Abstract C064: Neighborhood socioeconomic status, ethnic enclave, and hepatocellular carcinoma incidence in Hispanics and Asians/Pacific Islanders living in California: An update

Background: Disparities in hepatocellular carcinoma (HCC) incidence exist by sex and race/ethnicity, with rates higher in men than women and higher in Asians/Pacific Islanders (API) and Hispanics than non-Hispanic Whites. We sought to update previous studies that identified disparities in HCC incidence by neighborhood contextual factors such as SES and ethnic enclave among API and Hispanic populations in California by analyzing data from the California Cancer Registry (CCR) through 2012. Methods: All primary, invasive HCC cases diagnosed from 1988 through 2012 from the CCR were identified and their addresses geocoded. Neighborhood Hispanic or API ethnic enclaves are areas marked by greater immigrant composition and linguistic isolation, applicable to Hispanic and API residents, respectively. Neighborhood SES (nSES) is an index measure comprising data on education, occupation, and housing. Age-adjusted incidence rates (IRs; per 100,000 population; standardized to the 2000 U.S. standard million population), incidence rate ratios (IRRs) (with corresponding 95% confidence intervals (CI)) were calculated for each strata of nSES and ethnic enclave by sex and race/ethnicity. Results: The final analysis included 9,636 males (4,883 Hispanics, 4,753 APIs) and 3,524 females (1,744 Hispanics, 1,780 APIs). During 1988-2012, among Hispanics, there were no clear associations between HCC incidence and nSES or ethnic enclave when considered separately. However, compared to those in high nSES/low enclave neighborhoods, Hispanic males living in low nSES/low enclave neighborhoods and Hispanic females living in low SES/high enclave neighborhoods had higher incidence of HCC (males: IRR = 1.22, CI = 1.10 - 1.36; females: IRR = 1.20, CI = 1.04 - 1.38). Among APIs, there was no association between HCC incidence and ethnic enclave but there was a strong association of increased risk for those living in the lowest vs. highest nSES neighborhoods (males: IRR = 1.69, CI = 1.53 - 1.87; females: IRR = 1.32, CI = 1.12 - 1.56). API males living in low nSES/high enclave neighborhoods had higher incidence of HCC than those living in high nSES/low enclave neighborhoods (IRR = 1.36, CI = 1.22 - 1.52). Conclusions: We found significant variation in HCC incidence by two important neighborhood factors, nSES and ethnic enclave, among Hispanics and APIs living in California, with similar findings to previous studies. Future studies with longitudinal data are needed to explore which attributes of nS