The number of people under 50 diagnosed with cancer has increased worldwide over the past three decades, according to a large study published on Wednesday.
THE cancer case among 14-49 year olds jumped nearly 80%, from 1.82 million to 3.26 million, between 1990 and 2019, according to the study published in the British journal BMJ Oncology.
While experts warn that part of this increase is due to population growth, previous research has noted increasingly frequent cancer diagnoses among those under 50.
As the main underlying risk factors in this age group, the international team behind the new study pointed to poor diet, smoking, and alcohol. But the cause of the early cancer growth “is still unclear”, they added.
The numbers are expected to increase another 31% by 2030
Just over a million people under the age of 50 died of cancer in 2019 (+ 28% compared to 1990), according to the study. The deadliest cancers were those of the breast, trachea, lung, intestine and stomach.
Breast cancer has been the most frequently diagnosed for three decades. But the fastest growing cancers are those of the nasopharynx – where the back of the nose meets the top of the throat – and the prostate. Conversely, liver cancer decreased by 2.9% per year.
The researchers used data from the 2019 Global Burden of Disease Study, analyzing the rates of 29 different cancers in 204 countries. The more developed the country, the higher the rate of cancer among those under 50, according to the study.
This could suggest that wealthier countries with better healthcare systems detect cancer earlier. But only a few countries screen people under 50 for certain cancers, the researchers note.
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Genetic factors, physical inactivity and obesity could also contribute to this trend, according to the study. And the number of cancer cases in the world among people under 50 is expected to increase by another 31% by 2030, mainly among people aged 40 to 49, according to a model carried out by the researchers. They note, however, that cancer data from different countries varies widely, with developing countries potentially underreporting cases and deaths.