Our family practice concierge doctors in Jupiter have heard from some of our patients that they’re concerned about a new study regarding the safety of certain contraceptives.
In fact, many observers think this study’s findings are reassuring, and should not unduly alarm women.
According to the Centers for Disease Control and Prevention (CDC), among women ages 15 to 49 in the U.S., about 14 percent of those using contraception use oral contraception, and around 10 percent use long-acting devices like IUDs.
Contraceptive Risks and Benefits
Since their inception, birth control pills have been associated with various risks to the women who take them.
In 1960, the U.S. Food and Drug Administration (FDA) approved the first birth control pill, Enovid. It combined two types of hormones designed to prevent ovulation: estrogen and progestin. According to Planned Parenthood, it contained far more hormones than were needed to prevent pregnancy, which is why it was also responsible for occasional severe side effects and increased the risk of heart attacks and strokes.
Later forms of the pill, as it came to be called, used much lower formulations, but they are still implicated in a slightly increased risk of breast cancer, heart attack, strokes, blood clots, and liver tumors.
Many see these risks as being outweighed by the benefit of preventing unwanted pregnancies. In addition, studies have found a decreased risk of ovarian, endometrial, and colorectal cancers in long-term users of the pill, as compared with non-users.
Birth control pills are also prescribed for women with excessive bleeding and/or painful periods, apart from their use in pregnancy prevention.
Another UK study of more than 46,000 women who were followed for up to 39 years showed that their use of the pill not only didn’t increase their risk of mortality but also appeared to have increased longevity.
The New Study
Progestin-only formulations in various forms of birth control were thought to lower the risks of complications because estrogen is known to increase the incidence of the most common side effects.
Progestin-only pills thicken the mucus in the cervix, preventing sperm from reaching an egg. One form of the progestin-only pill can also stop ovulation.
“We’ve known for a while that estrogen and progestin birth control pills, oral contraceptives, have a slightly increased risk of breast cancer,” Dr. Jennifer Ashton, a board-certified OB-GYN, and ABC News chief medical correspondent said on “Good Morning America” when the new study was released.
“What we didn’t know is the newer forms of progestin-only pills, IUDs, injectable implants, what their associated risk, if any, was in comparison,” she explained.
The study that made the news last month was published in the journal PLOS One. Researchers in the U.K. analyzed data on nearly 10,000 women who had been diagnosed with invasive breast cancer between 1996 and 2017.
They then compared these subjects’ profiles with more than 18,000 women who did not have breast cancer.
“On average, 44 percent of women with breast cancer and 39 percent of matched controls had a hormonal contraceptive prescription, with about half the prescriptions being for progestagen-only [i.e., progestin-only] preparations,” the study authors wrote.
Explaining the Results
The findings “suggest that the 15-year absolute excess risk of breast cancer associated with the use of oral contraceptives ranges from eight per 100,000 users (an increase in incidence from 0.084 percent to 0.093 percent) for use from age 16 to 20 to about 265 per 100,000 users (from 2.0 percent to 2.2 percent) for use from age 35 to 39.”
In other words, those who use the progestin-only forms of contraceptives have about the same slight risk of breast cancer as women who use the combination pill.
They also found that the longer a woman is off hormonal birth control, the lower the risk.
Claire Knight, a senior health information manager at Cancer Research UK, which provided core funding for the study, told CNN that hormonal contraception is a personal choice, as “there are lots of possible benefits to using contraception, as well as other risks not related to cancer.
“Women who are most likely to be using contraception are under the age of 50, where the risk of breast cancer is even lower,” she explained.
Gill Reeves, a co-author of the study and professor of statistical epidemiology at the University of Oxford, told The Washington Post that “it may be reassuring to know that these newer contraceptives that women are using in increasing numbers do not have any untoward effects that might be unexpected.
“They do seem to behave pretty much like traditional contraceptives,” she added.
Ashton, who was not involved in the study, stressed that it’s important to recognize how slightly the use of hormonal contraceptives raises the risk of breast cancer.
“It’s about individualizing the risk-benefit and option risk for the woman,” she told GMA.
“If you talk to any OB-GYN, they will say, we have a line: ‘Pregnancy is much higher risk than any associated risk with birth control pills or hormonal contraception.’ ”
“For anyone looking to lower their cancer risk, not smoking, eating a healthy balanced diet, drinking less alcohol, and keeping a healthy weight will have the most impact,” Knight told CNN.
All the experts suggest that women discuss the risks and benefits with their doctors.