Nativity, ethnic enclave residence, and breast cancer survival among Latinas: Variations between California and Texas

Background: Among Latinas with breast cancer, residence in an ethnic enclave may be associated with survival. However, findings from prior studies are inconsistent. Methods: The authors conducted parallel analyses of California and Texas cancer registry data for adult (aged ≥18 years) Latinas who were diagnosed with invasive breast cancer from 1996 to 2005, with follow-up through 2014. Existing indices applied to tract-level 2000 US Census data were used to measure Latinx enclaves and neighborhood socioeconomic status (nSES). Multivariable Cox proportional hazard models were fit for all-cause and breast cancer–specific survival adjusted for year of diagnosis, patient age, nativity (with multiple imputation), tumor stage, histology, grade, size, and clustering by census tract. Results: Among 38,858 Latinas, the majority (61.3% in California and 70.5% in Texas) lived in enclaves. In fully adjusted models for both states, foreign-born women were found to be more likely to die of breast cancer and all causes when compared with US-born women. Living in enclaves and in neighborhoods with higher SES were found to be independently associated with improved survival from both causes. When combined into a 4-level variable, those in low nSES nonenclaves had worse survival for both causes compared with those living in low nSES enclaves and, in the all-cause but not breast cancer–specific models, those in high nSES neighborhoods, regardless of enclave status, had improved survival from all causes. Conclusions: Applying the same methods across 2 states eliminated previously published inconsistent associations between enclave residence and breast cancer survival. Future studies should identify specific protective effects of enclave residence to inform interventions.