Hormonal therapies for secondary breast cancer
Hormones occur naturally in the body and help control how cells grow and what they do. Female hormones, particularly oestrogen, can encourage some breast cancer cells to grow.
Hormonal therapies work by lowering the level of oestrogen in the body, or blocking oestrogen from attaching to the cancer cells. They are only effective for women who have oestrogen-receptor positive cancers.
Hormonal therapies are often the first treatment for women with ER positive breast cancer, especially when the cancer has spread to the bones. Some women may be given chemotherapy first followed by hormonal therapy.
There are different hormonal therapies. The type you have will depend on whether you have been through the menopause or not and on any hormonal therapies you had before.
You will be given a different hormonal therapy from any you have had before. It one drug doesn’t work, or stops working, your oncologist can prescribe another hormonal therapy.
We have more information about individual hormonal therapies.
Hormonal therapies are usually easy to take and most are taken as tablets. Although side effects can sometimes be troublesome, they’re rarely serious. Some side effects are similar to menopausal symptoms. Certain hormonal therapies cause a temporary or permanent menopause.
You’ll need to take the drug for a few weeks or months before your doctors can tell if it is working.
Hormonal therapy after menopause
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After the menopause, oestrogen is no longer produced by the ovaries. But some oestrogen is still produced from hormones in the fatty tissues of the body.
If you have been through the menopause (you are postmenopausal) you may be offered treatment with:
Hormonal therapy for premenopausal women
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Before the menopause oestrogen is mainly produced by the ovaries. If you haven’t been through the menopause (you are premenopausal) you may be offered hormonal treatment with:
the anti-oestrogen drug tamoxifen
a pituitary downregulator drug to stop the ovaries from producing oestrogen (ovarian suppression)
surgery to remove the ovaries or radiotherapy to stop the ovaries working (ovarian ablation).
Some women may be given treatment with tamoxifen and ovarian suppression/ablation at the same time.
Anti-oestrogens (tamoxifen and fulvestrant)
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Tamoxifen works by preventing oestrogen from attaching to breast cancer cells and encouraging them to grow. It’s often used in premenopausal women to reduce the risk of breast cancer coming back. But it can also be effective in controlling secondary breast cancer for both pre- and postmenopausal women who have not taken it before.
Tamoxifen is taken as a daily tablet. The side effects may include:
hot flushes and sweats
For many women, these side effects are mild and may get better over time. If you continue to have problems, talk to your specialist nurse or doctor as there are sometimes ways of reducing the effects.
I feel quite positive in some ways, because I do think that this drug is definitely affecting me. I can feel in myself that it's easier, I'm walking easier, getting out of a chair much more easily.
In postmenopausal women, a less common side effect of tamoxifen is that it can slightly increase the risk of blood clots in the leg or lung. Let your doctor know straight away if you have pain, warmth, swelling or tenderness in an arm or leg, or any chest pain.
Women who are prescribed tamoxifen to treat secondary breast cancer in a bone may find it makes the bone pain worse for the first few days.
Fulvestrant is only used in women who are postmenopausal. It’s given as a monthly injection into a muscle in your buttock.
It may be used to treat secondary breast cancer after other hormonal therapies have been tried. The side effects are similar to tamoxifen.
Fulvestrant has not been approved by the National Institute for Health and Care Excellence (NICE) or by the Scottish Medicines Consortium (SMC). NICE and the SMC give advice on the use of new drugs in the NHS. As a result fulvestrant may not be widely available.
Aromatase inhibitors (AIs)
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AIs are only given to women who are postmenopausal. After menopause, hormones produced by the adrenal glands (small glands above the kidneys) are converted by a chemical called aromatase into oestrogen. AIs stop this from happening and reduce oestrogen levels.
Anastrozole, letrozole and exemestane are taken daily as a tablet. Side effects include tiredness, joint and muscle pain, and hot flushes. They can also cause bone thinning (osteoporosis).
Pituitary downregulators (ovarian suppression)
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You only have these drugs if you have not reached the menopause. Pituitary downregulators stop a gland in the brain (pituitary gland) sending messages to the ovaries to produce oestrogen and cause a temporary menopause. A commonly used pituitary downregulator for women with breast cancer is goserelin (Zoladex®).
The side effects are similar to menopausal symptoms and include hot flushes and sweats, joint pain, low sex drive, headaches and mood changes. You will be given Zoladex as a monthly injection under the skin of the tummy (abdomen).
Ovarian ablation (stopping the ovaries from working)
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This is occasionally done in premenopausal women by removing the ovaries surgically, or rarely by giving radiotherapy to the ovaries.
The operation can often be done during a short stay in hospital using keyhole surgery. The surgeon makes a small cut in the tummy area and inserts a long thin tube called a laparoscope with a tiny light and camera on the end. The ovaries are removed through the cut on your tummy using the laparoscope, which has surgical instruments attached to it. You usually recover quickly from this type of operation.
Radiotherapy to stop the ovaries working involves having a short course of radiotherapy directly to the ovaries.
Both treatments result in permanent menopause. With surgery your periods stop immediately. After radiotherapy women usually have one more period before they stop. It’s important to use contraception for three months after radiotherapy.
We have more information about ovarian ablation.
It can be difficult to cope with menopause symptoms when you’re already coping with cancer. Our cancer support specialists can give you more information and support.
Knowing treatment will make you infertile can be hard to cope with and to accept. We can talk issues through with you, and also give you details of any relevant support organisations.
If the cancer is no longer controlled with other hormonal therapies, drugs called progestogens may be tried. These are similar to the female hormone progesterone and are usually given as tablets. The commonest drugs used are megestrol acetate (Megace®) and medroxyprogesterone acetate (Farlutal®, Provera®).
The side effects include increased appetite, weight gain, feeling sick, or slight vaginal bleeding (spotting) and rarely breathlessness. Let your doctor know if this happens.