208 Lung Adequacy Assessment Is Dependent on Specimen Requirements for Next-Generation Sequencing Testing: An Institutional Experience in Changing Reference Laboratories

Introduction/Objective Endobronchial ultrasound-guided fine needle aspiration and core needle biopsy are minimally invasive procedures used for the diagnosis and treatment of lung cancer and are successful if they provide sufficient material for diagnosis and molecular testing. In March 2023, our institution changed reference labs for next-generation sequencing (NGS) for lung specimens, switching from pathologist-ordered NGS to clinician-ordered NGS. The original reference lab allowed for submission of aspirate smear slides while the new lab does not. Methods/Case Report We reviewed the OU Health electronic medical record for lung cytology specimens from 2019 to 2024. Specimen adequacy, diagnosis, molecular testing results, pathologist, and clinician were recorded for each patient procedure. Results Our search yielded 275 procedures. 156 occurred before the transition (pre-T) and 119 were post transition (post-T). Of the pre-T cases, 98 were malignant, with 46 of these diagnosed as primary lung adenocarcinoma (LAC) or non-small cell carcinoma (NSCC). Of these, 15 cases (33%) were adequate for NGS testing. Of the post-T cases, 79 were malignant, 32 of which were primary LAC or NSCC. Only 6 (18%) of the post-T primary lung cases were adequate for NGS testing. Conclusion The use of aspirate smear slides for NGS testing can increase the percentage of adequate molecular results.