books about hrt and breast cancer risk

Menopause Treatment > Knowledge > HRT and Breast Cancer Risk

HRT and Breast Cancer Risk

Sep 23, 2019

Did the latest Lancet article in August 2019 tell us anything new about HRT and breast cancer risk?

Once again unnecessary panic has been stirred up by the publication of information about the health risks of HRT. This last happened in 2003 when two studies, the American WHI (Women’s Health Initiative) and the British Million Woman Study, indicated that there was a significant increase in the risk of breast cancer in women using menopause hormone therapy. Subsequently, we saw the results of these trials being refuted, but this reassuring news was not given the same media coverage, so many women did not realise there was nothing to worry about. There was a 50% drop in HRT prescriptions and women were left with no clear information or options. 

The official NICE guidance in 2015 supported our view, which is that the proven benefits of HRT, in terms of quality of life and longevity of healthy life, still remain far greater than the small potential increase in risk of breast cancer. And this latest ‘scare’ is no different. There have been no new discoveries or revelations that we need to educate our patients about. 

It remains that we should always bear in mind that breast cancer is a common cancer in the first place. There are many other factors to bear in mind when calculating any potential increase in risk when consulting on highly individual treatment and therapy. 

We include a review of the Lancet article by Professor Michael Baum who is a British Surgical Oncologist of outstanding repute specialising in breast cancer treatment. He is Professor Emeritus of Surgery and Visiting Professor of Medical Humanities at University College London. He is highly respected for his contribution to the evaluation and support of patient quality of life.



Professor Michael Baum response August 30th, 2019

  • Two principles in the practice of medicine – improve length of life (LOL) and quality of life (QOL).
  • In the modern era paternalism of the profession has been replaced by the principle of partnership whereby patients are helped to make informed decisions.
  • The paper in today’s Lancet and its press release is alarmist and will frighten off thousands of women from taking HRT and is of no help for women in making informed choices.
  • This paper is extremely difficult to understand even by an expert like me, and I would need many hours to ingest it all.
  • The publication contains data from about 100,000 women taking part in clinical trials of complex design going back more than 20 years and provides a summation of both published and unpublished data using complex methodology.
  • The report is framed to prove relative risks (RRs) of the INCIDENCE of breast cancer. For the lay women to understand this I’ve found a description of absolute values below.
  • The simplest way I can distil the results for the lay reader is as follows:
    • If we consider a woman aged 50 who takes combined HRT for 5 years who is followed up for 20 years, the incidence of breast cancer goes up from 6.3% to 8.3%, an additional 2%.
    • If we consider a woman aged 50 who takes oestrogen alone (ERT) for 5 years and is followed up for 20 years the incidence goes up from 6.3% to 6.8%, an additional 0.5%.
  • NB we are only given numbers for INCIDENCE not breast cancer mortality or all-cause mortality.
  • Breast cancer mortality might be unaffected because there is an imbalance in the incidence of oestrogen receptor positivity (ER+) favouring those women on HRT/ERT.
  • All cause mortality might favour those on HRT/ERT because of reduction in heart disease, stroke, osteoporosis, dementia and suicide.
  • The benefits of HRT/ERT in improving quality of life are beyond questions.
  • Finally, the whole edifice might crumble if we correct the data for the numbers of “over diagnosed” cases from XS use of mammograms amongst women on HRT/ERT who are frightened of developing breast cancer. It thus becomes a self-fulfilling prophecy.

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 plunging thousands of women into a life of misery and for all we know shorten the lives of millions around the world. Remember there are more important threats to women’s lives than breast cancer, which is now only 7th in the league whilst those higher up the league might increase as a result of the withdrawal of oestrogen replacement therapy. “Statistical significance” does not always translate into “clinical significance”.