(ChemotherapyAdvisor) – Intermittent androgen suppression was noninferior to continuous therapy for overall survival and improved some quality-of-life factors in men with prostate cancer treated for rising prostate-specific antigen (PSA) level following radiotherapy, a study reported in the September 6 issue of the New England Journal of Medicine.
Patients with a PSA level >3ng/mL more than 1 year following primary or salvage radiotherapy for localized prostate cancer were randomly assigned to intermittent therapy (n=690), with treatment provided in 8-month cycles and nontreatment period determined by PSA level, or continuous therapy (n=696).
At a median follow-up of 6.9 years, 268 men had died in the intermittent therapy arm and 256 in the continuous therapy arm; median overall survival was 8.8 years and 9.1 years, respectively (HR 1.02; 95% CI, 0.86–1.21), Juanita M. Crook, MD, of the British Columbia Cancer Agency, Cancer Centre, Kelowna, BC, Canada, and colleagues reported. Estimated 7-year cumulative rates of disease-related death were 18% in the intermittent therapy arm and 15% in the continuous therapy arm (P=0.24).
Full testosterone recovery occurred in 35% of men in the intermittent-therapy group; testosterone recovery to the trial-entry threshold occurred in 79%, the investigators reported. “Intermittent therapy provided potential benefits with respect to physical function, fatigue, urinary problems, hot flashes, libido, and erectile function,” they wrote, and no significant between-group differences in adverse events were observed.
In an accompanying editorial, Oliver Sartor, MD, of Tulane University School of Medicine, New Orleans, LA, noted that although this study comparing the two treatment regimens is the most definitive to date, it remains “unclear which men with rising PSA levels needed treatment” or what might be “the best possible timing of androgen-deprivation therapy for those clearly in need of treatment.”
“Does early androgen-deprivation therapy in asymptomatic men with rising PSA levels provide more benefit than treatment in symptomatic men with metastases?” Dr. Sartor asked. “This question bedevils our field, and we are no closer to an answer now than we were before.”