Breast cancer and Mirena IUD: What’s the link?



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What is Mirena IUD?

Mirena is a hormonal intrauterine device. Similarly to other hormonal IUDs, it releases levonorgestrel, a synthetic form of the naturally occurring hormone progesterone.

Progesterone often fuels breast cancer. Consequently, there has been a question about a link between breast cancer and hormonal IUDs, specifically Mirena.

  • Mirena is used long-term and can prevent pregnancy for up to 5 years.
  • There have been varying reports about a link between the use of Mirena and breast cancer.
  • Other brands of hormonal IUDs on the market carry similar warnings as Mirena about breast cancer. All note the research but conclude there is no definitive evidence.
  • Mirena is only one long-term birth control option. If women have health concerns about using it, they should talk to their doctor and raise any worries before deciding.

How does the Mirena IUD work?

The Mirena IUD works by thickening the cervix which stops sperm from reaching the eggs released from the ovaries. It also thins the uterine walls, which means that, for some women, ovulation is suppressed.

Can a Mirena cause breast cancer?

What does the research say about the link with increased breast cancer risk?

Can a Mirena cause breast cancer, Breast cancer and Mirena IUD: What’s the link?
The Mirena IUD has been linked to an increased risk of breast cancer, but how accurate are the findings? Image credit: Sarahmirk (2016, December 8).

The most recent information-labeling leaflet acknowledges a potential risk for women. It states that women:

“who currently have or have had breast cancer, or suspect breast cancer, should not use hormonal contraception because some breast cancers are hormone-sensitive.”

The makers of Mirena further note that the research studies on the increased risk are not definite.

Research saying there is no link

Mirena has been on the market for more than 15 years, and more research is still needed to provide a conclusive answer about its link to breast cancer.

One of the earlier studies about a link between Mirena and breast cancer dates back to 2005 and was published in the journal Obstetrics…