Hormone treatment is normally used for men whose cancer has not been cured by surgery or radiotherapy. The timing of hormone treatment in response to a rising PSA level varies. It is based to some extent on the speed of tumour growth and its location.

Hormone treatment is the principal therapy for metastatic prostate cancer – when the prostate cancer cells have escaped from the prostate to grow in other sites of the body. The treatment may be started soon after this diagnosis is made. On occasions a delay in starting does not pose serious risk to the patient.

Hormone treatment may also be used to shrink a tumour before or together with radiotherapy. There is evidence that this hormone therapy is beneficial when used with external beam radiotherapy as a treatment for high risk localised prostate cancers. Once the radiotherapy is complete, the hormone treatment may continue for months to several years. PSA tests are used to check on the tumour control.