Abstract A104: How neighborhood social and sociocultural contexts are associated with mortality in Asian American breast cancer patients

Abstract PURPOSE: Asian American (AA) women with breast cancer on average have more favorable survival compared to other racial and ethnic groups in the US. Identifying how neighborhood factors are associated with mortality can inform interventions to optimize survival after breast cancer diagnosis. We examined associations between neighborhood socioeconomic status (nSES), living in ethnic enclaves, and presence of sociocultural institutions (SCIs) with survival in AA women with breast cancer. METHODS: We analyzed data from a pooled cohort of studies with AA women with breast cancer in California including the Pathways Study, Multiethnic Cohort Study, Northern California Breast Cancer Family Registry, and Asian American Breast Cancer Study. Participant addresses at diagnosis were geocoded to determine their census tract of residence, then linked to tract-level neighborhood data. nSES was measured using statewide quintiles of a composite score created from 2000 US Census and 2008-2012 American Community Survey that included tract-level education, household income, poverty, employment, occupation, median rent, and home values. Ethnic enclaves were measured using statewide quintiles of a composite score that included percentages of population that were AA, foreign-born, had limited English proficiency, and were linguistically isolated (no one over the age of 14 years speaks English in the household). SCIs, defined as businesses or organizations that facilitate social and cultural exchange for AA communities (e.g., civic organizations, educational centers, recreational centers, religious organizations, etc.), were identified using pre-defined keyword searches of business names within historical Dun and Bradstreet data. Confounders included age, year of diagnosis, marital status, and education. We used multivariable Cox proportional hazards models to estimate hazard ratios (HR) and 95% confidence intervals (CI) of overall mortality and breast cancer-specific mortality associated with living in ethnic enclaves, presence of SCIs, and nSES. RESULTS: The cohort included 3,233 AA women with breast cancer, consisting of 1,223 Chinese, 1,122 Filipina, 344 Japanese, 173 other Asians, and 260 multiethnic Asians. For nSES, 32.4% of the cohort lived in the highest SES quintile and 7.1% lived in the lowest. Of the cohort, 57.5% lived in the most ethnically distinct quintile, while 1.9% lived in the least. Living in a neighborhood with the highest nSES quintile was associated with lower overall mortality compared to the lowest quintile (HR=0.65, 95% CI: 0.50, 0.83). Living in an ethnic enclave compared to living in a non-enclave neighborhood was not associated with overall mortality. Neighborhood associations were not statistically significant for breast cancer-specific mortality. SCI data pending. CONCLUSION: Neighborhood context, namely nSES, was associated with mortality in AA women with breast cancer and may contribute to the survival advantage seen in this population. Citation Format: Brittany N. Morey, Iona Cheng, Scarlett Lin. Gomez, Esther M. John, Lawrence H. Kushi, Marilyn L. Kwan, Katherine Lin, Lenora Loo, Julie Von Behren, Anna Wu, Song Yao, Salma Shariff-Marco. How neighborhood social and sociocultural contexts are associated with mortality in Asian American breast cancer patients [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 A104.