“the cause of meningiomas is controversial, but there is strong evidence to suggest a plausible role for sex hormones in the onset,”
said keng siang lee
, lead author of the study and a medical student at bristol medical school at the university of bristol in england. “we know it has a predilection for females, especially after puberty.
“furthermore, fluctuations in meningioma growth during the menstrual cycle, pregnancy, and breastfeeding have also been well-documented,” he said. “we are also aware of the well-characterized distribution of progesterone, estrogen and androgen receptors in certain meningiomas located at the base of the skull.”
meningiomas account for 34 per cent of all primary brain tumours and are two to three times more common in women than men,
according to the brain tumour foundation of canada
. symptoms of the tumours, which have been known to arise after treatment involving ionizing radiation or excessive x-ray exposure, can include behavioural or cognitive changes, headaches, morning nausea and vomiting, seizures and changes in vision. often, no symptoms present and the tumours are discovered incidentally.
to explore the relationship between cyproterone acetate and meningiomas, researchers analyzed four studies comprised of a total of 8,132,348 patients, including 165,988 who had been prescribed cyproterone acetate in varying doses. they then analyzed the occurrence of meningioma in the patient pool and found a significant association between high doses of the drug and an increased risk of tumours. the same association was not seen with lower doses of the drug.