A major stumbling block to the use of estrogen replacement in women is the concern that it will increase the risk of breast cancer. The landmark study, The Women’s Health Initiative, was abruptly stopped in 2002 when data revealed a 26% increase incident of breast cancer in women taking the non-bio-identical hormone Prempro. Another arm of the WHI where women were taking estrogen alone because they did not have a uteris continued, This arm of the study did not show any increase in breast cancer and actually revealed less breast cancer risk compared to women in the placebo group. This information is explained in more detail under the “Science” tab. Some have recommended that hormone replacement be withheld from women with increased risk of breast cancer based on personal or family history, lifestyle, increased breast density or fibrocystic breast disease, and that hormone replacement should be offered for the shortest possible time after menopause. This belief results in many women being deprived of the many benefits of natural hormone replacement therapy that may extend the functional lives of women for many years.
Research on the incidence of breast cancer in estrogen replacement therapy offers uncertain conclusions. Some studies have implicated non-human identical estrogen as one cause of breast cancer. Other studies have demonstrated increased risk when progestins, which are non-bio-identical progesterones, are given with the estrogen.
A large French study, released in 2007, demonstrated NO increase in breast cancer incidence when human bio-identical progesterone was given with estrogen. A very recent study from the Women’s Health Initiative revealed a REDUCED rate of breast cancer in women given estrogens for 5.9 years, with that lower rate persisting over more than 10 years of follow-up.
There is no definitive conclusion about breast cancer risk and hormone replacement therapy. Every woman has unique sets of needs, circumstances, and risks. We believe that hormone replacement therapy may be carefully initiated in most post-menopausal women, using low effective doses, and maintained indefinitely, provided the women are closely monitored and the benefits continue to outweigh the risks. The benefits of hormone replacement are too substantial to be denied to the majority of women.