The intersection of neighborhood-level disadvantage and overall lung cancer survival.

Abstract

6551 Background: Despite recent advances in lung cancer therapeutics leading to considerable improvement in survival, disparities continue to persist among socially disadvantaged populations. Although the reasons underlying this phenomenon are uncertain, we posit that neighborhood-level factors could play a role. Furthermore, neighborhood disadvantage may lead to epigenetic changes which promote malignant progression. This study aimed to determine the effects of neighborhood-deprivation index (NDI), a validated 13-factor-based measure, that combines income, education, employment, and housing in a neighborhood, on lung cancer mortality. Methods: A retrospective cohort study assessed the relationship of NDI with survival weighted by age, stage, and DNA methylation among biopsy-proven lung cancer from two U.S. medical centers, Johns Hopkins University and the University of Illinois Chicago, between 2008-2020. In our analysis, U.S.-standardized NDI values for each year of sample collection were computed at the U.S. census tract level and categorized into quartiles. Participants’ residential addresses were geocoded to U.S. census tracts and linked to NDI quartiles. DNA extraction from liquid biopsy samples was performed for quantification of DNA methylation. Results: The study included 184 lung cancer patients, with 89 in the low-deprivation group and 95 in the high-deprivation group. The high-deprivation group had a higher percentage of females (57% vs. 48%), a higher percentage of African Americans (AA) (50% vs. 36%), a lower pack-year smoking history (30 vs. 39 median pack-years), and a higher percentage with stage IV disease (28% vs. 20%) than the low-deprivation group. Overall, NDI was significantly higher among AA when compared with Whites (p=0.003) and associated with lung cancer stage at diagnosis with an odds ratio of 1.17 (p=0.02). There was a significant correlation between DNA methylation and stage for HOXA7, SOX17, ZPF42, TAC1 and HOXA9. Only HOXA7 DNA methylation correlated with NDI (p=0.003).The high-deprivation group had a significantly shorter survival duration compared to the low-deprivation group, with a 1-year survival rate of 79% vs. 90%, a 2-year survival rate of 70% vs. 84%, and a 5-year-survival rate of 51% vs. 73% (p=0.02). After adjusting for age at diagnosis, stage, and DNA methylation status, belonging to the high-deprivation group was associated with a higher mortality risk with a hazard ratio of 2.02 (p=0.04). Conclusions: Neighborhood-level socioeconomic status and DNA methylation may be associated with late stage lung cancer at diagnosis; whereas NDI shows a potential association with shorter survival and increased mortality risk. Higher neighborhood deprivation among AA suggests that changes in health care policy that account for neighborhood-level indices of socioeconomic deprivation may enable more equitable improvement of lung cancer mortality.