BACKGROUND: The incidence of early-onset bowel cancer, defined as a diagnosis before age 50 years, is rising globally. However, the burden of early-onset bowel cancer among Indigenous populations remains unclear because of the absence of Indigenous data in global cancer statistics. This Article aimed to compare the global incidence, mortality, and survival rates of early-onset bowel cancer among Indigenous versus non-Indigenous populations. METHODS: For this systematic review and meta-analysis (PROSPERO CRD42024598809), PubMed, Scopus, CINAHL, and Embase were searched from inception to Nov 20, 2025. Observational studies reporting incidence, mortality, or survival among Indigenous populations were included. Studies without data for those younger than 50 years were excluded. Two reviewers conducted the quality appraisal and data extraction. The early-onset bowel cancer proportion among all-age bowel cancer cases was derived from data for Indigenous and non-Indigenous populations, then pooled within each group using random-effects meta-analysis. FINDINGS: 56 studies (12 737 cases of early-onset bowel cancer among Indigenous peoples and 663 342 among non-Indigenous peoples) were included in the systematic review, with 28 in the meta-analysis. The pooled proportion of early-onset bowel cancer was 16% (95% CI 14-18) in Indigenous populations and 9% (7-10) in non-Indigenous populations. These estimates could be confounded by population age structures and should be interpreted cautiously. Among 19 studies reporting age-standardised incidence, most found higher rates among Indigenous populations, although results were inconsistent across settings. Four of five studies reported a higher annual percentage change in early-onset bowel cancer incidence, and all six studies reporting survival rates showed poorer outcomes for Indigenous populations. INTERPRETATION: These findings are highly relevant for clinicians, researchers, and policymakers, emphasising a persistent inequity in early-onset bowel cancer burden for Indigenous populations that necessitates urgent, tailored, and equity-driven responses. Age-structure differences limit the pooled estimate interpretability. Improved standardised reporting is needed, particularly in under-represented regions such as Africa, Asia, and Latin America, to better inform global cancer control strategies. FUNDING: The National Health and Medical Research Council.
Baykeda et al. (Fri,) studied this question.