Hormone therapy

1. Why is hormone therapy given?
2. When is hormone therapy given?
3. Different hormone drugs
4. Side effects of hormone therapy

1. Why is hormone therapy given?

As the hormone oestrogen can play a part in stimulating some breast cancers to grow, there are a number of different hormone therapies that work in different ways to block the effect of oestrogen on cancer cells.

Hormone therapy will only be prescribed if your breast cancer has receptors within the cell that bind to the hormone oestrogen and stimulate the cancer to grow. This is known as oestrogen receptor positive or ER+ breast cancer.

All breast cancers are tested for oestrogen receptors using tissue from a biopsy or after surgery. Tests may also be done for progesterone receptors. Oestrogen receptor results play a more important role in planning treatment, so the benefits of hormone therapy are less clear for people whose breast cancer is progesterone receptor positive only (PR+ and ER-).

If your breast cancer is hormone receptor negative, hormone therapy drugs will not be of any benefit to you.

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2. When is hormone therapy given?

If you have invasive breast cancer which is oestrogen receptor positive, hormone (endocrine) therapy will usually be recommended.

After surgery

Hormone therapy is usually started after surgery (known as adjuvant treatment), to reduce the risk of the breast cancer coming back or spreading elsewhere in the body. If you’re also having chemotherapy it will probably start after this has finished. If you’re having radiotherapy after surgery but no chemotherapy, hormone therapy may be started during radiotherapy or after it has finished.

Before surgery

Hormone therapy may be given before surgery to reduce the size of the cancer (known as primary or neo-adjuvant treatment) or because surgery isn’t an option, for example for people who have other illnesses such as lung or heart conditions.

If cancer has come back or spread

Hormone therapy is used to treat breast cancer that has come back after treatment (recurrence) or that has spread to another part of the body (secondary breast cancer). It’s given either alone or alongside other treatments, depending on what treatments you had before.

If your breast cancer comes back when you're already being treated with hormone therapy, you'll probably be offered a different type of hormone therapy.

DCIS (ductal carcinoma in situ)

Hormone therapy is less commonly used to treat ductal carcinoma in situ (DCIS) because the benefits are less certain. Your specialist will discuss whether it’s appropriate for you.

Family history

Women at moderate or high risk of breast cancer because of their family history may be offered hormone therapy if appropriate to reduce their risk of breast cancer.

Find out more about risk-reducing treatment »

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3. Different hormone drugs

Some of the most commonly used hormone drugs are:

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4. Side effects of hormone therapy

Everyone reacts differently to drugs and some people have more side effects than others.

Side effects can generally be controlled and often improve over time as your body gets used to taking a drug. Some can be experienced with all hormone therapies, whereas others are specific to individual drugs.

Common side effects

The most common side effects are similar to menopausal symptoms, such as:

  • hot flushes
  • night sweats
  • vaginal dryness
  • mood changes. 

Find out more about menopausal symptoms »

Other common side effects with most hormone drugs include: 

  • joint pain and stiffness
  • headaches
  • nausea.

What to do if you have side effects

Talk to your GP, specialist or breast care nurse about your side effects and ways to manage them.

If side effects are putting you off taking your hormone therapy, it’s important to talk with your cancer specialist before making any decisions to stop it.

There may be ways to improve your symptoms or your cancer specialist may be able to switch you to a different drug.Back to top


Last reviewed: August 2015
Next planned review begins 2017

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