The mere mention of HRT can spark fears of breast cancer, but should it? Breast surgeon Professor Zoe Winters and Consultant Gynacologist Jeannie Yoon set the record straight.
Navigating the Menopause can be a huge challenge for many women. It can be a strange and isolating time for some as despite being well informed, there remains a taboo about acknowledging it and discussing it openly.
Approximately 95% of women will go through the Menopause between the ages of 45 and 55 years with an average age of 51 years. The symptoms can range from minor to debilitating and include hot flushes, night sweats, joint and muscle pain, ‘brain fog’ often described as ‘word salad’, poor concentration, disturbed sleep, low mood, anxiety, vaginal dryness, a reduction in libido and bone fractures in later life. These Menopausal symptoms typically continue for 5 years after the last period and for around 10% of these women, they can last up to 12 years.
It is important to remember that each woman will experience this journey differently. For many this natural transition can be relatively seamless, but for 25%, their personal and professional lives can be significantly affected.
In the past, clinicians approached women with menopausal symptoms with a rather fixed approach of ‘one size fits all’, but we now know that an integrated approach based on the individual woman’s needs works best.
A healthy lifestyle can minimise the effects of the menopause and certain complementary and alternative therapies may help. The most widely used and effective treatment for menopausal symptoms is Hormone Replacement Therapy (HRT) but only around 1 million women in the UK are currently using this.
“…there is now a generation of women who have been denied the opportunity of an improved quality of life during their menopausal years…”
HRT was first available in the 1940s before becoming widely used in the 1960s when it revolutionised the management of the menopausal woman. However, in 2002 and 2003 the results of the USA Women’s Health Initiative (WHI) and the UK Million Women Study (MWS) were published and their findings raised concerns about the safety of HRT, including the risk of Breast Cancer. There was widespread publicity which resulted in panic amongst clinicians and users. The number of women taking HRT fell by around 60%, and that has not changed significantly in the intervening years.
As a result there is now a generation of women who have been denied the opportunity of an improved quality of life during their menopausal years.
It is important to note that the WHI study had flaws. It demonstrated adverse effects of HRT in the older postmenopausal women (over the age of 60 years) but this is not the age group of women that presents with the new onset of menopausal symptoms that occur mainly in the late 40s to 50s.
“…other factors like lifestyle issues, obesity, alcohol consumption and smoking can have a greater effect on Breast Cancer risk than HRT…”
When advising women in the 40-50 age group, their age specific risk needs to be taken into consideration and the data suggests that the overall risk benefit profile is more favourable for women ages 50 to 59 years. Of course a full medical history is vital when assessing suitability for HRT as other factors like lifestyle issues, obesity, alcohol consumption and smoking can have a greater effect on Breast Cancer risk than HRT. According to NICE, obese women have a 6 times higher risk of developing Breast Cancer than the extra risk associated with combined HRT.
The current consensus is that HRT taken for less than 5 years does not significantly increase the risk of Breast Cancer, but studies have shown that after 5 years of use, a small increase in risk is possible. Once HRT has been stopped, this risk appears to return back to baseline, suggesting that HRT may promote the growth of Breast Cancer cells that are already present if HRT is taken for more than 5 years after the age of 50 years. In some women, however, there is no evidence that HRT causes Breast Cancer.
In 2019 the highly reputable journal, The Lancet, published a large meta-analysis looking at women with a normal body mass index who started HRT in their 40’s-50’s. It confirmed that different types of HRT are associated with different risk for women who started HRT in their 40’s-50’s.
Oestrogen-only HRT does not appear to increase the risk of breast cancer (1 in 200 women), while there appears to be a small increased risk with long-term (>5 years) use of combined HRT (oestrogen and progesterone) preparations (1 in 50 women), compared to the general population of women at 50-69 years of age who have never taken HRT ( 1 in 16). Consequently, breast surgeons recommend more frequent (annual versus 2 yearly) mammograms plus ultrasound in individual cases based on perceived increased risks of breast cancer.
The type of HRT and the ways it’s taken or used can influence risks too and should be discussed in detail with your expert clinician. For example, the safest form of HRT is oestrogen only versus combination oestrogen and progesterone recommended in women with an intact uterus. Transdermal or topical oestrogen is safer than oral administration, as the former bypasses being metabolised through the liver, thus avoiding the less safer liver metabolites of oestrogen. The type of progesterone is also thought to play a role.
“…Women now live longer in the post-menopausal period than in their reproductive phase and it is therefore of paramount importance that we focus not just on extending their lives, but to ensure that they have a quality of life that they duly deserve…”
Another important factor to note is the fact that if HRT is commenced at an earlier age due to Premature Ovarian Failure, the use of HRT up to the age of 50 years does not increase the breast cancer risk any more than in women who continue to have periods up to the age of 50 years. The additional risk from HRT only applies if it is then taken for more than 5 years after the age of 50 years.
This does not, however, mean that you have to stop taking HRT after the age of 50.
Women are often told that after 5 years or after the age of 60 that they should stop too, but this is not the case. If you are aware of the risks and benefits and your health is closely monitored you can opt to continue.
There are numerous health benefits derived from HRT in women who are symptomatic with the earlier timely recommended use of HRT being the most beneficial. Exposure to long term, or longer than 5 years of uninterrupted oestrogen and progesterone is just one of a number of breast cancer risk factors that may also increase breast density. Other breast cancer risk factors comprise family history, gene mutations and atypia (slightly abnormal appearing cells) on tissue biopsies, and finally common gene variants involving population or background genes called single nucleotide polymorphisms or SNPs.
Currently, there are exciting possibilities to offer all women over 40 years of age access to testing of their individual Breast Cancer Risk Score whereby if they are high risk, we would recommend annual clinical examination and breast mammogram screening. In women with prohibitively dense breasts, we can include focused ultrasound and breast MRI. There are two large high-quality studies in the USA and Europe evaluating the benefits of women selecting mammography based on personalised risk. We can now offer this testing in private care.
As a Clinician in modern times, we are aware that women now live longer in the post-menopausal period than in their reproductive phase and it is therefore of paramount importance that we focus not just on extending their lives, but to ensure that they have a quality of life that they duly deserve. It is therefore essential that we work together in an integrated fashion to empower women with accurate and appropriate information for them to make the right choices for themselves and to treat them as individuals.
You can find out more about the authors of this article here:
Miss Jeannie Yoon – Consultant Gynaecologist and Obstetrician
Professor Zoe Winters – Consultant Breast Surgeon and Breast Specialist