Factors such as obesity and alcohol consumption are contributing to an alarming rise in global cancer cases among younger people, according to a study.
The researchers estimated that there was a 79% increase in new cancer cases in people under the age of 50 between 1990 and 2019.
However, rates in the UK stabilized from 2010 to 2019 with the annual death rate from early cancer “declining steadily”.
A team from the University of Edinburgh and Zhejiang University School of Medicine in China analyzed data from the Global Burden of Disease 2019 study on 29 cancers in 204 countries and regions.
They looked at new cases, deaths, health outcomes and risk factors in people aged 14 to 49, calculating an annual rate for each year.
In 2019, there were 3.26 million new cancer diagnoses for people under the age of 50, a 79.1% increase since 1990.
Deaths also increased by 27.7%.
The researchers said that while genetics are likely to play a role, smoking, alcohol consumption and diets high in meat and salt but low in fruit and milk are the “main risk factors”, along with factors such as excessive weight, low physical activity and high blood sugar.
Breast cancer accounted for the largest proportion of cases – 13.7 per 100,000 people – while tracheal and prostate cancer cases are increasing the fastest at 2.28% and 2.23% per year respectively.
However, cases of early-onset liver cancer decreased by 2.88% each year.
The regions with the highest rates of early cancers were North America, Australia and Western Europe.
Study author Dr Xue Li, of the Center for Global Health at the University of Edinburgh's Usher Institute, said that while early cancer in the UK showed an “upward trend” from 1990 to 2010, “the overall incidence rate remained stable” from in 2010. to 2019.
He added: “Thankfully, the annual death rate from early-onset cancer in the UK is steadily falling, a testament to the outstanding efforts in cancer screening and treatment over the last three decades.”
The publication of the study – in the journal BMJ Oncology – comes after the charity Cancer Research UK claimed that advances in cancer care have helped save 1.2 million lives in the UK since the mid-1980s.
The number includes about 560,000 fewer deaths from lung cancer, 236,000 fewer deaths from stomach cancer, 224,000 fewer deaths from bowel cancer and 17,000 fewer deaths from breast cancer.
The charity said the improvement was down to advances in cancer prevention as well as diagnosis and treatment, including improvements in radiotherapy, the use of cancer screening programmes, drug development and gene discoveries.
Dr Claire Knight, senior director of health information at Cancer Research UK, said: “It is not entirely clear what is driving the rise in early-onset cancers, but exposure to risk factors in early life, better cancer detection and genetics may plays a part. part.”
Dr Knight said cancer remains “primarily a disease of older age”, however “disturbing” the study's findings are.
“We need more research to look at the causes of early cancer for specific types of cancer, such as the BCAN-RAY study which is looking at new ways to identify younger women at higher risk of breast cancer,” he added.
“If people are concerned about their risk of cancer, there are many ways to reduce it, such as not smoking, eating a balanced diet, getting enough exercise and staying safe in the sun.”
Montserrat Garcia-Closas, a professor of epidemiology at the Institute for Cancer Research, said the study “seeks to address important questions about the global increase in early-onset cancers,” but “there are methodological limitations that make it unclear what these findings add.” . current literature'.