About two-thirds of breast cancers are hormone receptor positive, which means that they need female hormones (oestrogen and/or progesterone) to grow and reproduce. Most women with hormone positive breast cancer will be recommended hormone therapy. These are oral medications that are taken daily for a minimum of five years following the completion of your other breast cancer treatments (surgery, chemotherapy and/or radiotherapy).
Tamoxifen is one of the best known of the hormone therapies. The aromatase inhibitors - Arimidex, Aromasin and Femara (and new generic brands of these drugs) - are also hormone therapies. While tamoxifen can be used to treat breast cancer in women who are pre-menopausal or post-menopausal, the aromatase inhibitors are only suitable for women who have completed menopause.
How does it work?
Hormone therapy works by stopping oestrogen from 'feeding' the breast cancer cells. It has been found to be very effective in reducing the risk of the cancer spreading to other parts of the body, or of a new breast cancer developing in either breast.
Side effects of hormone therapy
Side effects of hormone therapy can include menopausal symptoms such as hot flushes, night sweats, heart palpitations, anxiety, sleep disturbance and fatigue. The aromatase inhibitors can also cause joint stiffness and pain, and vaginal dryness. There are things you can do to help manage these side effects. BCNA's booklet Breast Cancer and Sexual Wellbeing includes suggestions on managing menopausal symptoms and the impact of treatments on sexual wellbeing. If you are finding side effects difficult to manage, talk to your doctor as there are often solutions.
Some hormone therapy treatments can also cause bone loss, which can result in bone fractures and osteoporosis. Your doctor may recommend that you have a bone mineral density scan, called a DXA or DEXA scan, before starting your treatment. You may also have your calcium and Vitamin D levels checked. More information is available on the Bone health page of this website.
Note
Hormone therapy is sometimes confused with hormone replacement therapy (HRT), but they are completely different.
More information
- The 'Treatment' section in Cancer Australia's Guide for women with early breast cancer in My Journey Kit has more information.
- Read an article on hormone therapy in Issue 58 (Autumn 2012) of The Beacon magazine.
- Join our online network if you think that talking to others online and sharing experiences will help.
- Contact the Cancer Council Helpline on 13 11 20.
- The Westmead Breast Cancer Institute has a Hormone (Endocrine) Treatment for Early Breast Cancer brochure which you can order free of charge through their website.
- The breastcancer.org website has up-to-date information on hormone treatments.
