Women who use intrauterine devices (IUDs) that release the hormone levonorgestrel, such as the Mirena IUD may be at an increased risk of breast cancer, according to a new study published in the journal Obstetrics and Gynecology.
Levonorgestrel is a synthetic form of the hormone progesterone which is naturally produced in a woman’s body to regulate ovulation. Not only does it hinder conception, it also strengthens the uterine lining, which reduces heavy menstrual bleeding. Not only is the Mirena IUD approved by the Food and Drug Administration (FDA) to prevent pregnancy, it is also used to treat heavy periods, endometriosis and chronic pelvic pain in women.
The study, conducted by researchers with the Department of Obstetrics and Gynecology at the Hyvinkaa Hospital in Finland, was designed to examine the association between premenopausal use of levonorgestrel-releasing IUDs and cancer, in particular endometrial adenocarcinoma, or cancer of the uterine wall. The study involved more than 93,000 women between the ages of 30 and 49, all of whom were using the hormone-releasing IUD to treat heavy periods.
Researchers found that, over time, the IUD was not associated with an increased risk of uterine or ovarian cancer, or pancreatic and lung cancer. But they did see a spike in the number of breast cancer cases, especially among women between the ages of 45 and 49, compared to women who did not have an IUD.
Researchers say the study offers more information for women who are considering getting an IUD. Recent studies have also shed more light on the safety of the Mirena IUD. The device is inserted in the cervix, but in some cases it can migrate to other parts of the abdomen, where it can puncture and damage organs. Surgery is usually required to remove these runaway IUDs, and in some cases women have been left sterile.
Hundreds of women who have suffered complications like these from the Mirena IUD have filed lawsuits against Bayer, the manufacturer of the device, claiming the company knew the risks associated with the device but failed to adequately warn women.
Source: CNN Health