Photo by Clay Eals
A commonly used treatment for relapsed prostate cancer may improve some aspects of cognitive functioning, according to preliminary results from investigators in the Hutch Clinical Research Division and the University of Washington.
Drugs that block the production of testosterone, a hormone that accelerates growth of prostate tumors, were associated with a significant improvement in a subset of cognitive skills, including multitasking ability, in 16 men after one month of treatment.
The results were presented at the American Urological Association's annual meeting in Anaheim, Calif., earlier this month.
Dr. Andrea Veatch, oncology fellow and lead author of the study, said she and Dr. Celestia Higano, UW professor of medicine and urology, were prompted to initiate the study by anecdotal reports from family of prostate-cancer patients.
"It's not uncommon for wives to complain that their husbands can no longer balance a checkbook or are forgetful when the men are being treated with androgen-suppression therapy," she said. "We hypothesized that men may be suffering from memory deficits as a result of testosterone suppression."
Men diagnosed with prostate cancer typically are treated initially with surgery or radiation and subsequently monitored for recurrence by blood testing for the presence of prostate-specific antigen (PSA). Patients who suffer relapse indicated by elevated PSA levels may be treated with testosterone suppression.
Because of the side effects caused by hormone suppression, Higano and colleagues have studied the efficacy of using intermittent therapy to treat men with relapsed prostate cancer. While initial work focused on the effects of the treatment on bone mineral density, Higano said that intermittent hormone suppression provides a unique opportunity to study many aspects of how testosterone affects physiology.
"This type of treatment allows us to measure a variety of parameters before men begin their therapy, during the treatment, and while men have stopped treatment before beginning a new cycle," she said.
For this study, Veatch and Higano collaborated with UW behavioral scientist Dr. Monique Cherrier, who designed tests to evaluate a variety of cognitive skills including verbal, spatial and multitasking abilities.
Men in the study complete cognitive testing twice before beginning a nine-month cycle of hormone suppression therapy to establish a baseline and are tested again at one and nine months after they initiate treatment. The participants also undergo testing at 12 months, when they have been free of the drugs for three months.
Surprisingly, Higano said, after one month of therapy, divided and selective attention - skills related to multi-tasking - significantly improved.
Veatch said it is unknown if the improvements are reversible, or if any cognitive functions will decline over the course of the therapy.
"We'll be testing the men three months after treatment stops to see whether these skills come back to normal levels or whether there are long-term effects," she said. "Obviously, the answers could have an impact on patient care."