Today Mumsnet launches our survey, which reveals that four in ten menopausal women are worried that taking HRT could increase their risk of breast cancer.
HRT Dr Louise Newson featured in the ‘Sex, Myths and Menopause’ documentary with Davina McCall that aired on Channel 4 in May. Here, Louise fact-checks some myths around the menopause and treatments and address concerns raised, particularly about the risk of breast cancer with HRT. A guest post by Dr Louise Newson:
"With all the increased conversation around menopause and perimenopause in the media recently, your thoughts may have turned to your own hormones, checking whether you tick a lot of boxes on the symptoms list, and even deciding if you should take the plunge and start HRT.
The results from the recent survey within the Mumsnet community echo what I see in my clinic and hear on social media every day. You know you’re perimenopausal (if you’re still having periods) or menopausal (if periods stopped more than a year ago) and you’re getting fed up of the toll it’s taking on your body and impact on your life. But the one thing that is stopping you getting help – and relief from symptoms – is that nagging doubt in your mind that HRT is too risky and causes breast cancer.
First of all, don’t worry, and secondly, let me have a few minutes of your time to explain where those rumours came from in the first place and show you what the good-quality evidence shows us.
A brief history of HRT
As part of the feminist movement in the 1960s the idea of ‘feminine forever’ was introduced in a bestselling book by an American doctor, Robert Wilson, who recognised menopause as a hormone deficiency that was curable and preventable by oestrogen replacement.
In European countries and the US, HRT grew in popularity over the decades, rising significantly in the 1990s. The majority of menopausal women took HRT and healthcare professionals were very happy and willing to prescribe it to most women. Women’s health on a larger scale saw fewer instances of heart disease (including heart attacks and strokes) and much less of the bone-weakening disease osteoporosis, as a result of the widespread use of HRT.
Everything changed virtually overnight with the publication of one study, the Women’s Health Initiative (WHI) study in 2002, that is referred to in Davina's documentary.
The WHI study
This notorious study was halted prematurely due to concerning results they were finding linking HRT with breast cancer. The conclusions were then leaked to the media before proper analysis could be carried out. Later, analysis of this data revealed the link was not statistically significant - in fact it had completely vanished - but of course, this news didn’t make the headlines. It was too late. The notion was now firmly planted, in the minds of women and healthcare professionals alike, that HRT causes breast cancer. And the number of women taking HRT in Europe and the US – much like their hormones – fell right off a cliff.
Taking a deep dive into the WHI study will show you that:
- The average age of women in the study was 63, yet researchers generalised their conclusions to include women entering menopause in their early 50s.
- Nearly half the participants were current or past smokers, many had heart disease in the past, more than a third had been treated for high blood pressure, and 70% were seriously overweight or obese.
- The study claimed HRT increased the risk of heart problems, but the fine print revealed that the risk occurred only among women who were starting in their 70s and older.
- The investigators then revised their findings five years after they were initially published and concluded that women who started HRT in the first 10 years following menopause actually reduced their risk of heart disease, but this didn’t make headlines either.
- The types of HRT used in this study were tablet oestrogen (derived from pregnant horses’ urine) with synthetic progestogen, which are very different from the body identical HRT (derived from yam plants) that we now usually prescribe, which has lower risks and is very safe.
The fallout from fake news
This study was 20 years ago and the good news about oestrogen is still struggling to break through the damage caused.
More than 70 years of findings from animal studies, human studies, observational studies and randomised control studies demonstrate the benefits of oestrogen and show HRT to be a very safe and effective treatment for perimenopause and menopausal symptoms, and for reducing your risk of future diseases. Today in the UK, only around 10% of women take HRT, and many who would like to struggle to find a doctor or healthcare professional who will prescribe it for them.
Factcheck: HRT and breast cancer
So what does the good-quality evidence show us about the risks of HRT?
- Most types of HRT do not increase the risk of breast cancer at all.
Oestrogen-only HRT has actually been shown to lower the future risk of breast cancer compared to women who don’t take HRT.
- Some studies have shown that women taking combined HRT (containing oestrogen and a progestogen – a synthetic progesterone) may have a very small increased risk of breast cancer. The risk is related to the type of progestogen in the HRT, not the oestrogen. However, this risk is very small and is less than the risk of breast cancer for women who are overweight or who drink a large glass of wine every evening. (Remember Davina in the ball pit and how many more pink balls there were for weight or alcohol intake than for HRT?)
- Taking micronised progesterone (‘Utrogestan’ in the UK) has not been shown to be associated with a statistically significantly increased risk of breast cancer.
‘Body identical’ HRT has the same molecular structure as the hormones we naturally produce and contains oestrogen that is transmitted through the skin via a patch, gel or spray, and micronised progesterone (needed to protect your womb, if you have one). This type of HRT is also safe for women who have migraines, have a history of a blood clots or stroke, and also for most women who have had cancer or have a family history of cancer.
It is important to remember that the risk of breast cancer is most influenced by factors that you can’t do much about, like your age and family history, and three key things you can influence – your weight, exercise and alcohol intake. These risk factors are associated with a greater risk of breast cancer than any type of HRT.
I believe (and the NICE menopause guidelines tell us) that most women would benefit from taking HRT to help their symptoms of perimenopause and menopause and also to help protect against heart disease, osteoporosis, dementia, depression, bowel cancer and type 2 diabetes.
It’s time to change the narrative around HRT, shake off false beliefs about the risks, and take back control of your wellbeing in the present and improve your health for the future."
Dr Louise Newson is a menopause specialist, and founder of The Menopause Charity and the free Balance menopause support app.