Intermittent androgen blockade in prostate cancer: rationale and clinical experience

Cancer of the prostate continues to be one of the most common malignancies in men in Europe, with a large number of patients presenting with advanced disease. The current standard treatment for metastatic cancer of the prostate, permanent androgen withdrawal, is palliative. Patients treated with permanent androgen blockade usually relapse and die secondary to prostate cancer's ability to progress to an androgen-independent state of growth. Based on experimental and preclinical studies, intermittent androgen blockade appears to be a potential alternative to permanent androgen blockade. Through the cycling of reversible androgen suppression, there appears to be recovery of apoptosis and subsequent slower progression to an androgen-independent state. In this paper experimental and preclinical studies concerning intermittent androgen blockade are reviewed. At present several prospective randomized trials are under way to test intermittent androgen blockade as an alternative treatment in various stages of cancer of the prostate. However, until the results of these trials are available, this approach remains experimental.