Overview

A 105-gene next-generation sequencing (NGS) panel for lung cancer is a targeted assay that reads the tumor genome to surface somatic alterations clinicians use to guide therapy. Rather than interrogating one gene at a time, the panel captures hundreds of clinically relevant regions in a single workflow, producing one integrated report. This article explains the molecular mechanism behind such panels — how DNA is prepared, sequenced, and interpreted — so procurement and clinical teams can understand what the result actually represents.

From Tissue to Sequence Library

The process begins with nucleic acid extracted from a formalin-fixed, paraffin-embedded (FFPE) tissue block or a small volume of plasma-derived circulating tumor DNA (ctDNA). Targeted regions are captured using hybridization-based probes or amplicon enrichment, then clustered and sequenced on a high-throughput platform. During sequencing, millions of short reads are generated and aligned to a reference genome. Unique molecular identifiers are often added so that low-frequency variants, common in ctDNA, can be distinguished from sequencing errors.

Variant Classes the Panel Detects

A well-designed lung cancer panel reports several alteration types within one assay. Single nucleotide variants (SNVs) and small insertions or deletions (indels) affect coding sequence and protein function. Copy number variants (CNVs) reveal gene amplification or loss, while gene fusions and rearrangements are identified from split reads or paired-end signatures. Together these classes describe the tumor's driver architecture rather than a single isolated mutation.

Turning Reads into Clinical Meaning

After alignment, a bioinformatics pipeline annotates each variant and filters artifacts. Remaining variants are classified by established frameworks that weigh population frequency, predicted impact, and prior clinical evidence. The output is a tiered report that separates variants with strong therapeutic or trial associations from those of uncertain significance. Accurate classification depends on validated pipelines and transparent laboratory methods, which is why assay validation and reporting standards matter as much as the gene list itself.

FAQ

Q: Does the panel require a fresh tissue sample? A: No. Most 105-gene lung panels are validated for FFPE sections, which are standard in pathology archives, as well as for ctDNA from plasma when tissue is limited.

Q: Can one test replace multiple single-gene assays? A: Yes. A single NGS panel reports SNVs, indels, CNVs, and fusions together, reducing the tissue and turnaround burden of running separate tests.

Q: Are all detected variants actionable? A: No. Reports distinguish variants with established therapeutic or trial relevance from variants of uncertain significance, and not every alteration has an approved matched therapy.

Q: How is low tumor content handled? A: Deep sequencing and unique molecular identifiers help recover signal from samples with low tumor fraction, though very sparse tissue may still yield limited data.