Birth control, brain tumors may be linked

Women younger than 50 with 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," Dr. David Gaist, the lead researcher, told CBS News.

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Researchers also found that there was a greater chance for developing glioma among women who used progesterone-based birth control, rather than estrogen-based options.

However, scientists did say that, given the rarity of this particular cancer, the benefits of long-term hormonal contraceptive use outweighed the risks for users.

Dr. Evan Myers, an OB-GYN professor at Duke University, said the study was "really well done," but "the actual increase in the chances of having a glioma diagnosed is quite small."

Myers said a statistical examination he conducted found glioma affected fewer than two out of every 100,000 American women between the ages of 15 and 29 from 2001-2011.
The study was conducted in Denmark and published online in the British Journal of Clinical Pharmacology.
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