“Lies, Dammed lies, and Statistics”
Mark Twain
Breast Cancer Observations

The Woman’s Health Initiative (WHI), which was aggressively reported by the lay press in 2002, stated that women taking hormones faced a 26% increased risk of developing breast cancer. These figures are scary – and misleading. The average person reading this statement in the newspaper would mistakenly interpret this to mean that if she took hormones, her risk of developing breast cancer was 26% or, one in four.

The fact is that the 26% increase is an increase in the underlying “normal” rate of breast cancer, which is about 2% for the age range that was investigated. This translates into an overall increase in the rate of breast cancer from 2% to 2.5%. This is a small but none-the-less significant increase in the risk of developing breast cancer. In other words, instead of four women per two hundred developing breast cancer, five would. This is obviously very significant for that extra one woman out of two hundred that develops cancer.

The question still remains, why was there any increase in the risk of breast cancer with hormone replacement therapy (HRT)? The answer lies in the nature of the study. It was conducted at the request of the drug company that manufactures synthetic hormones. These are equine (horse), synthetic hormones that are taken orally. While a large amount of the estrogens in them are bio-identical estradiol, the fact that they are taken orally is most likely the reason for the increased incidence of breast cancer. When estradiol is consumed orally, it is first digested (broken down into smaller pieces) and then circulated through the liver where 80% of it is converted into estrone.

Estrone is a naturally occurring estrogen that is normally present in pre-menopausal women at the 20% level. It is interesting to note that the levels of estrone reach 80% in untreated post-menopausal and extremely obese women. It is believed that this increased level is related to the increase in the rate of breast cancer in post-menopausal and obese women.

The use of transdermal hormone therapy bypasses the stomach and therefore, the liver circulation for the majority of the bio-identical estradiol. Then only about 20% of transdermal estradiol is converted to estrone. That is the same rate that is naturally seen in pre-menopausal women. Studies have shown that the risk of breast cancer with transdermal administration is decreased over that seen with oral estradiol.

The bottom line is that there seems to be no increase in the incidence of breast cancer with the use of transdermal, bio-identical estradiol and in fact, most likely there is a reduction (secondary to improved overall health and immune function).

Remember, newspapers don’t report safe landings at the airport!