Hormonal therapy is the main treatment for men with advanced prostate cancer. It can shrink the cancer, delay its growth, and reduce symptoms. In order to grow, prostate cancer depends on the hormone testosterone produced by the testicles. Hormonal therapies reduce the amount or activity of testosterone in the body.

There are a range of hormonal therapies that can be used to treat advanced prostate cancer. If you have already had hormone treatment you may be advised to change to a different type. Hormonal therapies can be given as injections or tablets, or occasionally an operation (subcapsular orchidectomy) may be done to remove the part of the testicles that produces testosterone.

Hormonal treatment works well for most men with advanced prostate cancer, and the cancer can often be controlled for some time. Your doctor will monitor the cancer’s response to the hormonal therapy by assessing any symptoms and examining you. Your PSA level will also be measured as this is usually a very good guide to the effectiveness of the treatment. If the cancer starts to grow again, your doctor may suggest you change to a different hormone therapy.

Although there are different medicines that can be used, at some point the cancer will stop responding to hormonal therapy. This is known as hormone-refractory prostate cancer. If hormonal therapy is no longer working, your doctor may suggest chemotherapy as an alternative treatment, or other palliative treatments to relieve symptoms.

Some drugs 'switch off' the production of hormones from the testicles by reducing the levels of a hormone produced by the pituitary gland. These drugs are called pituitary downregulators 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) in the cancer cells. This blocks the testosterone from acting on the cancer cells. The drugs are called anti-androgens and are given as tablets. Commonly used antiandrogens are flutamide (Chimax®, Drogenil®), bicalutamide (Casodex®) and cyproterone acetate (Cyprostat®).

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

If hormonal therapy with an anti-androgen drug has been given for some months or years and the cancer begins to grow again despite the treatment, stopping the anti-androgen may make the cancer shrink for a while. This is known as an anti-androgen withdrawal response and occurs in up to one-quarter (25%) of men who stop anti-androgen therapy.

Unfortunately most hormonal therapies can 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 some men who have hormonal therapies, the side effects that cause them the greatest problem are hot flushes and sweating. These stop if the treatment is stopped and the testosterone levels recover. In the meantime some medicines can help.

Hormonal treatment can also make you put on weight and feel tired, both physically and mentally. Some drugs (most commonly flutamide and bicalutamide) may also cause your breasts to swell and make them more tender. Your doctors may advise a short course of low-dose radiotherapy to your breasts before you start the drugs, to try to prevent swelling. If breast-swelling does occur then a tablet called tamoxifen may help ease this.

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.

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 under a local anaesthetic without the need to stay in hospital overnight. 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 it a problem. Orchidectomy is as effective as pituitary down regulators and avoids the need for regular injections.

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.