Circulating Tumor DNA for Mutation Profiling Among Patients With Advanced Lung Cancer

Circulating tumor (ct)DNA assays could provide additional analysis to tissue biopsies for mutation profiling among patients with advanced lung cancer.

In this study there were 173 patients with lung cancer who underwent next-generation sequencing. Of the 173 patients, there were 107 with paired tumor tissue samples and 71 with sufficient DNA for digital droplet PCR testing after the ctDNA next-generation sequencing test. The next-generation sequencing included a targeted enrichment panel of 20 lung cancer-related genes. The ability of the ctDNA assay to identify genetic mutations or alterations was compared to tissue biopsy and droplet digital PCR. Additionally, treatment response to EGFR tyrosine kinase inhibitor (TKI) therapies based on the ctDNA assay results were evaluated.

There was ctDNA detected in 61.85% of patients and tissue mutations in paired ctDNA in 38.57% of patients. Circulating tumor DNA mutations were detected in paired tissues in 89.1% of patients. The number of patients with advanced non-small cell lung cancer who received genetic testing, as recommended by NCCN guidelines, increased by 12% when ctDNA was used. Concordance between digital droplet PCR and ctDNA reached 99.43% which the study authors noted was “relatively high.” Of the 17 patients who underwent EGFR TKI therapies based on the ctDNA assay results, 12 achieved a partial response and 2 had stable disease.

According to these results, the study authors wrote, “the ctDNA assay could partially overcome tumor heterogeneity in detecting mutations and provide complementary information on tumor genomic profiling.” They added that their findings “contribute to the growing body of evidence supporting the value of ctDNA analysis in advanced lung cancer management,” but that the ctDNA next-generation sequencing assay “has certain limitations in fully identifying all genomic alterations present in the tumor.”

Source:

Li K, Zhang N, Xu B, et al. Utility of circulating tumor DNA assay in identifying mutations and guiding matched targeted therapy in lung cancers. Clin Med Insights Oncol. Published online October 16, 2024. doi:10.1177/11795549241285238