Confused about HRT? Professor Isaac Manyonda talks you through the risks and benefits.
What do you think the biggest killer of women in England is today? You might think it’s heart disease or cancer but it is, in fact, dementia. It’s not surprising since we’re living longer, but does that mean we need to think about our long-term health, and the risks to it, in a different way?
At the moment many women are afraid of taking HRT because they’re worried about the risk of developing breast cancer. Unfortunately, neither the magnitude of the risks nor the benefits of HRT are adequately reported in the media which means that the decisions that women are making may be based on less than optimal information.
The NICE guidelines currently recommend HRT as the first line treatment for the symptoms of the menopause in most women because it is considered that the benefits may outweigh the risks.
So lets take a look at the risks and benefits of HRT so you can make informed choices.
The Risks
1. Breast Cancer:
Since the 2002/3 reports from the Women’s Health Initiative studies were released this has been the primary concern for many women. But, it is now widely recognised that the risk of breast cancer (and blood clots) from modern HRT is much lower than previously thought.
What is the risk?
What we know now is that in the general population of women in the UK who don’t take HRT, in the age range 50-60 years over a 5 year period, 23/1000 will be diagnosed with breast cancer.
If 1000 such women take combined HRT – that is oestrogen and progesterone – an additional 4 women in 1000 will get breast cancer, taking the figure to 27/1000. This is the same risk as women who take the contraceptive pill face.
For women without a womb (those who have had a hysterectomy) the risk of developing breast cancer is lower.
They do not need progesterone and have oestrogen only. In that group 4 fewer people develop breast cancer bringing the number of cases down to 19/1000. So, you could almost argue, theoretically, that oestrogen has a “protective” effect.
What the public are often not aware of is the fact that lifestyle factors can increase the risk of breast cancer even more than HRT! Here are some figures:
a) Alcohol – drinking two units of alcohol a day results in an extra 5/1000 cases of breast cancer
b) Smoking – among smokers, there’s an additional 3/1000 women who develop the disease
c) Weight – being overweight or obese (BMI greater than 30) causes a massive increase in risk, with an extra 24 cases/1000. The media constantly reminds of the raging obesity epidemic, but the link to the rising cases of breast cancer is rarely made!

Courtesy Menopause Clinic London
What reduces the risk? The public should also be aware of a simple measure that lowers the risk of breast cancer – EXERCISE!
Yes – if you exercise moderately, as little as 2.5 hrs a week, you reduce the risk of developing breast cancer by 7 cases per 1000. This means 7 fewer women will develop breast cancer dropping the number to 16/1000 instead of 23/1000!
The take home message is a no-brainer – don’t smoke, keep your weight down and exercise!
2. Venous thromboembolism (blood clotting): Oral HRT (combined oestrogen and progesterone or oestrogen only) increases the risk of venous thrombo-embolism (venous blood clots) and pulmonary embolism (blood clot in lungs). In one big study carried out over five years, less than 1 in 100 women taking HRT developed a blood clot in their lungs. However, this number was about twice the number of women who were not taking HRT.
To put this into perspective the risk is a lot lower than that associated with taking the contraceptive pill, or that associated with pregnancy.
Research also shows that transdermal oestrogens patches of gels are safer than tablets when it comes to the risk of venous thrombo-embolism.
A past history of deep vein thrombosis, pulmonary embolism (blood clot on the lung) and stroke due to blood clot is a relative contra-indication to conventional HRT.
3. Stroke: The risk of stroke appears to be increased in women taking oestrogen only or combined HRT. It does not appear to be significantly increased in women under 60 years old. To put matters into perspective, if 2 in 100 women not taking HRT have a stroke, then 3 in 100 women taking HRT will have a stroke. Transdermal oestrogen appears to be associated with a lower risk of stroke.
4. Endometrial (womb lining) cancer: Oestrogen only HRT substantially increases the risk of endometrial cancer in women with a womb (uterus). The use of continuous combined HRT (both oestrogen + progesterone) or cyclical progesterone for at least twelve days every month eliminates this risk. It is also thought that insertion of the Mirena coil may protect against endometrial cancer and allows oestrogen to be given without the need for additional progestogen – which could protect against the side-effects of progestogens, and could lower the risk of breast cancer associated with combined oestrogen-progestogen therapy.
5. Heart disease: Women who are over 60 who start taking HRT more than 10 years after the menopause have an increased risk of heart disease. But the risk is small to begin with. Over five years, nearly 2 in 100 women taking HRT were at risk of heart disease, compared with 1.5 in 100 women not taking HRT. There is emerging evidence that commencing HRT early minimises or reduces the risks of heart disease.
6. Other risks:
- Evidence appears to suggest that taking HRT for a year or more could increase the risk of a woman developing gallbladder disease (gallstones).
- Current data on the role of HRT and the risk of ovarian cancer are still conflicting, with some research suggesting that HRT may slightly increase the risk, which disappears when HRT use is stopped.
What Are The Benefits?
1. HRT reduces hot flushes and night sweats: within two weeks of commencing treatment, sometimes sooner, HRT dramatically reduces and more often than not completely abolishes hot flushes and night sweats. No currently available alternative therapy is as effective as HRT for these symptoms.
2. HRT improves quality of life: this has been shown by all research that has studied quality of life in the menopause, and the impact of HRT. This is important, since menopausal symptoms can impact negatively on quality of life, but are not life threatening. Women find that the eradication of muscle aches and pains, the improvement in mood, the better quality sleep, reduced feelings of stress and anxiety, the perking up in libido and more – all contribute to an improvement in quality of life.
3. HRT improves vaginal dryness and urinary symptoms: intimacy becomes more comfortable, and the desire for it also often improves. The nuisance of losing small amounts of urine when one sneezes, coughs or plays a game of tennis is also reduced, as is the need to rush to the loo to empty the bladder.
4. HRT reduces the risk of developing osteoporosis (brittle bones): while there are other treatments that reduce the risk of developing, or treat established osteoporosis, no treatment is as effective as oestrogen replacement.
5. HRT reduces cardiovascular disease risk: a question mark has been put at the beginning of this statement because there is a degree of controversy and uncertainty. However, emerging evidence seems to suggest that HRT reduces the incidence of coronary heart disease if it is started within ten years of the menopause – which on the face of it makes sense: start therapy BEFORE potentially irreversible changes set in.
6. HRT has additional (miscellaneous) benefits:
- HRT has a protective effect against connective tissue loss in tissues such as skin, bones, joints and mucous membranes.
- There may be a possible reduction in the long-term risk of Alzheimer’s disease and all cause dementia in those women who take HRT.
- Most studies have demonstrated a reduction in risk of colorectal cancer with use of oral combined HRT.
In the end the decision to take or not to take HRT is a personal one, based on your family’s health history and your personal preferences. The symptoms of menopause can continue for many years after the periods have stopped, and as we are an ageing population, that means you could be spending 40-50 years with them. That’s half a lifetime, so quality of life, bone health and cognitive function are things that are well worth considering.