Biomarker Testing for Non-Small Cell Lung Cancer in Community Practices Operated by an Academic Cancer Center

Targeted therapy has transformed treatment of non-small cell lung cancer (NSCLC), with guideline-directed biomarker testing playing a critical role in decision making. Academic centers and large practices report high rates of comprehensive biomarker testing, but less is known about testing patterns in academically affiliated community practice settings. This study evaluated rates of guideline-concordant biomarker testing for patients with advanced, nonsquamous NSCLC treated at Dana-Farber Cancer Institute (DFCI) regional practice sites.

Patients with advanced NSCLC treated with palliative-intent therapy at DFCI regional sites from 2018 to 2021 were identified and medical records reviewed. Collected variables included patient demographics, cancer histology, biomarker testing (EGFR, ALK, ROS1, MET, BRAF, RET, NTRK, KRAS, and PD-L1), and treatment delivered. Next-generation sequencing (NGS) testing rates were also assessed.

Among 416 patients with advanced nonsquamous NSCLC, testing rates for EGFR, ALK, and PD-L1 exceeded 85%, while KRAS, BRAF, and MET testing ranged between 55% and 71%. During this period, 45% did not receive NGS-based testing. The most frequently detected alterations included mutations in KRAS (37%) and EGFR (14%). Targeted therapies were administered in biomarker-driven cases, including 67% of EGFR-mutant and 69% of ALK-rearranged cases. Among 109 patients with squamous disease, 86% had evidence of PD-L1 testing, and of 30 patients with PD-L1 at least 50%, 80% received checkpoint inhibitor-based therapy. The rate of NGS testing for squamous disease increased rapidly, from 14% in 2018 to 61% in 2021.

Most patients, especially those with nonsquamous NSCLC, treated at DFCI regional sites received guideline-concordant biomarker testing. Still, testing for rare biomarkers with recently approved targeted therapies lagged testing rates for long-established biomarkers, demonstrating the importance of rapid diffusion of novel biomarker testing into practice.