Androgen deprivation therapy may lead to cognitive impairment in prostate cancer patients
Men who are on androgen deprivation therapy (ADT) have greater chance of experiencing impaired cognitive function. These findings were published in the Journal of Clinical Oncology (2015; doi:10.1200/JCO.2014.60.1963).
Cognitive impairment can occur in cancer patients who are treated with a variety of therapies, including radiation therapy, hormone therapy, and chemotherapy. The effect is commonly called chemo brain when it occurs after chemotherapy treatment. Signs of cognitive impairment include forgetfulness, inability to concentrate, problems recalling information, trouble multi-tasking, and becoming slower at processing information. The number of people who experience cognitive problems following cancer therapy is broad, with an estimated range of 15% to 70% of patients.
Several studies have analyzed this side effect in patients with breast cancer, but few have investigated cognitive impairment in men following ADT for prostate cancer.
Androgen deprivation therapy is commonly used to treat prostate cancer, often on an open-ended basis as therapy for advanced prostate cancer. An estimated 44% of men with prostate cancer undergo ADT at some point. The goal of this type of therapy is to block the male hormones, including testosterone, from stimulating the growth of the prostate cancer cells. However, the effects of ADT on cognitive function in men with prostate cancer have not been given much attention.
In this study, researchers from the Moffitt Cancer Center in Tampa, Florida, used formal tests to compare the cognitive ability of 58 patients receiving ADT for prostate cancer with 84 patients with prostate cancer who did not receive ADT and 88 men with no cancer.
The men treated with ADT were 70% more likely to experience cognitive impairment at 6 months, and more than twice as likely to experience cognitive impairment at the 1-year time point.
The researchers also reported for the first time a possible genetic link among those men who experience cognitive impairment during ADT. They found that patients who have a particular version of the GNB3 gene were 14x more likely to suffer from cognitive problems following ADT.
“Studies like ours show the importance of identifying genetic predictors of cognitive impairment. This information can be used to further personalize cancer care based on patients' unique characteristics and to identify which patients may be prone to intolerance of this standard type of treatment,” said Mayer Fishman, MD, PhD, senior member of Moffitt's Genitourinary Oncology Program.
The results of this study may have implications for physicians trying to decide on the best therapeutic options for their patients.
“The risk of cognitive impairment should be considered when deciding whether or not to receive androgen deprivation therapy for prostate cancer,” said Brian Gonzalez, PhD, a postdoctoral fellow in the Health Outcomes and Behavior Program at Moffitt.
The research was supported by grants received from the National Cancer Institute.