Contraceptives linked to brain tumors

In a recent study published in the journal BMJ, a team of French researchers investigated the association between progestogen use and the risk of benign central nervous system tumors such as intracranial meningioma among women.

Meningiomas occur every 9.5 per hundred-thousand-person years in the United States and account for 40% of the central nervous system-associated primary tumors. Although histologically benign and slow-growing, they can cause problems by exerting pressure on adjacent tissue in the brain, requiring surgical intervention to decompress the area. Age is one of the factors that significantly increases the risk of meningiomas, especially after 65 years.

Female sex, neurofibromatosis type 2, and ionizing radiation exposure to the intracranial region are other known risk factors for meningiomas, apart from age. Recent research has also indicated that the long-term use of three progestogens — chlormadinone acetate, nomegestrol acetate, and cyproterone acetate — at high doses can also increase the risk of intracranial meningiomas.

In the present study, the researchers investigated the intracranial meningioma risk associated with numerous progestogens and various administration routes of these progestogens.

The results showed that long-term use of promegestone, medrogestone, and the injectable contraceptive medroxyprogesterone acetate was associated with a higher risk of intracranial meningioma. However, short-term use spanning less than a year of any of these progestogens was not found to increase the meningioma risk.

Furthermore, the use of intravaginal, percutaneous, and oral progesterone, dydrogesterone by itself or with estrogen, short—or long-term use of spironolactone, or levonorgestrel intrauterine systems was not associated with any increase in intracranial meningioma risk.

The use of promegestone, medrogestone, and medroxyprogesterone acetate was not found to be linked to the incidence of malignant meningiomas, and the number of cases of intracranial meningiomas that needed surgical treatment that was associated with promegestone, medrogestone, and medroxyprogesterone acetate was significantly fewer than those associated with nomegestrol acetate, chlormadinone acetate, and cyproterone acetate.