Biomarker testing for metastatic non-small cell lung cancer across Michigan Oncology Quality Consortium (MOQC) sites.

484 Background: Biomarker testing is recommended for all patients with metastatic non-small cell lung cancer (NSCLC) adenocarcinoma to inform systemic treatment. Despite evidence of improved survival and cost-effectiveness of biomarker testing, not all patients receive biomarker testing or the recommended targeted therapy based on the presence of biomarkers. This leads to inappropriate use of ineffective and expensive therapies like immunotherapy and chemotherapy. We aimed to characterize the current state of biomarker testing in metastatic NSCLC within a sample of Michigan oncology practices. Methods: This retrospective analysis was completed in January through March 2025. Data is reflective of the most recent ten patients with newly diagnosed, metastatic NSCLC adenocarcinoma at each site. A standardized form for collecting disease characteristics, biomarker testing information, and frontline therapy was created via REDCap© Version 15.0.21. Data was analyzed using descriptive statistics. Results: Data collection is ongoing, and updated results will be presented at the meeting. To date, 78 patients with metastatic NSCLC adenocarcinoma have been identified in 10 practices. Testing was performed for 76/78 (97%) patients, of whom only 62 patients (79%) had next generation sequencing (NGS) with large panels (> 50 genes). Of the remaining 14 patients tested, 9 (12%) had targeted point mutation testing, 4 (5%) had testing with smaller NGS panels, and the method used for testing was unknown for 1 patient. The most common biomarkers missed in the non-NGS patients were NTRK fusions, RET rearrangements, HER2 mutations, and nontraditional EGFR mutations. The tests were most often ordered by medical oncologists (n=61, 80% of tests ordered). 43 patients (55%) had an actionable biomarker identified, most commonly KRAS G12C (n=17, 22%) and EGFR exon 19del/L858R (n=14, 18%). Of the 24 patients with an actionable mutation in the front-line setting, 4 patients (17%) did not receive a guideline-recommended targeted therapy. Conclusions: While most patients with new metastatic NSCLC in our cohort received biomarker testing, 21% of patients did not receive testing of all frontline targetable biomarkers. In addition, 1 in 6 patients with identified targetable biomarkers did not receive appropriate frontline therapy. These results indicate a need for support for comprehensive biomarker testing that includes all recommended biomarkers as well as decision support tools for interpretation of results and therapy selection.