A recent study discovered that women who use hormonal birth control, particularly intrauterine devices (IUDs), have a greater risk of breast cancer – however scientists emphasized that the overall risk is modest.
Hormonal IUDs function by releasing modest amounts of hormones straight to the uterus.
Previous research has shown that they reduce the risk of breast cancer compared to hormonal pills because they send fewer hormones into the uterus.
But the new study, published on Wednesday in Journal JAMA Network, discovered that women who use levonorgestrel-releasing IUDs face an increased risk of breast cancer, an unexpected finding given that IUDs were thought to be lower risk.
Researchers compared 150,000 Danish women aged 15 to 49 who used levonorgestrel-releasing IUDs to those who did not.
There were approximately 1,600 new breast cancer diagnoses among women overall. However, women who utilized IUDs had a 40% increased risk. Over the next five years, this is expected to result in 14 additional breast cancer cases for every 10,000 women.
The researchers also discovered that the duration of IUD use did not raise the risk of cancer, and the total risk of using an IUD remains low.
Kelsey Hampton, director of mission communications for the Susan G. Komen Breast Cancer Foundation, encouraged people to utilize the data to guide their talks and decisions.
“It’s normal for people to see studies like this and feel panicked or worried because an increase in risk of developing any kind of cancer is worrisome,” she said.
“We don’t want people to see this data and feel fear. We want them to know that this is just more evidence and more information that they can use to have an educated conversation with their doctor.”
However, on her part, Eleanor Bimla Schwarz, professor of medicine at the University of California, criticised the study, saying it reported just a small fraction and it should not change women’s mentality about contraception options.
She said that the benefits of an IUD far outweigh the risks.
Schwartz further said hormonal IUDs can help reduce bleeding and cramping and may decrease a woman’s risk of endometrial cancer.
“It reports a very small, one-in-a-thousand risk of being diagnosed with breast cancer, which is not the same as dying of breast cancer,” she said.
“That risk is really lower than many other everyday risks that women frequently take that have an impact on their breast cancer risk.
“I really think we have to put these conversations in context. A breast cancer diagnosis is not the same as dying from breast cancer, and we don’t have studies that show the use of any form of hormonal contraception actually increases your risk of dying from breast cancer.”
Arif Kamal, the chief patient officer with the American Cancer Society, also advised women to consider other contraceptive options if they are worried about the risk of IUDs.
“There’s not a one-size-fits-all approach. A person’s risk of breast cancer and their underlying anxiety or worry about breast cancer should inform a decision that’s made between a woman and her doctor about what’s the right thing to do,” Kammal said.