HRT: is it safe?
Published 19 Oct 2015
Breast Cancer UK urges women to consider all of the evidence on HRT, not just one piece of research, amidst reports in the media today (1) that the links between HRT and increased risk of breast cancer have been overstated.
The latest assertion that HRT is safe and that women should not be worried about its potential to increase the risk of breast cancer are linked to the results of a (yet to be published) study by Dr Lila Nachtigall of New York University. The research followed 80 women who apparently “remained in good health despite taking HRT for a long time”. On this basis the researchers conclude that HRT does not damage health and “the risks of HRT have definitely been overstated.”
However, Breast Cancer UK are keen to remind women that results from other studies, including one of over 1.3 million women in the UK (2), contradict these latest assertions. Far from being safe, a number of other, significantly larger studies (3), suggest that HRT is linked to a range of adverse health effects including an increased risk of breast and other cancers.
A range of factors determine how much HRT will influence breast cancer risk, including time since menopause or whether HRT is oestrogen only or combined oestrogen and progestogen (4). It is generally accepted that once therapy ceases, the risk eventually returns to that of those who have never used HRT. As with any medical intervention, risks need to be weighed up against benefits.
Lynn Ladbrook CEO of Breast Cancer UK said “to suggest that a single study that follows 80 participants is proof that HRT is safe and does not influence breast cancer risk or the risk of other cancers shown to be linked to HRT, is misleading. We continue to urge women to think very carefully before taking HRT, to research all of the evidence available and to discuss all of the pros and cons with their GP.”
1)The Mirror (19th October 2015) ‘It's official: HRT is NOT a danger to women as experts conclusively dismiss worries over safety.’
2) The Million women study. Beral et al. (2003). Breast cancer and hormone-replacement therapy in the Million Women Study. Lancet. 362(9382):419-27.
3) e.g see Friisa et al. (2015) European Code against Cancer 4th Edition: Medical exposures, including hormone therapy, and cancer. Cancer Epidemiology (in press).
4) Beral, V. et al. (2011). Breast cancer risk in relation to the interval between menopause and starting hormone therapy. The Journal of the National Cancer Institute 103 (4): 296–305. http://jnci.oxfordjournals.org/content/early/2011/01/28/jnci.djq527.abstract