Etiology and Outcomes of Hepatocellular Carcinoma in an Ethnically Diverse Population: The Multiethnic Cohort

SIMPLE SUMMARY: Racial/ethnic disparities in the incidence and outcomes of hepatocellular carcinoma (HCC) is previously described. Yet, due to the challenges for ascertainment of the underlying etiology (e.g., hepatitis B and hepatitis C) in registry-based studies, the contribution of the underlying etiology to the racial disparities is poorly described. Utilizing comprehensive data on tumor characteristics, lifestyle, and outcomes in the Multiethnic Cohort Study, we explored racial disparities in HCC. We show significant racial disparities in the underlying etiology, mortality, and treatment patterns. We further show that underlying etiology is a significant contributor to racial disparities in mortality by race and should be considered in future research. ABSTRACT: Backgrounds: HCC incidence varies by race/ethnicity. We characterized racial differences in underlying etiology, presentation, and survival in the linkage of Multiethnic Cohort Study with SEER and Medicare claims. Methods: HCC characteristics, treatment, and underlying etiology in participants were obtained. Deaths were ascertained using state death certificates and the National Death Index. Risk factors were collected via questionnaires. Cox models were used to calculate hazard ratios (HR) and 95% confidence intervals (CI) for death. Results: Among 359 cases, the average age at diagnosis was 75.1. The most common etiology was hepatitis C (HCV) (33%), followed by nonalcoholic fatty liver disease (NAFLD) (31%), and different by ethnicity (p < 0.0001). African Americans (AA) (59.5%) and Latinos (40.6%) were more likely to be diagnosed with HCV-related HCC. In Japanese Americans (33.1%), Native Hawaiians (39.1%), and whites (34.8%), NAFLD was the most common etiology. Receipt of treatment varied across ethnic groups (p = 0.0005); AA had the highest proportion of no treatment (50.0%), followed by Latinos (45.3%), vs. whites (15.2%). HCC (72.2%) was the most common cause of death. In a multivariate analysis, AA (HR = 1.87; 95% CI: 1.06–3.28) had significantly higher mortality compared to whites. Conclusions: We found significant ethnic differences in HCC underlying etiology, receipt of treatment, and outcome. The findings are important for reducing disparities.