Abstract A109: The development of racial and ethnic-specific composite measures of structural racism for cancer inequities research: The Multiethnic Cohort Study

Introduction: Structural racism is a fundamental driver of health inequities in the US. Structural racism manifests through systems of mutually reinforcing institutions that perpetuate inequities in health through policies, practices, and norms across domains including housing, education, employment, criminal justice, and healthcare. Measures of structural racism that capture the interplay across such domains have been limited and have not addressed how different minoritized racial and ethnic groups may experience specific elements of structural racism. To address this gap, we developed composite measures of structural racism for four US racial and ethnic groups in California (CA) and Hawai‘i (HI). Methods: We developed place-based composite measures of structural racism using latent class analysis of city/place-based variables reflecting racial and ethnic-group specific disparities (i.e., residents of minoritized group in comparison to non-Hispanic White residents) incorporating contemporary redlining, residential segregation, education, employment, incarceration, fatal encounters with police, and home rentership. These variables were selected to represent multiple domains of structural racism based on the literature and were anchored on US Census, Home Mortgage Disclosure Act, fatalencounters.org and American Communities Project data for 2000. We also developed a data dashboard to visualize the data and disseminate for ground truthing. For California, we developed composite measures of structural racism for Black and Asian American populations. For Hawai‘i, we developed a composite measure of structural racism for Asian American and Native Hawaiian/Pacific Islander populations. Measures for other racial/ethnic populations are in development. Results: Across 445 cities in CA and 20 cities in HI, the variables that characterized structural racism across domains differed by racial and ethnic group and study site. For example, the measure of Black-White Structural Racism in CA was defined by disparities in poverty, unemployment, redlining, and incarceration; the measure of Asian American-White Structural Racism in CA was defined by disparities in education, poverty, and rentership; and the measure for Native Hawaiian/Pacific Islander-White Structural Racism in HI was defined by disparities across all the domains except incarceration and fatal encounters. Conclusion: Preliminary composite measures of structural racism indicate varying relevance for groups across race and ethnicity as well as geographic context, which indicates context- and group-specific patterns in how structural racism operates. Next, we will examine associations of these structural racism measures with overall mortality and years of life lost in the Multiethnic Cohort (58,072 Asian American, 28,106 Black, 40,190 Latino, and 8,533 Native Hawaiian/Pacific Islander adults). In addition, we will examine mediation by lifestyle behaviors and neighborhood attributes and test for heterogeneity by sex and life stage. Citation Format: Salma Shariff-Marco, Alice Guan, Katherine Lin, Mindy C. DeRouen, Lynne Wilkens, Serge Atherwood, Meera Sangaramoorthy, Debora L. Oh, Kevin Cassel, Gilbert C. Gee, Scarlett L. Gomez, Iona Cheng. The development of racial and ethnic-specific composite measures of structural racism for cancer inequities research: The Multiethnic Cohort Study [abstract]. In: Proceedings of the 18th AACR Conference on the Science of Cancer Health Disparities; 2025 Sep 18-21; Baltimore, MD. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2025;34(9 Suppl):Abstract nr A109.