Potentially deadly breast cancer is more likely among those who have had combined hormone replacement therapy (HRT), according to research.
A study completed by the Women’s Health Initiative (WHI) has revealed that oestrogen plus progestin hormone treatments increase the chances of advanced forms of breast cancer developing.
These results are in addition to previous WHI findings, which show that breast cancer death rates increase for women who undergo HRT for an average of 5.6 years.
Women involved in the research were either given the combined HRT treatment or a dummy ‘placebo’ pill.
Following the treatment, around 13,000 women had their condition monitored for 11 years, with invasive breast cancer occurring in 385 women who had received the treatment, compared with 293 who did not.
A larger percentage of the HRT-treated group with breast cancer also saw the disease spread to the lymph glands.
There were 25 deaths from breast cancer among the HRT group and 12 among the placebo group. At a population level, this was the equivalent of 2.6 against 1.3 deaths per 10,000 women per year.
The findings were reported in the latest issue of the Journal of the American Medical Association.