AUTHOR=Riviere Paul , Morgan Kylie M. , Deshler Leah N. , Demb Joshua , Mehtsun Winta T. , Martinez Maria Elena , Gupta Samir , Banegas Matthew , Murphy James D. , Rose Brent S. 

TITLE=Racial disparities in colorectal cancer outcomes and access to care: a multi-cohort analysis

JOURNAL=Frontiers in Public Health

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/public-health/articles/10.3389/fpubh.2024.1414361

DOI=10.3389/fpubh.2024.1414361

ISSN=2296-2565

ABSTRACT=Introduction: Non-Hispanic Black (NHB) Americans have higher incidence of colorectal cancer (CRC) and worse survival than non-Hispanic Whites (NHW), but the relative contributions of biological versus access to care remains poorly characterized. This study used two nationwide cohorts in different healthcare contexts to study health system effects on this disparity.
Methods: We used data from the Surveillance, Epidemiology, and End Results (SEER) registry as well as the United States Veterans Health Administration (VA) to identify adults diagnosed with colorectal cancer between 2010 and 2020 who identified as non-Hispanic Black (NHB) or non-Hispanic White (NHW). Analysis was performed using stratified survival analyses with primary endpoint of overall survival, and with sensitivity analyses performed using cancer-specific survival.
Results: We identified 263,893 CRC patients in SEER (36,662 (14%) NHB, 226,271 (86%) NHW) and 24,375 VA patients (4,860 (20%) NHB, 19,515 (80%) NHW). In SEER, NHB patients had worse OS than NHW patients: median OS of 57 months (95% confidence interval (CI) 55 – 58) versus 72 months (95% CI 71 – 73) (hazard ratio (HR) 1.14, 95% CI 1.12 – 1.15, p = 0.001). In contrast, VA NHB median OS was 65 months (95% CI 62 – 69) versus NHW 69 months (95% CI 97 – 71) (HR 1.02, 95% CI 0.98 – 1.07, p = 0.375). There was significant interaction in SEER between race and Medicare age-eligibility (p < 0.001); NHB race had more effect in patients <65 years old (HR 1.44, 95% CI 1.39-1.49, p < 0.001) than in those ≥65 (HR 1.13, 95% CI 1.11-1.15, p < 0.001). In the VA this age stratification was not significant (p = 0.21). 
Discussion: Racial disparities in CRC survival in the general US population are significantly attenuated in Medicare-aged patients. This pattern is not present in the VA, suggesting that access to care may be an important component of racial disparities in this disease.