researchers used a text-processing method to analyze electronic medical record data from Stanford University Hospital from 1994 to 2013. The median follow-up was 3.4 years.

Researchers found that the absolute increased risk of developing dementia was 4.4 percent at five years: 7.9 percent among those who received ADT versus 3.5 percent in those who did not.

Individuals with at least 12 months of ADT use had the greatest absolute increased risk of dementia. There was no evidence of an interaction between use of ADT and age. The mean age of the patients was 66.9 years, and they were mainly white (58.8 percent).

Last year, researchers published a study that discovered an association between Alzheimer’s disease and ADT, which has been a common treatment for prostate cancer since the 1940s. However, this study suggests a broader neurocognitive risk. Nead explained there are ways that ADT and low testosterone can increase the risk of something like dementia.

“Testosterone is really important for the health of neurons in the brain, and if you lower testosterone, you kind of decrease the ability of the body to prevent damage or repair things when they need to be repaired,” he said. “ADT and low testosterone also increase cardio metabolic disease risk and that can lead to changes in cardiovascular and vascular function, which might decrease many tissues, one of them being the brain.”

While the findings of this study are significant, Nead added that this is still in the research phase. More research and controlled studies need to be conducted for further evidence. He also reminded that ADT is still a proven effective treatment for prostate cancer.

“I think at this point, based on very early research that is more hypothesis-generating, we need to do more research,” said Nead. “It would be really hard to justify not using a medication that we know extends life for a possible negative consequence that at this point is potential, probable at best, but not proven.”

Patients and caregivers should remember to always talk about the risks and benefits for any treatment that they are considering with their physician, stated Nead.