Breast cancer risk persists even after termination of HRT, finds study

The study was conducted on 15,730 of the 16,608 postmenopausal women with an intact uterus who had participated in the Womenss Health Initiative (WHI) trial. The average age of the enrolled women was 63 years. The study found that women who were tracked for an average of 2.4 years after discontinuing combination hormone replacement therapy (HRT) had a 27% higher risk of developing invasive breast cancer than those in the original placebo group. Due to the increased risk of cancer during follow-up, the global risk index – which measured a variety of outcomes, including death – was also 12% higher in those women who had been randomly assigned oestrogen plus progestin.

But Wyeth, the company which markets the hormone replacement therapies Prempro and Premarin, contended that the WHI study was selective and cannot be generalized for all subsets of menopausal women who use the HRTs. The company, however, recommended the lowest effective dose for the shortest duration of time as per the clinical guidance outlined in product labelling and patient information for HRT.

Michael Lauer, director of the NHLBI Division of Prevention and Population Sciences, said: “While it is reassuring that the heart attack risk decreased and that the risks for strokes and blood clots did not grow after the women stopped taking hormones, this study provides further evidence that five years of combination hormone therapy is harmful. All the accumulated risks do not simply disappear.”