Intermittent versus continuous androgen deprivation therapy for advanced prostate cancer.

Androgen deprivation therapy (ADT) is still a mainstay of treatment for advanced prostate cancer. Continuous ADT causes considerable patient morbidity including sexual dysfunction, poor mood and physical capacity, changes in body composition and health-care-related costs. Intermittent ADT has been used as an approach to ADT monotherapy to limit morbidity by enabling cyclical recovery of serum testosterone levels. To date, a number of well-performed randomized controlled trials and meta-analyses have demonstrated statistically insignificant differences in oncological outcomes between intermittent and continuous ADT monotherapy. Sexual outcomes, morbidity profiles and cost-savings favour intermittent therapy in most randomized trials, but the benefit for clinical practice is unclear. Despite the growing body of evidence, the optimal administration regime for ADT has not been clearly established and incorporation of adjunctive upfront treatments such as chemotherapy and novel anti-androgen agents has further hampered progress. Recommendations by authoritative urological and oncological societies regarding the use of intermittent ADT are limited. The potential benefits of reduced morbidity for a particular patient must be considered in light of the possible oncological outcomes. Although the oncological changes associated with intermittent ADT are controversial, intermittent ADT does seem to provide symptomatic benefit in patients compared with continuous ADT. However, careful selection of suitable patients is crucial.