In the three decades since 1990, the number of cancer diagnoses among people under 50 has increased by almost 80 percent worldwide. Most of the cases recorded in 2019 were breast cancer, reports an international research group in the journal “BMJ Oncology”.

The fastest increase in the three decades was recorded in the number of cases of tracheal and prostate cancer. The number of recorded liver cancer cases in the age cohort examined fell by almost three percent. According to a German expert, the analysis cannot be directly transferred to Germany.

Strongest increases in kidney and ovarian cancer

For the analysis, Xue Li’s team from China’s Zhejiang University School of Medicine in Great Britain used the 2019 edition of the “Global Burden of Disease” study series. It contains data collected between 1990 and 2019 for 29 cancer types in 204 countries, focusing on 14 to 49 year olds. A total of 3.26 million new cancer diagnoses were made in 2019 – an increase of 79 percent compared to 1990.

In total, more than a million people under the age of 50 died of cancer in 2019, an increase of almost 28 percent compared to 1990. Breast, trachea, lung, colon and stomach cancer accounted for the largest number of deaths, with kidney and ovarian cancer deaths increasing the most. Geographically, the highest rates of cancer were found in North America, Australasia and Western Europe, but case numbers were also increasing in low- to middle-income countries, particularly among women.

Risk of underreporting or underdiagnosis

However, due to the different quality of the cancer registry data in different countries, under-recording or under-diagnosis can occur, the authors point out.

Volker Arndt from the German Cancer Research Center (DKFZ) comments on the study that comparative statements about the situation in Germany are difficult: nationwide figures are only available from 1999. “There has been no increase in the number of new cases among people under 50 across all cancer entities over the last 20 years in Germany,” said the head of the Baden-Württemberg Epidemiological Cancer Registry, who was not involved in the current study.

For individual types of cancer – including skin, breast, prostate and thyroid cancer – an increased number of cases is visible in the age group between 15 and 49 years, says Arndt. The reasons for this increase must primarily be the increased diagnostics.

For example, the numbers for skin cancer in this country rose significantly in 2007: new screening programs were introduced at that time. In the case of colon cancer, improved early detection has even reduced the number of cases. During a colonoscopy, the polyps identified are often removed straight away. “This catches a precursor to cancer and provides primary prevention,” explained Arndt.

Improved early detection is a factor

The study authors also speculate that the increase they observed could be related to improved early detection in industrialized countries. Above all, in addition to genetic factors, an unhealthy diet, alcohol and tobacco consumption, lack of exercise, obesity and high blood sugar played a role.

Based on their evaluation, the doctors predict that the number of new cancer cases and associated deaths among people under 50 will increase worldwide by a further 31 (diagnoses) and 20 percent (deaths) by 2030, with those over 40 are most at risk.

A look at the development between 1990 and 2019 shows that in the age group examined, 40 to 49 year olds are primarily affected. Therefore, in an accompanying commentary, Ashleigh Hamilton and Helen Coleman from Queen’s University Belfast suggest thinking about 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 about the possibility of certain cancers in younger adults to allow for earlier diagnosis, which in turn improves the outcome.” Measures for prevention and early detection are urgently needed, as is the determination of optimal treatment strategies: younger patients have different care and support needs.