Birth Control Pills & Breast Cancer
Nearly 10 million American women use oral contraceptives, including about 1.5 million who rely on them for reasons other than birth control. The number of women in the United States with intrauterine devices, many of which release hormones, has grown in recent years, as has the number of women using other types of hormonal contraceptive implants. Many women have believed that newer hormonal contraceptives are much safer than those taken by their mothers or grandmothers, which had higher doses of estrogen.
About 140 million women use some type of hormonal contraception, including about 16 million in the United States. Overall increased risk was small, amounting to one extra case of breast cancer among 7,700 women using such contraceptives per year. Experts who reviewed the research say women should balance the news against known benefits of the pill — including lowering the risk of other cancers. Current and recent use of hormonal contraceptives was associated with a 20% increased risk of breast cancer. Risk increased with longer use, from a 9% increase in risk with less than a year of contraceptive use to a 38% increase after more than 10 years of use.
Of course, finding a safe and effective form of birth control is more than just a personal concern. Unintended pregnancies cost the U.S. government $21 billion in 2010, according to a report. For many women, hormonal contraception —the pill, the patch, the ring, IUDs and the implant—is among the most safe, effective and accessible options available, said the American College of Obstetricians and Gynecologists. Studies of older birth control pills have shown “a net cancer benefit” because of lowered risk of cancer of the colon, uterus and ovaries despite a raised breast cancer risk, a breast cancer epidemiologist at the American Cancer Society. There was optimism that newer, low-dose contraceptives would lower the breast cancer risk, but these results have dashed those hopes.
Because risk increases with age, Older women may want to consider switching to a hormone-free birth control method, like a diaphragm, an I.U.D. that does not release hormones, or condoms. Though the older oral contraceptives were known to increase the risk of breast cancer, many doctors and patients had assumed the newer generation of pills on the market today were safer. Yet the new study found increased risks that were similar in magnitude to the heightened risks reported in earlier studies based on birth control pills used in the 1980s and earlier.
However, hormonal birth control does lower the risk of other cancers, including ovarian cancer and endometrial cancer, and it may lower the risk of colon cancer. Most breast cancers are fueled by estrogen. Over the years, makers of birth control pills and hormone replacement therapy for women past menopause have reduced the amount of estrogen in their products. No one should take (oral contraceptives) without careful thought, but the advantages in avoiding an unwanted pregnancy will usually more than outweigh the very slightly increased risk of breast cancer. There is also the reassuring thought that oral contraceptive use may decrease the risk of ovarian and endometrial cancer