Background: Few randomised studies have compared intermittent hormonal therapy with continuous therapy for the treatment of advanced prostate cancer
Objective: To determine if intermittent therapy is associated with a shorter time to progression.
Design Setting and participants: 766 patients with locally advanced or metastatic prostate cancer received a three month induction treatment. 626 patients whose PSA
decreased below 4 ng/ml or to 80% below the initial value, were randomised.
Intervention: Patients received cyproterone acetate (CPA) 200 mg for two weeks and then monthly depot injections of a LHRH analogue plus 200 mg of CPA daily during induction. Patients randomised to the intermittent arm ceased treatment while those randomised to the continuous arm received 200 mg of CPA daily plus a LHRH analogue.
Measurements. Primary outcome was time to subjective or objective progression. Secondary outcomes were survival and quality of life. Time off therapy in the intermittent arm was also recorded.
Results and Limitations: 127 intermittent and 107 continuous patients progressed with hazard ratio 0.81 (95% CI 0.63 to 1.05), p=0.11. There was no difference in
survival, with hazard ratio 0.99 (95% CI 0.80 to 1.23) and 170 deaths on the intermittent and 169 on the continuous arm. A slight excess of cancer deaths in the intermittent treatment arm (106 versus 84) is balanced by a slight excess of cardiovascular deaths in the continuous arm (52 versus 41). Side effects are more pronounced on the continuous arm. Men treated with intermittent therapy reported better sexual function. Median time off therapy for the intermittent patients was 52 weeks (95% CI 39.4, 65.7).
Conclusion: Intermittent therapy should be considered for use in routine practice since it is associated with no reduction in survival, no clinically meaningful
impairment in quality of life, better sexual activity, and considerable economic benefit to individual and community.
- prostate cancer
- hormonal therapy
- intermittent therapy
- quality of life