Hormones help control how cells grow and what they do in the body. The hormones oestrogen and progesterone can encourage breast cancer cells to grow, particularly oestrogen.
Hormonal therapies lower the level of oestrogen in the body, or block oestrogen from attaching to the cancer cells. They only work for women who have oestrogen receptor (ER) positive cancers.
There are different types of hormonal therapies. Most of them are taken as tablets or as an injection under the skin. They are usually easy to take.
- whether you have been through the menopause
- other hormonal therapies you have had before.
If you were taking a hormonal therapy drug when the cancer came back, your cancer doctor will prescribe a different one. Some women have hormonal therapy with targeted therapy drugs.
It takes a few weeks or months before your doctors can tell how well hormonal therapy treatment is working for you. Your cancer doctor will usually arrange for you to have a scan to check this. If one hormonal therapy does not work, or stops working, your cancer doctor can usually prescribe another type.
Aromatase inhibitors (AIs) are the main hormonal therapy used in women who have been through the menopause. They stop oestrogen being made in the fatty tissue of the body.
In women who have not been through the menopause, AIs can be given with treatments to stop the ovaries working (ovarian suppression).
There are different types of aromatase inhibitor tablets. These include:
Anti-oestrogen drugs stop oestrogen from attaching to breast cancer cells and encouraging them to grow.
There are different types of anti-oestrogen. These include:
- tamoxifen - a tablet. When you take tamoxifen for secondary breast cancer that has spread to the bone, the pain may be worse for the first few days. This will gradually improve.
- fulvestrant - an injection. Your doctor may prescribe fulvestrant if other hormonal therapies are no longer working. If you have not been through the menopause, you have it with a drug called goserelin. This stops the ovaries from working.
The side effects of tamoxifen and fulvestrant may include:
If you have not been through the menopause, you usually have either:
- drugs to stop your ovaries making oestrogen
- surgery to remove your ovaries.
You have these treatments along with an aromatase inhibitor drug, or sometimes with tamoxifen.
Drugs that stop ovaries from making oestrogen
If you have not been through the menopause, you may be given a drug called goserelin. It stops the pituitary gland in the brain sending messages to the ovaries to produce oestrogen. This stops the ovaries making oestrogen. You have a temporary menopause while you are taking the drug.
Your specialist nurse will give you goserelin as an injection every month under the skin of the tummy (abdomen).
Ovarian ablation reduces the amount of oestrogen in the body. This is done by removing the ovaries.
You can have a small operation to remove the ovaries. This 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 thin tube with a small light and camera on the end. This is called a laparoscope. They use this to remove the ovaries through the cut. Most people usually recover quickly from this type of operation.
If you have ovarian ablation, your periods will stop straight away and you will have the menopause.
The side effects are usually quite mild and will depend on the drug you are taking. Some side effects are similar to menopausal symptoms. They include tiredness, joint and muscle pain, and hot flushes.
Aromatase inhibitors can also cause bone thinning (osteoporosis). Your cancer doctor may prescribe vitamin D and calcium or bone strengthening drugs to help protect your bones
If you have problems with the side effects of hormonal therapy, talk to your specialist nurse or cancer doctor. They can usually help treat or manage any problems. Most women are already taking hormonal therapy and may already be used to managing their side effects.