UC San Diego

In the United States, lung cancer is the second most common cancer in men and women and is the leading cause of cancer death. Lung cancer survival is lower than other leading cancers, and approximately half of people with lung cancer die within one year of being diagnosed. While small advances in treatment and interventions in tobacco cessation have improved survival in recent years, persistent poor survival suggests that new approaches are needed to identify contextual risk factors to improve lung cancer survival.

It has become widely accepted that where an individual lives or works is an important determinant of health. Place-based exposures such as neighborhood contextual factors may be particularly valuable for intervention in lung cancer survival as they can be intervened on using population-level interventions such as local or state policies. Recently, studies have observed associations between two potential neighborhood contextual factors and lung cancer survival: ambient air pollution and racial residential segregation. However, neighborhood-level exposures require specific methodological considerations because they have spatial and temporal components that need to be appropriately considered in analyses.

The first chapter of this dissertation reviews the epidemiologic evidence regarding spatial heterogeneity in lung cancer survival and the relationship between both air pollution and racial residential segregation on lung cancer survival. The second chapter evaluates how lung cancer survival varies spatially in California and how these spatial patterns may change over time. The third chapter examines the association between air pollution and lung cancer survival and illustrates how a systematic error known as immortal time bias can be introduced when a time-varying exposure such as air pollution is mishandled in the context of a time-to-event outcome. The fourth chapter of this dissertation describes two considerations in the measurement of segregation, the spatial scale of geographies and the spatial relationships of populations. This chapter illustrates how these considerations impact both the absolute measurement of segregation and subsequent conclusions about the impact on lung cancer survival. The final chapter of this dissertation summarizes key findings and highlights future directions to advance the study of neighborhood contextual factors in lung cancer survival.