EBUS-TBNA Cytological Samples for Comprehensive Molecular Testing in Non–Small Cell Lung Cancer

SIMPLE SUMMARY: Endobronchial-ultrasound transbronchial needle aspiration (EBUS-TBNA) is essential in the diagnosis and staging of NSCLC, but its usefulness for a full molecular characterization remains controversial. The aim of this prospective study was to assess if EBUS-TBNA samples were reliable for a comprehensive molecular and immunohistochemical testing in NSCLC. We prospectively evaluated EBUS-TBNA specimens for molecular characterization showing that they are useful for NSCLC genotyping and have the same potential to improve the selection of patients for personalized therapies as bronchial biopsy samples. EBUS-TBNA samples are reliable samples for NSCLC genotyping with the consequent potential to improve patient’s selection for targeted therapies. ABSTRACT: Clinical guidelines promote the identification of several targetable biomarkers to drive treatment decisions in advanced non-small cell lung cancer (NSCLC), but half of all patients do not have a viable biopsy. Specimens from endobronchial-ultrasound transbronchial needle aspiration (EBUS-TBNA) are an alternative source of material for the initial diagnosis of NSCLC, however their usefulness for a complete molecular characterization remains controversial. EBUS-TBNA samples were prospectively tested for several biomarkers by next-generation sequencing (NGS), nCounter, and immunohistochemistry (PD-L1). The primary objectives were to assess the sensitivity of EBUS-TBNA samples for a comprehensive molecular characterization and to compare its performance to the reference standard of biopsy samples. Seventy-two EBUS-TBNA procedures were performed, and 42 NSCLC patients were diagnosed. Among all cytological samples, 92.9% were successfully genotyped by NGS, 95.2% by nCounter, and 100% by immunohistochemistry. There were 29 paired biopsy samples; 79.3% samples had enough tumor material for genomic genotyping, and 96.6% for PD-L1 immunohistochemistry. A good concordance was found between both sources of material: 88.9% for PD-L1, 100% for NGS and nCounter. EBUS-TBNA is a feasible alternative source of material for NSCLC genotyping and allows the identification of patient candidates for personalized therapies with high concordance when compared with biopsy.