Background: Despite improvements in colorectal cancer (CRC) outcomes, geographic disparities persist. Spatial mapping identified distinct "hotspots" of increased CRC mortality, including 11 rural counties in eastern North Carolina (ENC). The primary aims of this study were to measure CRC incidence and mortality by stage and determine if racial disparities exist within ENC.
Methods: Data from 2008 to 2016 from the NC Central Cancer Registry were analyzed by stage, race, and region. Age-adjusted incidence and death rates (95% CI) were expressed per 100,000 persons within hotspot counties, all ENC counties, and Non-ENC counties.
Results: CRC incidence [43.7 (95% CI 39.2-48.8) vs. 38.4 (95% CI 37.6-39.2)] and mortality rates [16.1 (95% CI 16.6-19.7) vs. 13.9 (95% CI 13.7-14.2)] were higher in the hotspot than non-ENC, respectively. Overall, localized, and regional CRC incidence rates were highest among African Americans (AA) residing in the hotspot compared to Whites or Non-ENC residents. Incidence rates of distant disease were higher among AA but did not differ by region. CRC mortality rates were highest among AA in the hotspot (AA 22.0 vs. Whites 15.8) compared to Non-ENC (AA 19.3 vs. Whites 13.0), although significant stage-stratified mortality differences were not observed.
Conclusions: Patients residing in the hotspot counties have higher age-adjusted incidence of overall, localized, regional, and distant CRC and mortality rates than patients in non-hotspot counties. Incidence and mortality rates remain highest among AA residing in the hotspot.
Impact: Increased CRC incidence and mortality rates were observed among all patients in the hotspot and were highest among AA, suggestive of ongoing racial and geographic disparities.
Keywords: Colorectal cancer; Disparities; Epidemiology.