Doctors have halted another major hormone replacement therapy (HRT) study after early findings showed women were being made to face an "unacceptably high risk" of breast cancer, it has emerged.
The Swedish trial assessed the effect of hormone replacement therapy (HRT) on women with a previous history of the disease.
It was stopped three years early when the results showed the was HRT significantly increasing the chances of recurring breast cancer or the appearance of a new tumour.
The study, known as Habits ( hormonal replacement therapy after breast cancer diagnosis - is it safe?), was originally meant to include at least 1,300 women monitored for five years.
Doctors halted it on December 17th last year after an average follow-up of just two years. Of 174 women assigned HRT, 26 reported a recurrence or new case of breast cancer.
In contrast, only seven women who received therapy other than HRT for menopausal symptoms re-encountered the disease.