Breast Cancer And Bioidentical Hormones - Good News

by PJ Hennessy 2008


Breast cancer rates have been dropping for the last five years. There is reason to believe that healthier behaviors get credit. A ten year study of over 50,000 French post menopausal teachers showed no difference in breast cancer rates when bioidentical hormone users were compared to women who never used hormones.


Starting out in search of encouraging words about breast cancer requires chest deep wading into the swift flowing river of health data. Some information published comes directly from source data such as big HMO’s, and some is prepared by analysts who use estimates such as SEER data that are then generalized to the whole United States population.

Last year both source and estimate data agreed. Breast cancer rates are truly declining. It is a trend since 1998 and not just a one-year blip on the radar. Take a look at these 2007 figures recently released by the American Cancer Society. It is clear almost all cancers for men and women are in decline.1

Experts are puzzled. Some believe the decline in breast cancer may be due to the decline in the mammography rate. This small decline varies by age and geographic area and doesn’t account for the total cancer decrease.2 Other experts claim the decline is due to the decrease in PremPro (Premarin and Provera) prescriptions.3 – the pharmaceutical industry reported a 30% drop in PremPro sales in 2003. However, the WHI (Women’s Health Initiative) data which associated Prem Pro with a higher rate of thromboembolic events and breast cancers was published in May of 2002 and the decline in breast cancer began in 1998. In fact current breast cancer rates are as low as they were in the mid 1980’s!


So, what is happening? My take is what I call the savvy consumer effect. Consumers are increasingly health and safety conscious. They are increasing their exercise and decreasing their alcohol consumption. They are changing their diets to include more fruits and vegetables, fewer fats and simple sugars, and are eating more organics and whole foods. In fact, organic food sales are increasing by almost 20% per year! Consumers are reading labels and chucking out questionable substances whether it’s lotions and cosmetics in the bathroom, or paints, varnish, and other VOC’s in the shop and garage.


There has been an astonishing surge in the use of nutritional supplements. Reversing a forty-year stance, even the AMA last year endorsed vitamin supplements. The surge in supplement use has been matched by a resurgence of research looking at the benefits of vitamin and mineral supplementation. We see good news here as well. Vitamin D prevents prostate and breast cancer. Vitamin D plus calcium (levels as low as 800IU/day for vitamin D and 1000mg/day for calcium) prevents all cancer.4,5,6 Keep up these savvy consumer behaviors!


For hormone users the best news comes from France.7 A bit of background will set the stage. When the WHI trial was published in 2002, it sounded a warning note not only in the USA but also in all developing countries where women use hormones. However, the WHI tested PremPro a synthetic mixture of hormones. It has never been clear if the adverse effects of Premarin and Provera could be attributed to bioidentical hormones. While researchers looked deeper, thoughtful clinicians urged caution and careful monitoring when taking hormones.


A team of researchers in France decided to assess the effects of different hormone regimens on breast cancer rates by using data from an ongoing study called E3N which began in 1990. Its aim was to investigate risk factors for all cancers in women. The participants were mostly schoolteachers and represented over 80,000 women followed for twelve years (70% of them used hormone replacement therapy for an average of seven years).


What is unique is that French women rarely used Premarin. Almost all (97%) used a bioidentical estrogen estradiol instead. The choice of progestin became the key variable since both synthetic and bioidentical are used in France. When groups were compared, data analyzed, and outcomes reviewed, results showed users of bioidentical estradiol and bioidentical progesterone had breast cancer rates equal to that of women who had never used hormones.


This research containing data collected for more than a decade (WHI was only 7 years) and scrutiny of more than 50,000 women has incredible power to detect adverse effects. The WHI outcomes created tremendous confusion and a loss of confidence in the use of HRT. This study begins to answer the lingering questions about bioidentical’s safety. We can expect more such studies in the future. Meanwhile, this is front-page news for Women Of A Certain Age.




1.  Jemal CA Cancer J Clin  2007

2.  Chagpar J Surgical Res 2007

3.  Glass J Nat Cancer Inst 2007

4.  Lin Arch Int Med 2007

5.  Gorhan Am J Preven Med 2006

6.  Lappe Am J Clin Nutr 2007

7.  Fournier Breast Cancer Res Treat 2007

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