Excess ovarian cancer deaths blamed on HRT use

Last Updated: 2007-04-19 9:45:32 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Since 1991, there have been roughly 1,000 ovarian cancer deaths attributed to the use of hormone replacement therapy (HRT) in the UK, according to a report in The Lancet.

Previous reports have indicated that ovarian cancer is the fourth most common malignancy in women in the UK, but there are few data regarding the number of cases associated with HRT use.

In the Million Women Study, Dr. Valerie Beral, from the Cancer Research UK Epidemiology Unit in Oxford, and colleagues addressed this issue by analyzing data from 948,576 postmenopausal women who were cancer-free at the beginning of the trial and were followed for 5 to 7 years.

Thirty percent of the women were current HRT users and 20 percent were past users, the report indicates. During follow-up, 2,273 women developed ovarian cancer and 1,591 of these women died.

Compared with women who never used HRT, current users were 20 percent more likely to develop ovarian cancer and 23 percent more likely to die from it. The investigators found that the risk of ovarian cancer was directly related to the duration of HRT use. Past HRT users did not have an increased risk for the malignancy.

Further analysis indicated that for every 2,500 HRT users, one extra case of ovarian cancer would occur; and for every 3,300 users, one extra ovarian cancer-related death would occur.

"Use of HRT has declined greatly in the UK and elsewhere since the report of the Women's Health Initiative, and is thought to be responsible for a recent reduction in breast cancer rates recorded in the USA. With these new data on ovarian cancer, we expect the use of HRT to fall further," the researchers note.

SOURCE: The Lancet, April 19, 2007.