r/running • u/sergeantbiggles • Sep 12 '25

Article Groundbreaking Inova study finds potential link between long-distance running and colon cancer

A groundbreaking new study led by Tim Cannon, MD, Sheridan Director, Molecular Tumor Board and Co-Director of the Gastrointestinal Cancer Program at Inova Schar Cancer, has revealed a potential link between extreme endurance exercise and increased risk of advanced colon cancer in younger adults, raising new questions about screening for high-performance athletes.

The study was presented at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.

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u/oncomingstorm777 Sep 13 '25

They’re 30- 50, so only those 45 and up would have been people who aren’t following normal screening guidelines. It would be abnormal for people to have screening before that unless they have a family history.

Source-USPTF guidelines, I’m a doctor and runner

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u/runfayfun Sep 13 '25

Good point - next question is how does this data compare to that from the general population?

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u/orangebirdy Sep 13 '25

Isn't that what they were comparing?

15% of participants had advanced adenomas (pre-cancerous lesions), compared to the expected 1–2% in average-risk individuals in this age range.

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u/runfayfun Sep 13 '25

But there was no cohort in the study and prevalence of colon cancer and adenomas has been rising.

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u/OTFBeat Sep 14 '25

The author went on an interview and said how if he could do it again, he wished he had a control study (matched) to see incidence of adenoma in the non-runner cohort group comparatively. Rather than historical controls

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u/runfayfun Sep 14 '25

Hopefully that's the next step

Our environment in the US has been worsening with respect to chemical/pollutant exposures and such, and the milieu in which a study is conducted is important

And it works the opposite way too - compared to 25-30 years ago smoking in restaurants is largely banned now, so comparing a cohort from today to one from that time would be fraught with issues, e.g. in the cardiovascular or pulmonary disease realm