Every year, 9.7 million women take birth control pills (BCPs), hormonal contraception. About 12 percent of women in the U.S. will develop invasive breast cancer. In 2017, approximately 252,710 new cases of invasive breast cancer were diagnosed.
What’s the connection between estrogen and breast cancer? Is there a link between BCP and breast cancer?
Birth Control Pills Increase Breast Cancer Risk
A study published on December 07, 2017 in The New England Journal of Medicine found a small, but higher risk for developing breast cancer in women using birth control pills.
The New England Journal of Medicine study found a higher risk for breast cancer in women who used hormonal contraception, “birth control pills.”
What’s even more troubling is that women who used BCPs for more than five years, the increased risk persisted even after they stopped.
A 2013 study found that having used synthetic estrogens not only increased a woman’s risk for breast cancer but that increased risk can be passed on to their daughters.
Four factors link hormone use to cancer: (1) use of synthetic estradiol and progesterone, (2) use of high dose estradiol, (3) the level of estradiol in the blood, and (4) how long a woman uses synthetic hormone BCPs.
BCPs contain ethinylestradiol (EE), a synthetic estrogen. Some also include progestin, a synthetic progesterone. There are many types of progestins including levonorgestrel, norethindrone, desogestrel, and norgestrel.
Progesterone can also increase cancer risk. Women who used intrauterine devices that release progestin, a synthetic progesterone, had a 21 percent increased cancer risk.
Hormone Replacement Therapy Increases Risk for Ovarian Cancer
Does HRT (Hormone Replacement Therapy) increase a woman’s risk for breast cancer? Is there a difference between bio-identical and synthetic estrogens?
Women over 50 who use HRT with synthetic hormones for more than five years have a higher risk for ovarian cancer.
Synthetic hormones (ethinylestradiol and progestins: levonorgestrel, norethindrone, desogestrel, and norgestrel) are stronger and absorb more readily than bioidenticals. Quicker absorption rapidly increases estrogen and progesterone levels in the blood. Often, they push hormone levels too high. The longer a woman uses hormone therapy, the greater her cancer risk. But, high estradiol and progesterone levels also increase the chance of developing breast and ovarian cancer. Women who had a complete hysterectomy cannot get uterine or ovarian cancer, but they are still vulnerable for developing breast cancer.
Other factors compound cancer risk in women who use long term hormone therapies. Cancer risk is higher in overweight women. Cancer is more likely in those who drink alcohol and take hormones, than those who are of average weight and don’t drink or rarely use alcohol.
No Balance with Synthetic Hormone Therapy
When it comes to synthetic hormone replacement, there is no delicate balance. Synthetic hormones increase the risk for cancer. The longer you use them, the higher your risk. Women who use BCPs for more than ten years have an even higher risk.
EE is toxic to the body. When taken orally, it’s absorbed in the intestinal tract and travels directly to the liver. This “first pass” effect in the liver removes 99 percent of the EE. The liver is good at what it does, but processing man-made pharmaceutical drugs and synthetic hormones that have no place in the natural biology of a woman’s body, can trigger liver toxicity. It can also increase the risk for gallstones.
Mostly younger women take BCPs. Doctors rarely discuss the risks of synthetic hormone contraception with their patients. And, doctors now prescribe low-dose birth control to ease the symptoms associated with hormone imbalances related to perimenopause. However, I do not advise BCP use in women over 45 years.
If you use BCPs, or take hormone replacement therapy, get semi-annual blood testing for liver enzymes. It’s wise to also test hormone your levels, including estradiol, progesterone, FSH, and sex-binding hormone.
If you use BCPs or HRT, get your hormones tested at least once a year. Hormone testing is done with standard blood testing and is usually covered by health insurance. Saliva testing is also available through ZRT Laboratory or others like the DutchTest from Precision Analytical.
There is a difference between blood and saliva hormone testing. Serum estradiol tests measure the total circulating amount of 17 beta-estradiol in your blood. Saliva tests measure the amount of “free” estradiol. Free hormone levels are not attached to carrier proteins. Supposedly, free hormone levels are a better way to determine hormone activity in the tissue. But free estradiol is also measured in serum from a blood test.
Though salivary testing has come a long way since first introduced in the 1980s, I still prefer to use total and free estradiol levels in a blood test for my patients.
Aim at keeping your estradiol and progesterone levels within physiological ranges. Remember that it’s high estradiol, sometimes called the estrogen dominant effect, that over time increases cancer risk. The average range for postmenopausal serum estradiol is less than 6.0 to 54.7 pg/mL. In my clinical practice, I consider an estradiol level over 64.0 pg/mL too high for women on HRT.