Cancer cases in people under 50 have risen nearly 80% in three decades - the risk factors

According to the largest study of its kind, the number of people under 50 worldwide who have been diagnosed with cancer has increased by almost 80% in three decades.

Global cases of early-onset cancer increased from 1.82 million in 1990 to 3.26 million in 2019, while cancer deaths among adults in their 40s, 30s or younger increased by 27%. More than one million people under the age of 50 are dying from cancer each year, research reveals.

Experts are still in the early stages of understanding the reasons for the increase in cases. The authors of the study, published in BMJ Oncology , say that poor diet, alcohol and tobacco use, physical inactivity and obesity are likely to be among the risk factors.

Genetic factors likely play a role, the researchers said. But diets high in red meat and salt and low in fruit and dairy, along with alcohol and tobacco use, are the main risk factors, including physical inactivity, obesity and factors that contribute to high blood sugar.

The highest rates of early-onset cancer in 2019 were in North America, Oceania (the region made up of thousands of islands across the central and southern Pacific Ocean), and Western Europe.