Androgen deprivation therapy for prostate cancer increases risk of Alzheimer disease and dementia

Androgen deprivation therapy for prostate cancer increases the risk of Alzheimer disease and dementia among the elderly, finds a new study.

A new population-based study spanning 10 years or more following the diagnosis of prostate cancer have suggested a possible relationship between androgen deprivation therapy (ADT), treatment for prostate cancer, and the risk of Alzheimer disease or dementia. The researchers have found that exposure to androgen deprivation therapy was associated with an increased risk of Alzheimer disease and dementia. The study has been published in the journal JAMA.

These results should influence decision making among elderly who are considering ADT for the treatment of prostate cancer, especially those with longer expected lifespan.

Prostate cancer grows in response to the presence of androgens -- male sex hormones such as dihydrotestosterone and testosterone.

Androgen deprivation therapy blocks the effect of androgens (by removing circulating androgens) on prostate cancer cells and is one approach doctors may use to tackle the disease. Side effects include osteoporosis, vasomotor symptoms, sexual dysfunction, and possibly adverse cardiovascular events.

Some previous studies have suggested a potential link between ADT and dementia but the evidence is not clear. Ravishankar Jayadevappa, Leonard Davis Institute of Health Economics, Perlman School of Medicine, University of Pennsylvania, Philadelphia, and colleagues conducted this retrospective cohort study to analyze the association between ADT exposure and diagnosis of Alzheimer disease or dementia among elderly men with prostate cancer.

For the purpose, they evaluated data from about 154,000 men (mean age, 75) with localized or advanced prostate cancer from a national cancer registry; 62,000 received ADT within 2 years of diagnosis, and 92,000 did not.

Key findings of the study include:

• During a mean follow-up of 8 years, patients who received ADT were more likely than those who did not receive ADT to receive diagnoses of Alzheimer disease (13% vs. 9%) or dementia (22% vs. 16%) during a mean follow-up of 8 years.


• For 1 to 4 doses of androgen deprivation therapy (ADT), the Hazard Ratio was 1.19 for Alzheimer disease and 1.19 for dementia.


• For 5 to 8 doses of androgen deprivation therapy (ADT), the HR was 1.28 for Alzheimer disease and 1.24 for dementia.


• For more than 8 doses of androgen deprivation therapy, HR was 1.24 for Alzheimer disease and 1.21 for dementia.

"Our results suggest that clinicians need to carefully weigh the long-term risks and benefits of exposure to ADT in patients with a prolonged life expectancy and stratify patients based on dementia risk prior to ADT initiation," concluded the authors.

To read the complete study follow the link: doi:10.1001/jamanetworkopen.2019.6562