Abstract
BACKGROUND: Geographic disparities exist for colorectal cancer (CRC) in the United States (US). Area-level socioeconomic status (SES) may influence CRC outcomes through multiple pathways, including by influencing screening adherence. We completed a systematic review and meta-analysis of area-level SES and CRC incidence, mortality, and screening among US individuals. METHODS: Original research articles were identified from biomedical databases. Eligible studies reported associations between area-level SES at the census block or tract level with CRC incidence, mortality, or screening in a US-based sample. A fixed-effects meta-analysis was performed to estimate summary hazard ratios (HRs) or odds ratios (ORs) with 95 % confidence intervals (CIs) for the associations between area-level SES and CRC outcomes. RESULTS: Twenty-six studies were included in the systematic review. Living in an area in the lowest SES quantile was associated with higher CRC risk (HR 1.37 [CI: 1.34-1.41]). Associations were similar in race-stratified analyses for White (HR 1.43 [CI: 1.39-1.47]), Black (HR 1.18 [CI: 0.96-1.44]), and Asian/Pacific Islander racial status (HR 1.18, [CI: 1.08-1.28]). For individuals with CRC, lower area-level SES was associated with risk for overall mortality (HR 1.26 [CI: 1.23-1.29]) and CRC-specific mortality (HR 1.24 [CI: 1.22-1.26]). Lower area-level SES was associated with lower completion of recommended screening for CRC (OR 0.76 [CI: 0.74-0.79]). CONCLUSIONS: Individuals who reside in areas with less socioeconomic resources have elevated risk for CRC incidence and mortality. Healthcare policies and interventions focused on low resource settings may increase uptake of preventative screening leading to a reduction in geographic disparities for CRC.