Over the course of three decades from 1990 to 2019, there has been an alarming increase of nearly 80% in cancer diagnoses among individuals under the age of 50. The majority of cases recorded in 2019 were related to breast cancer, as reported in the journal BMJ Oncology in September.

The fastest increase within the last three decades was recorded in the number of cases of tracheal and prostate cancer, according to the researchers, while the number of liver cancers recorded in under-50s has fallen by just under 3%.

For their analysis, the team led by Xue Li from China's Zhejiang University School of Medicine in the U.K. used the 2019 edition of the "Global Burden of Disease" study series.

It contains data collected between 1990 and 2019 for 29 types of cancer in 204 countries, focusing on 14 to 49-year-olds. According to the report, a total of 3.26 million new cancer diagnoses were made among them in 2019 – an increase of 79% compared to 1990.

Improved early detection

The study authors speculate that the increase they observed could be related to improved early detection in industrialized countries.

Above all, however, an unhealthy diet, alcohol and tobacco consumption, lack of exercise, obesity, and high blood sugar played a role in addition to genetic factors.

Based on their analysis, the doctors predict that the number of new cancer cases and the associated deaths among the under-50s will increase worldwide by another 31% (diagnoses) and 20% (deaths) by 2030, with people over 40 being most at risk.

Just looking at the development between 1990 and 2019 shows that in the age group studied, it is mainly the 40 to 49-year-olds who are affected.

In an accompanying commentary, researchers Ashleigh Hamilton and Helen Coleman from Queen's University Belfast have suggested the introduction of targeted early detection measures for this age group.

For Hamilton and Coleman, the study results challenged the perception of cancers diagnosed in younger age groups, "It is important to educate both the public and healthcare professionals regarding the possibility of certain cancers in younger adults to allow earlier diagnosis, which in turn improves outcomes."

Prevention and early detection measures are urgently needed, they wrote, as is identifying optimal treatment strategies: Younger patients have different care and support needs.

Deaths under 50

Overall, more than 1 million people under the age of 50 died from cancer in 2019, an increase of almost 28% compared to 1990. Breast, trachea, lung, colorectal, and stomach cancers accounted for the most deaths, with kidney and ovarian cancer deaths increasing the most.

Geographically, the highest rates of cancer were seen in North America, Australasia, and Western Europe, but low to middle-income countries also saw increases in the number of cases, particularly among women.

Due to the different quality of cancer registry data in the various countries, there may also be an under-recording or under-diagnosis of cancer cases, the authors point out.

The findings are also not applicable to all countries in the world equally, and Volker Arndt of the German Cancer Research Centre (DKFZ), not involved in the research, says, "There has been no increase in the number of new cases of cancer in the under-50s in Germany over the last 20 years."

However even in a country where numbers are not rising overall, there are rising numbers of certain types of cancer - including skin, breast, prostate, and thyroid cancer – in the age group between 15 and 49 years, says Arndt, pointing to increased diagnostics.