EGFR TARGETED MUTATION ANALYSIS
Label Name: EGFR
Lab Discipline: Molecular Diagnostics
Institution:  Duke University Health System 
EAP ID:  LAB6310 
Last Review:  5/4/2017 5:13:00 PM
Specimen Type
  Tissue
Container & Volume
  Age Group   Container   Volume  
  0  - 99 Years CHECK WITH LABORATORY 10  ML
Collection Notes
  All:
  • Formalin Fixed Paraffin Embedded Tissue: The laboratory can receive either a paraffin embedded tissue block or nine freshly cut (within one week)10uM thick unstained slides containing 3 to 20 square mm of tissue. Unstained slides should be accompanied by an H&E stained slide for histologic evaluation.

    Plasma - 10 mL of blood is required for testing. Forward unprocessed specimen promptly. Plasma sample may be stored at 2oC to 8oC for up to 3 days, and at ¡Ü-70oC for up to 12 months.
 
Transport
  Formalin fixed paraffin embedded tissue blocks and slides can be sent to the lab at ambient temperature.

Plasma - 10 ml of blood is required for testing. Forward unprocessed specimen promptly. Blood sample may be stored at 2oC to 8oC for up to 3 days.
Turn Around Time -  Routine: 14 DAYS   Stat: N/A
Reference Values
EGFR
NO MUTATION DETECTED
Methodology
  The cobas EGFR Mutation Test v2 is a FDA approved, real-time PCR assay designed to detect Gly719 substitution mutations in exon 18, deletion mutations in exon 19, Thr790Met and Ser768Ile substitution mutations in exon 20, insertion mutations in exon 20, and Leu858Arg and Leu861Gln substitution mutations in exon 21. Testing is performed on DNA extracted from formalin-fixed, paraffin embedded tissue that is microscopically enriched for tumor or plasma from peripheral blood. Detailed information regarding methodology, performance characteristics and limitations of this assay can be found in the cobas® Mutation Test v2 product insert at https://www.accessdata.fda.gov/cdrh_docs/pdf12/P120019S007c.pdf.

This assay is cleared for in vitro diagnostic use by the U.S. Food and Drug Administration and verified by the DUHS Clinical Molecular Diagnostics Laboratory. This laboratory is certified under the Clinical Laboratory Improvement Amendments of 1988 ("CLIA") as qualified to perform high complexity clinical testing.
   
   
Clinical Significance and Interpretive Data
    In the United States, approximately 10-20% of non-small cell lung cancers (NSCLC) contain activating mutations in the epidermal growth factor receptor (EGFR) tyrosine kinase domain. These mutations are more common in patients of East Asian ethnicity, women and patients who have never smoked. The majority of activating mutations occur in exons 18 to 22, with small in-frame deletions in exon 19 and the L858R point mutation in exon 21 comprising 80-90% of these mutations. Patients with point mutations at codons 719, 858 or 861 or in-frame deletions in exon 19 have a higher rate of response to small molecule tyrosine kinase inhibitors (TKIs) such as erlotinib and gefitinib when compared to patients without activating EGFR mutations. In addition, activating EGFR tyrosine kinase domain mutations are associated with improved prognosis in NSCLC, even in the absence of TKI treatment. In contrast, secondary mutations in codon 790 are associated with the development of resistance in patients treated with TKIs.

References:

Eberhard, D.A., et al., Mutations in the epidermal growth factor receptor and in KRAS are predictive and prognostic indicators in patients with non-small-cell lung cancer treated with chemotherapy alone and in combination with erlotinib. J Clin Oncol, 2005. 23(25): p. 5900-9.

Lynch, T.J., et al., Activating mutations in the epidermal growth factor receptor underlying responsiveness of non-small-cell lung cancer to gefitinib. N Engl J Med, 2004. 350(21): p. 2129-39.

Mok, T.S., et al., Gefitinib or carboplatin-paclitaxel in pulmonary adenocarcinoma. N Engl J Med, 2009. 361(10): p. 947-57.

Paez, J.G., et al., EGFR mutations in lung cancer: correlation with clinical response to gefitinib therapy. Science, 2004. 304(5676): p. 1497-500.

Pao, W., et al., Acquired resistance of lung adenocarcinomas to gefitinib or erlotinib is associated with a second mutation in the EGFR kinase domain. PLoS Med, 2005. 2(3): p. e73.

National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology-Non Small Cell Lung Cancer, Version 5.2017.

Prescription Information or package insert for IRESSA (gefitinib) and TARCEVA (erlotinib).

cobas® EGFR Mutation Test Kit v2 Package Insert
   
Indications
    The cobas® EGFR Test is used as a companion diagnostic test for TARCEVA®, a compound that reversibly inhibits the kinase activity of EGFR, preventing autophosphorylation of tyrosine residues associated with the receptor and thereby inhibiting further downstream signaling that promotes cell survival and proliferation. Erlotinib binding affinity for EGFR exon 19 deletion or exon 21 L858R mutations is higher than its affinity for wild-type receptor. Clinical trials have shown that patients with advanced NSCLC and with exon 19 deletion mutations or L858R substitution mutations in exon 21 that were treated with TARCEVA as first-line treatment, are likely to experience clinical benefit compared to patients treated with chemotherapy.
   
Limitations
    Variation in the sequences targeted by the primers or probes used in this test may result in failure to detect the presence of a mutation in EGFR exons 18, 19, 20, or 21. This assay may not detect mutations which are at a level below 5% or when less than 100 copies of mutant DNA per mL of plasma are present. This test has demonstrated cross-reactivity (results of “Mutation Detected”) to other exon 18, 19, 20, and 21 mutations, including the exon 19 Leu747Ser mutation, a rare acquired mutation that may confer resistance to TKI treatment.

The performance characteristics of this assay for the detection of EGFR mutations in plasma were assessed by correlating plasma and tissue samples from the ENSURE study, where the aggregate positive percent agreement between plasma and tissue was determined to be 76.7% (95% CI: 70.5-81.9%) and negative percent agreement to be 98.2% (95% CI: 95.4-99.3%). Additionally, a positive predictive value of 82.8-88.6% and negative predictive value of 97.4-96.0% were ascertained when assuming a mutation prevalence of 10-15% in the population.

   
Test Synonyms
  Synonym(s): erlotinib
Synonym(s): gefitinib
Synonym(s): Lung cancer
Synonym(s): NSCLC"cobas"
Molecular Diagnostics Laboratory
(MDX)

Medical Director:
 Michael Datto, M.D., Ph.D.
 Phone: 919-684-6965
 Email: michael.datto@duke.edu
Lab Director:
 Catherine Rehder Ph.D, FACMG
 Phone: 919-613-8434
 Email: catherine.rehder@duke.edu
Lab Director:
 Siby Sebastian Ph.D., DABMG
 Phone: 919-613-8432
 Email: siby.s@duke.edu

Address: 
 Wadsworth Bldg, Cytogenetics, Rm 0220
 2351 Erwin Rd
 Durham,  NC  27705
 Phone: 919-684-2698
 FAX: 919-668-5424

Performing Times: