Trends and projected burden of early-onset gastrointestinal malignancies in the United States: a population-based...

Early-onset colorectal cancer (CRC) has become a serious public health concern in recent years. This study aimed to contribute to the growing body of evidence on the rise in early-onset gastrointestinal (GI) cancers and anatomical subsites of early-onset CRC, and to explore racial and sex disparities in these trends.

We analyzed data from the National Program of Cancer Registries-Surveillance, Epidemiology, and End Results database (2001-2021) for people aged 20 to 49 years with GI cancers. The dataset covers cancer incidence rates for approximately 98% of the US population. Joinpoint regression was used to calculate average annual percent change, and polynomial regression was applied to forecast rates from 2021 to 2031.

A total of 527 411 cases were analyzed. Colorectal cancer made up the highest number of cases (n = 313 513), followed by pancreatic cancer (n = 50 448). Intrahepatic bile duct cancer saw the highest average annual percent change (+6.24%, 95% CI = 5.20 to 7.45), followed by small intestine cancer (+3.19%, 95% CI = 2.69 to 3.72), early-onset CRC (+1.65%, 95% CI = 1.45 to 1.92), pancreatic cancer (+1.52, 95% CI = 1.37 to 1.66), and stomach cancer (+1.20, 95% CI = 0.89 to 1.53). Among CRC cases, rectal cancer had the highest average annual percent change (+2.09%). Women (+1.81%) experienced a disproportionate rise to men (+0.83%). Our projection suggests a demographic shift, with women surpassing men in the overall age-adjusted rate of early-onset GI cancers.

The study highlights that early-onset CRC is not an isolated phenomenon but part of a broader epidemiologic shift across GI malignancies. The parallel rise in cancers of other sites suggests shared upstream risk factors or exposures and supports investigations into potential environmental, dietary, microbiome, and hormone risk factors.