Side effects of hormone therapy for prostate cancer

• A quick guide to what's on this page
• What causes side effects
• Erection problems (impotence)
• Hot flushes and sweating
• Breast tenderness
• Tumour flare pain
• Side effects from long term treatment

Hormone therapies for prostate cancer cause side effects because they reduce the levels of male hormones in the body. Some side effects are common to all hormone therapies used for prostate cancer. Some effects vary from drug to drug.

Difficulty getting an erection, or impotence, is a common side effect of hormone therapy for prostate cancer. You will not be able to get an erection as long as you are taking pituitary down regulators, such as goserelin (Zoladex) or leuprorelin (Prostap) or buserelin. This is because you aren't producing any testosterone. It may be possible for you to have erections again once the treatment stops. This can take 3 months to a year, or even longer, after you stop the treatment. It depends on the drug you are having and how long you have been taking it.

About half the men treated with anti androgens alone, such as bicalutamide (Casodex), keep their sex drive and can get erections. This is also true for high dose treatment with Casodex. But you may still become impotent with long term treatment. About 1 in 5 men (20%) keep their ability to get an erection, even with long term treatment. There is information about coping with erection problems in the sex and cancer for men section of CancerHelp UK. And there is information about how prostate cancer can affect your sex life in this section of CancerHelp UK

Hot flushes and sweating can be troublesome. They are the same as the hot flushes women friends and relatives may have had when going through menopause. The flushes are caused by your testosterone levels dropping. They may gradually get better as you get used to the treatment. Hot flushes are most likely with pituitary down regulators because these drugs cut off testosterone production altogether. Unfortunately, in some men flushes keep on happening as long as you take the drug.

Some men find that their flushes are relieved by a short course of hormones called progestogens, and you may want to discuss this with your doctor. Recently, there has been some evidence that a drug called venlafaxine (which is usually used to treat depression) may help with hot flushes. Getting overheated, drinking tea or coffee, and having nicotine can all make flushes worse. We have tips on dealing with sweating in our section about skin problems with cancer.

This is a particular problem with high dose Casodex. The breasts can become painful and enlarged. Taking the drug tamoxifen can help reduce breast tenderness. Or sometimes it can help to have a small dose of radiotherapy to the breasts before your hormone treatment starts.

Tumour flare pain can worsen when you start hormone treatment. If it carries on, your doctor can prescribe drugs called bisphosphonates to treat it. Your doctor should always prescribe another hormone therapy when you start leuprorelin or Zoladex injections to help prevent tumour flare causing bone pain.

The side effects listed above can all occur as soon as you begin treatment. There are other side effects that will only happen if you take hormone treatment for a long time. These are

• Weight gain
• Memory problems
• Bone thinning (osteoporosis)
• Risk of earlier heart attack

Weight gain

You may put on weight. You should be able to control this with diet and exercise, but it is sometimes a struggle to keep weight down when you are on hormone treatment. There is more information about managing weight gain in our questions and answers on prostate cancer section.

Memory problems

Some men feel that their memory gets worse when they have been having hormone treatment for a while. This will not improve while you are taking the hormone treatment, but there are ways to make life easier, such as making lists so you don't forget things. It is natural to feel cheated and upset if you have this particular side effect. Talk to your doctor or specialist nurse if you feel this is having a significant effect on your life.

Bone thinning (osteoporosis)

Men with prostate cancer are at risk of bone thinning, or osteoporosis. There is evidence that the risk of problems, such as bone fractures, is slightly higher for men on long term treatment to block testosterone (for example, Zoladex). Bone thinning is sometimes treated with bisphosphonates. But the National Institute for Health and Clinical Excellence (NICE), have recommended that bisphosphonates should not be used to prevent or reduce bone damage, from secondary cancers or osteoporosis, in men with prostate cancer.

The NICE guidance says that bisphosphonates should only be used to control pain from bone secondaries in prostate cancer if other treatments, such as painkillers or radiotherapy, are not working.

There is more about osteoporosis risk and treatment in our question and answer section. This particular 'question and answer' is in the breast cancer questions section, because osteoporosis is also a problem for women having treatment for breast cancer. Your doctor may suggest taking vitamin D and calcium to help lower your risk of problems from osteoporosis. Other advice is to stop smoking, reduce the amount of alcohol you drink and take regular weight bearing exercise, such as walking.

If your specialist is concerned, they may ask you to have tests to measure your 'bone mineral density'. This can show if your bones have become weaker and may be at increased risk of fracture.

Risk of earlier heart attack

There is some evidence that if you are over 65, and at risk of dying from a heart attack, that this is more likely to happen sooner if you have been taking hormone therapy for 6 months. This may be because some of the side effects of hormone therapy, such as weight gain, can make heart disease worse.