Hormonal Drug — Used in Some Birth Controls — Linked to Brain Tumors, Study Says
Recent research has shed light on a concerning link between the prolonged use of certain progestogen-based hormone medications, commonly utilized for contraception and the management of gynecological conditions like endometriosis, and an increased risk of developing meningiomas.
These tumors, which are generally benign and form in the membranes surrounding the brain, have been found to occur more frequently in women who have used these medications for over a year. Progestogens, synthetic forms of the natural hormone progesterone, are integral to various treatments, including hormonal contraceptives, therapies for conditions like polycystic ovary syndrome, and hormone replacement therapies during menopause.
Although some high-dose progestogens were previously known to elevate meningioma risk, a new study conducted by the National Agency for Medicines and Health Products Safety in France and published in the BMJ has expanded this concern to include eight more commonly prescribed progestogen forms.
The study leveraged data from the French national healthcare system, focusing on 18,061 women, averaging 58 years of age, who underwent surgical removal of intracranial meningiomas between 2009 and 2018. By comparing these patients with healthy controls, researchers identified a significant association between prolonged use of three specific progestogens and an increased necessity for surgical intervention due to meningiomas, the British Medical Journal on March 27.
Notably, two oral medications, medrogestone, and promegestone, along with the contraceptive injection medroxyprogesterone acetate (marketed as Depo-Provera), were linked to markedly higher risks of developing these tumors.
Although most meningiomas grow slowly and are not cancerous, their location and size can necessitate surgical removal due to pressure on the brain, posing risks to nearby brain structures. The observational nature of the study means it cannot conclusively prove causation between hormone use and tumor development, and no increased risk was associated with several other progestogens, including progesterone and dydrogesterone, or hormonal intrauterine systems widely used.
In response to these findings, Pfizer, the manufacturer of Depo-Provera, has acknowledged the potential risk associated with long-term progestogen use. The company is working with regulatory agencies to update product labels and patient information to reflect this concern.
The study’s authors have called for further research into the safety of these hormones, especially the injectable medroxyprogesterone acetate, given its global reach. With 74 million women worldwide using this form of contraception, the potential number of meningiomas linked to its use could be significant.
Despite these findings, experts like Prof. Paul Pharoah, a cancer epidemiologist with extensive experience in hormone-related cancers, urge women not to abandon their contraceptive methods without consulting their healthcare providers.
He emphasizes that the commonly used birth control pills and hormone replacement therapies in the UK do not carry an increased risk of meningiomas. Moreover, the absolute risk of developing such a tumor remains extremely low, suggesting that the benefits of using long-acting contraceptives like Depo-Provera might outweigh the risks for many women.