Hormone Replacement Causes Cancer, Right? Not Exactly...
Written by Devin Wilson, ND
“Fear of breast cancer is the strongest factor limiting postmenopausal hormone use. The most powerful study to date definitively demonstrated that estrogen does not cause an increase risk for cancer”
JAMA 2004;291(24): 2947-2958.
Does hormone therapy cause cancer? The answer is not so simple.
Unfortunately, two large and out dated studies on hormone replacement therapy has negatively impacted women’s health, even to this day. It is estimated that due to these two studies up to 90,000 women have died prematurely as a result of avoiding estrogen therapy.
The original analysis of Women’s Health Initiative (WHI) published the 1990s and the Million Women Study in 2003 claimed that hormone therapy increases the risk of cancer and adverse cardiovascular events in women. Not exactly true. In fact the conclusions of both of these studies are misleading.
Luckily, comprehensive, better designed and better analyzed research studies regarding hormone therapy in women have been completed all over the World.
“Estradiol and progesterone demonstrated no increased risk of breast cancer. Synthetic estrogen (Premarin® ) and synthetic progestins (medroxyprogesterone and noresterone) all dramatically increased the risk of breast cancer”.
Breast Cancer Res Treat 2007;101:125-134
The Danish Osteoporosis Prevention Study found “a significant reduction in risk of mortality, heart failure or myocardial infarction (heart attack) without any apparent increase in risk of cancer, venous thromboembolism, or stroke after the initiation of hormone replacement therapy”
https://www.bmj.com/content/345/bmj.e6409
“There is a long-held notion that estrogen exposure will increase the risk for breast cancer. Conversely, a body of emerging clinical and basic research evidence suggests that progestogens (synthetic or endogenous progesterone) are most likely the primary hormonal factor underlying seemingly estrogen-associated breast cancer risk.”
https://www.annalsofoncology.org/article/S0923-7534(24)04880-4/fulltext
In addition, researchers have revisited findings from the original WHI studies on breast cancer and developed a “New Consensus Statement” (See information graphic).
Some WHI researchers have also come forth with other things to say about the study.
“A principal investigator of a landmark women’s health study says initial results that linked hormone replacement therapy (HRT) to breast cancer and heart attacks were misleading and distorted for publicity. Others involved in the study claim the findings were merely misunderstood. Fifteen years on, a new consensus about risks and benefits is emerging, but too late for a generation of women who abandoned or avoided HRT due to reported risks”
https://pmc.ncbi.nlm.nih.gov/articles/PMC5415400/
In short, the original misinterpretation or false reporting of the two landmark studies on hormone therapy caused immense chaos among patients. This of course instilled fear among women, that hormone therapy caused cancer. Sadly, this had devastating effects.
“Over a 10-year span, starting in 2002, a minimum of 18,601 and as many as 91,610 postmenopausal women died prematurely because of the avoidance of estrogen therapy”
https://pubmed.ncbi.nlm.nih.gov/23865654/
“Over 90% of women will die from cardiovascular disease which estrogen can prevent”
https://pubmed.ncbi.nlm.nih.gov/8532268/
“Overall, current scientific evidence suggests that estrogen therapy, coupled with minimal use of a progestogen, is likely to offer net health benefits in women in need of HRT.”
https://www.annalsofoncology.org/article/S0923-7534(24)04880-4/fulltext
Please don’t take my word for it. At the end of this article you will find a link to some research articles regarding hormone therapy as it pertains to cancer, osteoporosis, cardiovascular disease and others. There are many more than articles available online and I encourage you to dive deeper if you wish.