Neighborhood Disadvantage and Lung Cancer Incidence in Ever-Smokers at a Safety Net Health-Care System A Retrospective Study

BACKGROUND: Neighborhood circumstances have an influence on multiple health outcomes, but the association between neighborhood conditions and lung cancer incidence has not been studied in sufficient detail. The goal of this study was to understand whether neighborhood conditions are independently associated with lung cancer incidence in ever-smokers after adjusting for individual smoking exposure and other risk factors. METHODS: A cohort of ever-smokers aged >= 55 years was assembled from 19 years of electronic health record data from our academic community health-care system. Patient demographic characteristics and other measures known to be associated with lung cancer were ascertained. Patient addresses at their index visit were geocoded to the census block group level to determine the area deprivation index (ADI), drawn from 5-year estimates from the American Community Survey. A multivariate Cox proportional hazards model was fit to assess the association between ADI and time to lung cancer diagnosis. Tests of statistical significance were two-sided. RESULTS: The study included 19,867 male subjects and 21,748 female subjects. Fifty-three percent of the patients were white, 38% were black, and 5% were Hispanic. Of these, 1,149 developed lung cancer. After adjusting for known risk factors, patients residing in the most disadvantaged areas had a significantly increased incidence of lung cancer compared with those in the least disadvantaged areas (hazard ratio, 1.29; 95% CI 1.07-1.55). CONCLUSIONS: Census-derived estimates of neighborhood conditions have a powerful association with lung cancer incidence, even when adjusting for individual variables. Further research investigating the mechanisms that link neighborhood conditions to lung cancer is warranted.