Immigration factors and prostate cancer survival among Hispanic men in California: does neighborhood matter?

BACKGROUND Hispanics are more likely than other racial/ethnic groups in the United States to be diagnosed with later stage of prostate cancer, yet they have lower prostate cancer mortality rates. The authors evaluated the impact of nativity and neighborhood-level Hispanic ethnic enclave on prostate cancer survival among Hispanics. METHODS A total of 35,427 Hispanic men diagnosed with invasive prostate cancer from 1995 through 2008 in the California Cancer Registry were studied; vital status data were available through 2010. Block group-level neighborhood measures were developed from US Census data. Stage-stratified Cox proportional hazards models were used to assess the effect of nativity and ethnic enclave on prostate cancer survival. RESULTS In models adjusted for neighborhood socioeconomic status and other individual factors, foreign-born Hispanics were found to have a significantly lower risk of prostate cancer survival (hazards ratio [HR], 0.81; 95% confidence interval [95% CI], 0.75-0.87). Living in an ethnic enclave appeared to modify this effect, with the survival advantage slightly more pronounced in the high ethnic enclave neighborhoods (HR, 0.78; 95% CI, 0.71-0.86) compared with low ethnic enclave neighborhoods (HR, 0.86; 95% CI, 0.76-0.98). CONCLUSIONS Despite lower socioeconomic status, Hispanic immigrants have better survival after prostate cancer than US-born Hispanics and this pattern was more striking among those living in ethnic enclaves. Identifying the modifiable individual and neighborhood-level factors that facilitate this survival advantage in Hispanic immigrants may help to inform specific interventions to improve survival among all patients.