Research Spotlight: Global Analysis Reveals Sharp Rise in Cancer Among People Under 50

Q: What did you find?

We found that many cancers in younger adults are rising significantly across multiple regions worldwide, especially in developed countries. For women, cancers such as colorectal, cervical, pancreatic, and multiple myeloma showed the steepest increases in adults under 50 compared to the same cancers in older adults. For men, early-onset prostate, colorectal, and kidney cancers had the most dramatic growth. In some places, these increases were especially pronounced for colorectal cancer, where rates in younger adults went up by about 2% per year while rates in older adults stayed flat or even slightly declined.

Importantly, for certain cancers, such as uterine and colorectal, we saw both incidence and mortality rising together, which suggests that these trends are not just due to better detection.

We also found strong links between obesity and cancer: countries with higher obesity rates among younger people tended to have bigger increases in obesity-related cancers, including thyroid, kidney, and colorectal cancers. These patterns suggest that lifestyle factors, such as diet and physical activity, may play a major role in the growing burden of cancer among younger adults.

Q: What are the implications?

The steep increase in cancers among younger adults signals a major shift in global health patterns. It suggests that risk factors traditionally associated with older age — such as obesity, poor diet, and sedentary lifestyles — are now affecting people earlier in life. This trend could point to changes in environmental exposures, biological factors, or even generational differences in lifestyle habits.

While improved screening may explain part of the increase, the fact that mortality of colorectal cancer and uterine cancer is also rising in several countries means that these cancers are not just being detected earlier — they are causing real harm. This growing burden could strain healthcare systems, as younger patients often require long-term treatment and support. It also raises questions about prevention: how can we reduce risk factors earlier in life? Public health strategies may need to shift toward younger populations, focusing on diet, physical activity, and awareness of symptoms.

Ultimately, these findings highlight the urgency of understanding why these cancers are increasing and how to intervene before they become an even larger global challenge.

Q: What are the next steps?

There are several important directions for future research.

First, we need to examine these trends in more countries and regions to understand whether the patterns we observed are truly global. Second, our study could not account for details like cancer stage at diagnosis, tumor characteristics, or treatment differences, so future studies should include these factors to clarify what is driving the rise.

Third, we need to better understand the role of screening and early detection in these trends, since screening can both help and complicate interpretation of incidence data. Finally, more research is needed to uncover potential biological, environmental, and lifestyle factors that may explain why certain cancers are increasing among younger adults. These steps will help guide prevention strategies and inform public health policies.

Paper cited: Terashima, M., et al. “Diverging global incidence trends of early-onset cancers: comparisons with incidence trends of later-onset cancers and mortality trends of early-onset cancers.” Military Medical Research. DOI: 10.1186/s40779-025-00670-8

Funding: This work was supported by the Prevent Cancer Foundation Grant, Harvey V. Fineberg Cancer Prevention Fellowship, and Brigham and Women’s Hospital Faculty Career Development Award, an Investigator Initiated Grant from the American Institute for Cancer Research (AICR). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Disclosures: None.