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Hormonal therapies| are one of the main treatments for breast cancer in men.
Breast cancer that has oestrogen receptors is called oestrogen receptor positive (ER+) breast cancer.| ER+ breast cancers need oestrogen to grow. Hormonal treatments work by stopping oestrogen from reaching breast cancer cells and are often very effective treatments for ER+ cancers. Most men who have breast cancer (about 9 out of every 10) have ER+ breast cancer, so that's why hormonal therapies are one of the main treatments for breast cancer in men.
The most commonly used hormonal therapy is tamoxifen| but other types of hormonal therapy may sometimes be used. Hormonal therapy is often used after surgery to reduce the risk of the breast cancer coming back. If you’re having chemotherapy you would usually have this first, followed by five years of treatment with tamoxifen.
Hormonal therapy can also be used to control breast cancer that has come back (recurrent cancer) or spread to another part of the body (secondary breast cancer). In this situation the treatment is usually given for as long as it is working to control the cancer. Men who have already had treatment with tamoxifen would be offered a different type of hormonal therapy.
All men have small amounts of the hormone oestrogen in their bodies. About 20% of this oestrogen is made by the testicles and the remaining 80% is made from male sex hormones (androgens). The process by which androgens are turned into oestrogen is called aromatisation.
Tamoxifen (Nolvadex®) is the most commonly used hormonal therapy and has shown to be effective at treating breast cancer in men. Tamoxifen is an anti-oestrogen treatment. It works by attaching to the oestrogen receptors on breast cancer cells. This stops the oestrogen from telling the breast cancer cells to grow.
Anastrozole (Arimidex®), letrozole (Femara®) and exemestane (Aromasin®) are a type of hormonal therapy called aromatase inhibitors (AIs). They reduce oestrogen levels in men by stopping male hormones (androgens) from being made into oestrogen.
How best to use these drugs to treat breast cancer in men is still being investigated. Not all of the oestrogen that men make comes from androgens (20% is made by the testicles). For this reason doctors often prescribe another type of hormonal therapy called goserelin (Zoladex®) to be used alongside an aromatase inhibitor.
Goserelin (Zoladex) is sometimes used to treat breast cancer in men in combination with an aromatase inhibitor. Normally the testicles are stimulated to make oestrogen and testosterone by messages sent from the pituitary gland in the brain. Goserelin blocks these messages so that the testicles stop making oestrogen and testosterone. Goserelin is given as a slow release implant that is injected just under the skin once every 1-3 months.
Fulvestrant (Faslodex®) is a newer type of anti-oestrogen that is given as an injection. It may occasionally be used to treat men who have already had other hormonal therapies for breast cancer.
Side effects vary from person to person. Some men have only a few mild side effects, while others will experience more. Often side effects gradually ease over the first 3-6 months of taking the treatment. Tell your doctor or specialist nurse if you are having problems as there are often things that can be done to help to relieve or manage side effects of hormonal therapy.
Sometimes, if side effects are very troublesome, a man may have to stop taking a particular treatment and a different drug may be prescribed.
Common side effects include:
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