In 2022, around 16% of the 20 million people with cancer worldwide were under 50. Cancer has always been markedly more of an older person’s disease, says Lynn Turner, director of research at Worldwide Cancer Research. But between 1990 and 2019, the incidence of the disease in under-50s rose by 79%, according to research published in the British Medical Journal in 2023. That short timeframe means the rise cannot be explained by genetic factors, according to Tracey Woodruff, director of the University of California, San Francisco’s programme on reproductive health and the environment.
Many of these “early-onset” cases are happening in wealthier countries, says Kathryn Bradbury, senior research fellow at the University of Auckland’s school of population health. The rates are striking because younger populations…