HRT Risks Misinterpreted: Experts Explain Why

Fiona Clark

 Health experts label HRT risk study reporting ‘Irresponsible’. But, should we still be worried?


It seems that every month or so a new study emerges that looks at the risks posed by HRT. It gets reported in the media and women are once again plunged into confusion about whether they should start or continue taking HRT.

But many doctors are not impressed claiming the way these studies are reported in the press is ‘irresponsible’ and ‘scaremongering’ with headlines such as ‘Breast cancer risk from using HRT is ‘twice what was thought’ appearing in national newspapers.

The study that prompted this headline was recently published in The Lancet. It examined the results of a host of published and unpublished studies between 1992-2018, selected on the basis of certain key search words, to draw its conclusions, but critics say it was very badly


What They Found VS What Was Reported

It found, in a nutshell, that the risk of developing breast cancer after menopause hormone therapy (MHT) or HRT as it’s more commonly known, was dependent on the type of HRT used and of the length of time it was taken for.

The authors wrote:

“For women of average weight in developed countries, 5 years of MHT, starting at age 50 years, would increase breast cancer incidence at ages 50–69 years by about one in every 50 users of oestrogen plus daily progestagen preparations; one in every 70 users of oestrogen plus intermittent progestagen preparations; and one in every 200 users of oestrogen-only preparations. The corresponding excesses from 10 years of MHT would be about twice as great.”

That translates to 2 cases in 50 people, for example, for the combined daily oestrogen and progestagen preparations.

The press headlines stating the risk of developing breast cancer was twice as high as previously thought were misleading. They confused ‘absolute risk’ with ‘relative risk’, and the findings were not put into perspective.

While a jump from one to two is ‘doubling’, it is a very low number to start with and an equally small jump. This figure was what’s known as the ‘relative risk’ – a measurement of how much an action can influence an outcome in comparable groups of people. In this case the groups were people who had used HRT in comparison to those who had not. It is not an individual’s risk.


The other term is ‘absolute risk’ – which is, if you like, more personal. It is often expressed as a percentage and looks at the the chance of developing a certain condition given certain variables. For example if you’re sedentary, overweight and have a poor diet your risk of developing heart disease would be X%.

So, in absolute terms what this study found was a 2% rise in incidence of breast cancer (from 6.3% to 8.3%)  in women aged 50 who had taken combined HRT for 5 years after being followed up for 20 years. For women who had taken oestrogen only (women who had had a hysterectomy for example who didn’t need the progestagen) the incidence went up 0.5% from 6.3% to to 6.8%.

Recent figures released by MHRA (Medicines and Healthcare products Regulatory Agency) show that on average 13 women out of 1000 will develop breast cancer without taking HRT.

Eight more individuals will be diagnosed if they use HRT for 5 years, bringing the number up to 21 in 1000. The figures after 10 years of HRT use are 47 for HRT users and 27 cases in women who had never used HRT – so an extra 20 cases per 1000 women, or to put it another way – 0.2%.

As menopause expert, gynaecologist and co-founder of The Menopause Clinic London, Mr Vikram Talaulikar says: “The ‘absolute risk’ for an individual is therefore still small and it is up to each woman to assess whether the benefits of HRT – suppression of severe menopausal symptoms, improved bone health, heart health and quality of life, outweigh these risks.”


Perspective: What Your Using Matters

The other thing that is important to note here is that the risk depends on the type of HRT the woman takes, and the study was looking at older forms, not the newer ones currently used.

“The study included women who took older forms of HRT which are generally no longer used. It did not include enough women who took natural progesterone to make comments on the risks women may have from using modern body-identical HRT which is safer than the older forms of HRT,” Talaulikar says.

“It was already known that [the older forms of ] combined oestrogen and progesterone HRT carries a higher risk of breast cancer than oestrogen only HRT, but modern HRT now uses natural hormones and transdermal or intrauterine routes of administration rather than orally taken equine or synthetic hormones which most of the women included in the study received.

This lack of perspective has spiked the ire of many working in the women’s health arena. They say it has caused unnecessary fear that will stop women from starting or continuing to take their HRT.


And they warn that in either case that decision could lower women’s quality of life and it may even cost them their lives in other ways.

