BACKGROUND: Sociodemographic disparities in cancer care outcomes are often related to delayed or limited care access. However, it is unknown whether outcome differences persist after establishing high-level care. This study evaluated the relationship between rectal cancer outcomes and sociodemographic status at academic cancer centers. PATIENTS AND METHODS: A retrospective cohort study of patients with rectal cancer treated at academic cancer centers was conducted utilizing the National Cancer Database. Primary outcome was overall survival, while secondary outcomes included 30- and 90-day mortality, time from diagnosis to treatments, hospital readmission rates, and hospital length of stay. RESULTS: Of the 127,023 patients, median age was 62.7 years (SD 11.92), 59.3% were male, 80.3% were white, and 39.4% presented with stage III disease. After adjustment, Black patients had the worst overall survival (HR 1.10, 95% CI 1.01-1.19, p = 0.016). Private insurance status conferred overall survival benefit (HR 0.66, 95% CI 0.58-0.75, p <
0.002) as well as the best protection against 30- and 90- day postoperative mortality (30-day OR 0.31, 95% CI 0.10-0.97, p = 0.044
90-day OR 0.37, 95% CI 0.16-0.83, p = 0.015). Black patients experienced longer time to first treatment than their white counterparts, with a delay of 3.23 days (95% CI 1.87-4.58, p <
0.002). CONCLUSIONS: This study demonstrated the existence of sociodemographic disparities even within the walls of academic institutions, where care should be evidence-based, standardized, comprehensive, and equitable. When analyzing causal pathways, delays in time to treatment initiation may be contributing to these outcomes, but may be modifiable.