Assessment of Differences in Colorectal Cancer Outcomes by Geographic Region for Black Patients in the United States

Black patients have the worst survival outcomes from colorectal cancer (CRC) in the US. In addition, disparities and differences in mortality outcomes among Black and NHW patients across the four US census regions (Northeast [NE], South, West, Midwest [MW]) remain unexplored. We hypothesized that survival outcomes for Black patients would differ across the US census regions and might correlate with socioeconomic factors.

Black and Non-Hispanic White (NHW) patients ≥ 45 years of age with a diagnosis of colon or rectal adenocarcinoma between 2010 and 2018 were identified in the National Cancer Database for survival analysis. Survival differences were further validated using the Surveillance, Epidemiology, and End Results (SEER) database to investigate 5-year cause-specific survival (CSS).

For colon adenocarcinoma, the largest difference in median overall survival (OS) between NHW and Black patients was in the MW (67 months Black vs. 74 months NHW, P < 0.001). For rectal cancer, the largest difference was in the West (60 months Black vs. 84 months NHW, P < 0.001). Black patients receiving care in the MW had the lowest median OS for CRC, while those in the NE had the highest (colon: 67 months MW vs. 100 months NE; rectum: 55 months MW vs. 79 months NE). In multivariable analyses of the Black patient cohort, cancer care in the NE was associated with decreased mortality risk compared to other regions.

Geographic region of care appears to correlate with survival differences for CRC. Exploring these differences may facilitate improved understanding of systemic and structural drivers of health inequities and aid improved resource allocation.