New study links birth control to cancer
Q In the 1960s, when the birth control pill first appeared, contraceptives played an important role in family planning. So when researchers found that women who take hormone contraceptives have a higher incidence of breast cancer, making contraception safer became a major public health priority. Many experts believe they have found a solution in options with much lower doses of estrogen, a hormone that has long been linked to the development of breast cancer. But a new study suggests that low-dose contraceptives haven’t had the effect doctors expected, and experts are urging women to talk to their doctors about the health effects of their breasts, even though the overall risk of developing breast cancer remains relatively small.
The study, published in December in the New England Journal of Medicine , followed 1.8 million women for an average of 11 years, and found that those who took hormonal contraceptives had a 20 percent higher risk of developing breast cancer, regardless of estrogen dose, compared to to women who have never used these methods. It’s an important finding, especially with an estimated 140 million women worldwide using some form of hormonal contraceptive. Now, the findings have led experts to take a closer look at another hormone the study has highlighted: progestin.
How do hormonal birth control methods work?
Hormonal birth control methods, including vaginal pills, patches, injections, rings or intrauterine devices, prevent pregnancy by delivering combinations of synthetic estrogen and progestin, or progestin alone, into the body. Estrogen and progestin prevent the ovaries from releasing eggs, thicken cervical mucus to prevent sperm from entering the uterus, and block the lining of the uterus to prevent implantation. Because high levels of estrogen can cause certain types of cancer cells to grow, experts have long believed that estrogen is the main hormonal culprit linking birth control to an increased risk of breast cancer, says Justin Chora, MD, chief of the division. Surgeon and Director of Gynecology. Oncology and robotic surgery at our hospital near Philadelphia.
“Now we see that progestin also affects the risk. We definitely had a wrong assumption.” – Justin Chura, MD – Chief of Surgery and Director of Gynecological Oncology
There’s no reason to panic, says Dr. Chora, because the risk of breast cancer from hormonal contraceptives remains relatively small for most women. “Oral contraceptives are still a great class of medication,” he says. “There is no ‘free lunch’ with regard to any of the medications we prescribe. There are always risks and benefits.” The risks of hormonal contraceptives include blood clots, strokes, and heart attacks. The benefits generally include reduced risk of other cancers, including ovarian and endometrial cancer, as well as lighter or more regulated menstrual cycles, and of course, help with family planning.
Should I stop using hormonal contraceptives?
Dr. Shura says each woman should weigh her individual risks. Because the risk of breast cancer increases with age and length of time using hormonal contraceptives, women who already have a higher risk of breast cancer and those who are older and no longer planning to have children may consider switching to non-hormonal contraceptives. Birth control, such as the female diaphragm or condom. Older women who have been using hormone-based contraceptives for several years may also consider having breast cancer screening at the earlier age recommended in the guidelines. Women who are taking progestogen-only birth control may want to consider talking to their doctor about changing their birth control method.
For women in their 20s, the benefits of hormonal contraceptives often outweigh the risks, but medical and family history still plays a role. “Even if you are 25 years old, if you are a carrier of a BRCA mutation, it makes sense to consider the risk of breast cancer that comes with hormonal contraception because you already have a higher risk of breast cancer than people who do not have it,” says Dr. Shura. However, oral contraceptives are also known to reduce the risk of ovarian cancer in patients with or without a BRCA mutation.
Despite the new findings, Dr. Shura says women should speak with their doctor before making any changes to their contraceptive method. “Women can now have more informed conversations with their doctors,” she says.
Know the signs of breast cancer.