Colon Cancer: Should Young People Worry? - Science Vs Recap

Podcast: Science Vs

Published: 2026-03-19

Duration: 2445

Guests: Dr. Michael Foote, Professor Ludmil Alexandrov, Becca Lynch

What Happened

Becca Lynch, a 30-year-old from Colorado, was diagnosed with stage three colon cancer at age 29, despite lacking typical risk factors. This highlights a worrying trend where more young people under 50 are being diagnosed with colorectal cancer, a disease historically associated with older adults. Rates of colorectal cancer in those over 50 are decreasing, but for younger populations, the incidence is rising significantly.

In the United States, one in five people diagnosed with colorectal cancer is now younger than 55, a stark contrast to the one in ten statistic from a few decades ago. This shift is alarming, given that colorectal cancer is the leading cause of cancer death in people under 50, resulting in nearly 4,000 deaths annually. The risk of developing this cancer under age 50 remains less than 1%, yet the upward trend is undeniable.

Dr. Michael Foote, a gastrointestinal oncologist, explains that the cancer in younger individuals is not inherently more aggressive, but it is often diagnosed at later stages. More than half of early-onset colorectal cancer cases are discovered at stage three or four, where the prognosis is significantly worse. For example, stage four colorectal cancer carries an 80% chance of death within five years.

The episode also delves into symptoms and risk factors. Young people often experience a longer delay in diagnosis, waiting 40% longer compared to older individuals. This delay is partly due to misdiagnoses and the misconception that young people are "too young" for colorectal cancer. Symptoms can be severe by the time they are fully recognized, contributing to later-stage diagnosis.

Professor Ludmil Alexandrov discusses potential causes for this increase, pointing to specific mutation patterns in younger patients linked to bacteria releasing a toxin called Colibactin. This toxin, produced by certain E. coli strains, can damage DNA in gut cells, potentially leading to cancerous tumors. Research indicates these mutations often occur very early in life, potentially before age 10, or even within the first two years.

Diet and lifestyle factors are also scrutinized. The consumption of ultra-processed foods is associated with a 45% higher chance of developing polyps, which can turn cancerous. Additionally, red meat, especially when charred, and processed meats have been linked to increased cancer risks. However, some young individuals with healthy lifestyles still develop colorectal cancer, suggesting other factors are at play.

Key Insights

• Colorectal cancer rates have increased among people under 50, with one in five diagnosed being younger than 55 in the US, up from one in ten a few decades ago.
• Young people's colorectal cancer is not more aggressive but is often diagnosed at later stages, with over half of early-onset cases caught at stage three or four.
• Specific mutation patterns linked to bacteria releasing the toxin Colibactin, found in certain E. coli strains, may contribute to higher cancer rates in those under 50.
• Ultra-processed foods and red or processed meats have been associated with higher colorectal cancer risks, yet lifestyle alone doesn't fully explain the increased incidence.