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Test Code EGFRS EGFR Gene, Targeted Mutation Analysis, 51 Mutation Panel, Tumor


Necessary Information


Pathology report must accompany specimen for testing to be performed.



Specimen Required


Submit only 1 of the following specimens:

 

Preferred:

Specimen Type: Tissue, smear stained with Diff Quik, fine needle aspirate (FNA), or pleural fluid in cell blocks

Container/Tube: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded (FFPE) tissue block.

 

Acceptable:

Specimen Type: Tissue, smear stained with Diff Quik, FNA, or pleural fluid in cell block or cytology blood smear

Container/Tube: Slides

Specimen Volume: 1 Hematoxylin and eosin stained and 5 unstained

Collection Instructions:

1. For FFPE tissue, FNA or pleural fluid: Submit 1 slide stained with hematoxylin and eosin and 5 unstained, non-baked slides with 5 to 10-micron thick sections of the tumor tissue.

2. For cytology blood smear: Submit up to 2 slides stained with Diff Quik


Useful For

Identifying non-small cell lung cancers that may respond to epidermal growth factor receptor-targeted therapies

Additional Tests

Test ID Reporting Name Available Separately Always Performed
SLIRV Slide Review in MG No, (Bill Only) Yes

Testing Algorithm

When this test is ordered, slide review will always be performed at an additional charge.

Method Name

Polymerase Chain Reaction (PCR)

Reporting Name

EGFR Gene, Mutation Analysis, Tumor

Specimen Type

Varies

Specimen Minimum Volume

Formalin-fixed, paraffin-embedded tissue block or Slides: see Specimen Required
Cytology smear stained with Diff Quik: >1000 cells

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Refrigerated 

Reject Due To

Specimens that have been decalcified (all methods) Reject

Clinical Information

Targeted cancer therapies are defined as antibody or small molecule drugs that block the growth and spread of cancer by interfering with specific cell molecules involved in tumor growth and progression. Multiple targeted therapies have been approved by the US Food and Drug Administration for treatment of specific cancers. Molecular genetic profiling is often needed to identify targets amenable to targeted therapies and to minimize treatment costs and therapy-associated risks.

 

Epidermal growth factor receptor (EGFR) protein is activated by the binding of specific ligands, resulting in activation of the RAS/MAPK pathway. Activation of this pathway induces a signaling cascade ultimately leading to cell proliferation. Dysregulation of the RAS/MAPK pathway is a key factor in tumor progression for many solid tumors. Targeted therapies directed to tumors harboring activating mutations within the EGFR tyrosine kinase domain (exons 18-21) have demonstrated some success in treating a subset of patients with non-small cell lung cancer.

 

As a result, the mutation status of EGFR can be a useful marker by which patients are selected for EGFR-targeted therapy.

Reference Values

An interpretive report will be provided.

Interpretation

The interpretation of molecular biomarker analysis includes an overview of the results and the associated diagnostic, prognostic, and therapeutic implications.

Cautions

A negative (wildtype) result does not rule out the presence of a mutation that may be present but below the limits of detection for this assay (approximately 10%).

 

A negative (wildtype) result does not rule out the presence of other activating mutations in the EGFR gene.

 

Not all patients that have activating EGFR mutations detected by this assay respond to EGFR-targeted therapies.

 

Rare genetic alterations (ie, polymorphisms) exist that could lead to false-negative or false-positive results.

Method Description

All ordered specimens will undergo EGFR testing. The EGFR test is a qualitative polymerase chain reaction (PCR)-based assay employing fluorescently labeled probes that are used to detect exon 18 (G719A/C/S), exon 21 (L858R, L861Q), exon 20 (T790M, S768I) mutations, exon 19 deletions and exon 20 insertions of the EGFR gene.(Unpublished Mayo method)

 

