Hormone Therapy

Hormone therapy is a way of treating breast cancer, even if it has (or potentially has) spread to other parts of the body. The other common way of doing this is chemotherapy.

Hormone therapy is only suitable for women with hormone sensitive breast cancer. It is usually given to such women after surgery (and after chemotherapy if you are also having that). Occasionally hormone therapy is used as a pre-surgical treatment to try and shrink a breast cancer such that it becomes easier to remove with surgery. In women who are not fit for surgery, hormone therapy may be a good 'second best' option and may be able to control the cancer for amny years without surgery.

There are different ways of giving hormone therapy principally depending on whether or not you have gone through the menopause or not.

For women who have not yet gone through the menopause.

In this situation, hormone therapy usually consists of giving a hormone therapy tablet (Tamoxifen).
In certain cases, the menopause is also induced.

Ways of inducing the menopause are:

  • Removing the ovaries surgically (this is called oophorectomy and is usually performed by keyhole surgery with a one night stay in hospital).
  • Giving radiotherapy to the ovaries.
  • Having a monthly injection (Zoladex).

The first 2 methods induce the menopause permanently and the third method induces the menopause only while you are having the injections. The third method is usually the most suitable one for young women who are many years before the natural menopause.

Either of the first two methods would be suitable for women who are within a few years of the natural menopause.

  • For women who are pre-menopausal at the time of starting treatment for breast cancer, the current standard for hormone therapy is Tamoxifen for 5 years.
  • For women who are post-menopausal at the time of starting treatment for breast cancer, the current standard for hormone therapy is taking an aromatase inhibitor (Arimidex or Letrozole) for 5 years.
  • For pre-menopausal women who have had the menopause permanently induced, a discussion will be had about the pros and cons of Tamoxifen versus an aromatase inhibitor.
  • For women who go through the menopause naturally whilst taking hormone therapy, a discussion will be had about changing from Tamoxifen to an aromatase inhibitor.
  • In some cases it is recommended that hormone therapy continue beyond 5 years.

All women having hormone therapy take a tablet once a day. Hormone therapy tablets are usually taken for 5 years and some women may be recommended to take them for longer. Some women may be recommended to switch from one tablet to another after 5 years. For higher risk women the option for extending hormone therapy beyond 5 years has been shown to be associated with less risk of cancer recurrence.

The different tablets have different side-effects and the choice of which to use and how long to use it is tailored to your individual situation.

Side-effects of Hormone Therapy

Hormone therapy is a treatment that a lot is known about in terms of side-effects. There is therefore a long list of possible (mostly rare) side-effects.

However some side-effects are common:

  • Menopausal-type symptoms
  • Hot flushes
  • Night sweats
  • Slight weight gain
  • Generalised joint ache (aromatase inhibitors)
  • Gynaecological symptoms - Vaginal dryness
  • Cognitive effects

In addition, of the less common side-effects important ones are: Tamoxifen is associated with a small risk of thrombosis Aromatase inhibitors are associated with a small risk of osteoporosis (you will have a bone density scan before starting an aromatase inhibitor).

A full list of side-effects can be read on an information sheet that will be given to you. Alternatively visit www.breastcancercare.org.uk and read the fact sheets.


Q. What can be done about the side-effects of hormone therapy?
Answer - Some women are more bothered than others with side-effects. In addition, many side-effects become better with time. For women who have troublesome side effects, there are sometimes measures that can be taken to improve them. There are a variety of ways to try and minimise hot flushes or night sweats with variable success rates. Local preparations (creams or pessaries) can be used with success for vaginal dryness. Some side-effects are more troublesome with some types of hormone therapy tablet than others. In some situations, therefore, the type of hormone therapy you are having may be changed. The breast care nurse will discuss these issues with you in detail. It is fair to say that there is a limit to what can be done to improve hot flushes.

Q. I have read about a new type of hormone treatment that is better. Can I have that one?
Answer - There are (fortunately) lots of new hormone treatments for breast cancer. Many of the treatments that have been used for years are still the best treatments for many women and we know a lot about them (and their side-effects). However, evidence that some new treatments are better for some women is accumulating and where there is evidence of benefit, new treatments are used. We are gradually getting better at being able to select the most appropriate hormone treatment for any individual woman.