Abstract PR14: Do Latinas with breast cancer who live in ethnic enclaves have better or worse survival? Analysis of cancer registry data from California and Texas
Authors: Shariff-Marco Salma , Gomez Scarlett Lin , Canchola Alison , Fullington Hannah , Hughes Amy E. , Pruitt Sandi L. 
Published: August 2020

Introduction: Many Latinos live in ethnic enclaves—culturally distinct neighborhoods with high concentrations of individuals of the same ethnic origin, high linguistic isolation, a large share of recent immigrants, and ethnic specific businesses and resources. Prior studies on the association of enclave residence and cancer mortality were often limited to a single state and demonstrated mixed results. It is unclear whether the mixed results are due to widely varying measures and analytic methods, or true regional differences in enclave effects.

Methods: We conducted parallel analyses of California and Texas cancer registry data from adult (≥18 years of age) Latinas diagnosed with invasive breast cancer from 1996 to 2005, with follow-up through 2014. Our key focus was to use the same measures and methods. We linked 2000 U.S. Census data to measure Latino enclaves and neighborhood socioeconomic status (nSES). We defined enclaves using an established multidimensional index of seven census tract measures (percent of residents who are Latino, foreign-born, recent immigrants, and linguistically isolated (general and of those who speak Spanish), with limited English proficiency (general and of those who speak Spanish) split into statewide quintiles. We fitted Cox proportional hazard models for all-cause and breast cancer specific mortality adjusted for year of diagnosis, patient age, birthplace (with multiple imputation), tumor stage, histology, grade, and size, and clustering by census tract. We explored interactions of enclave residence with nSES and patient birthplace.

Results: Among 40,716 Latinas, the majority (61.3% in CA, 70.5% in TX) lived in ethnic enclaves. Ethnic enclave residence was more common among foreign- vs U.S.-born Latinas (72.0% vs 52.3% in CA and 82.4% vs. 68.5% in TX). In fully adjusted models for both states, foreign- vs. US-born women were more likely to die from breast cancer and all causes. Living in an ethnic enclave and in neighborhoods with higher SES was independently associated with decreased mortality. Patterns were consistent in terms of direction and significance of associations across states for all-cause and breast cancer-specific mortality. Future analyses will further explore the statistically significant interactions (p&lt;.05) observed between enclave residence, nSES, and patient birthplace.

Discussion: Applying the same methods across two states eliminated previously published inconsistent results about the association of enclave residence and mortality among Latinas with breast cancer. Future studies should consider pooling cancer registry data across states and using the same methods to better understand the true impact of ethnic enclave residence across the cancer continuum. Future studies should also focus on identifying the specific protective effects of enclave residence to inform interventions.

This abstract is also being presented as Poster C073.

Citation Format: Salma Shariff-Marco, Scarlett Lin Gomez, Alison Canchola, Hannah Fullington, Amy E. Hughes, Sandi L. Pruitt. Do Latinas with breast cancer who live in ethnic enclaves have better or worse survival? Analysis of cancer registry data from California and Texas [abstract]. In: Proceedings of the Eleventh AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2018 Nov 2-5; New Orleans, LA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl):Abstract nr PR14.