Racial and socioeconomic disparities in non-small cell lung cancer molecular diagnostics uptake

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, possibly because of disparities in molecular diagnostic testing (or biomarker testing), which is a prerequisite to treatment.

We extracted a cohort of NSCLC patients from the Surveillance, Epidemiology, and End Results-Medicare linked data. The primary outcome was receipt of a molecular diagnostic test, based on claims data. The primary predictors were race and socioeconomic status. Likelihood of receiving a molecular diagnostic test and overall survival were investigated using logistic and Cox proportional hazards regression, adjusted for sex, age, residence, histology, marital status, and comorbidity.

Of the 28 511 NSCLC patients, 11 209 (39.3%) received molecular diagnostic testing. Compared with White patients, fewer Black patients received a molecular diagnostic test (40.4% vs 27.9%; P < .001). After adjustment, Black patients (adjusted odds ratio [OR] = 0.64, 95% confidence interval [CI] = 0.58 to 0.71) and those living in areas with greater poverty (adjusted OR = 0.85, 95% CI = 0.80 to 0.89) had statistically significant decreased likelihood of molecular diagnostic testing. Patients who did receive testing had a statistically significant decreased risk of death (adjusted hazard ratio [HR] = 0.74, 95% CI = 0.72 to 0.76). These results held in the stratified analysis of stage IV NSCLC patients.

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.