14 DAY TRIAL // A new study currently presented at the 33rd Annual CTRC-AACR San Antonio Breast Cancer Symposium, concluded that estrogen alone is effective for reducing breast cancer risks.
The estrogen produced by the human body – the endogenous estrogen, is known to help keep cancer away, but hormone replacement therapy (HRT) using only estrogen – exogenous estrogen, proved to effectively reduce breast cancer risks.
Joseph Ragaz, MD, medical oncologist and clinical professor in the faculty of medicine, School of Population and Public Health at The University of British Columbia, Vancouver, British Columbia, Canada, and colleagues reviewed data from the Women's Health Initiative (WHI) hormone replacement therapy (HRT) trials.
The trials involved two groups of women – the estrogen-alone women without a uterus and the estrogen-plus-progestin group of women with a uterus.
The researchers the WHI studies and found that there were subgroups of women without a strong family history of breast cancer, who received estrogen alone and showed a significant decrease in breast cancer incidence.
The reduced breast cancer risk was also noticed in the 75% of women without benign disease prior to the trial enrollment.
“Reduction of rates of breast cancer in the majority of women who are candidates for estrogen-based HRT is a new finding because estrogen was always linked with a higher incidence of breast cancer.
“Yet estrogen administered exogenously is actually protective for most women,” added Ragaz.
After these new results, Ragaz suggested that “while the use of HRT with estrogen alone may reduce the risk of breast cancer and may also be appropriate to manage menopausal symptoms, further research is warranted to elaborate on the optimum treatment regimen, to refine the selection of ideal candidates for estrogen therapy, and to understand the estrogen mechanisms that support the prevention of human breast cancer."
“The recommendations based on prior analysis of the results of the WHI HRT studies was not to use HRT, but we are optimistic this will change.
“Our conclusion, based on the data presented, should enhance considerations for an early approval of HRT based on estrogen-alone for the majority of selected women suffering with menopausal symptoms and galvanize new research on HRT to define the optimum regimens for individual women.”
According to Ragaz, the “analysis suggests that, contrary to previous thinking, there is substantial value in bringing HRT with estrogen alone to the guidelines.
“The data show that for selected women it is not only safe, but potentially beneficial for breast cancer, as well as for many other aspects of women's health.
“These findings should intensify new research into its role as a protective agent against breast cancer,” he added.
WHI is a nation-wide health study, launched in 1991 and including over 161,000 US women aged 50 to 79 years, that gathers data for preventing heart disease, breast and colorectal cancer, as well as fracture in postmenopausal women.
“Over the last 30 years HRT has been used almost indiscriminately by women expecting the benefit of reducing cardiac risks, while providing a protective effect against bone fracture, and improving overall quality of life.
“The WHI results as originally interpreted led to a major pendulum swing against HRT,” said Ragaz.