You may have heard about a recent research study about hormonal contraception use and breast cancer. The study took place in Denmark and it included different types of hormonal contraceptives such as oral contraceptive pills (OCPs) or birth control pills, IUD’s (intrauterine device), the contraceptive “patch”, hormonal vaginal ring, progestin-only implants and injections. The main finding was summarized in the December 2017 issue of the New England Journal of Medicine as: “The risk of breast cancer was higher among women who currently or recently used contemporary hormonal contraceptives than among women who had never used hormonal contraceptives, and this risk increased with longer periods of use; however, absolute increases in risk were small.”

What does this mean?

Does using hormonal contraception such as Oral Contraceptive Pills (OCP’s/birth control pills) and IUDs lead to an increased breast cancer risk?

The answer to this question is complicated since there are many things to consider.

First, it’s important to understand the numbers. When you hear a news report or read an article that says there is a 20% increase in breast cancer risk among women who used hormonal contraceptives compared to those who never used hormonal contraceptives, it can sound very scary. However, when you actually look at the numbers you can see that a 20% increased risk of an already very small number is not as alarming as you might think. Age is very important when thinking about risk because women under 35 years old have a very low risk of breast cancer. Breast cancer is five times more likely in women in their 40’s than their 30’s. As scientist David Hunter wrote in an Editorial in the same issue of the New England Journal, “The absolute increase in risk is 13 per 100,000 women overall but only 2 per 100,000 in women younger than 35 years of age.” In addition to understanding the breast cancer risk, it’s important to consider other risks and the many benefits to using hormonal contraception.

• Hormonal contraception can help prevent other types of cancer—endometrial, ovarian and colon cancer. In general, these types of cancer are harder to diagnose than breast cancer.
• Hormonal contraception is one of the most effective ways to protect against pregnancy.
• Hormonal contraception can treat many issues including menstrual cramps, irregular or heavy periods, endometriosis, and Polycystic Ovary Syndrome (PCOS), and other symptoms.

Similar to other medicines and procedures, there are risks associated with hormonal contraceptive use and that’s why we always consider a “risk to benefit ratio.” Since everyone’s medical conditions are unique, it’s important to compare the benefits of hormonal treatment with the possible risks.

As always, talk to your health care provider about what is best for you.

What are risk factors for breast cancer?

The American Cancer Society believes there are many “risk factors” that contribute to the development of breast cancer including some that you can change and others you can’t. In addition to age, some of those risk factors that can increase your chance of breast cancer are being female, having an inherited gene such as BRCA1 and BRCA2, drinking alcohol, being overweight or obese, exposure to radiation, not having children, and not breastfeeding.

What else do I need to know?

Many other research studies that have been done over the last twenty years or so have also observed this small increased breast cancer risk among current or recent hormonal contraception users.  Longer use of pills (but not IUDs) increased risk. Other research studies have noted that the increased risk of breast cancer disappears after 5 years of stopping hormonal contraception. This study also observed the risk disappearing after 5 years for many but not all users. More research is needed to answer these questions.

Unlike previous studies, this new study addressed not just OCP’s but multiple types of hormonal contraception. OCPs and hormonal IUDs were both connected with a 20% increased breast cancer risk. However, other types of hormonal contraception such as the implant (e.g., Nexplanon®) and shots (e.g., Depo-Provera®) were not associated with any increased breast cancer risk. Since this is the first study to look at multiple types of hormonal contraception, we have much more to learn through research. It’s important to balance the small risks and the many benefits of hormonal contraception.

We hope this information is helpful. We encourage you to talk to your primary care provider or your gynecologist about any concerns or questions that you might have.

References:

March, L. S., Ph.D., Skovlund, C. W., M.Sc., Hannaford, P. C., M.D., Inversen, L., Ph.D., Fielding, S., Ph.D, & Lindegaard, O., D.M. Sci. Contemporary hormonal contraception and the risk of breast cancer. New England Journal of Medicine. 2017; 377:2228-39

Hunter DL. Oral contraceptives and the small increased risk of breast cancer. New England Journal of Medicine 2017; 377:2276-77.

Breast Cancer Risk and Prevention. Retrieved December 8, 2017, from https://www.cancer.org/cancer/breast-cancer/risk-and-prevention.html (2017, September 6)