A new American Cancer Society (ACS) report highlights a troubling rise in colorectal cancer among younger adults. Published in CA: A Cancer Journal for Clinicians, the analysis found that while overall colorectal cancer incidence in the U.S. fell by nearly 1% per year from 2013 to 2022, that drop was driven by a 2.5% annual decline in people 65 and older. Meanwhile, cases rose 0.4% per year in ages 50–64 and climbed about 3% per year in adults 20–49.
The ACS projects that 45% of colorectal cancer diagnoses this year will be in people younger than 65—up from 27% in 1995—and predicts that roughly one-third of the roughly 55,000 expected colorectal cancer deaths will occur in individuals under 65. Rectal cancers now make up about 32% of colorectal cases, compared with 27% two decades ago.
Nikita Wagle, PhD, a principal scientist in cancer surveillance research at the ACS and coauthor of the report, said the trend is a wake-up call for clinicians and researchers. “Despite decades of progress, colorectal cancer death rates are increasing among younger men and women,” she said, urging intensified research to uncover causes and prevent deaths.
Why younger people?
Colorectal cancer is the third most commonly diagnosed cancer in both men and women in the U.S. and the second-leading cause of cancer death overall. The ACS estimates about 158,850 new colorectal cancer cases in the U.S. in 2026 (about 108,860 colon tumors and 49,990 rectal tumors). The organization says more than half of cases are attributable to modifiable risk factors, including overweight and obesity, physical inactivity, diets high in red and processed meat and low in fiber, heavy alcohol use, and tobacco.
Oncologists who treat colorectal cancer say the rising numbers mirror what they see in practice. Nilesh Vora, MD, medical oncologist and medical director at MemorialCare Todd Cancer Institute, and Geoffrey Buckle, MD, gastrointestinal medical oncologist at UCSF, said the increase in early-onset disease is real and concerning.
Experts point to multiple possible drivers:
– Unhealthy diets and sedentary lifestyles: greater consumption of ultra-processed foods, sugar, and red meat and less fiber and physical activity may raise risk.
– Environmental exposures: younger generations have had greater cumulative exposure to newer factors like microplastics, which some studies suggest may accumulate in the body.
– Microbial influences: research has proposed that toxins from certain gut bacteria, such as some strains of E. coli, can damage DNA and promote tumor development.
– Other environmental toxins and changes in early-life exposures that differ across generations.
Wagle noted that newer exposures since the late 20th century—ultra-processed foods and microplastics among them—may contribute to higher cancer risk in people who have had greater lifetime exposure. Vora agreed that environmental factors deserve further study.
High-profile cases and rising awareness
Public deaths from early-onset colorectal cancer—such as actor Chadwick Boseman at 43 and actor James Van Der Beek at 48—helped bring attention to the issue. Research presented at Digestive Disease Week reported that colorectal cancer cases among U.S. teens more than tripled from 1999 to 2020. Studies have also linked rectal bleeding with early-onset colorectal cancer in adults under 50.
Screening and prevention
Because of rising early-onset cases, the U.S. Preventive Services Task Force now recommends colorectal cancer screening begin at age 45 for most adults. Screening options include colonoscopy and at-home stool-based tests; clinicians stress that screening is the most effective tool for prevention and early detection.
Young adults should be alert to warning signs such as rectal bleeding, persistent changes in bowel habits, abdominal pain or cramping, unexplained weight loss, and signs of anemia (fatigue, weakness). Buckle said many people in their late 40s and 50s are now more aware of colorectal cancer risk, but awareness is lower in adults under 45.
What to do now
– Get screened on schedule, beginning at age 45 unless a clinician advises otherwise.
– Know your family history—discuss earlier or more frequent screening if colorectal cancer runs in your family.
– Adopt preventive habits: maintain a healthy weight, exercise regularly, avoid smoking, limit alcohol, eat plenty of fruits, vegetables and fiber, and reduce ultra-processed foods, sugar, and red meat.
– Seek medical care promptly for symptoms like rectal bleeding or significant bowel changes.
Clinicians and researchers emphasize vigilance: improve awareness, expand research into causes—including environmental and microbial factors—and ensure timely screening and care to reverse the rise in early-onset colorectal cancer.
