The results of a recently published clinical study suggest that taking the birth control pill for at least five years may double the risk of developing a glioblastoma multiforme (GBM), a rare but often fatal from of brain cancer.
Glioblastoma multiforme is one of the most common and fatal types of primary brain cancer. It develops from the glial cells, which are the most abundant cells in the nervous system. Glial cells provide supportive functions that facilitate the work of neurons (cells that transmit impulses between the brain, spinal column, and nerves). Current treatment for GBM includes surgery followed by radiation and chemotherapy. However, even with the most aggressive treatment available, many patients will survive less than one year after diagnosis. As such, researchers continue to evaluate new and innovative treatment strategies.
Researchers evaluated 317 women who had been diagnosed with GBM between 2000 and 2009 and compared them to a control group. They found that for women using progesterone-only methods of contraception the risk of a brain cancer was 2.4 times higher than the control group. For other methods of hormonal contraception the risk was raised, but not as high.
This study clearly raises concerns about possible links between contraceptive use and cancers of the brain, however other studies have not found a consistent link. Therefore it’s not yet possible to draw firm conclusions and additional research on this topic will continue.
As with anything, it’s important to weigh the risks and benefits of contraceptive use on an individual basis. While the results of this study do not prove that contraceptive use caused the brain tumors, they do suggest that there is a correlation. This is a modifiable risk factor that many individuals could avoid by not using oral contraceptives or at least avoiding higher dose progesterone containing preparations.
Reference: Andersen L, Friis S, Hallas, et al. Hormonal Contraceptive Use and Risk of Glioma among Younger Women: A Nationwide Case-control Study. British Journal of Clinical Pharmacology. 2014; DOI: 10.1111/bcp.