No need to panic over recent HRT and breast cancer study

Approximately 80% of menopausal women in the UK experience menopausal symptoms. While a quarter have severe symptoms, only a small proportion of menopausal women actually take HRT. Reasons for this are not completely clear, but many women are apprehensive about going to seek medical advice for symptoms that are not due to an ‘illness’, and they do not want to be seen as wasting a doctor’s precious time.

I am constantly surprised how women put up with severe symptoms which affect their abilities to function at home and at work. Many women buy herbal products over the Internet believing them to be natural and safe remedies, even though there is limited evidence of their efficacy.

The majority of women I speak to about the menopause are worried about taking HRT, and when I ask why, it is usually about the increased risk of breast cancer. Many women are worried about this risk and it leads to much concern and confusion.

Often, women think that all types of HRT can cause breast cancer in all ages of women and that this risk is high. Women are often unaware of the real facts, meaning they cannot make an informed decision about taking HRT.

Risks associated with HRT should be ‘interpreted with caution’

There is evidence that taking combined HRT over the age of 51 years is associated with a very small increased risk of breast cancer. There has been even more alarm following the publication of a study in the British Journal of Cancer.¹ This study used information from serial questionnaires from the UK Generations Study cohort to estimate hazard ratios for breast cancer among post-menopausal women with known menopausal age.

This retrospective observational study has shown that there is a 2.74 times increased risk of developing breast cancer (or preinvasive DCIS) for women using combined HRT for five years. This risk increases to around threefold with prolonged treatment, over 15 years. As shown with other studies, there was no increased risk of breast cancer seen for users of oestrogen-only therapy. This increased risk returned to normal after stopping HRT.

However, a very small number of breast cancer events occurred in this study. This means that it is important that these increased risks stated are interpreted with caution. There is no information about whether cancers were diagnosed via screening or presented symptomatically. It is well documented that women who are taking HRT are more likely to attend for breast screening.

In addition, this study has not differentiated between the various combined HRT products nor between different progestogens used. This is a shame as there is evidence to suggest that certain synthetic progestogens, such as medroxyprogesterone acetate, may increase breast cancer risk when used in combined HRT when compared to using micronised progesterone.² There has not been a study to show that taking HRT affects the risk of dying from breast cancer.

Importantly, women need to be made aware that the increased risk of developing breast cancer with taking combined HRT is less than being overweight or having a glass or two of wine each night. In addition, there is no increased risk of breast cancer in women who take HRT and who are under 51 years of age.

“Women should be focusing any worries about breast cancer not on HRT, but on their modifiable lifestyle risk factors”

It is so important that a woman’s individual risk factors for breast cancer, and indeed other conditions, are clearly assessed and evaluated. Women should be focusing any worries about breast cancer not on HRT, but on their modifiable lifestyle risk factors.

We should also be spending time and effort on educating women about the effectiveness of HRT, not only on improving vasomotor symptoms, but its effectiveness on reducing cardiovascular risk and also the risk of osteoporosis.

The results of this study should not lead to women panicking about HRT and stopping any treatment theyware on. I’m certainly am not going to change my clinical practice as a result of this study.

The British Menopause Society and the International Menopause Society recently have produced documents that also agree with these views.

References

1. Jones ME, Schoemaker MJ, Wright L, McFadden E, Grifn J, Thomas D, Hemming J, Wright K, Ashworth A, Swerdlow AJ. Br J Cancer. 2016 Aug 23;115(5):607-615
2. Panay N. Post Reprod Health. 2014 May