Hormonal contraception, whether in the form of the pill or IUD, is not harmless for women aged 40 and over. Danish researchers followed up 1.8 million women aged 15 to 49 between 1995 and 2012. To avoid distorting the results of the study, the women selected had no history of cancer and no previous hormone infertility treatment.
The study confirmed that 11,517 cases of breast cancer had been diagnosed during this period. Scientists were able to draw a comparison with women who had not used hormonal contraceptives: “The risk of developing invasive breast cancer was 20% higher in women using oral or other forms of hormonal contraceptives”, explained the authors of the study in the journal Prescrire. They recommend “using another method of contraception” especially since cardiovascular risks are associated with the use of hormonal contraceptive therapy in women over 40.
The study’s authors noted that the increased risk of breast cancer persisted despite discontinuation of hormonal therapy or the removal of the hormonal IUD. However, researchers confirmed that no difference had been highlighted between the various hormonal contraceptives, “or compared to IUDs releasing only levonorgestrel, a progestogen (Mirena and others)”.
This risk affects 1 in 7,700 women over 40, compared to 1 in 50,000 of women under 35.
For further reading:
“Hormonal contraception: breast cancers” Rev Prescrire 2018; 38 (416): 426.
La Dépêche (07/06/2018)