OBJECTIVES: Biomarker testing is recommended for patients with an advanced non-small cell lung cancer (aNSCLC) diagnosis, yet the real-world prevalence of these mutations (ALK, BRAF, KRAS, EGFR, ROS1, PD-L1) is not fully known among tested patients. The objectives of this study were to evaluate real-world biomarker positivity rates among patients with aNSCLC and to understand variations by demographic and clinical characteristics.

METHODS: A retrospective analysis of patients diagnosed with aNSCLC between January 2011–July 2021 was performed using the Flatiron Health aNSCLC database. Eligible patients were ≥18 years old, had ≥2 visits in the Flatiron Network, and had ≥2 months of continuous follow-up from the date of advanced diagnosis.

RESULTS: 56,972 patients met the eligibility criteria. Overall positivity rates among tested patients were 3% for ALK, 5% for BRAF, 27% for KRAS, 15% for EGFR, 1% for ROS1, and 16% for PD-L1. Positivity rates varied by: age, sex, race, smoking history, and histology for EGFR and KRAS; by age, race, smoking history, and histology for ALK; by age, race, and histology for BRAF; and by age and smoking history for ROS1. PD-L1 positivity rates did not vary by demographic or clinical characteristics. Patient characteristics associated with high prevalence rates within respective biomarkers include: 21% prevalence of ALK among patients <45 years old (compared to 3% overall) and 53% prevalence of EGFR among Asian patients (compared to 15% overall).

CONCLUSIONS: The occurrence of mutations is variable, with KRAS being the most prevalent and ROS1 being the least prevalent among tested patients. The prevalence of these mutations among patients with aNSCLC highlight the importance of biomarker testing to optimize treatment decisions.