Androgen Deprivation Therapy for Prostate Cancer May Increase Risk of Dementia: Study

For men diagnosed with prostate cancer, a common testosterone reducing therapy may place them at increased risk of developing dementia, according to the findings of new research.

In a study published this week in the medical journal JAMA Oncology, researchers analyzed data involving nearly 10,000 men with prostate cancer, concluding that those treated with androgen deprivation therapy were more likely to develop dementia than those who do not receive the therapy.

Androgen deprivation therapy is commonly used to treat prostate cancer in many men. The treatment is used to reduce testosterone levels to prevent the male hormones, androgens, from stimulating the cancer cells. The therapy can often make prostate cancers shrink or grow more slowly.

Typically, androgen deprivation therapy is done by removing the testicles or by using specific drugs to lower androgen levels. It is often referred to as “chemical castration.”

Researchers analyzed electronic medical record data from 9,455 patients with a prostate cancer diagnosis by the age of 18. Patients were selected from an academic medical center from 1994 to 2013 and followed up, on average, three years later.

Overall, researchers said there was a significant association between androgen deprivation therapy and increased risk of dementia. Androgen deprivation patients had more than double the risk of developing dementia than those who did not receive the therapy.

Researchers noted the results remained similar when patients with Alzheimer’s disease were excluded.

Comparatively, patients who underwent androgen deprivation therapy had an increased risk of 7.9 percent of developing dementia at five years after receiving the treatment. Whereas, patients who did not get androgen deprivation therapy had a 3.5 percent increased risk.

Patients who had undergone androgen deprivation therapy for at least one year had the greatest increased risk of dementia. Patients who received androgen deprivation therapy and were over the age of 70 had the lowest chance of staying dementia free.

The study also adjusted for smoking, diabetes, cardiovascular disease, cancer and other factors.

Other research has linked androgen deprivation therapy to increased risk of Alzheimer’s and depression. However, this new study focused on all types of dementia.

Researchers say more studies are needed to determine the relationship between androgen deprivation therapy and dementia. In the meantime, patients shouldn’t discontinue therapy, instead have a risk-benefit discussion with their doctors.

Nearly 200,000 men in the U.S. are diagnosed with prostate cancer every year, according to the U.S. Centers for Disease Control and Prevention. About 30,000 die from prostate cancer each year. Aside from non-melanoma skin cancer, prostate cancer is the most common cancer among men in the U.S. and is the leading cause of male cancer death.