"Meningiomas are the most common primary intracranial tumour in adults, and although more than 95% are histologically benign, their mass effect within a fixed cranial space means they can cause seizures, focal deficits, and cognitive impairment, often requiring surgery or radiotherapy. Their consistently higher incidence in women, together with progesterone receptor expression, has long suggested that hormones contribute to their development. This Danish study asks which specific progestogens, at contraceptive doses, actually increase the risk.

The study design relies on Denmark's linked national registers, which provide complete prescription records, validated cancer diagnoses, and eliminate recall bias. This approach is appropriate given how rare meningiomas are in reproductive-age women. It lets the authors examine many small exposure groups while matching on age, birthplace, and marital status, and, importantly, model time since exposure. That last point is significant because the research shows risk is concentrated in current and recent users and largely resolves within five years of stopping.

The increase in risk is very small for most types of progestogens. The number of women who need to take these compounds to develop one extra meningioma runs from the hundreds of thousands into the millions per year of use, and these numbers are most reassuring in younger women. To put it in perspective, the chance of dying on our roads is about 1 in 20,000. The chance of dying from a meningioma is less than 1 in 500,000.

The clinical bottom line depends on assessing this research considering what contraception delivers, namely: prevention of unintended pregnancy, reduced ovarian and endometrial cancer risk, and management of heavy or painful periods. For combined pills and Intra-Uterine Devices (IUDs), the absolute excess risk is negligible and shouldn't change clinical practice."

"This large population-based health register study provides further evidence of an association between progestogen exposure and meningioma. This association has been previously described and almost 90% of these usually benign tumours have progesterone receptors.

Meningioma occurs in roughly one in 10,000 people, with women having roughly double the rate that men do. It is well known that meningiomas grow during pregnancy and if extra progesterone is given, but decrease in size once the pregnancy is completed or progesterone withdrawn.

This study found an increased association with use of all of the currently available commercial progestogens to varying degrees.

The highest odds ratio 1.73 was found with injectable medroxyprogesterone acetate and the lowest odds ratio 1.14 was with IUDs with low-dose levonorgestrel. Progesterone-containing IUDs were previously thought not to increase the risk. The increased risk persists for up to five years after stopping the progestogen-containing treatment.

It is important to point out that a pregnancy in the preceding year also increases the risk of meningioma and carries other potential risks.

While interesting, it is important to point out that prevention of unwanted pregnancy is a major health issue.

Pregnancy in Australia carries a maternal mortality rate of 6.6 per hundred thousand, while the Australian five-year survival rate following meningioma diagnosis is greater than 90%.

Prescribers should certainly be aware of the association between progestogen exposure and meningioma and also of non-progestogen-containing contraceptive options, including barrier methods and copper-containing IUDs should this association be of concern to the woman.

This is further evidence of the importance of appropriate contraceptive consultations addressing risks and benefits of various means of contraception, taking place between prescribers and women, prior to writing a script or making a recommendation."