Real-world insights on biomarker testing patterns and implications for mNSCLC therapy selection

BACKGROUND: Biomarker testing is essential for guiding first-line treatment decisions in metastatic non-small cell lung cancer (mNSCLC). Despite guideline recommendations, real-world testing patterns remain variable and may contribute to disparities in outcomes. OBJECTIVES: This study examined real-world biomarker testing patterns and their associations with first-line treatment selection, clinical characteristics, and sociodemographic factors in patients with newly diagnosed mNSCLC. METHODS: Using the Healthcare Integrated Research Database, we identified adults diagnosed with mNSCLC between January 2019 and July 2022 with continuous health plan enrollment. Patients were categorized by the type of biomarker testing they received within 90 days of diagnosis; eligible patients had: (1) no biomarker testing, (2) immunohistochemistry (IHC) only, (3) testing of fewer than 5 genes (