The alarming rise in colorectal cancer among young adults is a modern medical mystery. This episode delves into the latest research uncovering potential reasons behind this trend. We explore the findings pointing to a potential microbial culprit: a bacterial toxin called **colibactin**, which researchers suggest may be triggering the increase. We also examine how **dietary factors**, particularly metabolites linked to the consumption of red and processed meats, are emerging as a significant driver of risk in younger patients. Genetic factors and familial risk are also discussed, noting that inherited predispositions account for nearly half of young adult cases, and advancements in genetic testing are improving detection. Beyond biological causes, we look at the challenge of diagnosis, as young patients often **dismiss obvious symptoms** like rectal bleeding and abdominal pain, attributing them to less serious issues like stress or diet, leading to delayed evaluation. The conversation also covers the shift in **screening guidelines**, including the recommendation to begin screening for average-risk adults at age 45, and the low screening rates observed in the newly eligible age group. We touch on the potential future of **precision cancer screening**, which could use a combination of genetic, environmental, and lifestyle factors to identify high-risk individuals earlier. Finally, we gain insight into how young people perceive their own risk and their understanding of preventive factors like physical activity. Tune in as we discuss the complex factors contributing to early-onset colorectal cancer and what is being done to address this growing public health concern.

References

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Jaber, N. (2025, March 4). *Study identifies potential warning signs of colorectal cancer in younger adults*. National Cancer Institute at the National Institutes of Health. Retrieved from [URL not provided in source]

Labios, L. (2025, April 23). *Childhood exposure to bacterial toxin may be triggering colorectal cancer epidemic among the young*. UC San Diego Today. Retrieved from [URL not provided in source]

Lerner Research Institute - Cleveland Clinic. (n.d.). *Diet revealed as a main risk factor for colon cancer in younger adults*. Retrieved from [URL not provided in source]

Murphy, C. C. (2019). Colorectal cancer in the young: does screening make sense? *Current Gastroenterology Reports*, *21*(7), 28. https://doi.org/10.1007/s11894-019-0695-4

Newby, K. V., Cook, C., Meisel, S. F., Webb, T. L., Fisher, B., & Fisher, A. (2017). Young people's beliefs about the risk of bowel cancer and its link with physical activity. *British Journal of Health Psychology*, *22*(3), 449-462. https://doi.org/10.1111/bjhp.12238

Stoffel, E. M., Koeppe, E., Everett, J., Ulintz, P., Kiel, M., Osborne, J., Williams, L., Hanson, K., Gruber, S. B., & Rozek, L. S. (2017). Germline genetic features of young individuals with colorectal cancer. *Gastroenterology*, *154*(4), 897–905.e1. https://doi.org/10.1053/j.gastro.2017.11.004

The American College of Surgeons. (n.d.). *Clinicians struggle to understand dramatic rise in early onset colorectal cancer*. Retrieved from [URL not provided in source]

The American Cancer Society. (n.d.). *Colorectal cancer screening rates in younger adults*. Retrieved from [URL not provided in source]

*Note: URLs for the web pages were not included in the provided source excerpts.*