Mediators of Racial Inequities in Non-Small Cell Lung Cancer Care

Black patients with non-small cell lung cancer (NSCLC) are more often diagnosed at a later stage and receive inadequate evaluation and treatment compared to White patients. We aimed to identify factors representing exposure to structural racism that mediate the association between race and NSCLC care.

We queried Surveillance, Epidemiology, and End Results-Medicare for non-Hispanic Black and White patients ≥ 67 years diagnosed with NSCLC from 2013 to 2019. Our outcomes were localized diagnosis stage, receipt of stage-appropriate evaluation, receipt of stage-appropriate treatment, two-year survival, and receipt of "optimal" care, an aggregate metric comprising the first three listed outcomes. We estimated indirect effects of mediators on the association between race and outcomes.

Of 69,130 patients, 8.2% were Black. Medicare-Medicaid dual eligibility, a marker of individual-level socioeconomic status (SES), accounted for the largest proportion of mediating effects for most outcomes, ranging from 13.6% (p < 0.001) for localized diagnosis stage to 25.0% (p < 0.001) for two-year survival. Receipt of an influenza vaccine, a marker of health care access, had the second largest mediating effects on the associations between race and diagnosis stage (9.5%, p < 0.001), treatment (15.3%, p < 0.001), and optimal care (11.4%, p < 0.001). Neighborhood-level SES accounted for the third largest proportion of the effects of race on each outcome, explaining between 9% and 16% of the racial inequities at each phase (all p < 0.001).

Individual- and neighborhood-level structural factors partly explain inequities in NSCLC care, and their effects vary based on the phase of care. Interventions should be adapted to the phase of care.