It is controversial whether ADT increases the risk of dementia. Previous research yielded inconsistent results, leaving clinicians and patients with lingering concerns.
Swedish researchers have now investigated the potential for dementia in men with prostate cancer who were treated with either ADT, watchful waiting, or orchiectomy. This was a retrospective analysis of data on over 25,000 prostate cancer patients. Men on ADT were further subdivided into those undergoing antiandrogen monotherapy and those who were on an LHRH agonists. To assess relative risk, all men with prostate cancer were compared to age-matched men without prostate cancer.
After a median follow-up time of 4.3 years, 6% of men in the prostate cancer group and 6% of men in the prostate cancer-free group were diagnosis with dementia.
The researchers found a weak but statistically significant increase in the risk of non-Alzheimer’s dementia in men treated with the LHRH agonists or orchiectomy. It isn’t clear though what mechanisms underlie these findings, or whether additional factors may contributing to the results. For example, many symptoms of depression overlap with those of non-Alzheimer’s dementia, and ADT can raise the risk of depression.
Overall, the researchers found no association between ADT and Alzheimer´s dementia or between antiandrogens and non-Alzheimer’s dementia. The data therefore do not support previous reports of increased risk of Alzheimer’s dementia in men on ADT. The findings do suggest though a need to further explore the potential relationships between non-Alzheimer’s dementia, depression, and ADT.
To read the study abstract, see:
Robinson, D., Garmo, H., Van Hemelrijck, M., Damber, J. E., Bratt, O., Holmberg, L., Wahlund, L. O., Stattin, P., & Adolfsson, J. (2019). Androgen deprivation therapy for prostate cancer and risk of dementia. BJU International. [Epub ahead of print]. doi: 10.1111/bju.14666