Intermittent endocrine treatment

Intermittent endocrine treatment or cyclic therapy of prostate cancer aims at prolonging survival by delaying progression to androgen independence and at improving quality of life by avoiding the side effects of continuous an drogen ablation. In this paper we first review the available experimental d ata suggesting the clinical application of this therapeutic strategy and in terpret them with caution. We then examine the published reports of phase I I clinical studies showing the feasibility of this approach. Intermittent e ndocrine treatment is capable of inducing multiple apoptotic regressions; i mprovement in the sense of well-being and quality of life - including sexua l function - is regularly reported. A period of 6-9 months on therapy is us ually recommended: the mean off-therapy interval approaches 50% of the dura tion of the treatment cycle. The mean time to disease progression was 32 mo nths. The definitive answer to the important question of prolonged survival awaits the completion of ongoing randomized studies.