County-Level Structural Racism Indices and Racial Disparities in Lung Cancer Care.

Importance: The degree to which structural racism is associated with racial disparities in lung cancer care and outcomes is unknown. Objective: To evaluate the association between 2 measures of structural racism and quality of care and outcomes for Black and White patients with non-small cell lung cancer (NSCLC) and whether this association differs by patient race. Design, Setting, and Participants: This cross-sectional study was a retrospective analysis of Medicare beneficiaries diagnosed with NSCLC between 2013 and 2019 using Surveillance, Epidemiology, and End Results Program and Medicare data. Patient inclusion criteria were age older than 67 years at the time of diagnosis, continuous fee-for-service Part A and B Medicare coverage for 24 months before through 12 months after diagnosis, NSCLC histology, and non-Hispanic Black or non-Hispanic White race and ethnicity. The data analysis was performed between September 1, 2024, and April 1, 2025. Exposures: Two county-level measures of structural racism: the Structural Racism Effect Index, which measures deprivation, and County Structural Racism, which assesses racial dissimilarity between Black and White patients across multiple domains. Main Outcomes and Measures: The dichotomous outcomes included localized stage at diagnosis, stage-appropriate evaluation and treatment, and 2-year survival. Multivariable mixed-effects logistic regression was used to assess the association between each structural racism measure and outcome, including interaction terms to determine whether structural racism moderated the association between patient race and NSCLC care and outcomes. Results: Of 54 344 patients (mean [SD] age, 77.7 [6.6] years; 51.6% female), 10.3% were Black and 89.7% were White. A lower proportion of Black patients compared with White patients were diagnosed at a localized stage (30.9% vs 38.4%), received stage-appropriate evaluation and treatment (20.3% vs 28.0%), and survived 2 years after diagnosis (28.7% vs 36.6%). Among White patients, 2-year survival was significantly higher in counties in the highest dissimilarity quintile (estimated probability, 36.8%) vs the lowest (estimated probability, 30.4%), while there was no difference for Black patients (26.8% vs 27.8%). Accordingly, while there was no significant difference in probability of 2-year survival between Black and White patients in the lowest dissimilarity quintile, the disparity was significant in the highest quintile (-10.0%; 95% CI, -12.2% to -7.7%). Conclusions and Relevance: This cross-sectional study of racial disparities in NSCLC care found that residence in counties with higher structural racism (as measured by the dissimilarity index) was associated with lower mortality among White patients but not among Black patients. Quantifying structural racism and its association with cancer care delivery may identify targets that allow for improvement in quality of cancer care and mitigation of disparities.