Cancer diagnoses in under-50s up nearly 80% worldwide in three decades - researchers explain reasons why

The number of under-50s around the world being diagnosed with cancer has surged by nearly 80% in three decades, according to an alarming new study.

Figures show that some 3.26 million cases of early onset cancer were recorded in 2019, up from 1.82 million in 1990. The biggest rise in diagnoses was seen in prostate cancer and trachea/windpipe cancer, while breast cancer made up the largest proportion of cases. On the other end of the spectrum, cases of early onset liver cancer fell by an estimated 2.88% each year.

Experts are still in the early stages of understanding the reasons behind the rise in cases, but the authors of the study, published in BMJ Oncology, believe that while genetics play a part, smoking, alcohol, obesity, and a lack of exercise are also contributing factors. Some other “risks” include diets high in meat and salt, but low in fruit and milk.

Looking specifically at the UK, the study’s lead author Dr Xue Li said that while early onset cancer in the country showed an “upward trend” from 1990 to 2010, “the overall incidence rate remained stable” in the nine years after. She also added that, although global mortality rates were up, the annual number of deaths from early onset cancer in the UK had been decreasing over the past three decades. Dr LI described this as a “testament to the outstanding cancer screening and treatment efforts” in the UK.

Meanwhile, Dr Claire Knight, senior health information manager at Cancer Research UK, sought to reassure those in their 20s, 30s, and 40s that “although this might seem alarming, cancer is primarily a disease of older age.” She also said that “better detection” of cancer had likely played a part in the rise in cases.

Studies have previously suggested that cancer in under-50s was rising across the world over the last few decades, but the latest study, led by the University of Edinburgh in Scotland and Zhejiang University School of Medicine in Hangzhou, China, was the first of its kind to examine the issue on a global scale - and to consider “risk factors” for younger adults.

Researchers analysed data on 29 types of cancer from 204 countries, looking at the number of new cases, deaths, and contributory risk factors for those aged between 14 and 49. Worldwide, breast cancer accounted for the highest number of deaths - at 3.5 for every 100,000 of the population - with the next highest death tolls linked to people with lung, stomach, and bowel cancers.

The most early onset cancer diagnoses in 2019 were in North America, Oceania, and western Europe, with low and middle-income countries most affected. In these countries, early onset cancer had a much greater impact on women than on men, both in terms of health and deaths.

The highest death rates among under-50s were recorded in Oceania, eastern Europe, and central Asia.

In the report’s conclusion, it says: “Early onset cancer morbidity continues to increase worldwide with notable variances in mortality between areas, countries, sex, and cancer types. Encouraging a healthy lifestyle could reduce early-onset cancer disease burden.”

In order to reduce your risk of cancer, the study suggests:

• Not smoking
• Maintaining a balanced diet
• Getting plenty of exercise
• Stopping or reducing alcohol consumption
• Staying safe in the sun
• Avoiding a diet high in red meat and sodium
• Prioritising a diet high in fruit and milk