Recent racial/ethnic disparities in cancer-specific mortality among patients diagnosed with rectal cancer.

Background: African American patients frequently receive nonstandard treatment and demonstrate poorer overall survival (OS) outcomes compared to White patients. Our objective was to analysis whether racial/ethnic disparities in rectal cancer-specific mortality remain after accounting for clinical characteristics, treatment, and access-to-care-related factors.

Methods: Individuals diagnosed with rectal cancer between 2011 and 2020 were identified using the Surveillance, Epidemiology, and End Results Database. The cumulative incidence of rectal cancer-specific mortality was computed. Sub-distribution hazard ratios (sdHRs) and 95% confidence intervals (CIs) for rectal cancer-specific mortality associated with race/ethnicity were estimated using Fine and Gray model with stepwise adjustments for clinical characteristics, treatment modalities, and factors related to access-to-care.

Results: Among 54,370 patients, non-Hispanic (NH) Black individuals exhibited the highest cumulative incidence of rectal cancer-specific mortality (39%), followed by American Indian/Alaska Native (AI/AN) (35%), Hispanics (32%), NH-White (31%), and Asian/Pacific Islander (API) (30%). After adjusting for clinical characteristics, NH-Black patients had a 28% increased risk of rectal cancer mortality (sdHR, 1.28; 95% CI: 1.20-1.35) compared to NH-White patients. In contrast, mortality disparities between Hispanic-White, AI/AN-White, and API-White groups were not significant. The Black-White mortality differences persisted even after adjustments for treatment and access-to-care-related factors. In stratified analyses, among patients with a median household income below $59,999, AI/AN patients showed higher mortality than NH-Whites when adjusted for clinical characteristics (sdHR, 1.32; 95% CI: 1.03-1.70).

Conclusions: Overall, the racial/ethnic disparities in rectal cancer-specific mortality were largely attributable to differences in clinical characteristics, treatment modalities, and factors related to access-to-care. These findings emphasize the critical need for equitable healthcare to effectively address and reduce the significant racial/ethnic disparities in rectal cancer outcomes.