Hormone replacement therapy is not safe for breast cancer survivors

Question

Is hormone replacement therapy safe for women with previous breast cancer?

Study design

Randomised controlled trial (interim analysis).

Main results

In 345 women surviving breast cancer, there were more new breast cancer events in women taking HRT for menopausal symptoms compared with women receiving symptomatic treatment without hormones at a median of 2 years follow-up (absolute risk for new breast cancer: 26/174 [14%] with HRT vs 8/171 [5%] with no HRT; relative hazard 3.5, 95% CI 1.5 to 8.1).

Authors’ conclusions

In women surving breast cancer, those who received HRT for menopausal symptoms were at a higher risk of developing new breast cancers compared with those who received symptomatic treatment without hormones. These findings led to the termination of the trial.