Colorectal malignancy rates, particularly for rectal cancer, are accelerating among Americans younger than 45, and unless something changes, the rate is predicted to continue increasing out to the year 2035, new evidence has suggested.
In 2025, colorectal cancer was the second leading cause of cancer death in the US, responsible for an estimated 8.6% of total cancer mortality, according to American Cancer Society figures. Among people younger than 50, however, it is now the leading cause of cancer-related deaths, which is “a drastic shift from prior generations,” said Mythili Menon Pathiyil, MBBS, a gastroenterology fellow at SUNY Upstate Medical University in Syracuse, New York.
“And it’s concerning because these individuals are not routinely screened,” said Pathiyil, lead author of a study previewed during a Digestive Disease Week (DDW) 2026 press briefing.
Pathiyil and colleagues analyzed 24 years of mortality records from CDC’s WONDER database. They focused on changes in mortality trends for colorectal cancer among US adults aged 20-44 from 1999 to 2023.
Rectal Cancer Driving Mortality Increases
The researchers found that death rates for colorectal cancer among adults 20-44 years old rose continually from 1999 to 2023.
“Our analysis found a striking and consistent pattern. Death rates for colorectal cancers steadily increased overall, with rectal cancer mortality rising two to three times faster than colon cancer mortality,” Pathiyil said. This trend was seen across demographic groups “and especially among adults between the ages of 35 and 44.”
Colon cancer deaths rose 0.74% among people aged 35-39 and by 0.56% among those aged 40-44. The annual average percent change in colon cancer mortality was higher among men than women, 0.43% vs 0.24%.
Rectal cancer mortality rose 1.77% among those aged 35-39 and by 1.71% among those aged 40-44. Men and women experienced similar increases in death rates, 1.83% for men vs 1.84% for women.
“This markedly increasing incidence in colorectal cancer in younger individuals is really one of the most important, hottest topics now in GI and actually oncology as well, so it's very good to have an update,” said moderator Loren Laine, MD, gastroenterologist and a professor of medicine at the Yale School of Medicine, New Haven, Connecticut, during the briefing. “Looking at the incidence over a long period of time was very important and the projection of continued increase is, of course, quite concerning.”
'Predicting Future Numbers'
In addition to analyzing past numbers, researchers projected trends through 2035 using ARIMA, a machine learning model. Assuming current patterns do not change, the model shows rectal cancer deaths will continue escalating over the next decade in younger adults, while colon cancer deaths are expected to increase more slowly.
Rectal cancer deaths in men are anticipated to grow to 459 per year in 2035 (90 more than 2023), as well as reaching 304 among women (60 more projected deaths than in 2023).
Colon cancer deaths among men are predicted to reach 834 per year in 2035 (42 more than in 2023). Annual deaths among women are expected to increase to 667 per year (19 more than 2023).
Laine noted that the absolute numbers are relatively small compared to cases of colon and rectal cancer among older adults.
Pathiyil agreed but said the important finding is the increasing trend in deaths, both past and predicted, among this otherwise young and healthy population.
A Delay in Diagnosis
Contributors to higher death rates among otherwise healthy adults include a lower suspicion for colorectal cancer in this age range, symptom misattribution, and a related delay in diagnosis.
Evidence shows that young adults with rectal cancer wait an average of 7 months from first symptoms before treatment compared to about 1 month in patients 50 and older. “This delay can be the difference between an early and a late stage diagnosis,” Pathiyil said.
In some cases, when a younger patient presents with rectal bleeding, providers will misattribute it to hemorrhoids and not order further workup, she explained. She cited a retrospective study looking at 3422 patients aged 18-40 who had a colonoscopy because of rectal bleeding. Those researchers found 48% had hemorrhoids.
“We need to revisit screening strategies, especially in high-risk subgroups, and we need to change how clinicians think about symptoms in younger patients,” Pathiyil said. Rectal bleeding in people younger than 45 years old should not be automatically attributed to hemorrhoids, nor should changes in bowel habits be automatically attributed to stress, she added.
It seemed unlikely to Pathiyil or Laine that official guidelines would drop the minimum age for colonoscopy screening below 45 years in the near future. Instead, more targeted screening for those who are symptomatic or otherwise at higher risk is warranted.
Pathiyil also suggested flexible sigmoidoscopy could play a role in screening. “It looks into the left side of the colon, where for most young individuals the prevalence of cancer is higher.”
Hispanic adults had the fastest growing mortality rates of any demographic group for both colon and rectal cancer, with rectal cancer mortality projected to rise at more than 2% per year. “The disparities were pretty clear,” Pathiyil said.
For this reason, “equity has to be a part of this conversation,” she added. “The disproportionate rise among Hispanic adults demands targeted outreach, culturally appropriate education, and accessible screening programs.”
White adults also experienced ongoing increases across both colorectal and rectal cancer. In contrast, colon cancer mortality actually declined among Black and Asian/Pacific Islanders. “While that was encouraging, both groups still are seeing rising rectal cancer deaths,” Pathiyil said.
In addition, rectal cancer death rates grew across each region of the US among people aged 20-44. She added, “These findings reinforce that rectal cancer is striking young Americans earlier and killing faster, and it is doing so at an accelerating pace.”
“Additionally, this is just an early signal, not the peak. Based on our projections, we see that the trend is not really plateauing. It seems to be accelerating, especially for rectal cancer,” Pathiyil said. If nothing changes in terms of awareness, symptom recognition or screening, she added, “this is just likely the front edge of a much larger wave.”
Pathiyil will present “A Growing Crisis: Two Decades of Rising Early-Onset Colorectal Cancer Mortality and Projected Trends Through 2035 in U.S. Adults <45 years” (Abstract Sa1371) at 12:30 PM CDT on May 2 at DDW 2026. The study was independently supported. Pathiyil and Laine reported no relevant financial relationships.
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