Denmark-wide cohort study of risk of recurrence in early-onset versus late-onset nonmetastatic colorectal cancer

The incidence of early-onset colorectal cancer (EOCRC; diagnosed before age 50 years) is increasing. EOCRC often presents at advanced stage, suggesting a more aggressive cancer course compared to late-onset colorectal cancer (LOCRC). A Denmark-wide retrospective study investigated risk of recurrence after treatment for nonmetastatic EOCRC compared with nonmetastatic LOCRC between 2004 and 2019. Among 25,729 CRC patients, 1441 (5.6%) had EOCRC. Five-year recurrence rate was 29% (95% CI 26-31) in EOCRC versus 21% (21-22) in LOCRC. The higher recurrence rate for EOCRC versus LOCRC persisted in stage-stratified analysis, indicating that the increased risk is not explained by delayed diagnosis. The excess risk diminished from 2004 to 2019: the aHR for recurrence (EOCRC versus LOCRC) was 1.37 (95% CI 1.17-1.60) in 2004-2008, 1.28 (1.08-1.53) in 2009-2013, and 1.07 (0.88-1.31) in 2014-2019. The authors conclude that EOCRC compared with LOCRC was associated with higher incidence of recurrence. The difference decreased during the study period.