Hormonal therapy for early prostate cancer
Hormonal therapy may be given on its own as a treatment for men who aren’t well enough for surgery or radiotherapy. It may also be given to men who have been monitored using watchful waiting and whose cancer has started to progress.
Hormonal therapy may be given before radiotherapy. This is known as neo-adjuvant therapy, which can help make radiotherapy treatment more effective. Hormonal therapy is also sometimes given after radiotherapy (adjuvant therapy), where the aim is to reduce the chance of the cancer coming back.
Hormones control the growth and activity of normal cells. In order to grow, prostate cancer depends on the hormone testosterone, which is produced by the testicles. Hormonal therapies reduce the amount of testosterone in the body. They can be given as injections or tablets.
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 antagonists (GnRH antagonists). They include:
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). 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. These drugs are called anti-androgens and are often given as tablets.
Commonly used anti-androgens are:
Anti-androgen tablets are usually given for two weeks before the first injection of a pituitary down-regulator. This prevents tumour flare, which is when symptoms from the prostate cancer get worse after the first dose of treatment.
Research trials are being carried out to find out whether it’s better to start hormonal therapy before or after the surgery or radiotherapy, and to find out how long to give the treatment for (it can range from two months to two years).
Unfortunately, most hormonal therapies usually cause erection difficulties (impotence) 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.
Hormonal therapy can cause bone thinning (osteoporosis), which can sometimes lead to tiny cracks in the bone (fractures). The risk of bone thinning increases if you are taking hormonal therapy for long periods. You may have to have a special type of x-ray called a DEXA scan (dual-energy x-ray absorptiometry scan). This scan allows doctors to check the bones for any areas of weakness or fractures. You might also be given bone-strengthening drugs called bisphosphonates, which can help if you experience problems. Our section about bone health has more information.
Most men who have hormonal therapy experience hot flushes and sweating. Your doctor can prescribe medicines to help relieve this side effect while you’re having treatment. The flushes and sweats will stop if treatment is stopped.
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.
Different drugs have different side effects, so it’s important to discuss the possible effects with your doctor or specialist nurse before you start treatment. By being aware of the effects that may occur, you may find them easier to cope with.
Advantages and disadvantages
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Hormonal therapy can slow or stop the growth of cancer cells for many years. It doesn’t involve surgery or radiation, so there’s little risk of bowel or bladder problems.
Hormonal therapy won’t get rid of all the cancer cells if it’s the only treatment given. It can cause a range of side effects that include breast swelling, hot flushes, erection problems (impotence) and a lowered sex drive.