A paper from the influential Million Women Study has shown that the risk of developing ovarian cancer is increased by HRT use. The question is: how should these data be incorporated into HRT consultations in primary care? A total of 1.3 million women were originally recruited to the study, beginning in 1996. Data were collected over an average of 5.3 years from nearly 950,000 women. Half the women had used HRT, 30% of whom were current users. [With external links to current evidence and summaries]