An important recent study found that even contraceptive pills and other contraceptives that release low doses of hormones increase the risk of breast cancer in women.
While the link between hormonal birth control and breast cancer has been known for years, many doctors and women hoped that new forms of birth control, such as IUDs, vaginal rings and implants, would put women in less risk.
The study by researchers at the University of Copenhagen, which followed 1.8 million Danish women for more than a decade, found that differences in the formulation of hormone-based birth control had little effect on risk Of cancer. The study also found that the risk of cancer increased the longer a woman used birth control.
In general, the risk of breast cancer was 20 percent higher for women who used or had used hormonal contraceptives recently than among those who never used it. The estrogen used in hormonal contraceptives can promote the development of cancer. mom.
"Compared with women who had never used hormonal contraception, there was an increased risk of breast cancer among women who had used hormonal contraceptives for a prolonged period of time," the researchers wrote in the study published in week in The New England Journal of Medicine.
For women who have used contraceptives for prolonged periods, the increased cancer risk may continue for five years after they stop using it, the researchers found. The risk of breast cancer was 9 percent higher for women who used contraception for less than a year and 38 percent for those who used it for more than 10 years.
The study offered a look at the effects of the use of modern birth control, over a long period of time, on a large group of women. The researchers followed women aged 15 to 49 years for an average of almost 11 years.
62% of women of reproductive age use contraception, according to a report by the National Center for Health Statistics that analyzed the period from 2000 to 2010. Most women used contraceptive pills, according to the report.
Approximately 255,000 women in the United States are expected to be diagnosed with breast cancer in 2017 and about 41,000 are expected to die. of it, according to the American Cance Society r.
The study raised concerns for some gynecologists in the Baltimore area, who said women should consult with their doctors if they were concerned about the correlation, particularly if they already had other risk factors for breast cancer.
risks and benefits should be discussed, "said Dr. Katherine Tkaczuk, professor of medicine at the University of Maryland School of Medicine and director of the breast evaluation and treatment program at the University of Maryland Marlene and Stewart Greenebaum Comprehensive Cancer Center. "I certainly do not want people to stop taking birth control. Most doctors think there are many benefits to birth control. Women should only be aware of the risks. "
Birth control has also been linked to a lower incidence of cancers of the uterus, endometrium and colon later in life, and can also help women who have strong cramps and menstrual bleeding.
Dr Mahsa Mohebtash, medical oncologist and director of the Cancer Center of Medstar Union Memorial Hospital, said the study raised real concerns.
Mohebtash said some women might want to consider other forms of control. The birth rate does not use hormones, such as condoms.Any IUDs do not use hormones either, she said.Women who do not want to get pregnant in the future can also have their tubal ligation.
"Even if they want to continue controlling the birth, they need at least to know the risks in order to be more attentive. "
Dr. Dona Hobart, medical director of the Center for Health The breasts at Carroll Hospital said that women should make a similar decision when deciding whether to take hormone replacement therapy, which can also increase the risk of breast cancer.
"The researchers who conducted the study said it was limited because they did not observe other factors, such as when the study participants started menstruating for the first time, their level of physical activity, or the amount of alcohol they consumed, all factors which may promote the development of breast cancer.
The study also looked at younger people, when older people are more often diagnosed with cancer, Hobart said 19659002] The American College of Obstetricians and Gynecologists said in a press release. statement that he was taking the results of the study "very seriously." However, he expressed some reservations about the search gs.
"While this study poses known risks associated with breast cancer and hormonal contraception, we believe it is A solid evaluation of the study, including the design of the study, is necessary to accurately interpret the findings and reach a conclusion ", Dr. Chris Zahn, a vice president of the organization, said in a statement. "This should include consideration of other factors that have a significant impact on the findings, including family history of breast cancer for pre and postmenopausal women, the stage of the disease and morbidity or mortality from breast cancer diagnoses." .
Zahn said that there should also be a comparison of the results for women using hormonal contraceptives with the results for pregnant women, to create a complete picture of the risks associated with both. Such a study would be useful, he said, to show that hormonal contraception, "risks and everything," may be essential to prevent pregnancy in some women at high risk of other medical conditions, such as diabetes.
In an editorial that accompanied the study, Dr. David Hunter of the University of Oxford wrote that the search should continue for birth control that does not increase the risk of breast cancer.