HRT link to breast cancer

Postmenopausal women taking hormone replacement therapy (HRT) are at increased risk of developing breast cancer, according to a new analysis from the Women's Health Initiative.

The study enrolled 25,328 women who did not use hormones and 16,211 who received oestrogen and progestin HRT. During a mean follow-up of 11.3 years, 2236 women developed breast cancers.

The risk of developing breast cancer was 55 per cent higher among HRT users than nonusers (annualised rates of 0.60% and 0.42% respectively). Women who started HRT at their menopause were 68% more likely to develop breast cancer than non-users. The risk declined as the gap between menopause and the start of HRT lengthened.