Some hormonal contraceptives linked to small increase in brain tumour risk
By Dr Joe Milton, the Australian Science Media Centre
Some hormonal contraceptives containing progestogens may slightly increase the risk of developing a common type of brain tumour, according to a large Danish study published this week.
The team looked for links between contraceptive use and the risk of meningioma brain tumours in around three million Danish women, 1,473 of whom had been diagnosed with meningioma.
Meningioma is the most common type of brain tumour. While the vast majority are non-cancerous, they grow inside the skull, so they can still cause serious health problems including headaches, seizures, vision changes and memory issues.
The researchers found the increased risk was highest among women using the injectable contraceptive medroxyprogesterone, while smaller increases were seen for several contraceptive pills and high-dose hormonal IUDs. The risk was greatest while women were using the contraceptives and generally returned to normal within five years of stopping.
Associate Professor Gino Pecoraro, an obstetrician and gynaecologist at the University of Queensland, told the AusSMC the findings add to growing evidence that some meningiomas are influenced by hormones because most of these tumours contain progesterone receptors.
"Prescribers should certainly be aware of the association between progestogen exposure and meningioma and also of non-progestogen-containing contraceptive options," he said.
However, he said the study should not discourage women from using effective contraception.
"Preventing unintended pregnancy remains one of the most important aspects of reproductive healthcare," he said, stressing that “a pregnancy in the preceding year also increases the risk of meningioma”.
Associate Professor Alex Polyakov, from the University of Melbourne and Genea Fertility Melbourne, said the study was one of the largest to examine the link between hormonal contraception and meningioma.
He said the findings should be considered alongside the well-established benefits of hormonal contraception, including preventing unintended pregnancy and treating conditions such as heavy or painful periods.
"For combined oral contraceptives and hormonal IUDs, the increase in absolute risk is negligible and is unlikely to change current prescribing practice," he said.
"The number of women who would need to use these medications for one additional case of meningioma ranges from hundreds of thousands to millions per year of use, particularly among younger women."
"The reassuring message is that the absolute risk remains extremely low.”
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This article originally appeared in Science Deadline, a weekly newsletter from the AusSMC. You are free to republish this story, in full, with appropriate credit.
Contact: Dr Joe Milton
Phone: +61 8 7120 8666
Email: info@smc.org.au