The proportion of Americans younger than 50 years getting screened for colorectal cancer has increased in the past 5 years since guidelines lowered the minimum age to 45 years. However, not all gains have been equitable, with screening rates varying by race/ethnicity, income, and age in two recent studies that examined the success of the recommendations for expanding screening.
At the same time, researchers in a third study evaluated rates of polyp detection in younger vs older people to assess what colonoscopy is revealing in these populations.
The three studies were presented this spring at Digestive Disease Week (DDW) 2026 in Chicago.
A Growing Problem
Colorectal cancer now leads cancer deaths among adults younger than 50 years, and the incidence has almost doubled since the 1990s.
“It’s not surprising to [gastroenterologists] that colorectal cancer incidence rates are increasing dramatically in young adults less than 50 years of age, also known as early onset colorectal cancer,” said Jeffrey Lee, MD, MPH, gastroenterologist at Kaiser Permanente San Francisco Medical Center, San Francisco, and a research scientist with the Kaiser Permanente Northern California Division of Research, Pleasanton, California.
The increasing incidence of colorectal cancer among younger people is not unique to the US; it’s a global phenomenon, Lee added. “And even more alarming is that colorectal cancer is now the leading cause of cancer death among young adults.”
Colorectal cancer has steadily increased by 1%-2% per year in this age group, Jason Chen, MD, a second-year internal medicine resident at the University of Texas Health Science Center in San Antonio, said at DDW 2026. He added that mortality also increased by 1% each year in those younger than 50.
Off to a Slow Start
In 2021 when the guidelines changed, 34.5% of newly eligible 45- to 49-year-olds were up-to-date on screening. This was well below the national target of 80%, said Jesus Mario Luevano, Jr, MD, assistant professor of gastroenterology at Morehouse School of Medicine in Atlanta.
In a study of 53,127 people aged 45-49 years, Luevano and his colleagues found the screening rate increased slightly to 35.1% in 2022. “This was followed by a significant increase to 49.8% in 2024, which of course was still below our goal,” he said.
Limitations of the study included self-reported data, a cross-sectional design, and the exclusion of the year 2023 for data quality reasons.
“The bottom line is that population-level improvement is real. I’ve seen it. We are making an impact, but the benefit has not been evenly distributed amongst all the populations of the United States,” Luevano said.
Uneven Progress
People with household incomes > $200,000, non-Hispanic individuals, and women were screened more often than other groups. For example, people with more than $200,000 in household income saw the largest screening gains (odds ratio [OR], 1.45) compared to income groups < $50,000 and < $25,000.
Screening among Hispanic individuals was initially low but accelerated by 2024 (OR, 1.18) compared to non-Hispanic individuals. Women continued to be screened more often than men (OR, 1.22).
Luevano also looked at BMI. “We actually found that BMI was slightly protective. Higher BMIs actually tend to be screened more often than the very low BMIs,” he said.
Alcohol use was protective, he added, whereas tobacco use was not.
Screening was also low among Kaiser Permanente Northern California members aged 45-49 before 2022. Fewer than 5% were up-to-date on recommended screening before 2022, said Lee, who studied about 580,000 members in this age group between 2018 and 2025. Being up-to-date was defined as a colonoscopy within 10 years, sigmoidoscopy within 5 years, multi-target DNA testing within 3 years, or FIT assessment in the year of assessment.
To address the expanded guidelines, Kaiser Permanente sent members a letter when they turned 45 and then mailed them a FIT kit 4 weeks later if they did not respond. As a result, screening jumped to 50% by the year 2025, “with nearly all the increase due to the FIT screen,” Lee said.
Men and women experienced gains at almost the same rate, 48% and 52%, respectively.
The organization sent out about 9546 FIT kits in 2020 and approximately 187,755 in 2025. During this time, the positivity rate remained steady at about 3%-4%.
Limitations of the research include a population that is not representative of most US health systems and inclusion of diagnostic colonoscopies in the screening rates. Also, the researchers did not analyze colonoscopies after a positive FIT result separately.
Polyp Detection Rate Varied
In a study of 5418 people aged 18-44 years who had a diagnostic colonoscopy in 2020-2025 at UT Health Science Center, Chen revealed that 14.5% had precancerous polyps. This detection rate included adenomas and sessile serrated lesions.
The detection rate rose with increasing age, from 7.7% in those in the 18- to 24-year-old group, up to 18.1% in those in the 35- to 44-year-old group. Men had higher detection rates, 17.1% vs 12.6% among women, “suggesting that sex-related risk differences emerge early,” Chen said.
Smokers were more likely to have polyps (OR, 2.12). Obesity was also associated with higher odds of finding polyps (OR, 1.59).
This study also found differences in polyp rates by race and ethnicity. Hispanic adults had about the same detection rate as non-Hispanic individuals. Non-Hispanic Black individuals and Asians had the lowest rates in the study.
An unexpected finding was that diabetes was inversely associated with detection of polyps (OR, 0.66). The reason for this result remains unknown, Chen said.
Chen noted the study population was about 70% Hispanic, which could limit generalizability of the findings. Other limitations included a retrospective, single-center design. The study only included diagnostic colonoscopies, so the results may not reflect a true screening population.
The Take-Home Messages
Taken together, these three studies confirm that colorectal cancer incidence is rising among younger adults; that screening rates have increased since the 2021 guideline change, although unevenly; and that large-scale outreach like the Kaiser Permanente initiative can make a difference.
The research suggests targeting more screening toward Hispanic populations, which are experiencing the fastest rising incidence of early onset colorectal cancer. In addition, more efforts are needed to screen lower income populations and younger men, who have more polyps but lower screening rates.
Lee also suggested tailoring the current phone call and mailed letter outreach on screening to a younger audience. Texting, AI, and social media messaging might engage people younger than 50 years more effectively, he added.
The studies were independently supported. Luevano and Chen reported having no relevant financial relationships. Lee reported serving as the principal investigator for a Patient-Centered Outcomes Research Institute-funded randomized trial comparing colonoscopy and FIT for surveillance in older adults with prior low-risk polyps.
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