Molecular Biomarker Testing Patterns and Turnaround Time in US Patients With Advanced Non–Small Cell Lung Cancer

Background: Patients with advanced non–small cell lung cancer (aNSCLC) are recommended to undergo molecular testing for targetable genomic alterations. However, as high-throughput methods are increasingly used, long test turnaround time (TAT) may lead to lower receipt of appropriate targeted therapy. Guidelines recommend a 2-week TAT for ALK and EGFR testing, 2 prevalent pathogenic alterations with highly effective targeted therapies. Patients and Methods: Using an electronic health record–derived, deidentified database, we conducted a retrospective cohort study of patients with aNSCLC diagnosed between 2011 and 2023 who received testing for ≥1 of 8 molecular markers. We assessed the number of biomarkers tested per patient, testing modality, and TAT (defined as the interval between specimen collection and result date) over time. We also evaluated patients with ALK / EGFR -altered aNSCLC who initiated early nontargeted treatment prior to test result availability, examining associations with TAT and clinical outcomes. Results: The study sample comprised 33,945 patients, with a mean age of 68.2 years; 49.4% were female, 58.3% were White, and 83.4% reported a history of smoking. From 2011 to 2023, the mean number of biomarkers tested per patient (range, 2.0–6.8) and the use of next-generation sequencing (NGS) increased, whereas the mean TAT converged to 3 weeks. Fewer than half of the patients with ALK / EGFR -altered aNSCLC had a TAT of ≤2 weeks, and 1 in 8 initiated early nontargeted treatment. Longer TAT was associated with early nontargeted treatment when analyzed as both a continuous variable (odds ratio, 1.83 per week) and a binary variable (TAT >2 vs ≤2 weeks; odds ratio, 6.02). Early treatment was associated with worse median progression-free survival (9 vs 11 months) in patients with ALK / EGFR -altered aNSCLC. Conclusions: Biomarker testing and NGS use have increased over time in US patients with aNSCLC. TAT has plateaued and remains longer than recommended in consensus guidelines. Longer TAT was associated with early nontargeted therapy in patients with ALK+ / EGFR + aNSCLC, leading to suboptimal first-line treatment and poorer clinical outcomes.