Brain tumour link with the POP – really??

The mainstream media is awash with news of new research showing a ‘deadly’ brain tumour is linked to the mini pill. So, what is the evidence behind the hysteria? 

New research from the French group Roland et al. assessed the risk of intracranial meningioma associated with oral contraceptives containing either desogestrel 75mg, levonorgestrel 30mg, or levonorgestrel 50-150mg combined with oestrogen (BMJ June 2025). As a reminder meningiomas are predominantly benign, more common in women, and incidence increases with age (Brain Tumour Research). 

What did they do?

This was a case-control study using data from the French national health data system (SNDS). As an observational study, causation cannot be established. They identified 8391 women living in France who had undergone surgery for intracranial meningioma between 2020-23 and matched each with 10 controls based on age and geographical location (n= 83910). The mean age was 59.7yrs, with 75% older than 45yrs. Those with a pregnancy in the preceding 3yrs or previous history of meningioma were excluded. Among those treated for meningioma 3.4% (n=287) used desogestrel 75mg.

What did they find?

Reassuringly no excess risk with observed with oral levonorgestrel either alone or combined with oestrogen. 

There was a slightly higher risk of meningioma associated with continuous use of desogestrel 75mg for over 5 years (OR 1.7 (1.39-2.08)). This risk was not seen with shorter durations of usage, and was not observed after one year of stopping desogestrel. The number needed to harm through taking desogestrel of any duration was estimated at 67 300 women for one intracranial meningioma needing surgical intervention, and 17 000 women for one intracranial meningioma needing surgical intervention if taken continuously for over 5 yrs. Excess risk was greatest in those who also used a different progestrogen known to increase the risk of meningioma within the past 6 yrs (BMJ 2024). 

Is age important? 

Yes the absolute risk of meningioma increased with age: the AR was 11 per 100 000 in women aged 45-54 yrs, versus 3.1 per 100 000 in women aged 20-44 yrs. 

How does this fit in?

This is not the first time that progestrogens have been linked to meningioma. MHRA guidance states that cyproterone acetate (low dose contained in Dianette^â) is contraindicated in patients with a history of meningioma due to the increased risk. In 2024 Roland et al  published research highlighting six progestrogens associated with an increased risk of meningioma with prolonged exposure, with those used in the UK including cyproterone acetate, medroxyprogesterone acetate and nomegesterol acetate (BMJ 2024). Following this the FSRH issued guidance regarding prescribing of Zoely^â(nomegesterol acetate), advising that it should not be prescribed to those with a history of meningioma,  and that patients should be counselled that prolonged usage could increase the risk of meningioma. 

As discussed in the linked editorial from neurosurgeon Gilles Reuter (BMJ 2025), the risks associated with desogestrel are much lower than for the six previously identified progestrogens. For context number the needed to harm with high dose cyproterone acetate is estimated at 518, compared to 67 300 for desogestrel  (BMJ June 2025). 

Practical implications for practice

Reuter suggests that in general there is no need to alter the indications for desogestrel as the risks are so small. However, it is important to be aware of the slight increased risk of meningioma and avoid it if there is personal or family history of meningioma. Roland et al. are more cautious, suggesting considering other options if over 45yrs old. 

For those on desogestrel, Zoely^â or  Dianette^âwe should be alert to potential symptoms of meningioma (e.g. headache, personality change, cranial nerve palsies- especially ocular, seizures or cognitive impairment) and arrange imaging if suspected. If meningioma is found, stop the medication, and refer for neurosurgical opinion. Clear communication of medication history is vital to inform treatment decisions, as progestrogen related mengingiomas may spontaneously regress on cessation meaning surgery may be avoided.