|Title||Women who use estrogen-only form of (HRT) appear less likely to develop breast cancer in the longer term|
|Date||8 March 2012|
Response from Nick Panay, Chairman The British Menopause Society, to the Lancet article:
New research published in Online First in The Lancet Oncology has shown that women who use estrogen-only form of hormone replacement therapy (HRT) appear less likely to develop breast cancer in the longer term. A follow-up study of 7645 women from the Women’s Health Initiative (WHI) trial who took estrogen for about 6 years and then stopped has found that they are over 20% less likely to develop breast cancer and remain significantly less likely to die from the disease than those who never used HRT, a period of nearly 5 years after stopping treatment.
The WHI trial was in two parts, one examined the effects of the use of combined HRT (estrogen and progestogen) in women who had an intact uterus and was reported initially in 2002, and the other examined the effects of estrogen only compared to placebo (an inactive tablet) taken for almost 7 years in 10,739 women aged 50 to 79 who had had a hysterectomy. Results of the estrogen only part were initally reported in 2004 and even then showed a reduced risk of breast cancer in women taking estrogen compared to those taking placebo. This latest publication reports on the overall effects of estrogen use on breast cancer incidence and mortality, including extended follow-up of 7645 women (78% of the original surviving members) who were followed up from March 2005 until August 2009, a median (midpoint) 4.7 years after stopping estrogen therapy.
The researchers found a 23% reduction in the incidence of invasive breast cancer compared with placebo (151 cases, 0.27% per year vs 199 cases, 0.35% per year) during an overall follow-up period of nearly 12 years, whilst women in the estrogen group who did develop breast cancer had a 63% reduction in deaths from the disease (six deaths, 0.009% per year vs 16 deaths, 0.024% per year) compared with those in the placebo group.
The lower risk of breast cancer was restricted to women without a history of benign breast disease or a strong family history of breast cancer.
While it is not being suggested that women should now take estrogen therapy as a means of preventing breast cancer, these results should give significant reassurance to women taking estrogen only HRT, for whom, in the majority, the benefits of therapy will far outweigh the risks.
Women taking HRT who have not had a hysterectomy are advised to take estrogen and progestogen (combined HRT), the progestogen providing protection from estrogenic stimulation of the womb lining. In these women, we know that long term (more than 5 years after the age of 50) combined HRT may be associated with a small increased risk of breast cancer, but still for the majority, when used appropriately, the benefits of HRT outweigh the risks.
Urgent action is required to carry out further research on effects of different types and routes of HRT, to provide therapy options which provide the significant benefits of estrogen, while minising side effects and risks.
Lancet article: www.thelancet.com
< Go Back
<< News Index