Abstract Introduction: Differences in rates of surgery performed for gastrointestinal (GI) cancers contribute to racial disparities in cancer mortality. The National Cancer Database (NCDB) contains data obtained from Commission on Cancer-accredited hospital cancer registries and collects reasons for nonreceipt of surgery as a registry item. This study aims to examine whether racial disparities exist in this provided reason for not receiving surgery. Methods: The NCDB was used to obtain data for patients diagnosed with gastric, pancreatic, and colorectal cancer in years 2004-2015. Analysis was limited to patients who were Black or White, and cancers stages 1-3. Unadjusted and adjusted differences between Black and White patients were examined for all variables in the model. Variables included demographics, receipt of surgery, reason for not having surgery, tumor stage and characteristics, and hospital factors. Reasons for patients' not receiving surgery were evaluated with Generalized Linear Modeling regression to see if certain responses, such as “contraindicated due to patient risk factors,”, “not part of the planned first course treatment,” and “refused by the patient” were more frequently assigned to Black compared to White patients. Results: 540,205 patients with stage 1-3 gastrointestinal cancer were included in the study. 43% of the cohort had colon cancer, 24% rectal cancer, 11% gastric cancer, and 22% pancreatic cancer. For stage 1-3 disease, the raw operative rate for Black patients was 0.3%, 6.6%, 2.0%, and 6.7% lower than in White patients for stomach, pancreas, colon, and rectum cancers, respectively. These gaps widened when adjusted for age, comorbidities, and stage. On multivariate regression, Black patients were more likely to be recorded as being denied surgery due to patient risk factors even after controlling for age, stage, comorbidities, tumor characteristics, demographics, and hospital factors: OR 1.03 (95% CI 0.91-1.16), 1.25 (1.18-1.33), 1.43 (1.22-1.66), 1.63 (1.41-1.88) for stomach, pancreas, colon, and rectum cancer, respectively. Similarly, Black patients were more likely to reportedly not receive surgery due to surgery “not being the first course of treatment”: OR 0.99 (0.93-1.05), 1.14 (1.09-1.19), 1.30 (1.21-1.39), 1.33 (1.26-1.41). These two factors explain more than 80% of the difference in operative rates. Lastly, Black patients were disproportionately more likely to be recorded as having refused surgery: OR 1.84 (1.61-2.12), 1.07 (0.96-1.19), 1.59 (1.45-1.75), 1.81 (1.61-2.02). Conclusion: Compared to White patients, Black patients are more likely to be described as not receiving surgery due to patient risk factors, surgery not being part of their first course of treatment, and their having refused surgery. Further studies are needed to evaluate whether the differences in operative rates are attributable to factors not captured in cancer registries, such as frailty and lack of social support. Citation Format: John Bliton, Michael Parides, John McAuliffe, Peter Muscarella, Haejin In. Racial disparities in reasons for not receiving surgery for gastrointestinal cancer [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr A105.