Understanding racial disparities in gastrointestinal cancer outcomes: Lack of surgery contributes to lower survival in African American patients

Background: Race/ethnicity-related differences in rates of cancer surgery and cancer mortality have been observed for gastrointestinal (GI) cancers. This study aims to estimate the extent to which differences in receipt of surgery explain racial/ethnic disparities in cancer survival. Methods: The National Cancer Database was used to obtain data for patients diagnosed with stage I–III mid-esophageal, distal esophagus/gastric cardia (DEGC), noncardia gastric, pancreatic, and colorectal cancer in years 2004–2015. Mediation analysis was used to identify variables influencing the relationship between race/ ethnicity and mortality, including surgery. Results: A total of 600,063 patients were included in the study: 3.5% mid-esophageal, 12.4% DEGC, 4.9% noncardia gastric, 17.0% pancreatic, 40.1% colon, and 22.0% rectal cancers. The operative rates for Black patients were low relative to White patients, with absolute differences of 21.0%, 19.9%, 2.3%, 8.3%, 1.6%, and 7.7%. Adjustment for age, stage, and comorbidities revealed even lower odds of receiving surgery for Black patients compared with White patients. The observed HRs for Black patients compared with White patients ranged from 1.01 to 1.42. Mediation analysis showed that receipt of surgery and socioeconomic factors had greatest influence on the survival disparity. Conclusions: The results of this study indicate that Black patients appear to be undertreated compared with White patients for GI cancers. The disproportionately low operative rates contribute to the known survival disparity between Black and White patients. Impact: Interventions to reduce barriers to surgery for Black patients should be promoted to reduce disparities in GI cancer outcomes.