|Increased risk of breast cancer from hormone therapy continues over time|
|Wednesday, 20 October 2010 11:20|
Estrogen-plus-progestin hormone replacement therapy increases the risk of breast cancer in postmenopausal women. Now a longer-term study of the problem shows the higher risk of breast cancer continues among women who took hormones but stopped, that the cancer in these women may be more advanced and that the likelihood of dying of breast cancer is increased.
The link between hormone therapy and breast cancer was confirmed with the conclusion of the Women's Health Initiative study in 2005, based on about 5 1/2 years of data. However, researchers at the Los Angeles Biomedical Research Institute obtained consent from more than 12,000 of the women enrolled in the study to continue to follow them for breast cancer incidence.
With an average of 11 years of follow-up data, the researchers, led by Dr. Rowan T. Chlebowski, found 385 cases of invasive breast cancer in women who took estrogen-plus-progestin hormone therapy during the study compared to 293 cases of women who were in the placebo group and took no hormones. Moreover, among all of the women who developed breast cancer, those who took hormones were more likely to have positive lymph nodes -- an indication that the cancer has spread -- compared with the women in the placebo group and were more likely to die of the disease.