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Test ID: EGFR
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EGFR Mutation Analysis
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EGFR mutation detection by Real Time - PCR
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Useful For
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This analysis is based on current knowledge of the most common EGFR mutations and their presence in adenocarcinoma of the lung.
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Method name and description
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The tumor area was marked by consultant pathologist on a formalin-fixed paraffin-embedded (FFPE) slide. Genomic DNA was extracted and analyzed. The kit is based on a Real Time–PCR qualitative genotyping assay that uses fluorescently labeled probes for detection of 30 recurrent mutations G719X in exons 18, deletions in exon 19, T790M, S768I and insertions in exon 20 (resistance mutations) and L858R and L861Q in exon 21 of EGFR gene. This test will not identify rare mutations, such as E709K and D770-N771ins and is not appropriate for squamous cell carcinomas of lung. Only adenocarcinoma of the lung or lung cancers with adenocarcinoma component should be sent for testing.
The lower limit of mutation detection using this assay is 5 %.
Also, EGFR gene is tested by sequencing method in which exon 18, 19, 20 and 21 of EGFR gene are amplified and sequenced for detection and confirmation of the EGFR mutation if required.
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Reporting name
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EGFR mutation analysis:
Results are reported either EGFR mutation Detected or No mutation detected.
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Clinical information
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Somatic mutations in the EGFR tyrosine kinase domain are present in 10 – 40 % of non-small cell lung cancers. The presence of these mutations will predict clinical response or resistance to EGFR inhibitors. Rarely, T790M occurs in untreated patients and may be present as an underlying germline mutation; this test will not discriminate germline T790M mutations testing of tumor alone.
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Specimen type / Specimen volume / Specimen container
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FFPE tissue:
Option 1: Tissue sections of 10X (5-7 µm) fixed on non-charged slides with an H&E stained slide with marked tumor area.
Option 2: Tissue curls of 6 sections (10 µm) collected in 2 mL tube (e.g. Eppendorf).
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Collection instructions / Special Precautions / Timing of collection
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Specimens are arranged from Sunday to Wednesday from the Anatomical Pathology Department to the Molecular Genetics Laboratory at room temperature.
Please avoid direct sun light exposure.
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Relevant clinical information to be provided
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The following points must be provided:
- The tumor rich area on the must be marked by a consultant pathologist.
- Tumor percentage.
- Cancer type.
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Storage and transport instructions
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The specimens are stored and transported at Room Temperature (16 - 25° C).
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Specimen Rejection Criteria
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Consistent with Diagnostic Genomic Division policies.
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Biological reference intervals and clinical decision values
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For Real Time PCR: Detected amplifications of the mutant target with mutant allele frequency >5% are referred as Detected.
No amplification of the mutant allele due to low mutant allele frequency (<5%) or due to absence of mutant target are referred as No mutation detected.
For DNA sequencing: the lower limit of detection is >20%.
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Factors affecting test performance and result interpretation
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This test was validated for DNA extarcted from FFPE, the FFPE process has effect on the DNA quality and might result on DNA degradation. In addition, PCR inhibitors due to FFPE fixation might affect the PCR amplification.
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Turnaround time / Days and times test performed / Specimen retention time
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Days Test is Performed :Arranged by laboratory Rota.
TAT :
Single gene testing: 10 working days.
Reflex testing: 10 working days for the first test and an additional week (5 working days) for every following test.
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