Exploring racial differences in outcome for metastatic colorectal cancer: Results from a large prospective observational cohort study (BRiTE).

Abstract

e14039 Background: African-Americans are more likely to be diagnosed with metastatic colorectal cancer at the time of presentation than whites, and have shorter survival once diagnosed. This study examines racial differences in clinical outcomes in the setting of a large observational cohort study. Methods: The study cohort consisted of 1,589 white (81.4%) and 227 African-American (11.6%) patients with metastatic colorectal cancer receiving front line bevacizumab therapy enrolled in a large prospective observational cohort study. Differences in time to event endpoints and response incidence were examined by race. Differences in the incidence of baseline and treatment related toxicities associated with bevacizumab were also examined. Finally, differences in patterns of care by race were explored. Results: Median OS was 22.6 months for African Americans and 22.9 months for whites. Median PFS was 9.5 months for African Americans and 9.8 months for whites. Response rates (CR+PR) were 37.5% for African Americans and 46.3% for whites (Adjusted OR 0.66; 95%CI: 0.49-0.89). African Americans had higher rates of baseline diabetes (18.9% vs. 11%; p = 0.002) and hypertension (52.9% vs. 41.4%; p = 0.001), and worsening hypertension while on therapy (13.7% vs. 8.9%; p = 0.02) but no differences in on-treatment Arterial Thromboembolic Events were seen. Conclusions: This large observational cohort study of patients with metastatic colorectal cancer demonstrates that when treated in a similar fashion with modern chemotherapy, African Americans and whites have equivalent cancer outcomes. Encouragingly, no significant differences in bevacizumab related toxicity or patterns of care were seen between African Americans and whites. The lower response rate among African Americans deserves further study. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration Genentech Genentech Genentech Genentech