Pfizer faces possible class action after contraceptive Depo-Provera linked to brain tumours

Chanel Stuart-Clarke was just 31 when doctors discovered by accident she had a 15mm brain tumour.

The tumour showed up unexpectedly in a scan ordered for a face lesion and was resting on the part of her brain responsible for personality.

It was a meningioma, a type of slow-growing tumour that will need to be monitored for the rest of her life.

"The hardest part was explaining to my family it could change my personality in the future," she said.

The 33-year-old is one of many women globally questioning whether their use of a popular contraceptive called Depo-Provera contributed to the development of their brain tumour.

Depo-Provera, also called Depo-Ralovera, is a high-dose injection of a synthetic progesterone called medroxyprogesterone acetate which is given to women every three months to prevent pregnancy.

In March, the British Medical Journal (BMJ) published a major study which found women who used Depo-Provera for more than a year had a five-to-six-fold increase of developing a meningioma compared to women who didn't use it.

Meningiomas are not malignant but they can grow in problematic parts of the brain and need removal.

Ms Stuart-Clarke took the contraceptive for more than a decade to help stop heavy periods.

"No-one ever said you could potentially get a brain tumour," she said.

"I need to get an MRI every two years for the rest of my life — $500 each time."

Patients preparing to sue Pfizer

In response to the study's findings, patients are preparing lawsuits in the United States and Canada.

In Australia, law firm Shine have announced they are recruiting participants for a possible class action.

The BMJ research was a large study that looked at more than 108,000 women in France over a decade — including 18,000 who developed brain meningiomas — and compared a range of contraceptives.

Study author epidemiologist Dr Noemie Roland said given its use was relatively low in France it was likely their results under-represented the real risk.

Globally it's estimated 74 million women use Depo-Provera.

In Australia, PBS figures show an estimated 24,000 women use Depo-Provera currently and it has been dispensed 3.6 million times since 1992. The drug has been available in Australia since 1972.

"Our results are not isolated internationally. They have been confirmed by results from Indonesian studies and recently by a large-scale study from the USA," Dr Roland said.

Brisbane mother Nicole, 38, used the Depo-Provera shot on and off for a decade. Earlier this year, she discovered she had a meningioma the size of a grape sitting between two lobes of her brain that few specialists would operate on.

Nicole gets migraines and has symptoms including tinnitus and memory problems and lives with the risk of possible seizures.

"You're just waiting for it. As soon as you get a strange tingle you think, 'Oh my goodness, is this today I'm going to have a seizure?'," she said.

"It's quite difficult, especially having a young child and a family because you just want to make sure that they're taken care of. It's probably one of the hardest things I've had to deal with.

"It just turns your world upside down, because everything's so uncertain."

Neurological Society of Australasia president and neurosurgeon Professor Kate Drummond said researchers had long surmised there was a hormonal link to meningiomas because they were common in middle aged and older women, and sometimes after pregnancy.

"It's been a rolling story over the last decade or so, and this [study] adds to it," she said.

Professor Drummond said the tumours were slow-growing but could cause problems once they reached a certain size and needed removal.

"It's still a very rare event overall."

Dr Roland said they also found the hormone-linked meningiomas were more likely to occur in the base of the skull, which were difficult to operate on.

"We think that the cumulative dose of progesterones is a major issue, and when you have long exposure," she said.

Early days for possible class action

Lorne Franks from Shine Lawyers said they were investigating whether legal action against Pfizer — the drug's makers — was viable, but it was still "early days".

"There's been studies going back at least to the early 2000s which is at least suggestive of the link [to meningioma]," he said.

"Until February of this year, there was no disclosure or a warning whatsoever in any of the material that's provided to consumers or their doctors."

Mr Franks said a number of women who'd developed meningiomas early in life and had used Depo-Provera long term had already contacted the law firm.

"There does seem to be a significant problem in this country," he said.

He said the BMJ article was the "final nail in the coffin" for Depo-Provera.

Nicole is among the women considering legal action.

"I've spoken to at least three different doctors about this. None of them ever said to me that it could contribute to the growth of brain tumours," she said.

"If I was told, I wouldn't do it. It's too big of a risk.

"There are just so many women out there who weren't equipped with the knowledge to make an informed decision."

Long term use of Depo-Provera under question

Dr Nisha Khot from the Royal Australian and New Zealand College of Obstetricians and Gynecologists said the BMJ study was important because it showed which contraceptives were associated with meningiomas, and consequently showed others were safer.

"We should be questioning whether it is the right contraceptive to give to women in the long term," she said.

"There is still a place for using Depo-Provera as a short-term method of contraception for a select group."

Dr Khot said it was important to remember the overall risk of meningioma was still low — the study found a 0.01 per cent chance overall and 0.05 per cent chance on Depo-Provera — and contraception was important for preventing unwanted pregnancies.

She said women with concerns should talk to their doctor.

Depo-Provera is also used as a treatment for some types of breast and endometrial cancer, endometriosis and heavy periods.

"It is a good treatment option for those women who have endometriosis or who have heavy periods — it would be a treatment probably in the short term," Dr Khot said.

A spokesperson for Pfizer said they continuously monitored the safety of all their medicines in collaboration with independent health bodies including Australia's Therapeutic Goods Administration (TGA).

"Depo-Provera has been approved in more than 60 countries over the last 30 years and has been a safe and effective treatment option for millions of patients during that time," the spokesperson said in a statement.

The TGA said the meningioma risk was included in its regular Medicines Safety Update to health professionals in March.

"In the case of Depo-Provera, the benefits continue to outweigh the risks for its intended use," they said in a statement.

Chanel Stuart-Clarke said women who'd taken Depo-Provera shouldn't ignore any symptoms they might have like migraine or vision issues and should see their doctor with concerns.

"There's probably a lot of other women who are in my situation who potentially don't know that they have a meningioma, which are put down to being normal side effects of any contraception," she said.