Prostate cancer

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Potential side effects of hormonal therapy for prostate cancer

Side effects can occur with any type of treatment for prostate cancer, but not everyone has them or experiences them in the same way. Side effects of hormonal therapy will depend mainly on the:

  • type of drug 
  • dose and duration of drug
  • whether surgery is done
  • man's overall health

Side effects can happen any time during hormonal therapy. Some may happen during, immediately after or a few days or weeks after hormonal therapy. Most side effects go away after hormonal therapy is over. Late side effects can occur after months or years on hormonal therapy. Some side effects may last a long time or be permanent.

It is important to report side effects to the healthcare team. Doctors may grade (measure) how severe certain side effects are. Sometimes hormonal therapy needs to be adjusted if side effects are severe.

Decrease in sexual desire

Decrease in sexual desire, or loss of libido, affects almost all men taking hormonal therapy, although it is less severe with anti-androgens compared to other forms of hormonal therapy. This can be a permanent side effect when the man has an orchiectomy (removal of the testicles) or long-term hormonal therapy. It will generally continue as long as the hormonal drug therapy is taken, but sometimes it may persist after discontinuing hormonal therapy, especially if the testosterone level does not return to normal.

Once hormonal drug treatments are stopped, sex drive often gradually returns to normal. Discuss this with the healthcare team if it is a concern.

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Erectile dysfunction (impotence)

Erectile dysfunction (ED) is also called impotence. ED is the inability to keep an erection sufficient for sexual intercourse. This is a very common side effect of hormonal therapy. Whether ED is permanent or temporary depends on the type of hormonal therapy:

  • removal of both testicles – ED is usually permanent.
  • hormonal drug therapy – ED occurs for as long as hormonal therapy is given.
    • It can take 3–12 months after hormonal drug therapy is stopped to regain erectile function.
    • If erectile function does not come back on its own, treatments are available.

Check with the healthcare team about treatments for ED, such as prosthetic penile implants, vacuum devices and medications.

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Hot flashes

Sudden sweating and feelings of warmth are called hot flashes. They can occur in about 50–80% of men on hormonal therapy. How hormonal therapy causes hot flashes is not known. The severity varies from person to person. This usually gets better as the body gets used to the treatment or when the drug is stopped. Various treatments are available to control hot flashes.

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Weight gain and muscle loss

Weight gain and muscle loss are common side effects of hormonal therapy for prostate cancer. An increase in fat tissue causes weight gain, and loss of muscle tissue causes a decrease in strength. Diet and exercise help to reduce weight gain and muscle loss.

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Loss of bone density (osteoporosis)

Osteoporosis is a long-term side effect that may occur with some hormonal drug therapies such as luteinizing hormone–releasing hormone (LHRH) agonists. The doctor may order a bone mineral density test before starting some hormonal treatments in order to provide a baseline for comparison with follow-up tests. Prevention and management of bone loss include calcium and vitamin D supplements, physical activity and drug therapy.

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Changes in male characteristics

Hormonal therapy results in loss of body hair as well as a decrease in the size of testicles.

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Breast swelling or tenderness

Swelling of the breasts in men is called gynecomastia. It is a common side effect of hormonal therapy for prostate cancer, especially with oral anti-androgen drugs such as bicalutamide. Estrogen treatment and preventive breast radiation reduce the risk of breast tenderness and gynecomastia.

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Fatigue causes a person to feel more tired than usual and can interfere with daily activities and sleep. Fatigue may get better as time goes by. It can continue long after the man has finished their hormonal therapy. Exercise may help the man cope with fatigue.

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Hormonal therapy for prostate cancer sometimes causes depression and changes in emotional stability. Depression may be treated with antidepressants.

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Hormonal therapy causes anemia in some men. When the red blood cell count or hemoglobin level is low, body tissues don’t get enough oxygen. This causes fatigue and shortness of breath.

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Increased heart disease risk

Hormonal therapy for prostate cancer may lead to a significant increase in heart disease. This is because the hormonal therapy causes weight gain, decreased ability to exercise and increased blood levels of lipids and glucose. Damage to blood vessels of the heart, heart attacks and sudden death may result from these side effects. It is important to monitor the risks of heart disease and try to prevent or correct them as much as possible.

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Increased diabetes risk

Hormonal therapy causes a decrease in how sensitive cells are to insulin. It also causes an increase in fat and a decrease in muscle mass. These effects increase the risk of diabetes in men treated with hormonal therapy.

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Tumour flare reaction

When LHRH agonists are first taken, they cause a temporary rise in testosterone that lasts for about a week. This rise results in a temporary worsening of symptoms, called a tumour flare reaction. During the flare reaction, men may have more urinary difficulties or bone pain. The doctor may prescribe anti-androgensanti-androgensTreatment with drugs that stop the production or block the actions of androgens (male sex hormones). for a period of time to reduce the symptoms of the flare.

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Blood clots

A blood clot in the leg is called a deep vein thrombosis (DVT). A DVT may rarely occur during hormonal therapy. Symptoms of DVT include tenderness or pain in the calf of the leg, a hardened vein, or pain or swelling in the legs. In the most serious cases, a blood clot can break away and travel to the lung. This is called a pulmonary embolus and causes shortness of breath and chest pain.

If you have symptoms of DVT, see your doctor. Go immediately to the nearest emergency department if you have DVT or develop chest pain or shortness of breath. A blood clot is treated with a blood-thinning medication called an anticoagulantanticoagulantA substance that prevents blood clots from forming..

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Orchiectomy-related side effects

Surgical removal of the testicles (orchiectomy) may cause pain, bleeding or a wound infection. It may also alter the man's body image and self-esteem. Removal of both testicles causes permanent side effects, including erectile dysfunction (impotence) and a decrease in sexual desire because of low testosterone levels. It also causes infertility due to loss of sperm production.

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Note: Other side effects may occur. For more detailed information on specific drugs, go to sources of drug information.


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