eP611 - Adjuvant Therapy for High-Risk Stage II Colon Cancer: An NCDB Study

Purpose/Background: Racial disparities in both treatments and outcomes of colon cancer represent an area where further investigation is indisputably needed. Guideline differences based upon race previously emerged for screening colonoscopy, however, now average-risk patients of all races are recommended to begin screening at 45 years. Another area of deliberation within colon cancer management is among patients with stage II colon cancer with high-risk features, in whom consideration for adjuvant chemotherapy is currently recommended, yet the rates of administration have been historically low. Given the potential for inequitable use of adjuvant therapy among races, we examined parity of outcomes between races among patients with stage II high risk colon cancer, including rates of adjuvant therapy and factors that may contribute to disparate outcomes.Methods/Interventions: Individuals with high-risk features associated with stage II colon cancers diagnosed between 2004 and 2020 that underwent curative resection were selected from the National Cancer Database. Cases were stratified by receipt of adjuvant chemotherapy. Kaplan-Meier analysis and Cox-proportional hazard ratios were used to compare survival, and multivariate logistic regressions were used to control for factors influencing administration of adjuvant therapy.Results/Outcomes: 84,445 individuals were identified, 27.06% of whom underwent adjuvant chemotherapy. Black patients were less likely to have more than one high risk feature than were white patients (19.2% vs 21.6%, p < 0.001). In unadjusted analysis, rates of adjuvant therapy were higher in black individuals than in white individuals (32.3% vs 26.3%, p < 0.001), with a significantly higher median survival time (103.7 vs 94.2 months, p < 0.001). However, when adjusting only for differences in age at diagnosis as a covariate, black patients were less likely to undergo adjuvant therapy (OR = 0.89; 95% CI 0.849-0.953, p < 0.001) than were white patients. When controlling for other socioeconomic factors, such as income, education, and type of treatment center, this difference persists. Adjusting for these same variables, black patients had a 1.13 fold increased risk of death compared to white patients, (HR = 1.13; 95% CI 1.091-1.171, p < 0.001).Conclusion/

Discussion: Despite lower numbers of high-risk features, black patients with high-risk stage II colon cancer initially appear to undergo adjuvant therapy at higher rates and have better survival than do white patients. However, these differences are completely inverted after adjusting for age alone, suggesting both that (1) there are ongoing differences in age at diagnosis which should be reevaluated in further guideline revisions, and (2) there are ongoing disparities in the treatment of different races which must be mitigated, and that we must make continued efforts to promote equity in administration of adjuvant therapy when warranted.KM Curve for Overall Survival in High-Risk Stage II Colon Cancer