Hormone replacement therapy (HRT) alleviates the symptoms of the menopause and reduces the risk of osteoporosis in post-menopausal women. This article discusses the benefits and risks associated with HRT for women who have had breast cancer.
- Introduction to HRT
- Should I use HRT?
- HRT in women who have had breast cancer
- Which HRT should I use?
- Alternatives to HRT
The ovaries produce two important sex hormones in a woman: oestrogen and progesterone. The levels of these hormones decline dramatically after the menopause. Normal menopause begins around the age of 50 years in the majority of women. Although most women can tell when the menopause begins, some women will require blood tests to measure their hormone levels and confirm the menopausal state.
The menopause is characterised by the ceasing of menstrual periods, hot flushes, mood swings, insomnia and vaginal dryness and discomfort. These symptoms are fairly mild and tolerable in most women, but in others they can be very severe and unpleasant. The decline of female sex hormones increases the risk of osteoporosis, heart diseases, stroke, and ageing skin.
Hormone replacement therapy (HRT), which contains the female sex hormones oestrogen and/or progesterone, can be considered to alleviate the symptoms of the menopause and reduce the risk of osteoporosis. Other benefits of HRT include protection from diabetes and bowel cancer, and maintaining a youthful skin appearance.
Before being considered for HRT, it is important to ask the following questions.
Hysterectomy is the surgical removal of the uterus (womb). Oestrogen can increase the risk of womb cancer when given on its own, so women who still have their womb should be given combined HRT containing both oestrogen and progesterone to reduce this risk. The oestrogen tablets and progesterone tablets may have to be taken on different days over a one-month cycle.
Women who have had a hysterectomy do not require progesterone and can use an HRT containing only oestrogen. If a woman has had a previous hysterectomy then the patch or the gel will be sufficient. If the patient has a womb then micronised progesterone or an intrauterine device such as a coil can be added to protect the womb.
Women with a personal or family history of blood clots in the leg veins or lungs have an increased risk of developing these conditions if they start taking HRT. Caution should be exercised when considering administering HRT to any of these individuals, especially in the form of oestrogen tablets.
Caution should be exercised when considering HRT in women with high blood pressure, as HRT can cause fluid retention that would make matters worse.
Patients suffering from any of the following conditions should take HRT with caution.
- Heart disease
- Kidney disease
- Liver disease
- Multiple sclerosis
- Sickle cell disease
Women who have had breast cancer will probably be taking tamoxifen or an aromatase inhibitor. Tamoxifen has similar beneficial effects on the bones as HRT whereas aromatase inhibitors have the opposite effect. If you have had breast cancer, it is worth asking your breast specialist about the type of cancer you had. Some types of breast cancer are sensitive to oestrogen and the hormone can stimulate tumour growth, while other types of breast cancer are not affected by the hormone. Oestrogen seems to promote the growth of breast cancer by expressing special proteins known as (o)Estrogen Receptors (ER). If your cancer was of the non-oestrogen-sensitive type, HRT is less likely to increase the risk of the breast cancer returning.
If women suffering from breast cancer have severe menopausal symptoms, such as hot flushes and vaginal dryness, then some form of HRT can be considered in selected cases although it is usually preferable to try alternative drugs to improve these symptoms. Taking combined HRT is not recommended in women who have had ER-positive breast cancer since this can increase the risk of the breast cancer returning.
Oestrogen taken orally is broken down by the liver and its by-products can have adverse effects on the cardiovascular system and increase the risk of heart disease, thrombosis and stroke. Therefore it is safer to take oestrogen through the skin in the form of a patch or a gel.
The main concerns regarding the use of HRT arise from the possible increase in the risk of heart disease (as the Women Health Initiative Study suggested in 2003) and breast cancer.
The Women's Health Initiative Study in the USA has shown that taking HRT increases the risk of heart disease and breast cancer but decreases the risk of brittle bone disease and large bowel cancer. The study suggested that the disadvantages of HRT outweigh its benefits and that the hormone therapy should be used only as a last resort. The findings of this study do not, however, apply to bio-identical HRT given in the form of transdermal oestrogen as a patch or a gel combined with oral micronized progesterone (50–100 mg daily for days 1–25 of cycle). Alternatively, the oestrogen patch or gel can be used in combination with a coil.
As explained, using the skin route avoids the production of chemicals harmful to the cardiovascular system. Furthermore the impact on breast cancer risk will be reduced.
The risk of breast cancer is increased by 30% in women who have taken oral HRT for more than five years. It is worth pointing out that breast cancers that develop in women taking HRT are usually early cancers and have a good prognosis.
Women taking HRT should practise self-examination of the breasts and participate in breast cancer screening programmes (one mammogram every two years on the NHS Breast Screening Programme). The above advice also applies to women with a family history of breast cancer.
Alternatives to treating hot flushes with HRT include flaxseed and vitamin E supplements, venlafaxine 37.5 mg daily, progesterone tablets, clonidine and gabapentin. Vaginal oestrogen creams and simple moisturizers can be used in the vagina to improve dryness and discomfort although it is important to note that oestrogen creams applied in the vagina can still be absorbed into the blood stream and should only be used in small amounts for short periods and repeated as necessary. In women with a recent history of breast cancer, vaginal oestrogen creams are safer in women taking tamoxifen than in those taking aromatase inhibitors.
Transdermal oestrogen (gel or patch) represents the safest form of HRT and micronised progesterone (or a coil) should be added in women who never had a hysterectomy. It is my opinion that women with oestrogen-sensitive breast cancer should avoid using HRT (except vaginal oestrogen creams) for at least two years after diagnosis. The development of new drugs to reduce the risk of bone loss or osteoporosis (such as bisphosphonates and raloxifene) and treat hot flushes (such as venlafaxine and gabapentin) should minimise the need for these women to use HRT.
For further information on the author of this article, Consultant Breast Surgeon, Professor Kefah Mokbel, please click here.
The time of a woman’s life when her ovaries stop releasing an egg (ovum) on a monthly cycle, and her periods ceaseFull medical glossary