A comparison of overall survival from early-onset and late-onset colorectal cancer stratified by TNM stage: a systematic review.

BACKGROUND

There is conflicting evidence whether survival outcomes are better for early-onset colorectal cancer (EOCRC) or late-onset (LO) CRC. This review aimed to determine overall survival (OS) differences between EOCRC and LOCRC stratified by TNM stage.

METHODS

EMBASE, Ovid MEDLINE and Cochrane Library were searched using approved search terms for CRC, survival outcomes and early onset disease. Studies which compared OS between early- and late-onset CRC, irrespective of age cut-off, stratified by TNM stage, were included. The Methodological Index for Non-randomized Studies was used to assess methodology and risk of bias. Data on 5-year OS, TNM stage, histopathological features, cohort study type and use of confounder-adjusted analyses were extracted and descriptive statistics presented as study heterogeneity prevented meta-analysis.

RESULTS

A total of 21 studies described the OS of 332451 patients: 29199 EOCRC and 303252 LOCRC. Studies mostly found favourable outcomes in EOCRC, but where multiple age groups were compared, worse survival was frequently observed in the very youngest patients, especially in stage II and III disease.

CONCLUSION

EOCRC may have worse OS in age and stage subgroups. This warrants further study using large, granular datasets with detailed information on staging and histopathological features. PROSPERO ID CRD42024563472. An earlier version of this review was presented at the Association of Coloproctologists of Great Britain and Ireland Annual General Meeting in July 2023 and the Tripartite Colorectal Meeting 2025.