What you need to know about Estrogen Dominance and Breast Cancer

What you need to know about Estrogen Dominance and Breast Cancer

Remarkably still today, there are many opposing views on the effects of Estrogen as a hormone replacement and its side effects. It is the widely known hormone to consider as a woman goes through menopause. It is touted to increase energy levels and improve skin, nails and vaginal dryness and regain the feeling of youth.

What women don’t know is most doctors are not trained on hormone balancing and are encouraged to prescribe synthetic estrogen -- even use estrogen to treat breast cancer.

The fact is that there are many clinical studies that have established that an underlying and untreated condition of "estrogen dominance" significantly increases your breast cancer risk: women who develop breast cancer have higher estrogen levels than women without breast cancer.

Some studies have also shown that women who had been treated for breast cancer, and who continued to have high estrogen levels, had a return of the disease sooner than breast cancer survivors with lower estrogen levels. The reason is that one of estrogen's functions in the body is to foster cell growth, or "cell proliferation." At a cellular level, unchecked cell growth can be a precursor for cancer. 

The term "estrogen dominance" was coined by Dr. John Lee  to describe the 'adverse' symptoms often encountered by women if they have a naturally high level of estrogen, or when women have been on HRT (hormone replacement therapy) or a contraceptive pill for any length of time and therefore have low progesterone levels.

Too much estrogen can wreak absolute havoc on your whole body. It can cause things such as fatigue, fibroids, endometriosis, abnormal menstruation, and most importantly breast cancer. Read my blog on the “12 Major Symptoms of Estrogen Dominance.”

While I am not entirely against estrogen as a hormone replacement, as it has its benefits, including reducing the effects of hot flashes, vaginal dryness, and improved cognitive function, energy levels, etc., it must be countered with Progesterone to prevent estrogen dominance. In addition, I only recommend Estriol 2.5 transdermal cream as it is the weakest and most safe hormone for HRT.

You should know there are three types of Estrogen:  Estrone, Estradiol, and Estriol. Estrogen is the most commonly replaced hormone.  In fact, it is the most commonly prescribed drug in the world.  And, at the same time, it is the most controversial.

The simplest way to assess a woman’s need for estrogen is to look at the benefits it offers and compare them to the potential risks.  Let me begin by stating that for the most part women never stop making estrogen.  It is produced by fat cells, skin cells, and the adrenal gland.  It is probably the only hormone that never has to be replaced.

However, when a woman becomes menopausal, either naturally or surgically, the ovaries stop producing estrogen.  This sudden decrease in estrogen often causes the pituitary gland, which is the gland that controls other endocrine glands, to put out luteinizing hormone. The function of this hormone is to stimulate the ovaries to produce more estrogen. It is this hormone that is often responsible for all the vasomotor effects that women experience – i.e. hot flashes and night sweats.

The use of estrogen, preferably natural estrogens, are known to be beneficial for reducing and eliminating these particular symptoms. In this instance, a woman can titrate her own dosage to make her feel comfortable with the goal of eventually eliminating the estrogen altogether.

Since there are three different types of estrogen – estrone, estradiol, and estriol.  The latter, estriol, is the weakest estrogen and is the only estrogen not associated with breast cancer.  It is also the preferred estrogen for vaginal dryness.  

If estriol, by itself, does not eliminate hot flashes or sweats then adding estradiol to the preparation usually suffices.  

The preferred route of delivery is in a cream; oral estrogen is absorbed through the GI tract and goes directly to the liver.  This will result in a decrease of IGF-1 which is the mediator of the action of growth hormone.

The reason for the concerns about estrogen is that it can be a toxic hormone. The last eight major studies about estrogen have indicated a causal relationship to strokes, heart attacks and blood clots.  It is contraindicated in coronary artery disease.  The best case scenario with regard to estrogen and the heart is that it won’t cause damage; there is absolutely no benefit from a cardiac standpoint.

Estrogen dominance can lead to cancer in one of two ways. Estrone and estradiol both work within the body to increase expression of the BCL2 gene that causes cell development and growth, particularly in hormone-sensitive tissue such a breast or uterine lining. If unopposed, this cell proliferation can lead to cancer. In fact, nearly every risk factor for breast and uterine cancer can be either directly or indirectly linked to an increase in estrone, estradiol, or their receptor activity.  

One such study in 2008 determined that high levels of estradiol were associated with a significantly higher incidence of breast cancer recurrence(1). In many cases of breast cancer, a gene known as the P53 tumor suppressor pathway is disrupted. The P53 gene is the opposing force for the BCL2 gene; it causes natural cell death (known as apoptosis), and is responsible for balancing the effects of cell proliferation.

In a nutshell: estrone and estradiol stimulate the production of the BCL2 gene, while progesterone stimulates the production of the P53 gene. When the body is experiencing estrogen dominance, what it desperately needs is progesterone to counter the effects of cell proliferation. Some studies have demonstrated that, by stimulating the P53 gene, progesterone can affect apoptosis (cell death) in cancer tumors(2)(3).

