Alternative Name
EGFR, epidermal growth factor receptor
Methodology
Molecular
Test Description
Bi-directional sequencing of exons 18-21 of the EGFR gene for detection of EGFR-activating mutations and TKI resistance mutations (including T790M) in these exons. Tumor enrichment is performed before extraction. Testing is approved for specimens from the state of New York.
Clinical Significance
EGFR mutation analysis is recommended in non-small cell lung carcinoma (NSCLC) to detect mutations (commonly L858R and exon 19 deletions) associated with increased sensitivity to EGFR tyrosine kinase inhibitors. Detection of TKI resistance mutations such as T790M in patients being treated with a TKI is useful for planning alternate treatment.
Specimen Requirements
- FFPE solid tumor tissue: Paraffin block is preferred. Alternatively, send 1 H&E slide plus 5-10 unstained slides cut at 5 or more microns. Please use positively-charged slides and 10% NBF fixative. Do not use zinc fixatives.
- Fine needle aspirate (FNA): Requisition must note specimen is FNA. FFPE cell blocks are acceptable if pathologist attaches note verifying sample has >30% tumor or abnormal cells (required). Minimum 10^6 cells.
Storage and Transportation
Use cold pack for transporting block during summer to prevent block from melting. Slides can be packed at room temperature.
CPT Code(s)*
81235
Turnaround Time
7 days
Level of Service
Global