Alternative Name
EGFRvIII, epidermal growth factor receptor variant III
Methodology
Molecular
Test Description

The EGFRvIII Analysis test is a real-time quantitative RT-PCR assay that is capable of detecting the EGFRvIII mutation that results from an inframe deletion of 801 base pairs spanning exons 2-7 of the coding sequence. Expression of EGFRvIII is quantified by calculating the ratio of (EGFRvIII/EGFRVIII + wild-type EGFR) x 100.

Clinical Significance

The EGFRvIII Analysis assay is capable of detecting the EGFRvIII mutation. The mutant receptor is incapable of binding any known ligand. The pro-tumorigenic effects of EGFRvIII seem to rely directly on its ability to signal. EGFRvIII activates several downstream pathways, but a considerable amount of evidence indicates that it preferentially activates the PI3K/Akt signal transduction pathway. EGFRvIII is the most common mutation in glioblastoma multiforme (GBM), occurring in 25-64% of these tumors. It is also found in 20-36% of breast cancers and in about 33% of head and neck squamous cell carcinoma (HNSCC) patients. Compared with wild-type EGFR, EGFRvIII appears to be relatively resistant to treatment with conventional anti-EGFR agents. So the therapeutic potential of targeting EGFRvIII in brain and other tumors is becoming increasingly apparent, with agents against EGFRvIII.

Specimen Requirements

FFPE 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.

Storage and Transportation

Use cold pack for transport, making sure cold pack is not in direct contact with specimen. All slides can be packed at room temperature.

CPT Code(s)*
81479x1
Turnaround Time

10 days

Level of Service
Global

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.