Note that Premarin, one of the most popular "synthetic" hormone replacement drugs, is composed of 49.3% estrone, almost ten times the amount that occurs naturally in the body--is it any wonder that this drug was found to increase the risk of invasive breast cancer in post-menopausal women by 41 percent? 

Metabolizing Estrogen 

The second factor influencing your cancer risk has to do with how your body metabolizes its estrogen. Estrogen can be "metabolized" (converted) down a "bad" pathway--one that is more cancer-inducing -- or a "good" pathway -- one that is more cancer-protective. The chemical name for the "bad" pathway is 16-hydroxyestrone. The "good" pathways are 2-hydroxyestrone and 2-hydroxyestradiol.

Each woman's estrogen metabolism is different, so the balance between your "good" and "bad" pathways is unique. The balance of anti-carcinogenic and pro-carcinogenic estrogen can be investigated with a urine test (trademarked Estronex). Studies have demonstrated that post-menopausal women with more hydroxylation along the 2-pathways have a lower risk of breast cancer(4).

Some studies suggest that this is also the case for pre-menopausal women, but due to the varying levels of menstruating women's hormones, it is more challenging to conduct research. (Imagine trying to coordinate hundreds of volunteers to schedule blood draws on a certain representative day of their menstrual cycles!)

To sum it up, let me just say that nature is a lot smarter than we are.  The only need for having high estrogen levels is if a woman is planning to get pregnant.  Nature is aware that when women reach a certain age, they stop procreating and so nature allows for a reduction in estrogen production and stops the ovary from releasing this hormone.  But, as mentioned previously, women never stop making estrogen, so very often it never has to be replaced.  In essence, what we have done is that we have taken a natural condition called menopause and turned it into a disease that doctors say has to be treated.

Bottom line:  My recommendation is to use estrogen only as needed for the control of hot flashes, and/or vaginal dryness.  In these instances it should be used as a natural estrogen in the form of a cream and titrated to a dosage suitable for the individual patient. Women should be aware that the use of any type of estrogen, natural or synthetic, may contribute to weight gain.

Please note: The primary source of estrogen after the menopause is the fat cell.  Obviously, women who are thin are often in a position to receive the most benefit from supplemental estrogen.


It is important to understand that progesterone cream; ie., 2% used in low doses can cause some of these same effects because progesterone in low doses can stimulate estrogen receptor sites. That is why it is important to use a 5% progesterone cream. 

It is essential to use enough progesterone, about 100-200mg/day, to overcome the excess estrogen.

If symptoms are severe, for instance heavy continual bleeding or debilitating hot flashes, up to 400mg/day will be needed.

It is easy enough to reduce the amount of progesterone to the optimum level, once symptoms have resolved. The reduction should always be done slowly over several weeks.

Low levels of vitamin D3 reduce the benefits of progesterone, so make sure that you are taking 10,000 IU of D3 along with at least 180 mcg of vitamin K2 (MK-7). 


(1) Cheryl L. Rock, Shirley W. Flatt, Gail A. Laughlin, et al., "Reproductive Steroid Hormones and Recurrence-Free Survival in Women with a History of Breast Cancer," Cancer Epidemiology Biomarkers and Prevention 17 (2008): 614-20. https://www.ncbi.nlm.nih.gov/pubmed/18323413

(2) Formby, B., Wiley, T.S., "Progesterone inhibits growth and induces apoptosis in breast cancer cells: inverse effects on Bcl-2 and p53," Annals of Clinical & Laboratory Science. Nov-Dec;28(6):360-9 (1998). https://www.ncbi.nlm.nih.gov/pubmed/9846203

(3) Horita K1, Inase N, Miyake S, Formby B, Toyoda H, Yoshizawa Y. "Progesterone induces apoptosis in malignant mesothelioma cells," Anticancer Research, Nov-Dec;21(6A):3871-4 (2001). https://www.ncbi.nlm.nih.gov/pubmed/11911261

(4) Roni T. Falk, Louise A. Brinton, Joanne F. Dorgan, et al., "Relationship of serum estrogens and estrogen metabolites to postmenopausal breast cancer risk: a nested case-control Study," Breast Cancer Research 15 (2013): online 2013 Apr 22.  https://www.ncbi.nlm.nih.gov/pubmed/23607871

Dr. Michael E. Platt has been a pioneer in the research and advancement of the therapeutic use of progesterone cream for use in managing adrenaline and hormonal imbalance. Dr. Platt is considered an important pioneer in observational, functional, alternative, and allopathic medicine focused on bio-identical hormones and adrenaline overload.  His three books “The Miracle of Bioidentical Hormones”, “Adrenaline Dominance” and “Platt Protocol” have received 11 literary awards. 

The Platt Wellness Team is pleased to assist you with information about our products. Please know we are not licensed medical professionals and therefore cannot provide you with any medical advice or information. If you require medical advice or information please contact a medical or health care professional. Please remember the information contained in this email message is for informational purposes only. The statements in this email have not been evaluated by the Food and Drug Administration and are not intended to diagnose, treat, cure, or prevent any disease.

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