Women battling infertility are often given medications to help them conceive, and potential side effects are always a concern. Now, research suggests use of the drugs won't raise a woman's odds for breast cancer.
Researchers at King's College London in the United Kingdom analyzed studies from 1990 to January 2020 that included 1.8 million women of all reproductive ages who underwent fertility treatment. The women were followed for an average 27 years after treatment.
Over that time, there was no significant increase in breast cancer risk among women who received fertility treatment, compared to untreated women who were infertile, according to the report published June 21 in the journal Fertility and Sterility.
"Fertility treatment can be an emotional experience," said study author Yusuf Beebeejaun, a clinical research fellow in reproductive medicine. "Patients often ask us if taking ovarian-stimulating drugs will put them at increased risk of developing cancers, including breast cancer."
Senior study author Sesh Sunkara said this study provides the evidence needed to reassure women and couples seeking fertility treatments.
"Our study showed that the use of drugs to stimulate ovaries in fertility treatment did not put women at increased risk of breast cancer," she said in a college news release.
The researchers described the long-term study as the largest ever to assess whether widely used fertility drugs increase women's cancer risk.
Fertility drugs to stimulate ovaries to release eggs have been used to treat infertility since the early 1960s. Because the drugs boost estrogen hormone production and can act on breast cells, there has been concern that this could turn the cells cancerous.
According to Katy Lindemann, a patient advocate who underwent fertility treatment, "So much of the fear, stress and anxiety associated with fertility treatment is rooted in navigating uncertainty. This study not only gives patients peace of mind at an emotional level, but also enables us to make more informed decisions about treatment risks and benefits at a rational level."
While the findings are reassuring, researchers said more long-term and detailed studies are needed to confirm these results.
The U.S. National Institute of Child Health and Human Development has more on fertility treatment for women.
SOURCE: King's College London, news release, June 21, 2021