In patients with metastatic hormone-sensitive prostate cancer (PCa), intermittent androgen deprivation is associated with slightly, but not significantly, worse survival than continuous androgen deprivation, according to a study published in the New England Journal of Medicine (2013;368:1314-1325).
Maha Hussain, MD, from the University of Michigan in Ann Arbor, and colleagues analyzed data from 1,535 men with metastatic hormone-sensitive PCa who had been receiving a luteinizing hormone-releasing hormone analog and an antiandrogen agent for seven months. If PSA levels fell to 4 ng/mL or lower after treatment, the men were randomly assigned to continuous or intermittent androgen deprivation.
After a median follow up of 9.8 years, the researchers found that median survival was lower for the intermittent therapy group (5.1 vs. 5.8 years). Erectile function and mental health were significantly better after intermittent therapy, but only at three months. The two groups had similar numbers of treatment-related high-grade adverse events.
Among men with metastatic hormone-sensitive PCa, the investigators concluded, the confidence interval for survival exceeded the upper boundary for noninferiority, suggesting that they would not rule out a 20% greater risk of death with intermittent therapy than with continuous therapy, but too few events occurred to rule out significant inferiority of intermittent therapy.