Early-onset colorectal cancer in Sweden: increase in distal tumors but a shift in right-sided incidence, 2020–2024

Abstract

Early-onset colorectal cancer (EOCRC; age <50 years) has increased in high-income countries. We updated a nationwide Swedish cohort study with data from 2020–2024 to compare recent trends with those reported during 1993–2019. Using the National Cancer Register, we identified all incident EOCRC at ages 20–49 years. Temporal trends in age-standardized incidence were assessed using segmented Poisson regression with a breakpoint at 2020 to estimate annual percentage changes (APCs). A total of 1,616 EOCRC cases were diagnosed during 2020–2024. APCs for left-sided colon and rectal cancers were consistent with continued increases in incidence. In contrast, right-sided colon cancer showed a significant change in trend (P = 0.01), with a non-significant decline during 2020–2024 (APC −3.48, 95% CI − 7.88–1.14). These findings indicate that the continued rise in EOCRC is primarily driven by distal tumors, i.e., left-sided colon and rectal cancers. Continued surveillance is needed to clarify long-term patterns and underlying drivers.