Exon

Mutation

Protein change

Nucleotide change

Genotype

18

G719A

p.Gly719Ala

c.2156G>C

G719A/C/S

G719C

p.Gly719Cys

c.2155G>T

G719C

p.Gly719Cys

c.2154_2155delinsTT

G719S

p.Gly719Ser

c.2155G>A

19

Deletion 9

p.Leu747_Ala750delinsPro

c.2238_2248delinsGC

Exon 19 deletion

c.2239_2248delinsC

p.Leu747_Ala750delinsSer

c.2240_2248del

p.Leu747_Glu749del

c.2239_2247del

Deletion 12

p.Leu747_Thr751delinsPro

c.2239_2251delinsC

p.Leu747_Thr751delinsSer

c.2240_2251del

Deletion 15

p.Glu746_Ala750del

c.2235_2249del

c.2236_2250del

p.Leu747_Thr751del

c.2239_2253del

c.2240_2254del

c.2238_2252del

p.Glu746_Thr751delinsAla

c.2237_2251del

p.Glu746_Thr751delinsIle

c.2235_2252delinsAAT

p.Glu746_Thr751delinsVal

c.2237_2252delinsT

p.Lys745_Ala750delinsThr

c.2234_2248del

p.Glu746_Thr751delinsLeu

c.2236_2253delinsCTA

p.Glu746_Thr751delinsVal

c.2237_2253delinsTA

p.Glu746_Thr751delinsAla

c.2235_2251delinsAG

p.Glu746_Thr751delinsGln

c.2236_2253delinsCAA

p.Ile744_Ala750delinsValLys

c.2230_2249delinsGTCAA

Deletion 18

p.Leu747_Pro753delinsSer

c.2240_2257del

p.Glu746_Ser752delinsVal

c.2237_2255delinsT

p.Leu747_Ser752del

c.2239_2256del

p.Glu746_Thr751del

c.2236_2253del

p.Leu747_Pro753delinsGln

c.2239_2258delinsCA

p.Glu746_Ser752delinsAla

c.2237_2254del

p.Glu746_Ser752delinsAsp

c.2238_2255del

p.Glu746_Pro753delinsValSer

c.2237_2257delinsTCT

p.Glu746_Ser752delinsIle

c.2236_2255delinsAT

c.2236_2256delinsATC

p.Glu746_Ser752delinsVal

c.2237_2256delinsTT

c.2237_2256delinsTC

c.2235_2255delinsGGT

Deletion 21

p.Leu747_Pro753del

c.2238_2258del

p.Glu746_Ser752del

c.2236_2256del

Deletion 24

p.Ser752_Ile759del

c.2253_2276del

20

T790M

p.Thr790Met

c.2369C>T

T790M

S768I**

p.Ser768Ile

c.2303G>T

S768I

InsG

p.Asp770_Asn771insGly

c.2310_2311insGGT

Exon 20 insertion

InsASV(9)

p.Val769_Asp770insAlaSerVal

c.2307_2308insGCCAGCGTG

InsASV(11)

p.Val769_Asp770insAlaSerVal

c.2309_2310delinsCCAGCGTGGAT

InsSVD

p.Asp770_Asn771insSerValAsp

c.2311_2312insGCGTGGACA

InsH

p.His773_Val774insHis

c.2319_2320insCAC

21

L858R

p.Leu858Arg

c.2573T>G

L858R

c.2573_2574delinsGT

c.2573_2574delinsGA

L861Q

p.Leu861Gln

c.2582T>A

L861Q

Day(s) Performed

Monday through Friday

Report Available

4 to 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

81235-EGFR (epidermal growth factor receptor) (eg, non-small cell lung cancer) gene analysis, common variants (eg, exon 19 LREA deletion, L858R, T790M, G719A, G719S, L861Q)

88381-Microdissection, manual

LOINC Code Information

Test ID Test Order Name Order LOINC Value
EGFRS EGFR Gene, Mutation Analysis, Tumor 21665-5

 

Result ID Test Result Name Result LOINC Value
616123 Result Summary 50397-9
616124 Result 21665-5
616125 Interpretation 69047-9
616126 Specimen 31208-2
616127 Source 31208-2
616128 Tissue ID 80398-1
616129 Released By 18771-6

Disease States

  • Non-small cell lung cancer

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.