The Impact of Residential Racial Segregation on Non-Small Cell Lung Cancer Treatment and Outcomes.

Background: Despite decreases in lung cancer incidence, racial disparities in diagnosis and treatment persist. Residential segregation and structural racism have effects on socioeconomic status for black people, affecting health care access. This study aims to determine the impact of residential segregation on racial disparities in non-small cell lung cancer (NSCLC) treatment and mortality.

Methods: Patient data were obtained from Surveillance, Epidemiology, and End Results Program database for black and white patients diagnosed with NSCLC from 2004-2016 in the 100 most populous counties. Regression models were built to assess outcomes of interest: stage at diagnosis and surgical resection of disease. Predicted margins assessed impact of index of dissimilarity (IoD) on these disparities. Competing risk regressions for black and white patients in highest and lowest quartiles of IoD were used to assess cancer-specific mortality.

Results: Our cohort had 193,369 white and 35,649 black patients. Black patients were more likely to be diagnosed at advanced stage than white patients, with increasing IoD. With increasing IoD, black patients were less likely to undergo surgical resection than white patients. Disparities were eliminated at low IoD. Black patients at high IoD had lower cancer-specific survival.

Conclusions: Black patients were more likely to present at advanced disease, were less likely to receive surgery for early stage disease, and had higher cancer-specific mortality at higher IoD. Our findings highlight the impact of structural racism and residential segregation on NSCLC outcomes. Solutions to these disparities must come from policy reforms to reverse residential segregation and deleterious socioeconomic effects of discriminatory policies.