Biopsy Method and Needle Size on Success of Next-Generation Sequencing in NSCLC: A Brief Report

Introduction: Next-generation sequencing (NGS) is essential to the care of patients with NSCLC. Nevertheless, NGS is dependent on adequate material from biopsy. We evaluated the impact of biopsy method and needle gauge necessary for optimizing success in tissue NGS.

Methods: A total of 1660 formalin-fixed, paraffin-embedded samples were submitted to Caris Life Sciences from 2007 to 2022 for tumor profiling. The results of NGS assays were linked with retrospective biopsy data for patients with lung cancer treated at USC/Norris Cancer Center to create a database with the following parameters: demographics, biopsy method, tumor location (lung mass versus lymph node versus metastasis), needle gauge, number of needle passes, complications, tumor volume, DNA content, and status of NGS. Fisher's exact test and analysis of variance were performed to determine the impact of biopsy method and needle gauge (G).

Results: In total, 77 computed tomography (CT)-guided transthoracic core needle (CT-TTCN) biopsies, 74 endobronchial ultrasound (EBUS)-guided transbronchial needle aspirations (TBNAs), 27 bronchial forceps biopsies, and 107 surgical resections were included. Furthermore, 41 of 77 CT-TTCN biopsies (53.2%), 43 of 74 EBUS-TBNAs (58.1%), 22 of 27 bronchial forceps biopsies (81.5%), and 105 of 107 surgical resections (98.1%) underwent successful NGS assays. The probability of successful NGS completion for lung cancers was highest in surgical resections and bronchial forceps biopsies. Needle-based biopsies were more successful when a needle larger than 20G was used. Complication rates were higher for CT-TTCN biopsies compared with EBUS-TBNA (p < 0.0001). Overall, the DNA yield was significantly higher in EBUS-TBNA compared with CT-TTCN biopsies in primary lung sites (p = 0.0002). EBUS-TBNA was found to have higher success rates in NGS compared with CT-TTCN for both primary lung lesions (p = 0.023) and lymph node targets (p = 0.035).

Conclusions: The less invasive EBUS-TBNAs had higher success rates in NGS than CT-TTCN biopsies and resulted in higher DNA concentrations. In CT-TTCN biopsies, use of 20G or smaller needles is associated with a higher risk of obtaining an inadequate specimen regardless of the number of passes taken. Surgical and bronchial forceps biopsies had highest success in achieving NGS.