Cases in under-50s jump 79% since 1990 but population rise and better reporting are likely factors.
Image source, Getty ImagesThe number of cancer cases among the under-50s around the world appears to have risen sharply in the past 30 years, a study suggests.
Research published in BMJ Oncology found there had been 3.26 million cases in 2019 – 79% more than in 1990.
But experts cautioned against reading too much into the findings.
The research did not take into account a 40% rise in the total population, while factors such as better reporting may also have played a role.
The team, of experts from around the world, including the US, China and the UK, agreed no firm conclusions could be drawn.
But they were concerned lifestyle factors – including excess weight, diets high in red meat and salt and physical inactivity – could be pushing cancer cases up among 14- to 49-year-olds.
Genetic factors could also be playing a role, they added.
Death rate
Cancers of the digestive system, skin and breast were the most common.
Cancer killed more than a million under-50s in 2019, a rise of over 25% – but with the 40% population rise, this could actually indicate a falling death rate.
The data was taken from the Global Burden of Disease dataset, which covers more than 200 countries.
The researchers said more work was needed for a “full understanding” of the rise in cases but it suggested efforts were needed to improve detection and prevention in younger adults.
Prof Dorothy Bennett, a cell-biology expert at the University of London, agreed it was “not possible” to draw detailed conclusions.
Cancer Research UK said there was some evidence of rising cancer rates among 18- to 49-year-olds in the UK.
But Dr Claire Knight, of CRUK, added: “However alarming this might seem, cancer is primarily a disease of older age, with the majority of new cancer cases worldwide being diagnosed in those aged 50 and above.”