Colon Cancer linked to marathons, half-marathons, long-distance running? Read shocking details

A research paper, which is yet to be peer-reviewed, has revealed shocking details regarding marathon running and cancer. The three patients should have been portraits of health. They were young, lean and physically active. Unusually active, in fact: Two regularly ran 100-mile ultramarathons, and one had completed 13 half-marathons in a single year. By the time they came to see Dr. Timothy Cannon, all three had advanced colon cancer. He was mystified; the oldest of them was 40, and none had any known risk factors. The doctor couldn't help wondering if extreme running might have played a role, as per a report.

So Doctor Cannon, an oncologist with Inova Schar Cancer in Fairfax, Virginia, launched a study, recruiting 100 marathon and ultramarathon runners ages 35 to 50 to undergo a colonoscopy. The results were staggering. Almost half the participants had polyps, and 15 per cent had advanced adenomas likely to become cancerous, NYT News Service reported.

The rate of advanced adenomas was much higher than that seen among adults in their late 40s in the general population, which ranges from 4.5 per cent to 6 per cent, according to recent studies.


The research was presented at an American Society of Clinical Oncology conference but has not yet been published in a medical journal.

The new study comes amid heightened concerns about a rise in colon and rectal cancer rates among adults younger than 50, a population that historically has had a low risk of cancer.

Older adults still make up the vast majority of those diagnosed with colon cancer. But the increase in so-called early-onset colorectal cancer led in 2021 to a change in screening recommendations. The age for a first colonoscopy was lowered to 45, from 50, for those at average risk.

The rise in colorectal cancer among younger adults has mystified experts. Physical inactivity and rising rates of obesity are frequently blamed -- one reason his very fit, lean patients struck Cannon as worth investigating.

"You never want to give people an excuse not to exercise, because by and large, we have bigger problems from people not exercising enough," Cannon said. "But I do believe, after what I've seen from my patients and what we've found here, that extreme exercise may increase the risk of this cancer," Cannon said.

Several doctors interviewed for this story went out of their way to emphasize that most of the young colon cancer patients they see are not marathon runners. But experts said Cannon's work was provocative and called for more research.

FAQs

Q1. Who has conducted the study?
A1. The research was presented at an American Society of Clinical Oncology conference but has not yet been published in a medical journal.

Q2. What do we know about recent development about colon and rectal cancer?
A2. The new study comes amid heightened concerns about a rise in colon and rectal cancer rates among adults younger than 50, a population that historically has had a low risk of cancer.