Hormone replacement therapy and breast cancer: what are the facts?

Selective quotation in the popular press of studies showing a potential association between hormone replacement therapy (HRT) and breast cancer has fuelled women's concern. However, the increase in detected breast cancer among long term HRT users that was seen in some studies is compatible with surveillance bias and confounding caused by increased risk factors among HRT users (e.g., higher socioeconomic class, alcohol intake and body mass index). Until adequate data are available from randomised controlled trials, the evidence-based conclusion is that HRT has no effect on breast cancer rates. HRT may reduce mortality and morbidity from other diseases and the overall risk-benefit ratio should be considered for each woman.