Feasibility of Endobronchial Ultrasound-guided Transbronchial Needle Aspiration Cytology Specimens for Next Generation Sequencing in Non-small-cell Lung Cancer

Abstract

Introduction: Next generation sequencing (NGS) testing of lung cancer is recommended by guidelines, and endobronchial ultrasound (EBUS)-guided transbronchial needle aspiration (TBNA) often provides the only material available for testing. Previous studies have demonstrated successful NGS testing on cell block samples obtained by EBUS; however, cytology smears provide a more reliable sample with better DNA quality for testing. In this study, we aimed to determine the success rate of OncoScreen (50 gene) and OncoPlus (1213 gene) panel NGS testing of cytology samples obtained by EBUS utilizing 22- and 25-gauge needles.

Methods: Fifty-four patients underwent EBUS-TBNA of lung cancer for which NGS testing was requested. Data was analyzed for needle gauge, cytologic assessment, NGS test success, and sample type (cytology smear or cell block) used for testing.

Results: Eighty-five NGS tests were ordered on 54 samples. Overall, 95.3% of samples had successful testing. OncoScreen and OncoPlus panels were successful 98.0% and 91.4% of the time, respectively. Cytology smears provided testing material for 85% of the tests. OncoScreen testing was successful in 97.5% and 100% of the 22- and 25-gauge samples, respectively (P = 1.00). OncoPlus testing was successful in 91.3% and 100% of the 22- and 25-gauge samples, respectively (P = 1.00).

Conclusions: NGS can be reliably performed on cytology smears obtained from EBUS-TBNA. The size of the needle does not seem to affect the success rate of small or large panel NGS tests.

Keywords: Bronchoscopy; Cytologic techniques; Endosonography; High-throughput nucleotide sequencing; Lung neoplasms.