Health Column: Progesterone, the breast cancer shield

In In The News by Barbara Jacoby

LLH network pressby: Scott Rollins, M.D.


Breast cancer is understandably the greatest concern of women who are considering hormone replacement therapy (HRT), and yet the media and medical community have only confused the issue with blanket statements regarding risk and a sorry lack of specifics. Before deciding whether HRT is right for you, it is essential to learn more about the risk of cancer.

Results from the Women’s Health Initiative (WHI) show an increased risk of breast cancer with the use of the drug called Provera, even for several years after stopping it, but then (the makers of Provera reassure us) the risk drops off with time. The original WHI data showed a 26-percent increased risk for invasive breast cancer in women taking the mixture of Premarin and Provera.

Provera (medroxy-progesterone) is a drug that is similar to our native progesterone — not identical, merely similar, like hundreds of chemical compounds that will stimulate progesterone receptors in the body. These chemicals are called “progestogens,” and synthetic drugs in this category are known as “progestins.”

If one brand of automobile is defective and killing people as a result, should we then cast blame on the entire auto industry and recall every brand of automobile? That is precisely what is happening in the world of HRT!

A bioidentical hormone has a molecular structure that is 100-percent identical to the hormone molecule the body makes. Progesterone is bioidentical, Provera is not, and this does make a difference.

There are numerous reviews that suggest progesterone has a protective effect on breast tissue. Low levels of progesterone have been associated with increased risks of breast cancer. Progesterone, and not progestins, provides a control mechanism to regulate the proliferative effects of estrogen. This means it prevents cancer.

A French study showed no increased risk of breast cancer in women using progesterone cream topically, and actually a reduced risk when adding a progesterone capsule.

Another French study showing no increased breast cancer risk when taking progesterone as opposed to synthetic progestins.

The largest study to date that most conclusively addresses the debate over progesterone and breast cancer is the French E3N-EPIC (European prospective investigation into cancer and nutrition) which is a cohort study looking at more than 50,000 women. It showed the same results as the WHI in women using synthetic progestins, that is a 26-percent increased risk for invasive breast cancer. But, it showed a 10-percent decreased risk for breast cancer in women using progesterone — a 10-percent decrease!

I am not aware of any prospective trials that assess the safety of bioidentical progesterone with respect to breast cancer. Distinguishing causality from correlation cannot usually be done with results of a cohort study alone, but the above referenced cohort studies provide a very strong case for the safety of bioidentical progesterone.


There are many proven methods to reduce the risk of breast cancer. Start with diet and include plenty of cancer fighting fruits and vegetables, preferably raw and organic. A raw foods diet, especially with juicing, is particularly helpful. Avoid packaged, over-processed foods in general. Eliminate sugar and high-glycemic carbs. Shun trans-fats and hydrogenated oils. Limit alcohol to less than two drinks daily. I have patients that have reversed cancer with diet alone. There is no point in glossing over how important diet is in cancer prevention.

Inflammation also plays a role in cancer. Part of the benefit of good diet is to control inflammation. Supplements such as curcumin, green tea, boswellic acid, ginger, and pomegranate are well known for their anti-inflammatory and anti-cancer properties. These plant compounds, called polyphenols, regulate cell growth and metabolism. Some of them encourage the programmed self-destruction of cancer cells, called “apoptosis.” Others control oxidation, block new blood vessel growth to cancer, or help slow metastases.

Women with the lowest vitamin D levels have higher rates of breast cancer. By blocking signals that encourage cancer cell growth, turning on signals that inhibit cancer cell growth, and playing a role in the cellular life cycle, vitamin D has several mechanisms to improve cancer risk. The only way to know how much vitamin D to take is to get serial blood levels over a few years. A typical dosage is 2,000-5,000 units per day, and D3 is the best form to supplement.

Fermented soy is another food that lowers the risk of breast cancer. This is due to soy’s ability to stimulate the estrogen receptors that down-regulate breast cancer growth while effectively “blocking” the receptors that promote cancer when they are exposed to our own estrogens or foreign chemicals that stimulate estrogen receptors.


The current conventional medical recommendations are to not take hormone replacement, and if it is necessary to treat menopausal symptoms then to quit HRT as soon as possible. This is based solely on the studies showing Provera causes cancer, heart attack, stroke and blood clots. I would agree with not taking synthetic hormone “look-alike” drugs, and I’ve not prescribed Provera in more than 15 years. Frankly, I think it should be removed from the market.

Bioidentical HRT is an established, researched science that is truly about preventing disease and maintaining quality of life. Bioidentical HRT is very effective at providing symptom relief for acute menopausal symptoms, as well as preventing many symptoms and diseases associated with aging.