- Prior hormone therapy in the form of either medical or surgical castration is required. If the patient is receiving medical androgen abalation a castrate level of testosterone (1.7nmol/L) must be present. Therapy with LHRH agonist must continue for those prostate cancer patients already receiving this treatment at the time of registration. If the patients has discontinued the LHRH agonist, this must be restarted and a castrate level of testosterone must be present.