Hormonal Contraceptives May be Linked to Increased Risk of Brain Tumors, Study FindsJan 26, 2015
A Danish study published in the British Journal of Clinical Pharmacology suggests that there may be an increased risk of brain tumors associated with the use of hormonal contraceptives, such as the pill. Researchers found that there may be an increased risk of glioma of the brain, a rare tumor, after taking a hormonal contraceptive for at least five years.
The study analyzed Danish women between the ages of 15 and 49. Data was obtained through Denmark's national administrative and health registries, where researchers were able to identify women who were diagnosed with glioma for the first time between 2000 and 2009; 317 cases were found. Each of these women were compared to 8 age-matched women who were not diagnosed with glioma as a control.
The causes of glioma and other brain tumors are largely unknown. Some previous studies showed that female sex hormones are associated with an increased risk of some cancers, while others found that birth control may decrease this risk in certain age groups. "This prompted us to evaluate whether using hormonal contraceptives might influence the risk of gliomas in women of the age range who use them," said lead researcher Dr David Gaist of the Odense University Hospital and University of Southern Denmark.
Although the study found a potential link, Dr. Gaist emphasizes the importance of interpreting the findings in context. "It is important to keep this apparent increase in risk in context," he said. "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."
"While we found a statistically significant association between hormonal contraceptive use and glioma risk, a risk-benefit evaluation would still favour the use of hormonal contraceptives in eligible users," Gaist said. "Despite that, we feel our study is an important contribution and we hope that our findings will spark further research on the relationship between female hormonal agents and glioma risk,"