Current HRT Use Increases Ovarian Cancer Risk

Using hormone replacement therapy (HRT) during menopause, even briefly, is associated with an increased risk of the 2 most common forms of ovarian cancer, a recent meta-analysis suggests.

The study, which involved reviewing 52 epidemiological studies of women with ovarian cancer, found there is about 1 extra case of ovarian cancer for every 1000 women who take hormones for 5 years starting around age 50. In terms of deaths, the data suggests that 1 additional woman will die from ovarian cancer for every 1700 women who take HRT.

Key Points:

- Use of HRT is associated with a significantly increased risk of the 2 most common types of ovarian cancer.

- This risk is greatest during use of HRT and diminishes after the treatment is discontinued.

- Researchers suggest this risk should be strongly considered when evaluating options for managing symptoms of menopause.

The increased risk, however, was only found when looking at serous and endometrioid ovarian cancers, and the correlation was not found when researchers looked at the data involving the 2 less common types of ovarian cancers, mucinous and clear cell.

The effect of using hormone therapy on the risk of developing ovarian cancer was the same for the two main types of therapy prescribed: estrogen only, or estrogen combined with a progestogen, the analysis revealed. In addition, the authors found that the proportional increase in risk was not materially affected by the age at which replacement therapy began, body size, past use of oral contraceptives, hysterectomy, alcohol use, tobacco use, or family history of breast or ovarian cancer.

The risk is greatest in women currently on hormone therapy, and the risk falls after the therapy ends, the authors report. The data strongly suggests there is a causal relationship between developing ovarian cancer and using hormone therapy, the authors concluded. They suggest the medical advice and guidelines on the practice of using hormone therapy should be influenced by their analysis.

Finally, the increased risk associated with taking hormone therapy was documented among women who used the therapy for less than 5 years.

This analysis has been published in The Lancet.