Impact and Reproducibility of In-House Targeted Next-Generation Sequencing Biomarker Testing in Non-Small-Cell Lung Cancer: An Italian Multi-Institutional Experience

Next-generation sequencing (NGS) allows the detection of multiple genetic targets in different tumor types. This study aimed to confirm the benefits of implementing NGS testing in-house for non-small-cell lung cancer (NSCLC) samples in molecular pathology laboratories. A multi-institutional study was conducted to evaluate the analytical performance, turnaround time, and feasibility of in-house NGS testing of 50 genes from 283 NSCLC samples. The first phase was a retrospective study with interlaboratory testing (21 samples), and the second phase was a prospective study with intralaboratory testing (262 samples). The retrospective study showed a 100% sequencing success rate for DNA and RNA, high interlaboratory concordance (95.2%), and a strong correlation (R2 = 0.94) between observed and expected single-nucleotide variant/insertion and/or deletion variant allele fraction. The prospective study showed a sequencing success rate of 99.2% for DNA and 98% for RNA. NGS identified 285 relevant variants (81.1% single-nucleotide variants/insertion and/or deletion variants, 9.8% copy number variants, and 9.1% gene fusions). Co-mutations with potential clinical relevance were detected in 20.5% of samples positive for the main oncogenic drivers in NSCLC. In addition, 11% of samples wild type for the main oncogenic drivers were positive for alterations in other relevant genes. The in-house NGS experience showed a median turnaround time from sample processing to molecular report of 4 days. In conclusion, this study demonstrates the advantages of implementing in-house NGS testing in molecular pathology laboratories.