Intermittent versus continuous androgen deprivation therapy in advanced prostate cancer.

Intermittent androgen deprivation is increasingly employed as an alternative to continuous life long androgen deprivation therapy for men with advanced or recurrent prostate cancer. Two recent phase III trials have clarified the benefits of intermittent therapy. In men with non-metastatic disease with PSA recurrence after definitive local therapy, intermittent therapy showed equivalent survival to continuous therapy, with significant improvements in quality of life. Patients on intermittent therapy experience improved bone health, less metabolic and hematologic disturbances, fewer hot flashes, as well as improved sexual function. In men with metastatic disease, the data is less clear. The long-awaited results of SWOG 9324 comparing intermittent to continuous therapy in metastatic disease showed a trend to worse outcome in the patients with 'minimal' metastatic disease, and no difference in those with widespread bone mets. The significance of this observation is in dispute. This review also addresses practical issues in the use intermittent therapy, including patient selection, follow-up and cycling of therapy. The recent results of randomized clinical trials now establish that intermittent androgen deprivation therapy is an approach that should be considered the standard of care for most patients with non-metastatic prostate cancer requiring hormonal therapy.