Hormonal drugs linked to increased brain tumour risk

Women who take certain drugs that contain the hormone progestogen as a contraceptive or for other gynaecological issues are more likely to develop a type of brain tumour known as an intracranial meningioma, finds a French study published in The BMJ. Progestogens are used by millions of women for contraception and other gynaecological conditions such as endometriosis, polycystic ovary syndrome and in hormone replacement therapies used during menopause.

Meningiomas are mostly non-cancerous tumours that grow in the layers of tissue that cover the brain and spinal cord. Though mostly benign, meningiomas can grow large and press on nearby brain tissue, nerves and vessels causing serious disability and can be life threatening. The study included 18,061 women, average age 58, who underwent intracranial meningioma surgery. Each case was matched to five other women who did not have intracranial meningioma, for a total 90,305 women.

The progestogens examined were progesterone, hydroxyprogesterone, dydrogesterone, medrogestone, medroxyprogesterone acetate, promegestone, dienogest and levonorgestrel intrauterine systems (IUD). Using medrogestone for a year or more was associated with a 4.1-fold increased risk of intracranial meningioma requiring surgery. Prolonged use of medroxyprogesterone acetate was associated with a 5.6-fold increased risk and prolonged use of promegestone was linked to a 2.7-fold increased risk. Use of these progestogens for less than one year did not appear to increase the risk.

According to the study, since an estimated 74 million women worldwide use medroxyprogesterone acetate for birth control, the number of attributable meningiomas may be high.