Higher levels of neighborhood deprivation and risk for incident colorectal cancer and mortality outcomes: A systematic review and meta-analysis.

Abstract

131 Background: Significant geographic and racial disparities exist for colorectal cancer (CRC) incidence and mortality in the United States (US), which may be caused by neighborhood-level deprivation and limited access to preventative cancer screening. We completed the first systematic review and meta-analysis of neighborhood-level deprivation in relation to CRC incidence, mortality, and screening among individuals from the US. Methods: A systematic literature review was completed to identify original research articles from PubMed, Scopus, and Web of Science. Eligible studies reported associations between deprivation at the census block or tract level using a validated deprivation index (e.g. the Area Deprivation Index or Yost Index) and CRC incidence, mortality, or screening outcomes in a US-based sample. A fixed-effects meta-analysis was completed using inverse-variance weighting to estimated hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) for CRC incidence, mortality, and screening outcomes, comparing the highest vs. lowest quantiles of neighborhood-level deprivation. All analyses were completed using the meta package in R. Results: In total, 19 studies were included in the meta-analysis. Living in a neighborhood in the highest quantile of deprivation was associated with significantly higher risk for incident CRC (HR 1.37, 95% CI 1.34-1.41, seven studies). In stratified analysis, positive associations with incident CRC were observed for White (HR 1.43, 95% CI 1.39-1.47, three studies), Black (HR 1.18, 95% CI 0.96-1.44, three studies), and Asian/Pacific Islander individuals (HR 1.18, 95% CI 1.08-1.28, two studies). For individuals diagnosed with CRC, higher deprivation was associated with elevated risk for overall mortality (HR 1.11, 95% CI 1.10-1.13, four studies) and CRC-specific mortality (HR 1.17, 95% CI 1.15-1.19, seven studies). Higher deprivation was associated with lower completion of recommended screening for CRC, including colonoscopy, sigmoidoscopy, or fecal occult blood testing (OR 0.76, 95% CI 0.74-0.79, four studies). Conclusions: Individuals who reside in neighborhoods with high levels of deprivation have significantly elevated risk for CRC incidence and mortality compared to individuals from low deprivation neighborhoods. Targeting healthcare resources to highly deprived neighborhoods to increase uptake of preventative screening may help to address racial and geographic disparities for CRC.