From The Doctor’s Desk: Hormone Imbalance A Contributing Factor In Breast Cancer

Hormone Replacement Therapy (HRT) increases breast cancer. Have you read headlines like that? Or perhaps you were told that HRT caused someone’s breast cancer.

Do hormones really cause or lead to breast cancer? Think about this: every women continues to produce hormones, even after menopause. So, it cannot be that hormones in and of themselves cause cancer. Scientific evidence indicates that synthetic hormones and hormone imbalance do contribute to breast cancer.

The ABC’s of Estrogen.

Estrogen’s effects in the body are regulated through two different kinds of receptors: alpha and beta receptors. Estrogen-alpha receptors stimulate breast cell growth. Estrogen-beta receptors inhibit breast cell growth.

• Estradiol, the most potent estrogen, equally stimulates alpha and beta receptors = growth stable
• Estrone, the second most potent estrogen, stimulates alpha receptors 5:1 over beta receptors = pro growth
• Estriol, the weakest variety of estrogen, actually stimulates beta receptors 3:1 = growth inhibitory

The key element here is balance of hormones. Higher levels of estrone present in your body (produced by fat cells) result in more breast stimulation. Higher levels of estriol present in your body results in less breast cell stimulation and, therefore, breast protection. Estriol = Good. Estrone = Bad. If you have heard of someone developing breast cancer after starting Premarin, there’s a logical explanation for that. Guess what Premarin is loaded with? Premarin contains (48%) estrone (estrone = bad = breast cell stimulation).

Here are some more ugly facts about Premarin, also know as conjugated equine estrogen. Premarin actually decreases estrogen beta receptors. So, if you take Premarin, then you are taking high doses of estrone (estrone = bad) and decreasing your estrogen receptors that inhibit breast cell growth. In a nutshell: you are taking more of the bad estrogen and decreasing your amount of the good estrogen. This equates to a prime set up for breast cancer.  Don’t take my word for it. See the wonderful article by Kent Holtorf.

Progesterone: The Growth-Inhibitor Hormone

The confusion out there about estrogen and breast cancer is bad enough, but the confusion is even greater on the subject of progesterone.

Pregesterone is the key hormone in the second half of a woman’s cycle. Estrogen is the dominant hormone in the first half of your cycle (estrogen = growth = growth of the uterine lining to support implantation of an egg). The counteractive hormone to this growth phase is progesterone (progesterone = no growth = sloughing off of the uterine lining). It’s the amazing and fascinating way that woman was created.

Synthetic progestins, often prescribed, are NOT the same as the progesterone your body produces. Just look at the structure and you see that they are not. The one thing they do have in common is they both protect the lining of the uterus against excessive estrogen growth. But, that is where the similarities end.

While there are many differences between the two, our focus here will be on the difference in breast cancer potential. Simply stated, synthetic progestins are pro-breast cancer and bioidentical progesterone is breast protective. The Women’s Health Initiative (link) revealed a 26% increase in breast cancer as a result of taking synthetic progestin. The Nurse’s Health Study (link) found that synthetic progestins tripled breast cancer risk over that of estrogen only. The use of Provera, a synthetic progestin and component of Prempro, has been shown to increase the risk of breast cancer by 800%!

The statistics for bioidentical progesterone are the opposite. Bioidentical progesterone has many positive breast benefits:

• Progesterone decreases estrogen production
• Progesterone moves estradiol to weaker estrone
• Progesterone moves estrone to inactive (sulfated) form
• Progesterone moves estrone to weakest/safest estriol
• Progesterone down-regulates estrogen receptors all together
• Progesterone activates the cancer protection gene, p53

The idea that progesterone is a safer alternative to synthetic progestins is not new at all.  As early as the early 80’s, there has been a call for safer progesterone over synthetic progestin counterparts. In 1981, nearly 30 years ago, L.D. Cowan showed that just having low progesterone levels increases the risk of premenopausal breast cancer risk 5.4 times.

Unfortunately, progesterone-deficient states, (or estrogen dominance) are very common in women today as a result of many factors: being overweight, PCOS, environmental xenoestrogens, excessive estrogen therapy, and perimenopause. Another study, showed progesterone to have a 400% decreased breast growth rate.

The Scientific Evidence Is Clear.

The evidence in the scientific literature is clear with regards to estrogens, progesterone, and hormone balance.

Bioidentical and synthetic hormones should NOT be used interchangeably. They are not equal. They have very different physiologic effects on the breast:  synthetic progestins (Provera notably) increase breast cancer (800%) and bioidentical progesterone protects against breast cancer (400% decrease breast growth rate).

Estrogen therapy is not for everybody and is definitely not a panacea drug; in fact estrogen dominance is a major contributor to breast cancer risk. But if estrogen therapy is needed, then estriol (Estriol = good) is the best.

Hormone balance is the key. Without estrogen and progesterone balance, a women’s cycles are irregular, and infertility can be a big problem.

You know, once we understand hormones and the balancing cycle between estrogen and progesterone, it makes perfect sense that imbalance would cause breast problems. And the scientific evidence indicates just that. In honor of Breast Cancer Awareness Month, it’s time make sure your hormones are balanced and protect yourself from breast cancer.