Abstract PO-228: Racial disparities and the impact on recurrence and survival in non-metastatic colon cancer patients undergoing colectomy at a comprehensive cancer center
Authors: Thompson Hannah M. , Yuval Jonathan B. , Luthra Anisha , Wu Fan , Iwayemi Tolulope , Wei Iris H. , Pappou Emmanouil P. , Smith J. Joshua , Nash Garrett M. , Garcia-Aguilar Julio , Sanchez-Vega Francisco 
Published: January 2022

Abstract
Introduction/Purpose: Colorectal cancer has worse outcomes among Black patients; however, few studies have evaluated differences in recurrence rates after surgery. Our goal was to compare recurrence between Black and white patients with colon cancer treated at a comprehensive cancer center with a standardized quality of care. Methods: A retrospective review of Black and white patients with Stage 0-III colon cancer undergoing surgical resection from 2006-2018 was conducted. Patients with neoadjuvant therapy, adjuvant radiation, and missing median family income or body mass index data were excluded. Demographic and clinical data were collected and compared between the groups. Median family income was estimated using patients' zip codes and Census data. Freedom from Recurrence (FFR) was the primary endpoint with an event defined as colon cancer recurrence. A Kaplan-Meier curve evaluated differences between the racial groups with a log-rank test to assess significance. A multivariable analysis using Cox proportional hazards was conducted, and a p value of &lt;0.05 was considered significant. Results: Two thousand and sixty-one patients were included with 1912 white (93%) and 149 (7%) Black patients. Black patients had a median age of 61 compared with 65 in the white cohort (p=0.003) and had a higher median BMI prior to colectomy (p=0.01). Most had right-sided tumors in both groups (58% for Black and 50% for white patients; p=0.13). About 8% of Black patients had Medicaid insurance compared with 2% of white patients (p=&lt;0.005), and Black patients had a lower estimated median family income (p=&lt;0.005). On surgical pathology, more Black patients had node-positive disease (44% for Black and 33% for white patients; p=0.009) and received adjuvant chemotherapy (48% for Black and 37% for white patients; p=0.006). More Black patients underwent open colectomies (39% and 28% respectively, p=0.02). To assess resection quality, 5 white and 0 Black patients had positive margins, and the median total lymph node count was 25 for Black versus 23 for white patients (p=0.04). Few patients in each group had a colectomy with less than 12 lymph nodes resected (1% for Black and 4% for white patients; p=0.17). The survival analysis showed that white patients had a higher FFR compared to Black patients (p=0.005). However, only T4 classification (hazard ratio 2.03, confidence interval 1.52-2.71; p=&lt;0.001) and node-positive disease (hazard ratio 2.88, confidence interval 2.20-3.79; p=&lt;0.001) correlated with lower FFR on multivariable analysis. Race was not significantly correlated (hazard ratio of 1.47, confidence interval 0.97-2.23; p=0.07). Conclusion: We found significant differences in clinical and tumor characteristics between Black and white colon cancer patients who underwent resection consistent with more advanced presentation in Black patients. While Black patients were found to have a lower FFR, after controlling for other factors, Black and white patients had similar stage specific survival when treated at this comprehensive cancer center.
Citation Format: Hannah M. Thompson, Jonathan B. Yuval, Anisha Luthra, Fan Wu, Tolulope Iwayemi, Iris H. Wei, Emmanouil P. Pappou, J. Joshua Smith, Garrett M. Nash, Julio Garcia-Aguilar, Francisco Sanchez-Vega. Racial disparities and the impact on recurrence and survival in non-metastatic colon cancer patients undergoing colectomy at a comprehensive cancer center [abstract]. In: Proceedings of the AACR Virtual Conference: 14th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2021 Oct 6-8. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr PO-228.