A study of Danish women of reproductive age suggests that long-term use of hormonal contraceptives is associated with an increased risk of brain tumors.
Hormonal contraceptives, which contain female sex hormones, are commonly prescribed in pill form. “The Pill” first became widely available in the 1960s and gave women all over the world control over childbearing. The new study, which appeared in the British Journal of Clinical Pharmacology, reports that taking a hormonal contraceptive for at least five years is associated with a possible increase in the woman’s risk of developing a rare tumor, glioma of the brain, Science 2.0 reports.
The researchers used data from Denmark’s national registries to identify women between 15 and 49 years of age who had a first-time diagnosis of glioma between 2000 and 2009. They found 317 cases and compared each of these women with eight age-matched women who did not have gliomas. The researchers found a statistically significant association between hormonal contraceptive use and glioma risk. Dr. David Gaist of the Odense University Hospital and University of Southern Denmark, who led the research, said women under 50 with a glioma were “90 percent more likely to have been using hormonal contraceptives for five years or more, compared with women from the general population with no history of brain tumor,” according to Philly.com.
“It is important to keep this apparent increase in risk in context,” Gaist said, according to Science 2.0. “In a population of women in the reproductive age, including those who use hormonal contraceptives, you would anticipate seeing 5 in 100,000 people develop a glioma annually, according to the nationwide Danish Cancer Registry.”
Dr. Gaist emphasizes that the findings should be interpreted with care, and he said he hopes the results “will spark further research on the relationship between female hormonal agents and glioma risk,” according to Science 2.0.