April 26, 2007- Not only does hormone therapy increase the risk of developing breast cancer in postmenopausal women, it also makes them more likely to develop and die from ovarian cancer .
Almost 950,000 postmenopausal women took part in a UK cohort study1 from 1991 to 2005. According to the results, since 1991, hormone replacement therapy would have been responsible for 1,300 new cases of ovarian cancer and 1,000 additional deaths.
In other words, hormone therapy would cause an additional case of ovarian cancer for every 2,500 women who take replacement hormones. It would also cause one more death for every 3,300 women treated with hormones.
Less breast cancer |
According to the authors, the increased risk of ovarian cancer observed in their study is “slight, but significant.” However, they warn that it is the impact of hormone therapy on the increase in cancer cases in general that must be taken into account by public authorities.
“Globally, the incidence of breast, endometrial and ovarian cancer is 63% higher in women who are treated with hormones (31 cases per 1,000 women), compared to those who have never taken them. (19 cases out of 1,000) ”, they indicate.
According to the researchers’ data, the onset of ovarian cancer occurred, on average, two and a half years after starting hormonal treatments in women who were diagnosed. In addition, the longer the use of hormone therapy lasted, the greater the risk of developing ovarian cancer, regardless of the type of treatment used (estrogen alone or a combination of estrogen and progesterone).
In Canada, ovarian cancer is the seventh largest cancer in women3. It is the fifth most fatal cancer for Canadian women. This cancer is diagnosed each year in more than 2,500 women in the country, in addition to being responsible for approximately 1,400 deaths.
Martin LaSalle – PasseportSanté.net
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1. Million Women Study Collaborators, Ovarian cancer and hormone replacement therapy in the Million Women Study, The Lancet, April 19, 2007. The summary is available at www.thelancet.com [consulté le 24 avril 2007].
2. Ravdin PM, Cronin KA, et al. The decrease in breast-cancer incidence in 2003 in the United States, N Eng J Med, April 19, 2007, vol. 356, no 16, 1670-4.
See also our new Less Breast Cancer Without Hormone Therapy? on this subject.
3. Canadian Cancer Society and National Cancer Institute of Canada, Canadian Cancer Statistics 2007. The document (in PDF format) is available at www.cancer.ca [consulté le 25 avril 2007].