Hormone Replacement Therapy
Hormone Replacement Therapy (HRT) is used to treat symptoms of the menopause when – a woman’s ovaries no longer produce female hormones, known as oestrogen and progesterone when the ovaries have been surgically removed. HRT may be given as patches for the skin, tablets, a cream or gel. Preparations contain either oestrogen alone (oestrogen-only HRT) or both oestrogen and progesterone (combined HRT). Tibolone is another type of HRT that contains a steroid that acts like oestrogen and progesterone. Oestrogen-only HRT can increase the risk of womb (endometrial) cancer, whereas combined HRT does not. If you have not had a hysterectomy, you will usually be prescribed combined HRT to protect your womb. If you have had a hysterectomy, you are not at risk of womb cancer, so will usually be prescribed oestrogen only HRT. In addition to reducing menopausal symptoms, HRT may also be used to prevent osteoporosis (where bones lose their strength and become fragile), especially if menopause has taken place before the age of 45. Women who enter the menopause at a young age may be given HRT up to the age of 50 without increasing their risk of breast cancer. The Institute for Cancer Research also recommends HRT following surgical removal of the ovaries until a woman is 50 years of age, unless there is a specific reason why she cannot take HRT.
HRT and Increased Risk of Breast Cancer Both oestrogen-only and combined HRT slightly increase the risk of breast cancer. The risk associated with oestrogen-only HRT is less than that with combined HRT. It is unclear to what degree Tibolone increases breast cancer risk, but it is thought to lie somewhere between the risks associated with oestrogen–only and combined HRT. This risk increases the longer HRT is used. Short-term use (less than 5 years) is likely to have only a small effect on breast cancer risk. The increased risk begins to fall as soon as HRT is stopped, and within 5 years of stopping HRT, a woman’s chance of developing breast cancer is the same as if she had never taken HRT.
Age of Women HRT Status
50 - 59 No HRT
In a 1000 women the number who will develop Breast Cancer over a 5 year period In a 1000 women the number who will develop Breast Cancer over a10 year period Age of Women HRT Status
2 extra cases
6 extra cases
In a 1000 women the number who will develop Breast Cancer over 5 years In a 1000 women the number who will develop Breast Cancer over a 10 year period
3 extra cases
Combined Oestrogen and progesteron e HRT (estimated) 9 extra cases
9 extra cases
36 extra cases
60-69 No HRT
Oestrogen Only HRT (estimated)
Oestrogen Only HRT (estimated)
Combined Oestrogen and progesterone HRT (estimated) 6 extra cases
24 extra cases
Taking HRT may increase the density of the breast, increasing the amount of glandular and supportive tissue compared to fat, which can make it more difficult to identify breast cancers on the mammogram.
Other risks and benefits of HRT HRT offers many women relief from menopausal symptoms and can significantly improve their quality of life. It also reduces the risk of bone fractures and the possibility of bowel cancer. However, as well as increasing the risk of breast cancer, both oestrogen-only and combined HRT may increase the risk of ischaemic heart disease (angina and heart attacks), blood clots on the lungs (pulmonary emboli) and stroke. These risks will also be dependent on other factors, such as a woman’s age and medical history.
Having a Diagnosis of Breast Cancer About 75% of breast cancers are sensitive to oestrogen (oestrogen receptor or ER positive). This means that the body’s own naturally produced oestrogen or additional oestrogen taken as HRT may stimulate growth of cancer cells. We routinely test breast cancer tissue to see if the individual cells are receptive to the effects of oestrogen and or progesterone. If this test shows that the cancer is ER positive, most women will be prescribed medication such as tamoxifen or an aromatase inhibitor (anastrazole, letrozole or exemestane). These work by blocking oestrogen receptors (tamoxifen) or reducing the amount of oestrogen produced (aromastase inhibitors).
These medications are a very effective way to reduce the risk of the cancer coming back, not only in the breast but also anywhere else in the body. Using HRT whilst on these medications is never advised, as the oestrogen contained in the HRT directly counteracts the effects of hormone blockade. It is not clear whether any type of HRT is safe for women who have had breast cancer as there is no substantial research to support the use of HRT, after any time interval, following breast cancer treatment. Relief of menopausal symptoms poses a real dilemma for women successfully treated for breast cancer, particularly as many of the treatments can bring on early menopause. In the first instance, your medical team will recommend trying an alternative to HRT if menopausal symptoms are severe. This may include: Self-help measures such as: alterations to diet weight management life style changes exercise and relaxation If self-help measures fail to work, your GP may consider prescribing Non hormonal medications. Women who have had breast cancer are not usually prescribed HRT, but some specialists will prescribe it on a case-by-case basis, having considered all the risks and benefits.
Contact Information If you have any questions or concerns after reading this leaflet, please do not hesitate to contact the Clinical Nurse Specialist or one of the Breast Care Nurses. 01536 492532/3 Monday to Friday 9am to 4.40pm
References www.mhra.gov.uk/drugsafetyupdate Drug Safety Update 2007:1 (2): 2-6 Hormone Replacement Therapy and Breast Imaging: A Review http://www.eradimaging.com/site/article.cfm?ID=790
If you need this information in another format or language, please telephone 01536 492510. Further information about the Trust is available on the following websites: KGH - www.kgh.nhs.uk | NHS Choices - www.nhs.uk Ref: PI 965 October 2015
Next review: July 2017