Associations Between Medicaid Insurance, Biomarker Testing, and Outcomes in Patients With Advanced NSCLC

Evidence suggests that patients with Medicaid experience lower-quality cancer care than those with commercial insurance. Whether this trend persists in the era of personalized medicine is unclear. This study examined the associations between Medicaid (vs commercial) insurance and receipt of biomarker testing, targeted therapy, and overall survival in patients with advanced non-small cell lung cancer (aNSCLC).

We conducted a retrospective study of patients who received an aNSCLC diagnosis from January 2011 to September 2019 using a nationwide US healthcare database. Eligible patients were aged 18 to 64 years with Medicaid or commercial insurance at diagnosis. Receipt of biomarker testing (ALK, EGFR, ROS1, BRAF, and PD-L1) was assessed. The likelihood of testing, biomarker-driven therapy (cancer immunotherapy or tyrosine kinase inhibitor treatment), and mortality were compared by insurance type using adjusted Cox regression.

Our sample included 6,145 commercially insured and 865 Medicaid beneficiaries. Medicaid beneficiaries were more likely to be Black or African American (20% vs 9.3%; P <.001) and were less likely to have undergone biomarker testing (57% vs 71%; P <.001). In the adjusted analysis, Medicaid beneficiaries were less likely to have evidence of testing (hazard ratio [HR], 0.81; P <.001), any first-line treatment (HR, 0.72; P <.001), and first-line biomarker-driven therapy (HR, 0.70; P <.001). Medicaid beneficiaries with evidence of biomarker testing had a lower risk of death compared with those without evidence of biomarker testing (HR, 1.27 [95% CI, 1.06-1.52]; P =.010). Higher risk of death was observed in patients with Medicaid versus commercially insured patients (HR, 1.23; P <.001); this result remained unchanged after adjusting for biomarker testing (HR, 1.22; P < .001) but was partially ameliorated after adjustment for testing and treatment type (HR, 1.12; P =.010).

Medicaid beneficiaries with aNSCLC were less likely to receive biomarker testing and biomarker-driven therapies, which may in part contribute to a higher observed risk of mortality compared with commercially insured patients.