Retrospective study of association between early-onset colorectal cancer outcomes and established prognostic factors

Previous studies suggest that early-onset colorectal cancer (eoCRC; < 50 years) have poorer outcomes than older patients. Whether this reflects distinct tumor biology or differences in stage at diagnosis and treatment patterns is not clear. A nationwide population-based study in The Netherlands compared clinicopathologic features, treatment, and survival of eoCRC with average-onset (ao; 50-69 years) and older onset (oo)CRC. Among 80,551 CRC patients from 2016 through 2022, 5% were eoCRC, 43% were aoCRC, and 52% were ooCRC. EoCRC patients more often presented with advanced disease (stage III or IV) and left-sided colon or rectal cancer. Five-year relative survival (RS) rates for eoCRC, aoCRC, and ooCRC patients was 70%, 77%, and 69%, respectively (crude excess hazard ratio for eoCRC versus aoCRC 1.32; 95% CI 1.24-1.41). Among patients with mismatch repair proficient stage IV disease, eoCRC was associated with better RS than aoCRC (EHR 0.87; 95% CI 0.80-0.94), concurrent with more intensive first-line systemic therapy. After matching for disease characteristics and treatment, RS was similar between eoCRC and aoCRC, whereas ooCRC patients retained worse survival. The authors conclude that the poorer crude survival observed in eoCRC is largely associated with more advanced disease at diagnosis, rather than evidence of distinct tumor biology.