A new study showing a concerning spike in colon cancer cases among Americans younger than 50 is leading some experts to question what might be causing the marked change.

While cancer genetics haven't changed much in recent times, some doctors believe a societal increase in processed food diets and sedentary lifestyles may be at least partially to blame, Fox News Atlanta-based correspondent Jonathan Serrie reported.

Serrie told "America Reports" on Friday the story hits close to home, as his younger brother Keir died at age 48 from colon cancer.

"Keir was my best friend growing up, and in 2017 he started not feeling well. Doctors spent about a month trying to find out what was wrong. Finally, they ordered a colonoscopy and they found a large mass in his colon that they think had been growing there for about five years -- It had already spread," Serrie said.

DISTANT-STAGE COLON CANCER SHOWING UP MORE IN YOUNGER ADULTS, STUDY SAYS

Dark blue ribbon for colon - colorectal cancer awareness on medical doctor's hand support

Dark blue ribbon for colon - colorectal cancer awareness on medical doctor's hand support (iStock)

"He had great doctors. They did what they could to save him. But several months later, before the end of the year, he had passed away."

Serrie reported doctors did not recommend routine colonoscopies for people from families without colon cancer histories until the standardized age of 50. Keir was therefore not due for his first screening until what would have been two years after his passing.

"Some doctors are already calling for it," Serrie said. "And so [it's] definitely a story I'm going to be paying close attention to because I miss my brother terribly."

Anchor John Roberts reported some medical experts are recommending the screening age be dropped to 45, as one study showed a 90% increase in colon cancer among people aged 20 to 34, while those 35-49 saw an increase of 28%.

"This is a story that I hear far too common. You have a young individual who has been diagnosed with a cancer that is a late stage cancer, more difficult to treat. And about 43% of all colorectal cancers are being diagnosed in those 45 to 49 years of age, which is why the American Cancer Society has recently decreased that age of onset for screening from 50 down to 45," added Dr. Nicole Saphier, a radiologist at Memorial Sloan Kettering Hospital in Monmouth County, N.J. and a Fox News contributor.

REDUCE COLON CANCER RISK WITH REGULAR SCREENINGS

"About 15 to 30% of all colorectal cancers in young adults have some sort of genetic mutation. But we also have an increase in diet, dietary-associated cancers, and we've linked sedentary lifestyles, antibiotic use and even some fungal infections to this rise in colon cancers," said Saphier.

She said screening patients under 45 for colon cancer doesn't yet make sense, but that those younger patients could consider fecal occult blood tests that examine stool samples, to see if there is a proclivity to develop cancer.

"If you have a young patient coming in with some symptoms, colon cancer needs to be on your radar," she said.

Saphier reiterated how a bad diet, and lack of exercise and activity can attribute to higher risk, citing an Ohio study.

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"A new study out of the Cleveland Clinic is looking at the metabolites in the colon and in the body from how bodies break down certain foods. And all of this plays a part, but it is a rise in obesity, sedentary lifestyles and also our diets that, in my opinion, are linking the rise in colorectal cancers in younger adults," she said.

"And unfortunately, we have to get to a healthier place as a society. It's not just colorectal cancer. We're seeing many other cancers as well as other conditions secondary to poor lifestyle choices."