Gastrointestinal cancers, including colorectal, stomach, and pancreatic cancer, have seen a sharp increase among younger adults, though the reasons aren’t entirely clear. A recent review in JAMA highlights that these cancers are the fastest-growing type diagnosed in those under 50 in the U.S. This comprehensive analysis looked at major cancer databases and reviewed 115 studies on gastrointestinal cancers published from January 2014 to March 2025.
The authors emphasize the importance of adhering to colon cancer screening guidelines, recommending that people at average risk begin screenings—like colonoscopies or stool tests—by age 45. Since routine screenings for pancreatic, stomach, and esophageal cancers aren’t common in the U.S., the researchers suggest finding new methods to increase screening for these cancers. Dr. Kimmie Ng, co-author of the review and director of the Young-Onset Colorectal Cancer Center at Dana-Farber Cancer Institute, stated that enhancing screening and early detection could be crucial.
Colorectal cancer stands out as the most frequent type of early-onset gastrointestinal cancer, with nearly 185,000 cases globally in 2022 and around 21,000 in the U.S. alone. The American Cancer Society reports a 2% annual increase in diagnoses for those under 50 since 2011. Dr. John Marshall, a chief medical consultant at the Colorectal Cancer Alliance, noted a significant rise in colon cancer cases among individuals in their 20s, 30s, and 40s—something that was quite rare in the past. A notable case is actor Chadwick Boseman, who was diagnosed with colon cancer in 2016 and passed away at 43.
The review also points out that early cases of pancreatic, stomach, and esophageal cancers are rising. Previous studies have indicated that diagnoses are more prevalent among Black and Hispanic populations. Notably, pancreatic cancer is one of the most lethal, with only 13% of patients surviving five years post-diagnosis.
Since colorectal cancer is the most common, there’s a clearer understanding of its early-onset cases compared to others. Dr. Scott Kopetz, a professor of gastrointestinal oncology, explained that multiple factors likely contribute to this increase. He stated that rather than one single cause, there may be various influences.
Ng’s review suggests that lifestyle factors—like obesity, physical inactivity, unhealthy diets, smoking, and alcohol consumption—are closely linked to most gastrointestinal cancers in those under 50. One study indicated that adolescent women consuming more sugary drinks had a higher chance of early-onset colorectal cancer. “It’s really what people were doing or exposed to when they were young that likely contributes to cancer risk later on,” Ng remarked.
Health Secretary Robert F. Kennedy Jr. has voiced concerns regarding sugary beverages and health issues, including cancer. Meanwhile, President Donald Trump announced that Coca-Cola would use cane sugar instead of corn syrup in the U.S., though the company did not confirm this change.
Marshall speculated that the increased cases of early-onset colorectal cancer might relate to alterations in gut microbiomes—the bacteria residing in our gastrointestinal systems. Factors like diet, antibiotic consumption, microplastics, and environmental chemicals could all impact gut bacteria, yet researchers still lack a clear understanding of what a healthy microbiome looks like and its health implications. The field is actively being studied.
Ng’s review also highlighted that 15% to 30% of early-onset gastrointestinal cancer patients carry hereditary genetic mutations that predispose them to cancer at a young age. Thus, she advocates for genetic testing in all young patients diagnosed under 50.
Despite improvements in treatment and screening, younger patients often experience worse outcomes. Ng noted that they tend to receive more aggressive treatments, yet still face challenges. One complicating factor may be that primary care providers might dismiss symptoms like abdominal pain or heartburn in younger patients, leading to delays. Dr. Howard Hochster suggested that these patients might be diagnosed at more advanced stages because such nonspecific complaints aren’t typically associated with colorectal or gastrointestinal cancers at a young age.
However, even when accounting for the stage at diagnosis, younger patients still appear to have poorer survival rates. Ng expressed curiosity about whether cancers in younger individuals might possess distinct biological characteristics that make them more aggressive or less responsive to treatments.
