Epidermal Growth Factor Receptor (EGFR) Gene Mutation Analysis, Non−Small-cell Lung Cancer (Single-base Extension)

Formalin-fixed, paraffin-embedded (FFPE) tissue block or slides from NSCLC

Five unstained slides and one matching H&E-stained slide at 10 μM or formalin-fixed, paraffin-embedded tissue block

Two unstained slides and one matching H&E-stained slide at 10 μM (samples with >4 mm² and ≥50% tumor content are preferred)

Slides or blocks

Submit blocks/slides at room temperature.

Tumor block containing insufficient tumor; tissue or tumor fixed in a heavy metal fixative; broken or stained slides

In non-small cell lung cancer, many mutations in EGFR are associated with responsiveness to EGFR tyrosine kinase inhibitor (TKI) therapy. In contrast, some mutations in EGFR are associated with resistance to EGFR TKI therapy, including T790M and EGFR exon 20 insertions. The T790M mutation is a known mechanism of resistance and is commonly associated with relapse following initial therapy with EGFR TKI.

The EGFR test is designed to detect mutations in exon 18, 19, 20 and 21 of the EGFR gene. These mutations account for >99% of all reported EGFR mutations in NSCLC patients. Samples with results reported as "no mutation detected" may harbor EGFR mutations that are not detected by the assay.

Detection of mutation is dependent on sample integrity and the amount of amplifiable DNA present in the specimen. The methods used in this assay are highly selective and, depending on the total amount of DNA present, can detect approximately 2% to 20% of mutant in a background of wild-type genomic DNA.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

SNaPshot Multiplex PCR (primer extension-based method)