Prostate cancer is the most frequent cancer in men. A discovery of major importance in the endocrinology of prostate cancer is that the testes contribute only 60% of total androgens in adult men; the remaining 40% are synthesized in peripheral tissues, including the normal and cancerous prostate, from inactive androgen precursors of adrenal origin. Using a combination therapy that includes a pure blocker of the androgen receptor or antiandrogen and castration (medical with luteinizing hormone-releasing hormone agonist or surgical by orchiectomy), the duration of response and survival have been demonstrated to be prolonged for the first time in advanced prostate cancer.