Yes, and it seems like it's really a 7.5x risk increase. Still pretty spectacular, though!
I really wonder what could cause that. Randomly throwing out possible causes: 1) blood redirected away from gut, 2) overuse of NSAIDS, 3) ultraprocessed foods (gels etc), 4) strange microbiome issues (gels + stress in gut from extreme exertion = altered gut flora?)
The study that found the result is DOI: 10.1200/JCO.2025.43.16_suppl.3619
We're not really optimized for this sort of extreme endurance and long-term development of serious pathologies is unsuprising.
This pattern is quite old. Already ancient Egyptians suffered from civilizational diseases much more than hunter-gatherers, especially the richer ones (heart attacks, gout, cancer).
Colorectal cancer is not the same thing as high blood pressure, or type 2 diabetes, or any other cancer that isn't colorectal cancer. Diseases are not a monolith and you cannot assume low risk of some diseases means low risk of others. That is wild guesswork passed off as logic, like measuring the shadow your testicles cast on the wall and announcing it is 24.1 degrees Celsius. Ultra-marathon runners also have low risk of type 2 diabetes!
Do you have specific evidence that modern hunter-gatherers have low rates of colorectal cancer that cannot be explained by survivorship bias, screening, genetic differences, and all other confounders, and that they are representative of historical hunter-gatherers? No? Then you cannot confidently conclude that hunter-gatherers didn't experience elevated rates of CRC.
Diseases are not a monolith, but they do tend to arise and fall in some specific clusters, and that is not "logic", good or bad (too many computer-minded people drag logic into the chaos that is biology), but rather a long-time empirical observation, albeit with some exceptions.