Princess Kate revelation shines light on under-50s cancer mystery

PARIS, France — When Catherine, Princess of Wales, revealed she was being treated for cancer last week, part of the shock was that an otherwise healthy 42-year-old has a disease that mostly plagues older people.

However, researchers have been increasingly sounding the alarm that more and more people under 50 are getting cancer -- and no one knows why.

Across the world, the rate of under-50s diagnosed with 29 common cancers surged by nearly 80 percent between 1990 and 2019, a large study in BMJ Oncology found last year.

The researchers predicted the number of new cancer cases among younger adults will rise another 30 percent by the end of this decade, with wealthy countries particularly affected.

The increase in cases -- and soaring global population -- means that the number of deaths among under 50s from cancer has risen by nearly 28 percent over the last 30 years.

This occurred even as the odds of people of all ages surviving cancer have roughly doubled over the last half century.

Shivan Sivakumar, a cancer researcher at the UK's University of Birmingham, called it an "epidemic" of young adult cancer.

Since Kate Middleton revealed on Friday that her cancer was discovered after she received abdominal surgery earlier this year, Sivakumar and other doctors have spoken out about the uptick in younger cancer patients they have been seeing at their clinics.

While breast cancer remains the most common for people under 50, the researchers expressed particular concern about the rise of gastrointestinal cancers -- such as of the colon, pancreas, liver and oesophagus -- in younger adults.

Colon cancer is now the leading cause of cancer deaths in men under 50 in the United States, according to the American Cancer Society. For women, it is number two -- behind only breast cancer.

One high profile case of colorectal cancer was "Black Panther" actor Chadwick Boseman, who died at the age of 43 in 2020.

"We just don't have the evidence yet" to say exactly what is causing this rise, Sivakumar told AFP, adding it was likely a combination of factors.

Helen Coleman, a cancer epidemiology professor at Queen's University Belfast who has studied early onset cancer in Northern Ireland,