Cognitive impairment in men treated with luteinizing hormone-releasing hormone agonists for prostate cancer: a controlled comparison

Data suggest that treatment with luteinizing hormone-releasing hormone (LHRH) agonists may be associated with reduced cognitive functioning. The purpose of the current study was to compare rates of clinically significant cognitive impairment in men treated with LHRH agonists to a matched sample of healthy men without cancer. Participants were 48 men receiving LHRH agonist therapy for prostate cancer and 48 men with no history of cancer matched to patients on age and education. Participants were administered a battery of neuropsychological tests assessing the domains of verbal memory, verbal fluency, visuospatial memory, visuospatial abilities, and executive function. Clinically significant impairment on individual tests was defined as -1.5 SD below the normative mean; overall impairment was defined as impaired performance on two or more tests. Patients did not differ from comparison subjects in age, ethnicity, race, education, or annual household income (p's > 0.05). No statistically significant differences in test means were found. Nevertheless, patients displayed greater overall impairment in cognitive functioning than comparison subjects (42% of patients versus 19% of comparison subjects, p < 0.05). Among patients, prior prostatectomy was associated with impaired immediate and delayed verbal memory (p's < 0.05). Current findings suggest that LHRH agonists and surgery for prostate cancer are associated with clinically significant impairment in cognitive functioning. Longitudinal studies are needed to examine changes in cognitive impairment before and after surgical and hormonal treatment for prostate cancer. Patients undergoing LHRH agonist therapy should be monitored for cognitive changes while on treatment.