A small study of prostate cancer (search) patients taking hormone therapy shows small, temporary effects on some areas of thinking.

Prostate cancer hormone therapy -- doctors call it androgen deprivation therapy (search) -- has been increasingly used in recent years.

Prostate cancer grows when exposed to the male hormone testosterone. Prostate cancer hormone treatment is used to stop the production of testosterone, either temporarily or permanently.

Estrogen Levels and Thinking

Participants were 23 men who were 65 years old, on average. All had been recently diagnosed with prostate cancer and hadn’t taken hormone therapy before. None showed signs of dementia.

Like many patients, the men were started on prostate cancer hormone therapy. The study was conducted by researchers including Eeva Salminen, MD, of the oncology and radiology department at Finland’s University of Turku.

Hormone therapy also lowers estrogen levels. And since lower estrogen levels have been tied to decreased thinking ability in women (and to a lesser degree in men), Salminen and colleagues wanted to see how hormone therapy affected men’s thinking. Their findings appear in the April 1 edition of the journal Cancer.

The men received prostate cancer hormone therapy for a year. They took thinking tests three times during the year. The tests covered 31 mental skills including visual memory, visual recognition, and verbal ability.

Blood samples were taken to measure the men’s hormone levels. As expected, testosterone levels dropped significantly and stayed low throughout prostate cancer hormone therapy. Estrogen levels, measured as estradiol, also dropped significantly during the first six months and stayed low.

As prostate cancer hormone therapy continued, some -- but not all -- areas of thinking changed as estradiol declined.

Quick Improvement

After six months of hormone therapy, visual memory of figures and recognition speed of numbers were marginally worse than before the men started treatment. But by one year, both skills had improved. In addition, verbal fluency improved after one year of prostate cancer hormone therapy.

The greatest changes in thinking were seen in men with the largest declines in estradiol levels.

The results suggest marginal associations between hormone levels and certain mental abilities, say the researchers.

But despite those changes, mental ability appears to be well preserved during one year of prostate cancer hormone therapy in men, write the researchers. They add that they’re not sure how longer periods of treatment affects thinking, or what the effects are on men with brain or psychological problems.

By Miranda Hitti, reviewed by Michael W. Smith, MD

SOURCES: Salminen, E. Cancer, April 1, 2005; vol 103: pp 1-7. WebMD Medical Reference from Healthwise: “LH-RH Agonists/GnRH Agonists for Prostate Cancer.” News release, John Wiley & Sons, Inc.