Abstract B090: Breast cancer incidence rates by neighborhood socioeconomic status and ethnic enclaves among Asian American, Native Hawaiian, and Pacific Islander females in California
Authors: Truong Alya , Kim Mi-Ok , Mckinley Meg , Gomez Scarlett L. , Shariff-Marco Salma , Cheng Iona 
Published: December 2023

Abstract
Background—Among Asian American, Native Hawaiian, and Pacific Islander (AANHPI) females in the U.S., breast cancer incidence has steadily increased1. Of note, California has the largest population of AANHPI residents in the United States2. Few studies have examined whether the incidence rates of breast cancer among AANHPI populations differ by the neighborhood social environment. Thus, we examined the incidence of invasive breast cancer by AANHPI ethnic enclave (ethnically distinct neighborhoods) and neighborhood socioeconomic status (nSES) among AANHPI females in California. Methods— With 14,738 AANHPI females diagnosed with invasive breast cancer from 2008 through 2012 from the California Cancer Registry, we calculated the incidence rates of breast cancer. The 2007 to 2011 American Community Survey (ACS) data was used to assess AANHPI ethnic enclave index and nSES at the census tract level. Incidence rate ratios (IRRs) were analyzed by statewide quintiles of AANHPI ethnic enclave index and nSES. For analyses of AANHPI ethnic enclave index and nSES combined, low and high levels were defined as quintiles 1-3 and quintiles 4-5, respectively, and IRRs were calculated for joint AANHPI and nSES as low-low, low-high, high-low, and high-high. IRR associations of ethnic enclave and nSES by stage (localized vs. advanced (regional/distant)) were also assessed. Results— Overall, neighborhoods of lower AANHPI ethnic enclave index had higher incidence rates of breast cancer for AANHPI females in California. The incidence rate of breast cancer among AANHPI living in low ethnic enclave neighborhoods were 1.16 times that of AANHPI females living high ethnic enclave neighborhoods (95% CI 1.12 to 1.20; p&lt;0.001). In addition, AANHPI females living in higher SES neighborhoods had higher incidence rates of breast cancer (IRR = 1.16 comparing highest to lowest nSES quintile, 95% CI 1.12 to 1.20). The incidence rate of breast cancer among AANHPI females living in low ethnic enclave+high SES neighborhoods was 1.32 times that of AANHPI females living in high ethnic enclave+low SES neighborhoods (95% CI 1.25 to 1.39; p&lt;0.001). Similar patterns of associations were observed for localized and advanced stages of the disease. Conclusion—For AANHPI females in California, incidence rates of breast cancer differed by nSES, ethnic enclave, and jointly. Impact— Future studies should examine whether the impact of these neighborhood-level factors on breast cancer incidence rates differ across specific AANHPI ethnic groups and investigate the pathways through which they contribute to breast cancer risk.
Citation Format: Alya Truong, Mi-Ok Kim, Meg Mckinley, Scarlett L. Gomez, Salma Shariff-Marco, Iona Cheng. Breast cancer incidence rates by neighborhood socioeconomic status and ethnic enclaves among Asian American, Native Hawaiian, and Pacific Islander females in California [abstract]. In: Proceedings of the 16th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2023 Sep 29-Oct 2;Orlando, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2023;32(12 Suppl):Abstract nr B090.