Does Mirena cause Breast cancer?

Mirena IUD is a highly effective form of contraceptive for women. Unlike contraceptive pills, Mirena releases a progesterone-like hormone directly into the womb.  This means that levels of the hormone are much lower than when you take it as a tablet.

However, a Danish study has found a link between Mirena IUD and breast cancer which is perceived by media as a huge risk which is not true.

This may be causing unnecessary panic and worry amongst the members of the public.

 

Mirena and Contraception

Mirena is a type of intrauterine devices (IUD) that prevents pregnancy for up to 8 years. It works by releasing progestin. For most women, it’s a very safe and effective choice in contraception.

To prevent pregnancy, Mirena slowly releases progesterone to:

• Thicken the mucus in your cervix, so sperm can’t reach an egg
• Thin the lining of your uterus
• Stop your eggs from fully developing each month

In addition, Kyleena another progesterone releasing IUD also prevents pregnancy for up to 5 years.

 

Benefits of Mirena

When choosing contraception, discuss the pros and cons with your doctor. For you, the benefits may outweigh any possible risks. With Mirena, these benefits may include:

• Lighter periods after 3 or more months
• Less menstrual pain
• Less pain from endometriosis
• Lower risk of endometrial cancer
• Lower risk of pelvic infection

 

Mirena and Cancer risk

The Danish study found that there were 14 extra cases of breast cancer per 10,000 women in the group using Mirena compared to those not using contraceptive medication.

It is unfortunate that this study did not compare breast cancer risk between the Mirena and oral contraceptive pill. But it is important that smoking, alcohol and obesity are much more important risk factors for breast cancer than contraceptive medications.

Study from Sweden based on data from more than half a million users of Mirena.

This suggested only a 13% relative risk increase in breast cancer – much smaller than the risk increases in the Danish study. This would mean an additional 1.46 cases of breast cancer for every 10,000 women per year.

The other studies also found a much smaller risk than the new Danish paper.

 

Take Home Message

Based upon the available evidence, the association between Mirena and breast cancer is very low.

The other factors such as smoking, alcohol, physical inactivity and obesity are much more important risk factors for breast cancer than Mirena.

Our advice for women is that breast cancer risk caused by Mirena is not established but warrants a closer look.

When to see us?

If you require further information,

Please contact Rockingham Women’s Health Centre on 0895918943 to book an appointment or www.rockinghamwomenshealth.com.au