Racial and socioeconomic disparities in NSCLC molecular diagnostics uptake

Abstract Background Precision therapies, such as targeted and immunotherapies, have substantially changed the landscape of late-stage non-small cell lung cancer (NSCLC). Yet utilization of these therapies is disproportionate across strata defined by race and socioeconomic status (SES), possibly due to disparities in molecular diagnostic testing (or “biomarker testing”), which is a prerequisite to treatment. Methods We extracted a cohort of NSCLC patients from the Surveillance, Epidemiology and End Results (SEER)-Medicare linked data. The primary outcome was receipt of a molecular diagnostic test, based on claims data. The primary predictors were race and SES. Likelihood of receiving a molecular diagnostic test, and overall survival (OS), were investigated using logistic and Cox proportional hazards regression, adjusted for sex, age, residence, histology, marital status, and comorbidity. Results Of the 28,511 NSCLC patients, 11,209 (39.3%) received molecular diagnostic testing. Compared to White patients, fewer Black patients received a molecular diagnostic test (40.4% vs 27.9%; p < .001). After adjustment, Black patients (ORadj [odds ratio]: 0.64; 95% CI [confidence interval]: 0.58-0.71) and those living in areas with greater poverty (ORadj: 0.85; 95% CI: 0.80-0.89) had statistically significant decreased likelihood of molecular diagnostic testing. Patients who did receive testing had a statistically significant decreased risk of death (HRadj [hazards ratio]: 0.74; 95% CI: 0.72-0.76). These results held in the stratified analysis of stage IV NSCLC patients. Conclusion Disparities exist in comprehensive molecular diagnostics, which is critical for clinical decision making. Addressing barriers to molecular testing could help close gaps in cancer care and improve patient outcomes.