Oestrogen-only HRT reduces breast cancer risk
WOMEN taking oestrogen-only HRT are less likely than non-HRT users to develop breast cancer or to die from the disease in the long term, US researchers say.
A follow-up to the Women’s Health Initiative trial looked at breast cancer outcomes for 7500 women who had taken oestrogen for a median of 5.9 years.
Those taking oestrogen were 23% less likely to develop invasive breast cancer than those who had been on placebo.
And the longer term effects of the HRT meant the women remained significantly less likely to die from breast cancer even five years after stopping treatment, with a 63% reduction in deaths from the disease compared to the placebo group.
The preventative effect of oestrogen was present across all age groups.
Experts caution that the effect applied only to women with a previous hysterectomy receiving oestrogen-only treatment, and not to those taking combined HRT.
Professor Ian Olver, CEO of Cancer Council Australia, said the findings should be reassuring for women taking short term oestrogen but cautioned that the finding did not apply to those higher risk patients with benign breast disease or with a family history.
“This is not something that could be recommended for routine use to prevent breast cancer,” Professor Olver said.
“Women should also be warned that the treatment does carry an increased risk of clots and strokes.”
Dr Jane Elliott, president of the Australasian Menopause Society and a lecturer in obstetrics and gynaecology at the University of Adelaide agreed, adding:
“It is however disappointing that the findings come amidst a climate of reduced HRT options for Australian women, with the number of TGA-approved and PBS-funded options now reduced,” Dr Elliot said.
Lancet Oncology 2012, online 6 March