Professor Michael Baum, Professor Emeritus of Surgery, visiting Professor of Medical Humanities in University College London, and a surgical oncologist who specialises in breast cancer treatment, didn’t hold back in his condemnation on GP and menopause specialist Louise Newson’s website:

“I think the press release put out by the Lancet is irresponsible and will undoubtedly lead to a drop in the use of HRT/ERT (estrogen replacement therapy) plunging thousands of women into a life of misery and for all we know shorten the lives of millions around the world.”

His logic?

Breast cancer is not the biggest killer of women. In fact, depending on the year, it ranks around 7th or 8th in the UK with heart disease, dementia/Alzheimers, strokes, lung diseases and lung cancer all claiming many more female lives than breast cancer.


A Rise In Other Diseases That Kill Women?

And because HRT offers a protective benefit for the heart, bones and brain, he points out that the cost of not taking it could mean that these other killers “might increase as a result of the withdrawal of oestrogen replacement therapy.”

He adds the study shows very low-level risks that are outweighed by the benefits in reduced heart disease, dementia and suicide – which incidentally, in women, rises sharply in the over 50 age group.

Leading oncoplastic breast surgeon, Professor Kefah Mokbel, wrote in the Daily Mail: “Put bluntly, what it shows is that at most two in every hundred women who take HRT will develop breast cancer as a result. The other 98 will have had the benefit of an increased quality of life, freed from the distress of their menopausal symptoms, and will not get cancer as a result.”

“What the study does not show is the mortality rate of the breast cancer that HRT causes – that is to say how many die as a result. Because if you do develop breast cancer, but can be cured, then that is an important distinction,” Mokbel adds.

Dr Louise Newson, known as ‘the menopause doctor’ runs a clinic dedicated to helping women during this phase of life. Every day she sees women who are enduring disabling symptoms ranging from suicidal thoughts and depression to the physical discomforts of hot sweats and vaginal atrophy.


Dr Louise Newson

She understands how distressing these can be, but also how big a decision it is for women to take HRT – especially given all of the poorly reported studies in the headlines. She told The Telegragh:

“Alarm is a natural reaction when you hear the words ‘breast cancer’ in the same sentence as HRT, and my fear is that the headlines, and not the drugs themselves, will impact negatively on women’s health. I fear women will decide to come off HRT, or not to even start it in the first place. That would indeed be detrimental to the health of so many.

“I don’t feel alarmed by the findings. They arise from an epidemiological study looking at numerous other studies undertaken in the past. It is not a randomised controlled  study, which is the gold standard study to demonstrate cause and effect.  There are so many different reasons why women develop breast cancer – which affects around one in seven women in the UK – and often not one single cause. Obesity, not exercising and drinking alcohol are all independent risk factors for developing breast cancer in the future.”


Obesity: the risk factor the headlines missed

In fact, one thing reports on the study failed to mention was the finding that the risk for women who were overweight or obese was higher than for women within ‘normal’ BMI ranges, and taking HRT made very little difference in this group.

Some 62% of UK women are overweight or obese and the study found that obese women who had never taken HRT had almost as high a risk of developing breast cancer as women who had taken HRT for ten years. Overweight women also had a higher risk that their leaner counterparts.

This is because the body’s fat cells have an oestrogenic effect of their own that increases the risk of breast cancer.

“The real important public health message from the study was that obesity is the main problem in relation to risk of breast cancer and women should make wise lifestyle choices to minimise their risk of breast cancer,” Talaulikar says.

Indeed, one study cited by the authors showed 85% of the women who developed breast cancer were obese.


What’s New Then?

According to Talaulikar, this study adds little to what we already know.

“The overall findings from this study are in keeping with the NICE Menopause guideline recommendations. …We have always known that there is a small increase in risk of breast cancer with HRT after 50. It is important every woman is made aware of this risk and it is then individual woman’s’ choice whether to take HRT or not.  Most women I see in my clinic will consider this risk far below the benefits they obtain from HRT in their daily lives,” he says.

The MRHA has advised women who are concerned about their HRT to see their GP. It may be an opportune time to make sure you are on the newest forms which carry lower risks.


To find doctors who consult on women’s health and menopause click here.

Related Products