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YvetteM's avatar
YvetteM
Member
21 days ago

Did you have a Mirena in place like me when diagnosed with breast cancer?

I was diagnosed with breast cancer 3.5 months ago and had a double mastectomy 3months ago. I am 44 years old. I started doing some research as a number of people I know with breast cancer who were young also had a Mirena. There is new research coming out of:

-Europe that indicates that there is a 40% higher risk of breast cancer if you had a Mirena, and

-Germany that shows that the Mirena can change hormone levels in the breast based on scans

I had breast ultrasound scans that show I did not have breast cancer just before my Mirena was inserted 5 years ago, and that it developed post Mirena insertion. I had no genetic factors (based on testing), and no risk factors for breast cancer. It seems highly co-incidental.

I also looked up the FDA documentation for Mirena approval and it states that "Spontaneous reports of breast cancer have been received during postmarketing experience with Mirena. Because spontaneous reports and voluntary and from a population of uncertain size, it is not possible to use postmarketing data to estimate the frequency or establish causal relationship to drug exposure..."

I am keen to connect with other women who had a Mirena in place and then were diagnosed with breast cancer. If this is you, please respond to this post- I would love to hear your story!

clinical trials and research
young women

7 Replies

  • Nicola_Holiday's avatar
    Nicola_Holiday
    Member
    18 days ago

    Hi there, I was diagnosed stage 3 ER + with full lymph node involvement right side in October 2025 age 48. I had a Mirena for 8 years and was on the contraceptive pill for decades before that.  

    • YvetteM's avatar
      YvetteM
      Member
      15 days ago

      Thank you Nicole. I hope your treatment is going well, and I am sorry to hear of your diagnosis.

      I actually had a breast scan 5 years ago just before my Mirena insertion which showed no sign of cancer, and then directly after the Mirena, 5 years later cancer on both sides.....

  • Suki's avatar
    Suki
    Member
    21 days ago

    Hi YvetteM​ 

    I had a Mirena in.  I was 47 years old, peri-menopausal and diagnosed with Triple Positive BC.  I have since completed chemo/targeted therapy, had a double mastectomy and now on hormonal therapy.  I had no familial link to breast cancer and my only risk factors were being a low-level drinker of alcohol and having my first child at 31 years old.

    I loved having the Mirena (which I got after I finished having kids and had replaced a couple of times).  Prior to having kids, I was on the progesterone only contraceptive pill, so similar hormonal impact perhaps???

    Because my cancer was highly ER/PR+ (as well as HER2+), I was recommended to remove the Mirena after I was diagnosed as it was likely contributing to its growth.  But I couldn't say that there was any link between the Mirena and the cause of my cancer.  

    • YvetteM's avatar
      YvetteM
      Member
      20 days ago

      Thanks that is very interesting. I was told that the Mirena's effect is localised to the uterus, but recent studies show detection of hormone impacts in breasts. Perhaps the impact is the same as the oral contraceptive pill...perhaps not.

      I hope your recovery continues to go well and any remaining treatments you may need- or even better if you are in remission!

  • Afraser's avatar
    Afraser
    Member
    21 days ago

    I have never used Mirena but the following report may be of interest:

    Recent studies, particularly from Denmark (2024), indicate a potential 30–40% relative increase in breast cancer risk for users of hormonal IUDs like Mirena compared to non-users. However, the absolute increase is very low, with studies suggesting roughly 14–29 additional cases per 10,000 women over 5-10 years, which is considered a minor increase overall.

    Key Findings on Mirena and Breast Cancer

    • Study Data: A large Danish study tracking ~80,000 users found a 30-80% relative increase in risk depending on duration, but in absolute terms, the risk remained under 1% of users.
    • Absolute Risk: The actual risk is small. One study found only 14 extra cases per 10,000 women after 5 years. Another estimate suggested 1 additional case of breast cancer for every 7,690 users.
    • Duration of Use: While some data suggest risk increases with duration, others found the risk does not significantly increase with longer use.
    • Mechanism: The slight increase may be due to the progestogen (levonorgestrel) in the IUD affecting the growth of pre-existing, undetected cells.
    • Other Factors: The studies often could not fully account for lifestyle factors like obesity, alcohol, or smoking, which are major, independent risk factors for breast cancer.
    • Risk vs. Benefit: Medical experts largely agree that for most women, the benefits of Mirena (contraception, treatment of heavy bleeding) still outweigh the small increased risk of breast cancer.
    • YvetteM's avatar
      YvetteM
      Member
      20 days ago

      Thank you. I am aware of the study :-) Although the absolute risk is low, a 40% increase is very significant. It is true that the risk in my age category is only 1%, but an increase to 1.4% seems high (especially if you are in the 0.4%).

       

      I appreciate the share