Intersectional analysis of race/ethnicity, geography, and socioeconomic status on colorectal cancer screening utilization and stage at diagnosis: A SEER analysis, 2016-2021.

Abstract

e15714 Background: Despite effective screening modalities, colorectal cancer (CRC) remains the second leading cause of cancer-related mortality in the USA. Persistent disparities in CRC outcomes by race/ethnicity, socioeconomic status (SES), and geographic residence are well documented, these factors rarely operate independently. National data evaluating how intersecting social determinants jointly influence CRC stage at diagnosis and how these disparities have evolved over time remain limited. Understanding these synergistic effects is essential for designing precision public health strategies that equitably improve cancer prevention and early detection. Methods: We analyzed SEER data (2016–2021) including adults 50–75 diagnosed with CRC across 17 registries. Patients were classified by race/ethnicity (NHW, NHB, Hispanic/Latino, API, AI/AN), geography (metropolitan, urban, rural), and neighborhood deprivation (ADI quintiles). Stage at diagnosis (localized vs regional/distant) served as a downstream marker of screening access. Multivariable logistic regression estimated adjusted odds ratios (aORs) for late-stage diagnosis, adjusting for age, sex, insurance, and comorbidity. Interaction terms assessed synergistic effects; temporal trends evaluated disparity changes over time. Results: Among 156,847 patients, 39.4% were diagnosed at localized stage. NHB (aOR 1.31, 95% CI 1.26–1.36), Hispanic (aOR 1.21), and AI/AN patients (aOR 1.35) had higher odds of late-stage diagnosis, while API patients had lower odds (aOR 0.87). Rural residence (aOR 1.18) and highest ADI quintile (aOR 1.52) were independently associated with late-stage diagnosis. Intersectional analysis showed compounding effects: rural NHB patients in the highest ADI quintile had the greatest burden (71.4% late stage; aOR 2.34), with similar rates among rural AI/AN patients. Significant interactions were observed between race/ethnicity and geography (p = 0.003) and race/ethnicity and SES (p < 0.001). Although overall late-stage diagnoses declined modestly from 2016–2021, disparities widened over time. Conclusions: Race/ethnicity, geography, and socioeconomic deprivation exert synergistic effects on CRC stage at diagnosis. Disparities disproportionately affect rural NHB and AI/AN populations in highly deprived areas. Findings underscore the need for precision public health interventions—targeted outreach, patient navigation, and expanded access to at-home and mobile screening—to achieve equitable CRC prevention and early detection.