Skip to main content

Breast cancer treatment can include hormone-blocking drugs that trigger menopausal symptoms.


Breast cancer will occur in 1 in 8 women over the space of a life time.

It is a common cancer but modern treatments mean cure rates are high and most women with breast cancer die from other causes. Heart disease being the most common cause of death for any adult woman.

Some breast cancers have receptors on them that respond to hormones. This is to be expected as most cells in our body do. Receptors are proteins locks that sit on the outside of a cell waiting for a specific key, for example a hormone, to trigger them. That then sets in motion activity within the cell.

Breast cancer cells can be oestrogen receptor positive (ER), progesterone receptor positive (PR) or human epithelial growth factor receptor 2 positive (HER2). Breast cancers that do not have ER, PR or HER2 are called triple negative breast cancers.

Medications can be targeted at these receptors to have a negative impact on the cancer cell and prevent it from growing. This is called hormone-blocking therapy and can be done in various ways.

Block ovarian function 

  • Surgically removing the ovaries
  • Using GnRH agonists that act on the brain control of ovaries eg Zoladex

Reduce oestrogen production 

  • Aromatase inhibitors block the conversion process to make oestrogen eg Arimidex

Block oestrogen’s effect

  • Selective oestrogen receptor modulators (SERMs) bind to oestrogen receptors, preventing oestrogen from binding eg tamoxifen
  • Other oestrogen blockers

Each woman will be advised on her best choices based on her health, her age, her menopausal status and her cancer.

Premenopausal women may experience an abrupt and shocking transition to having menopausal symptoms she did not have before. This is called “medical menopause” and may also occur early.
Postmenopausal women can experience worsening of flushes and vaginal dryness.

Treatment options for hot flushes for such women are limited to non-hormonal options-

  • anti-depressants
  • clonidine or gabapentin
  • lifestyle modification
  • CBT
  • meditation
  • yoga
  • magnesium / taurine
  • herbal extracts.

Vaginal dryness and bladder symptoms can generally be treated with vaginal oestrogen as very little is absorbed into the system. Many women fear unnecessarily about using this form of hormone and even some doctors are cautious to prescribe it. Ask your breast surgeon or cancer doctor if you can try as these tissues suffer more the longer they are without oestrogen.

Treatments for vaginal dryness

  • vaginal oestrogen pessary or cream
  • good quality vaginal moisturiser daily
  • good quality lube for sex.
Vaginal oestrogen in the form of a pessary or cream can usually be used safely in women with breast cancer. Ask your breast doctor.


Unfortunately the risk of osteoporosis is high in women treated with hormone-blockers at a young age. Some medications are worse than others. Make sure you have a lifestyle that will keep your bones healthy and check your bone density along the way.

Some women choose to use HRT if their breast cancer diagnosis is in the distant past or their symptoms are so disabling that for them quality of life is more important than the risk of breast cancer recurrence. This is a difficult decision and both the woman and her doctor need to feel fully informed.

Often you and your team focus on the best way to cure your cancer and keep it away but once this is done, you have a life to lead that might include sex, sleep and recreation. At this time, make sure you have received all the advice you need to make an informed decision about your choices for treatments. If your flushes are really bad, a trial off your blockers or changing to a different one might be worthwhile. Obviously discuss any change in your treatment plan with your doctor.


This information is for general educational purposes only and does not constitute medical advice. Please see your health professional for advice that is personalised to you.
Key Take Aways

Many breast cancers have receptors for oestrogen or progesterone

Hormone-blocking drugs can cause menopausal symptoms

Vaginal oestrogen is still generally safe to use


Other resources

Breast Cancer Network Australia

Leave a Reply