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.