Incidence of lung cancer histologic cell-types according to neighborhood factors: A population based study in California.

BACKGROUND: The relationships between neighborhood factors (i.e., neighborhood socioeconomic status (nSES) and ethnic enclave) and histologic subtypes of lung cancer for racial/ethnic groups, particularly Hispanics and Asian American/Pacific Islanders (AAPIs), are poorly understood.

METHODS: We conducted a population-based study of 75,631 Californians diagnosed with lung cancer from 2008 through2012. We report incidence rate ratios (IRRs) for lung cancer histologic cell-types by nSES among racial/ethnic groups (non-Hispanic (NH) Whites, NH Blacks, Hispanics and AAPIs) and according to Hispanic or Asian neighborhood ethnic enclave status among Hispanics and AAPIs, respectively. In addition, we examined incidence jointly by nSES and ethnic enclave.

RESULTS: Patterns of lung cancer incidence by nSES and ethnic enclave differed across race/ethnicity, sex, and histologic cell-type. For adenocarcinoma, Hispanic males and females, residing in both low nSES and high nSES neighborhoods that were low enclave, had higher incidence rates compared to those residing in low nSES, high enclave neighborhoods; males (IRR, 1.17 [95% CI, 1.04-1.32] and IRR, 1.15 [95% CI, 1.02-1.29], respectively) and females (IRR, 1.29 [95% CI, 1.15-1.44] and IRR, 1.51 [95% CI, 1.36-1.67], respectively). However, AAPI males residing in both low and high SES neighborhoods that were also low enclave had lower adenocarcinoma incidence.

CONCLUSIONS: Neighborhood factors differentially influence the incidence of lung cancer histologic cell-types with heterogeneity in these associations by race/ethnicity and sex. For Hispanic males and females and AAPI males, neighborhood ethnic enclave status is strongly associated with lung adenocarcinoma incidence.