Hormonal therapy may be given before radiotherapy, and sometimes before surgery - this is known as neo-adjuvant therapy. It is also sometimes given after either radiotherapy or surgery, which is known as adjuvant therapy. The aim is to reduce the chance of the cancer coming back.

Hormonal therapy can also be given as a treatment on its own, and has been shown to improve survival.

Hormones control the growth and activity of cells. In order to grow, prostate cancer depends on the hormone testosterone produced by the testicles. Hormonal therapies reduce the amount of testosterone in the body. They can be given as injections or tablets, and occasionally an operation (subcapsular orchidectomy) will be done to remove the part of the testicles that produces testosterone.

Some drugs 'switch off' the production of male hormones from the testicles by reducing the levels of a hormone produced by the pituitary gland. These drugs are called pituitary down-regulators or gonadotrophin releasing hormone analogues (GnRH analogues). They include goserelin (Zoladex®), leuprorelin (Prostap®) and triptorelin (Decapeptyl®).

They are usually given as a pellet injected under the skin of the abdomen (goserelin), or as a liquid injected under the skin or into a muscle (leuprorelin or triptorelin). Injections are given either monthly or every three months.

Other hormonal therapy drugs work by attaching themselves to proteins (receptors) on the surface of the cancer cells. This blocks the testosterone from going into the cancer cells. The drugs are called anti-androgens and are often given as tablets. Commonly used anti-androgens are flutamide (Chimax®, Drogenil®), bicalutamide (Casodex®) and cyproterone acetate (Cyprostat®).

Anti-androgen tablets are also usually given for two weeks before the first injection of a pituitary down-regulator. This prevents tumour flare, which is where symptoms get worse after the first dose of treatment.

Different drugs have different side effects, so it is important to discuss the possible effects with your doctor before you start treatment. Being warned about possible side effects can make them easier to cope with.

We have sections about individual hormonal therapies, with more information about how the drugs work and tips on coping with possible side effects.

Unfortunately most hormonal therapies usually cause erection difficulties and loss of sexual desire for as long as the treatment is given. If the treatment is stopped, the problem may disappear. Some types of anti-androgens are less likely to cause impotence than others.

In about half the men who have hormonal therapies, the side effects that cause them the greatest problem are hot flushes and sweating. Flushes stop if the treatment is stopped. Some medicines can help while you are having treatment.

Hormonal treatment can also make you put on weight and feel constantly tired, both physically and mentally. Some drugs (most commonly flutamide and bicalutamide) may also cause breast swelling and tenderness.

Subcapsular orchidectomy is a simple operation. A small cut is made in the scrotum (the sac that holds the testicles), and the part of the testicles that produces testosterone is removed. The scrotum will be smaller than before. The operation can be done as a day patient under a local or general anaesthetic. Sometimes both testicles are completely removed.

Some men find the idea of this operation very distressing and feel that it makes them less of a man. However, others do not find this a problem. Orchidectomy can be effective in controlling the cancer and reducing symptoms in up to 90% of men (9 in 10). 

After the immediate effects - some pain, and often swelling and bruising of the scrotum - the side effects of hot flushes and sexual impotence are similar to those of hormonal therapy drugs. Subcapsular orchidectomy avoids the use of drugs and some of the possible side effects such as breast enlargement and tenderness.

Subcapsular orchidectomy and other hormonal treatments are equally effective.