MONDAY, July 8, 2019 (HealthDay News) — Soon after a man is diagnosed with prostate cancer, drugs that lower levels of testosterone are often offered as treatment, since testosterone fuels the cancer’s growth.
But a major new study suggests that this approach might have an unwanted side effect: Higher odds for Alzheimer’s disease and other dementias.
“Our results suggest that clinicians need to raise their awareness about potential long-term cognitive effects of hormone therapy and discuss these risks with their patients,” said study author Ravishankar Jayadevappa.
He’s a research associate professor of geriatrics at the University of Pennsylvania’s Perelman School of Medicine in Philadelphia.
One expert said it does raise troubling questions.
“Most of us are becoming as afraid of getting Alzheimer’s as we are of getting cancer,” said Dr. Elizabeth Kavaler, a urology specialist at Lenox Hill Hospital in New York City. “When a study pits one debilitating condition against another, it instills fear in patients.”
But the treatment — called androgen-deprivation therapy — remains the “gold standard” for many cases of prostate cancer, according to Kavaler. Therefore, the new data means “tough decision-making” for patients and their physicians, she said.
In the new study, Jayadevappa’s group took a look back at U.S. National Cancer Institute data on over 154,000 prostate cancer patients who were diagnosed between 1996 and 2003. About 62,000 received hormone-depleting therapy within two years of their diagnosis, while about 92,000 did not.
In total, 13% of men who had received the therapy went on to develop Alzheimer’s disease over eight years of follow-up, compared to 9% who hadn’t gotten the treatment, the study found. According to the researchers, the lifetime prevalence of Alzheimer’s disease in men generally is about 12%.
When the team looked at diagnoses of all forms of dementia, 22% of those who’d received the therapy received such a diagnosis, compared to 16% of those who hadn’t undergone hormonal therapy.
Jayadevappa’s team noted that earlier, smaller studies have found similar trends.
However, “to our knowledge, this is one of the largest studies to date examining this association, and it followed patients for an average of eight years after their prostate cancer diagnosis,” he said in a university news release.