a v a i l a b l e a t w w w . s c i e n c e d i r e c t . c o m j o u r n a l h o m e p a g e : w w w . e u r o p e a n u r o l o g y . c o m Article info AbstractBackground: Few randomised studies have compared antiandrogen intermittent hormonal therapy (IHT) with continuous maximal androgen blockade (MAB) therapy for advanced prostate cancer (PCa). Objective: To determine whether overall survival (OS) on IHT (cyproterone acetate; CPA) is noninferior to OS on continuous MAB. Design, setting, and participants: This phase 3 randomised trial compared IHT and continuous MAB in patients with locally advanced or metastatic PCa. Intervention: During induction, patients received CPA 200 mg/d for 2 wk and then monthly depot injections of a luteinising hormone-releasing hormone (LHRH; triptoreline 11.25 mg) analogue plus CPA 200 mg/d. Patients whose prostate-specific antigen (PSA) was <4 ng/ml after 3 mo of induction treatment were randomised to the IHT arm (stopped treatment and restarted on CPA 300 mg/d monotherapy if PSA rose to 20 ng/ml or they were symptomatic) or the continuous arm (CPA 200 mg/d plus monthly LHRH analogue). Outcome measurements and statistical analysis: Primary outcome measurement was OS. Secondary outcomes included cause-specific survival, time to subjective or objective progression, and quality of life. Time off therapy in the intermittent arm was recorded. Results and limitations: We recruited 1045 patients, of which 918 responded to induction therapy and were randomised (462 to IHT and 456 to continuous MAB). OS was similar between groups ( p = 0.25), and noninferiority of IHT was demonstrated (hazard ratio [HR]: 0.90; 95% confidence interval [CI], 0.76-1.07). There was a trend for an interaction between PSA and treatment ( p = 0.05), favouring IHT over continuous therapy in patients with PSA 1 ng/ml (HR: 0.79; 95% CI, 0.61-1.02). Men treated with IHT reported better sexual function. Among the 462 patients on IHT, 50% and 28% of patients were off therapy for 2.5 yr or >5 yr, respectively, after randomisation. The main limitation is that the length of time for the trial to mature means that other therapies are now available. A second limitation is that T3 patients may now profit from watchful waiting instead of androgen-deprivation therapy. Conclusions: Noninferiority of IHT in terms of survival and its association with better sexual activity than continuous therapy suggest that IHT should be considered for use in routine clinical practice.