Hormonal therapy for advanced prostate cancer

Transcription

1 Hormonal therapy for advanced prostate cancer This information is an extract from the booklet Understanding advanced (metastatic) prostate cancer. You may find the full booklet helpful. We can send you a copy free see page 5. 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, which is 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. You may be offered a combination of different hormonal therapy drugs. If you ve 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 called a 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 hormonal therapy. Although there are several 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, or other palliative treatments to relieve symptoms. Macmillan and Cancerbackup have merged. Together we provide free, high quality information for all. Questions about cancer? Ask Macmillan of 5

2 Hormonal therapy for advanced prostate cancer Benefits Hormonal therapies can shrink the cancer, delay its growth, and relieve symptoms for many months or years. Risks It can cause a range of side effects that include breast swelling, hot flushes, difficulty getting and maintaining an erection (impotence) and lowered sex drive. Injections Some drugs switch off the production of hormones by 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 ) 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. Tablets 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 anti-androgens are: bicalutamide (Casodex ) flutamide (Chimax, Drogenil ) 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 when symptoms get worse after the first dose of treatment. Page 2 of 5 Questions about cancer? Ask Macmillan

3 Anti-androgen withdrawal response Hormonal therapy for advanced prostate cancer 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 antiandrogen may make the cancer shrink for a while. This is known as an anti-androgen withdrawal response and occurs in up to a quarter of men (25%) who stop antiandrogen therapy. Side effects of hormonal therapy Unfortunately most hormonal therapies can cause erection difficulties (impotence) and loss of sexual desire (libido) for as long as the treatment is given. If the treatment is stopped, the problem may resolve. Some anti-androgens are less likely to cause impotence than others. In some men who have hormonal therapies, the side effects that cause 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. We can send you information about this. 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 feel 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 to ease this. Different drugs have different side effects, so it s 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 fact sheets about individual hormonal therapies, with more information about how the drugs work and tips on coping with possible side effects. Questions about cancer? Ask Macmillan Page 3 of 5

4 Hormonal therapy for advanced prostate cancer Subcapsular orchidectomy (removal of testicles) 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 don t 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. Other hormonal treatments Once the cancer is no longer responding to GnRH analogues or anti-androgens, many men can have further periods of remission and good quality of life with either diethylstilbestrol (Stilboestrol ) or steroids. Stilboestrol is a man-made drug that is very similar to the female hormone oestrogen. It reduces the amount of testosterone in the body. It s taken as a tablet once a day. It can cause loss of sex drive, loss of facial hair and may cause some breast tenderness and fullness. Stilboestrol can also increase the risk of getting a blood clot (deep vein thrombosis). Steroids are also taken as tablets and either prednisolone or dexamethasone may be used. They may cause some weight gain and increase in appetite, but are usually well-tolerated. Page 4 of 5 Questions about cancer? Ask Macmillan

5 More information and support Hormonal therapy for advanced prostate cancer If you have any questions about cancer, ask Macmillan. If you need support, ask Macmillan. Or if you just want someone to talk to, ask Macmillan. Our cancer support specialists are here for everyone living with cancer, whatever you need. Call free on , Monday Friday, 9am 8pm We make every effort to ensure that the information we provide is accurate but it should not be relied upon to reflect the current state of medical research, which is constantly changing. If you are concerned about your health, you should consult your doctor. Macmillan cannot accept liability for any loss or damage resulting from any inaccuracy in this information or third party information such as information on websites to which we link. Macmillan Cancer Support Registered charity in England and Wales (261017), Scotland (SC039907) and the Isle of Man (604). Registered office 89 Albert Embankment, London, SE1 7UQ Questions about cancer? Ask Macmillan Page 5 of 5