The WHO agency says that talc is ‘probably’ a cause of cancer

The World Health Organization’s cancer agency on Friday classified talc as “probably carcinogenic” to humans, but an outside expert warned against misinterpreting the announcement as a “smoking gun”.

The decision was based on “limited evidence” that talc can cause ovarian cancer in humans, “sufficient evidence” that it was linked to cancer in mice and “strong mechanistic evidence” that shows signs of carcinogenicity in human cells, the International Agency said. for WHO Research. said on Cancer (IARC).

Talc is a natural mineral that is mined in many parts of the world and is often used to make talc baby powder.

Most people are exposed to talc in the form of baby powder or cosmetics, according to the Lyon-based IARC.

But the most significant exposure to talc occurs when talc is mined, processed or used to make products, he added.

The agency said there were multiple studies that consistently showed an increased rate of ovarian cancer in women who use talc on their genitals.

But it could not be ruled out that the talc in some studies was contaminated with cancer-causing asbestos.

“A causal role for talc cannot be fully established,” according to the agency’s findings published in The Lancet Oncology.

Kevin McConway, a statistician at the UK’s Open University who was not involved in the research, warned that for the IARC estimate, “the most obvious interpretation is actually misleading”.

The agency is only aiming “to answer the question of whether the substance has the potential to cause cancer, under some conditions that IARC does not specify,” he said.

Because the studies were observational and thus could not prove causation, “there is no smoking gun that talc use causes any increased risk of cancer,” he added.

The announcement comes just weeks after US pharmaceutical and cosmetics giant Johnson & Johnson agreed to pay $700 million to settle allegations that it misled customers about the safety of its talcum powder products.

Johnson & Johnson did not admit wrongdoing in its settlement, although it pulled the product from the North American market in 2020.

A review of studies published in 2020 covering 250,000 women in the United States found no statistical association between genital talc use and risk of ovarian cancer.

Also on Friday, the IARC classified acrylonitrile, a chemical compound used to make polymers, as “carcinogenic to humans,” the highest level of warning.

He cited “sufficient evidence” linking acrylonitrile to lung cancer.

Polymers made with acrylonitrile are used in everything from fibers in clothing to carpets, plastics and other consumer products.

© 2024 AFP