An analysis of ovarian cancer in the Million Women Study.

In a reanalysis of the Million Women Study (MWS), their authors concluded that prolonged use of hormone replacement therapy (HRT) in postmenopausal women increases the risk of ovarian cancer. Although statistically significant their results are clinically irrelevant, since the attributable risk over 5 years is only 4 per 10 000 HRT users, a figure that is not confirmed by other large studies. This risk is much lower than those associated with obesity, lack of physical exercise, smoking and nulliparity, all of which are preventable. Therefore HRT should continue to be prescribed for symptom relief and improvement of quality of life because the benefits far outweigh the very low potential risks.