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Updated: Jun 2, 2026
Ultra-Fast Amplicon-Based Next-Generation Sequencing in Non-Squamous Non-Small Cell Lung Cancer
Published on: September 8, 2023
Pyrosequencing, a method approved to detect the two major EGFR mutations for anti EGFR therapy in NSCLC
Sandrine Dufort1, Marie-Jeanne Richard, Sylvie Lantuejoul
1UM Biochimie des Cancers et Biothérapies, CHU Grenoble, Institut de Biologie et Pathologie, Grenoble, France.
Background:
Epidermal Growth Factor Receptor (EGFR) mutations, especially in-frame deletions in exon 19 (ΔLRE) and a point mutation in exon 21 (L858R) predict gefitinib sensitivity in patients with non-small cell lung cancer. Several methods are currently described for their detection but the gold standard for tissue samples remains direct DNA sequencing, which requires samples containing at least 50% of tumor cells.
Methods:
We designed a pyrosequencing assay based on nested PCR for the characterization of theses mutations on formalin-fixed and paraffin-embedded tumor tissue.
Results:
This method is highly specific and permits precise characterization of all the exon 19 deletions. Its sensitivity is higher than that of "BigDye terminator" sequencing and enabled detection of 3 additional mutations in the 58 NSCLC tested. The concordance between the two methods was very good (97.4%). In the prospective analysis of 213 samples, 7 (3.3%) samples were not analyzed and EGFR mutations were detected in 18 (8.7%) patients. However, we observed a deficit of mutation detection when the samples were very poor in tumor cells.
Conclusions:
pyrosequencing is then a highly accurate method for detecting ΔLRE and L858R EGFR mutations in patients with NSCLC when the samples contain at least 20% of tumor cells.
