NICE on brink of U-turn on dyspepsia referral advice
Combined HRT carries a greater overall cancer risk than oestrogen-only therapy, new results from the largest ever study of female health reveal.
The UK-based Million Women Study, which examined records from 717,000 postmenopausal women, found the risk of breast cancer from combined HRT outweighed benefits from reduced risk of endometrial cancer.
The findings, published in The Lancet this week, appear to support the use of low-dose oestrogen-only therapies even in women with an intact uterus.
But GP HRT experts said GPs should be wary of changing their practice unless presented with a consensus statement from leading clinicians.
Researchers assessed overall cancer risk after accurately quantifying risk of endometrial cancer with different forms of HRT.
Incidence of breast and endometrial cancers was 32 per 1,000 over five years for users of combined HRT, but just 22 per 1,000 for oestrogen only.
Oestrogen-only therapy increased risk of endometrial cancer by 45 per cent compared with non-users and
tibolone, a synthetic steroid taken by 28,000 study participants, increased risk by 79 per cent.
Continuous combined HRT reduced risk by 29 per cent while cyclic preparations had no effect.
Study leader Professor Valerie Beral, director of the Cancer Research UK epidemiology unit at the University of Oxford, said: 'Since breast cancer is much more common than endometrial cancer, combined HRT poses the greatest overall cancer risk.'
Dr Martyn Walling, a GP in Boston, Lincolnshire, and member of the Primary Care Gynaecology Group, said: 'I think we don't change our policy. There have been too many questions raised about the Million Women Study and we are using HRT for a very short time so the risk is small.'
But Dr Pawan Randev, chair of the Cancer Primary Care working group, said: 'Certainly this is an important finding and the idea of putting combined risk together is a good one.'
What we knew
·Postmenopausal women who use HRT containing oestrogen alone are at increased risk of endometrial cancer
·Women using combined oestrogen-progestagen HRT are at increased risk of breast cancer
What this adds
·When endometrial and breast cancers are added together, combined HRT causes a greater increase in total cancer incidence than the use of other therapies
By Cato Pedder