Racial Disparities in Lung Cancer Stage of Diagnosis Among Adults Living in the Southeastern United States

Abstract

Background: Black Americans receive a diagnosis at later stage of lung cancer more often than White Americans. We undertook a population-based study to identify factors contributing to racial disparities in lung cancer stage of diagnosis among low-income adults.

Research question: Which multilevel factors contribute to racial disparities in stage of lung cancer at diagnosis?

Study design and methods: Cases of incident lung cancer from the prospective observational Southern Community Cohort Study were identified by linkage with state cancer registries in 12 southeastern states. Logistic regression shrinkage techniques were implemented to identify individual-level and area-level factors associated with distant stage diagnosis. A subset of participants who responded to psychosocial questions (eg, racial discrimination experiences) were evaluated to determine if model predictive power improved.

Results: We identified 1,572 patients with incident lung cancer with available lung cancer stage (64% self-identified as Black and 36% self-identified as White). Overall, Black participants with lung cancer showed greater unadjusted odds of distant stage diagnosis compared with White participants (OR,1.29; 95% CI, 1.05-1.59). Greater neighborhood area deprivation was associated with distant stage diagnosis (OR, 1.58; 95% CI, 1.19-2.11). After controlling for individual- and area-level factors, no significant difference were found in distant stage disease for Black vs White participants. However, participants with COPD showed lower odds of distant stage diagnosis in the primary model (OR, 0.72; 95% CI, 0.53-0.98). Interesting and complex interactions were observed. The subset analysis model with additional variables for racial discrimination experiences showed slightly greater predictive power than the primary model.

Interpretation: Reducing racial disparities in lung cancer stage at presentation will require interventions on both structural and individual-level factors.

Keywords: United States; lung cancer; multilevel factors; racial disparities; stage at diagnosis.

Graphical abstract

Figure 1

Bar graph showing the percentage of cases of lung cancer diagnosed at localized, regional, and distant stage by patient race among patients with incident lung cancer in the Southern Community Cohort Study, 2002 through 2019 (N = 1,572).

Figure 2

Coefficient plot of features that add to model predictive power among patients with incident lung cancer in the Southern Community Cohort Study, primary analysis, 2002 through 2019 (N = 1,572). The reference categories for these variables are: Black/African American reference of White, education reference of less than high school, deprivation index quartile reference of quartile 1, and comorbidity index reference of score = 1. The ":" symbol represents an interaction effect between two variables.

Figure 3

Coefficient plot of features that add to model predictive power among patients with incident lung cancer in the Southern Community Cohort Study, subset analysis of follow-up data, 2002 through 2019 (n = 472). The reference categories for these variables are: Black/African American reference of White, male reference of female, widowed reference of married, and comorbidity index reference of score = 1. The ":" symbol represents an interaction effect between two variables.