The number of early onset cancer cases has grown significantly over the past three decades, with high-income countries particularly affected.
Researchers estimated there was a 79 per cent increase in new cases of cancer in those under the age of 50 between 1990 and 2019.
A team from the University of Edinburgh and the Zhejiang University School of Medicine in China analysed data from the 2019 Global Burden of Disease. which focused on 29 cancers reported in 204 countries and regions.
They looked at new cases, deaths, health consequences and risk factors in people aged 14 to 49, estimating an annual percentage for each year.
The regions with the highest rates of early onset cancers were North America, Australasia and Western Europe.
The UAE (1127.6 per cent), Qatar (1,089.5 per cent) and Saudi Arabia (896.0 per cent) exhibited the sharpest increases in the number of cases from 1990 to 2019, according to the study.
The findings upend received wisdom about the types of cancers typically affecting those under 50, with breast cancer, windpipe and prostate cancers growing markedly in the examined time period.
In 2019, there were 3.26 million new cancer diagnoses for under-50s. Deaths were also up by 27.7 per cent.
Researchers have blamed smoking, alcohol consumption and diets high in meat and salt, along with factors such as excess weight, low physical activity and high blood sugar, for the spike in cases.
Breast cancer made up the largest proportion of cases – 13.7 per every 100,000 people – while windpipe and prostate cancer cases are growing the fastest at 2.28 per cent and 2.23 per cent per year, respectively.
However, early onset liver cancer cases were down by 2.88 per cent each year.
Study author Xue Li, of the Centre for Global Health at the University of Edinburgh’s Usher Institute, said while early onset cancer in the UK showed an “upward trend” from 1990 to 2010, “the overall incidence rate remained stable” from 2010 to 2019.
“Fortunately, the annual mortality rate from early-onset cancer in the UK has been steadily decreasing, a testament to the outstanding cancer screening and treatment efforts over the past three decades,” she added.
The study was published in the journal BMJ Oncology.
Montserrat Garcia-Closas, a professor of epidemiology at the Institute of Cancer Research, said the study “seeks to address important questions on global surge in early-onset cancers” but there are “limitations with the methodology make it unclear what these findings add to current literature”.