Abstract C70: Disparity in liver cancer incidence and chronic liver disease mortality by US nativity in Hispanics: The Multiethnic Cohort

Background and Aims: Hispanics have experienced the greatest increase in hepatocellular carcinoma (HCC) incidence and mortality among ethnic/racial groups during the last two decades in the US. Chronic liver disease (CLD) is a major cause of morbidity and mortality in Hispanics. HCC risk in US-born Hispanics is reportedly higher than that in foreign-born Hispanics. Few studies, however, have examined the extent to which detailed individual risk factors for HCC could account for the observed risk disparity by nativity. The objective of the present study was to evaluate the difference in risk of HCC and CLD, respectively, by nativity in Hispanics, and to assess the extent to which risk factors can account for the risk differences. Methods: A prospective analysis was conducted among 36,864 Hispanics who participated in the Multiethnic Cohort (MEC). Nativity was categorized into US-born (N=18,485) and foreign-born (N=18,379; 74% Mexican-born, 26% Central/South American-born). Demographic and potential risk factors were assessed at baseline using self-administered questionnaire. Hepatitis B and C viral (HBV/HCV) status were determined using the Medicare claim files in a subset of participants (N=16,436). Incident HCC cases were identified through linkages to the SEER registries and CLD deaths were determined through linkages to state death certificate files in California and Hawaii and the National Death Index. Hazard ratios (HRs) and 95% confidence intervals (CIs) for HCC incidence and CLD deaths associated with nativity were calculated using Cox proportional hazard models adjusted for age, risk factors and potential confounders. Results: During a median follow up of 19.6 years, 189 Hispanics (118 US-born, 71 foreign-born) were diagnosed with HCC and 298 Hispanics (194 US-born, 104 foreign-born) died of CLD. The age-adjusted HCC incidence rate (per 100,000) was almost twice as high in US-born as in foreign-born Hispanic men (44.7 vs. 23.1), but comparable for US- and foreign-born Hispanic women (14.5 vs. 13.4). US-born Hispanic men and women had an 89% to 114% higher CLD mortality rate compared to their foreign-born counterparts, respectively. HBV/HCV and diabetes were the strongest risk factors for HCC in both US- and foreign-born Hispanics. Heavy alcohol consumption, current smoking status, diabetes, and HBV/HCV were associated with risk of CLD deaths in US- and foreign-born men. HBV/HCV, diabetes and body mass index (BMI) were associated with risk of CLD death in US- and foreign-born women. After adjustment for age, level of education, BMI, alcohol intake, smoking status, and history of diabetes, the HRs (95% CIs) of HCC incidence and CLD death were 1.77 (1.21, 2.59) and 1.78 (1.29, 2.43), respectively for US-born compared to foreign-born Hispanic men. The corresponding figures were 1.01 (0.60, 1.70) and 1.89 (1.27, 2.81) for women. The results were similar in the subgroup of Medicare study participants with further adjustment for HBV/HCV infection status. Conclusions: US-born Hispanic men are at greater risk of developing HCC and CLD than their foreign-born counterparts. In Hispanic women, while the risk of developing HCC is similar between the nativity groups, the risk of CLD death is much greater in US-born than in foreign-born women. Overall known difference in demographic and risk factors do not account for the observed disparities in HCC and CLD risk between US- and foreign-born Hispanics. Future studies are warranted to identify factors that contribute to the elevated risk of HCC and CLD in US-born Hispanics. Citation Format: Veronica Wendy Setiawan, Pengxiao C. Wei, Brenda Y. Hernandez, Shelly C. Lu, Kristine R. Monroe, Loic Le Marchand, Jian Min Yuan. Disparity in liver cancer incidence and chronic liver disease mortality by US nativity in Hispanics: The Multiethnic Cohort. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C70.