So Birth Control Causes Breast Cancer? There’s more to this story…
In December 2017, the New England Journal of Medicine released this statement:
“Women who use hormonal [contraceptives] for more than a year are at a 20 percent higher risk for breast cancer, [though] the overall risk remains low,” and is called “safe and effective.”
What in the world is that supposed to mean, Doc?
Is it safe? Or are my breasts gonna kill me? Well I, Dr. Wendy, am here to run the numbers. For the longest time we believed that breast cancer risks were pretty much unaffected by birth control. This post will cover these important and life-altering topics:
- What is Cancer?
- What types of cancer risks are reduced by birth control?
- What factors can increase cancer risk?
- What does birth control do to breast cancer risk?
What is Cancer?
I was in medical school before I really understood what cancer was, so I thought it deserved an explanation. (This section is an excerpt from my book, It Smells Just Like Popcorn, fyi.) Cancer is not an alien beast that finds its way into your body. Cancer, generally speaking, is caused by rogue cells of your own body. Our whole body is composed of cells, tiny building blocks with specific functions that work together. When a few cells decide to do their own thing, it is like a mutiny. I recently watched Guardians of the Galaxy 2. *Spoiler alert*
When Yondu’s crew was overthrown by Taserface, they killed all of the loyal crew mates by tossing them off of the ship into the vacuum of space. Taserface was like a cancer, turning the formerly good crewmates against Yondu.
If we keep with the cancer analogy, what would have then happened is the newly corrupted crew members would have started multiplying and forming new corrupt crew members like that agent in the black suit with the earpiece in the Matrix. Eventually those crew members would multiply beyond capacity, use up all of the resources, food and water on the ship, and everyone would die. The way that chemotherapy works is that it targets the cells that replicate quickly. Cells that rapidly divide and multiply use certain building blocks that chemotherapy and radiation can target and attack. Hair follicles have rapidly dividing cells, which is why people lose their hair during chemotherapy.
What types of cancer risks are reduced by birth control?
Regarding Ovarian Cancer risk, “Oral contraceptive use has consistently been found to be associated with a reduced risk of ovarian cancer. In a 1992 analysis of 20 studies, researchers found that the longer a woman used oral contraceptives the more her risk of ovarian cancer decreased. The risk decreased by 10 to 12 percent after 1 year of use and by approximately 50 percent after 5 years of use (4).” The protective effect of oral contraceptive use persisted more than 10 years after pill use was discontinued. (Source: the CDC.)
Regarding uterine cancer risk: “Women who use oral contraceptives have been shown to have a reduced risk of endometrial cancer. This protective effect increases with the length of time oral contraceptives are used and continues for many years after a woman stops using oral contraceptives (11).”
Regarding cervical cancer risk: Results were inconsistent. “Virtually all cervical cancers are caused by persistent infection with high-risk, or oncogenic, types of HPV, and the association of cervical cancer with oral contraceptive use is likely to be indirect. The hormones in oral contraceptives may change the susceptibility of cervical cells to HPV infection, affect their ability to clear the infection, or make it easier for HPV infection to cause changes that progress to cervical cancer.” (Cancer.gov) Then the American Association for Cancer Research (AACR), said their wasn’t an evidence-based association between cervical cancer and oral contraceptives because studies lacked the proper controls.
Regarding colon cancer risk: Per AACR, “We found that the risk of colorectal cancer was significantly decreased for women who have ever used oral contraceptives compared with women who have never used oral contraceptives.”
What factors can increase cancer risk?
Did you know Catholic nuns have a significantly higher risks of developing breast, ovarian and uterine cancer? Birth control is forbidden and these women never have babies. They just ovulate (release eggs and have menstrual cycles), and ovulate, and ovulate. Along those same lines, women experiencing their first period before age 12 years have a slightly higher risk of breast cancer than those who were older than 15 at menarche.5 Similarly, the risk of breast cancer is increased by 17% for every 5-year delay in menopause.6 Bilateral oophorectomy (removal of the ovaries) before age 40 years led to a 45% reduced risk of breast cancer compared with women with a natural menopause at ages 50—54 years.5 The point is not to have your ovaries remove without a reason. The point is to understand that prolonged uninhibited ovulation has health risks too.
Why is that? The increased number of cycles between menarche (the first ever period) and menopause leads to increased risk of ovarian and uterine cancers. My analogy here is that of an engine that never stops running. Eventually it will be more likely to malfunction and break than an engine that you turn off and give a break every so often. Pregnancy and birth control provide that break or change for your ovaries and uterus.
What does birth control do to breast cancer risk?
As I quoted earlier: “Women who use hormonal [contraceptives] for more than a year are at a 20 percent higher risk for breast cancer, [though] the overall risk remains low,” and is called “safe and effective.” The 20 percent translates to about ONE MORE case of breast cancer a year for ever 7,700 women.”
The New York Times (12/6, Rabin, Subscription Publication) calls it “a small but significant increase in the risk for breast cancer. […] While the increase for a 20-year-old means that her risk of breast cancer is still ‘less than one-tenth of 1 percent,’ but for a 40-year-old, it means a change from 1 in 69 to 1 in 57.”
Bloomberg News (12/6, Lauerman) reports that while it was thought that “newer birth control drugs” would reduce the risk, “it turns out they didn’t.” The study found that “the longer they take them, the greater the chance they will develop breast cancer,” thought, it adds, the risk is “somewhat offset by reduced risks of cancer – of the ovaries, endometrium, and digestive system”
What are the take home messages here?
Birth control has it’s risks, but also many advantages. Nothing that we do is perfect or without risks, including homeopathic remedies. As you read above, even not using birth control EVER has its risks (#nunlife). I never advise a woman to start birth control without a reason. Good reasons include heavy periods, painful periods, strong ovarian cancer risk, and let’s not forget, pregnancy prevention. The latest breast cancer risk data is a tough pill to swallow (#punlife), but I think that as long as we all understand the risks and look out for any signs of trouble, birth control use is not wrong or reckless.
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You may not know this, but I am no stranger to shameless plugs. The cancer excerpt from above is from my book that I have linked there and below. Also for healthy eating and nutrition tips from another amazing M.D., check out TheDocsKitchen.com.
Be Healthy, 2018!
Dr. Wendy Goodall McDonald is a board certified OBGYN. She began practicing medicine in 2007 and now uses her extensive knowledge and growing following to increase health awareness in a fun and viral way. She is the founder of The Gyneco-blogic and an author of numerous books for adult and childhood health education and social growth. For more, check me, I mean her out at dreverywoman.com