Colorectal cancer is generally considered a disease of older adults. However, a new analysis of German cancer registries shows that the number of new colorectal cancer cases among younger adults has risen slightly over the past two decades. Those most affected are people between the ages of 20 and 39. The findings are based on data from ten German cancer registries and cover the period from 2003 to 2023.
“Early-onset” colorectal cancer (EOCRC) refers to cases diagnosed before the age of 50. However, reports of rising colorectal cancer rates among younger people—particularly from the U.S.—prompted scientists at the German state cancer registries to take a closer look at the disease situation in Germany
Marked Increase Among the Youngest
For the current analysis, the experts evaluated more than 28,000 cases of colorectal cancer in people aged 20 to 49. They found that the incidence of colorectal cancer increased among 20- to 29-year-olds as well as among 30- to 39-year-olds. The increase was particularly pronounced in the youngest age group. Among 40- to 49-year-olds, however, the incidence rate remained largely stable overall.
“Our results show that the rise in colorectal cancer among young adults in Germany is real, but—at least so far—it is significantly more moderate than in the U.S.,” says Volker Arndt of the German Cancer Research Center (DKFZ) and the Baden-Württemberg Cancer Registry, one of the study’s two senior authors.
Germany Well Below U.S. Levels
An important part of the study was the comparison with the United States, where the rise in colorectal cancer among younger adults has been the subject of intense debate for years. The researchers show that incidence rates in Germany are significantly lower than in the U.S., both at the beginning of the study period and currently. Furthermore, the increase has been much slower in Germany.
Why Are the Numbers Rising?
The causes have not yet been fully explained. Lifestyle changes, including obesity, lack of physical activity, and dietary habits, are being discussed as possible contributing factors. Changes in gut flora could also play a role.
At the same time, the results suggest that part of the observed increase could be attributed to earlier and improved diagnosis. In particular, there was an increase in tumors with a comparatively favorable prognosis, which are often detected at an early stage.
No Reason to Lower the Screening Age Across the Board
Despite this trend, the authors currently see no sufficient reason to lower the age limit for colorectal cancer screening in the general population to under 50 years. “Colorectal cancer before the age of 50 remains rare overall in Germany,” emphasizes Jacqueline Müller-Nordhorn of the Bavarian Cancer Registry at the Bavarian State Office for Health and Food Safety. “Of the approximately 56,000 new cases of colorectal cancer each year, only about five percent occur in people under 50. Nevertheless, it should be noted that younger people should, of course, seek prompt, individualized medical care if they experience symptoms. The priority is to consistently identify known risk groups—such as people with a family history of the disease—and offer them the recommended screening tests.
The researchers recommend continuing to closely monitor trends in the incidence of the disease. Future studies should focus on clarifying the role that early life lifestyle factors, obesity, the consumption of highly processed foods, antibiotic use, and/or changes in the gut microbiota play in the development of colorectal cancer at a young age.
Sven Voigtländer, Hiltraud Kajüter, Ina Wellmann, Andras Szentkirályi, Bernd Holleczek, Volker Arndt, Jacqueline Müller-Nordhorn, and the ALSTER Working Group: Incidence trends of early-onset colorectal cancer in Germany: A registry-based study from 2003 to 2023
International Journal of Cancer, 2026, DOI: 10.1002/ijc.70600
Journal
International Journal of Cancer