Table 2.
Main target genes and mutations in non-small cell lung cancer (NSCLC) and summary of most frequently used liquid biopsy assays used for their assessment. Abbreviations: ddPCR: digital droplet PCR; NGS: next-generation sequencing; RT-PCR: real-time PCR; * e.g., Oncomine™ Lung cfDNA Assay, FoundationOne® Liquid CDx, GUARDANT360®, InVisionFirst®-Lung).
| Target Genomic Alteration | Most Frequent Liquid Biopsy Assays |
Relevant Features | ||
|---|---|---|---|---|
| EGFR | Del19 and p. L858R | RT-PCR | -Cobas® EGFR Mutation Test v2 -IdyllaTM ctEGFR Mutation Test -EntroGen ctEGFR Mutation Detection Kit |
-Cobas®: 79% concordance with positive tissue test (FLAURA trial) |
| p. T790M | RT-PCR | -Cobas® EGFR Mutation Test v2 -IdyllaTM ctEGFR Mutation Test -EntroGen ctEGFR Mutation Detection Kit |
-Cobas®: 51% concordance with positive tissue test (AURA3 trial) -Relevance of tissue rebiopsies in case of negative plasma test |
|
| Droplet Digital™ PCR | -71% vs. 41% sensitivity, 83% vs. 100% specificity as compared to Cobas®, and 74% concordance with tissue test (AURA trial, 38 samples) | |||
| BEAMing digital PCR | -81% vs. 73% sensitivity, 58% vs. 67% specificity as compared to Cobas® (AURA trial, 72 samples) | |||
| NGS * | -For GUARDANT360® 70-gene NGS: 85% concordance with positive tissue test (Therascreen EGFR RGQ PCR Kit, Qiagen) | |||
| p. C797S | RT-PCR (EntroGen ctEGFR Mutation Detection Kit) | |||
| ddPCR or NGS* | ||||
| ALK | Fusions and mutations | RT-PCR | -From plasma or platelets (65–79% sensitivity, higher for platelets; 89–100% specificity) | |
| NGS * | -Allows identification of distinct fusion partners | |||
| MET | Exon 14 skipping and amplifications | ddPCR or NGS * | -ddPCR for MET amplification: 86% sensitivity and 100% specificity as compared with positive tissue FISH | |
| BRAF | Mutations | RT-PCR | -Competitive Allele-Specific TaqMan® PCR | -29% sensitivity, 93% specificity, and 89% concordance as compared with positive tissue test |
| -IdyllaTM ctBRAF Mutation Test | ||||
| ddPCR or NGS * | ||||
| ROS1 | Fusions and mutations | NGS * | -InVisionFirst®-Lung: 67% sensitivity for ROS1/ALK fusions at diagnosis | |
| RET | Fusions and mutations | NGS * | -Allows identification of distinct fusion partners | |
| KRAS | Mutations | RT-PCR, ddPCR, or NGS * | ||