Use of oestrogen-only HRT by women with prior hysterectomy is associated with a lower risk of death from breast cancer, according to long-term follow-up of two landmark trials.
Women with no uterus who took conjugated equine oestrogen 0.625mg a day during a seven-year trial had a lower risk of developing breast cancer and a 40% lower risk of dying from it than women on placebo.
It meant in absolute terms that for every 10,000 patient-years, there would be four fewer breast cancer deaths, the US researchers said.
In contrast, for women with an intact uterus prescribed oestrogen 0.625mg plus medroxyprogesterone 2.5mg a day in an intervention lasting a median of 5.6 years, the risk of breast cancer was increased nearly 30%. But the women had no increased risk of death compared with placebo.
The findings were reassuring overall, allowing doctors to be more confident in conversations about HRT, said endocrinologist Professor Susan Davis, a professor of women’s health at Monash University, Melbourne.
HRT is Safer than you think
“HRT is safer than people think,” she told Australian Doctor.
“If women have had a hysterectomy and take oestrogen, not only is their risk of breast cancer less, but their chance of dying from breast cancer is less, and we know from other studies their heart disease risk is less.
Professor Davis said many women were still wary of HRT in the wake of trials being stopped early in 2002 and 2004 when data flagged an increased risk of breast ca, sparking a worldwide flight from HRT prescribing.
In a linked editorial, Dr Rachael Freeman, from the Dana-Farber Cancer Institute in Boston, US, said the latest data from the Women’s Health Initiative could reassure women taking oestrogen alone that they were not elevating their breast cancerous risk.