EGFR by qPCR, with reflex to ALK and ROS1 by FISH
Epidermal growth factor receptor; ERBB; ERRP; HER1; mENA; ERBB1; PIG61; NISBD2; T790M; Exon_19 Deletion; L858R; L861Q; S768I; G719A; G719S; G719C; 2319-2320 insCAC; 2310-2311 insGGT; 2307-2308 insGCCAGCGRG (ins9); anaplastic lymphoma receptor tyrosine kinase; EML4-ALK fusion; ROS1 kinase marker; ROS; ROS 1; Crizotinib
- Tech Only CPT
- Tech Pro CPT 81235, G0452, 88381, 88363 reflex to additional 88374, G0452
- PowerPath Code EGFR reflexFISH
- Schedule Monday to Friday (Variable)
- Turn Around Time 4-7 Days
- Disease State Adenocarcinoma, Non Small Cell Lung Carcinoma (NSCLC)
- Methodology FISH, Real-Time PCR, Real-time Polymerase Chain Reaction (qPCR)-based analysis of 29 somatic mutations in the EGFR oncogene; FISH analysis utilizes 2 multicolored breakapart probes that span the ALK and ROS genes
Organs
Specimen Requirements
Transport block or 7 unstained sections on positively charged slides (cut at 4 microns).
Formalin-fixed, paraffin-embedded tissue blocks; fixed in 10% neutral-buffered formalin for at least 6 hours, and not more than 48 hours. Tissue should be prepared in sections between 4 and 6 microns thick.
Cell blocks and cytospins made from FNA (fine needle aspirates).
Cytopathology ThinPrep slides with morphologic correlation.
EDTA decal specimens are accepted.
Diagnostic Utility
EGFR affects tumor growth by modulation of cell proliferation, apoptosis, and neovascularization and present in 10-12%, of non-small cell carcinomas, primarily adenocarcinomas. EGFR mutants contain increased tyrosine kinase (TK) activity that signals increased cell turnover. Small molecule tyrosine kinase inhibitors (TKIs) currently approved for use in tumors with mutated EGFR include erlotinib (Tarceva).
ALK encodes receptor TK (intracellular) that can fuse with amino terminus portion of other genes. Present in 4-5% non-small cell carcinomas, primarily adenocarcinomas.EML-ALK fusion generates activated protein TK that is involved in inhibiting of apoptosis, promotion of proliferation and has shown sensitivity to crizotinib (Xalkori).
Gene fusions involving ROS1 are present in 1-2% of non-small cell carcinomas, primarily adenocarcinomas. ROS1 fusion is recommended for screening in cases that are EGFR mutation and ALK fusion negative.Resulting activation of ROS1 TK activity appears to be a growth driver in these tumors and can be sensitive to crizotinib (Xalkori).
Required Patient Info
Copy of the referring client's requisition form and pathology report to accompany specimen.
Storage and Transportation
Room temperature or refrigerated. Ship in cooled container during summer months.
Cause for Rejection
Specimens must have two matching patient identifiers.
Tissue not verified for the presence of tumor and specimens fixed in fixatives other than formalin are not acceptable.
Samples <5-10% tumor burden will not be tested for EGFR, as false negative results cannot be ruled out.
FISH testing will not be tested on slides containing fewer than 50 cells of interest.
Surgical pathology report not included.
Only specimens decalcified in EDTA will be accepted for molecular testing.
Testing may be cancelled if a sufficient amount of DNA cannot be extracted.
Retention
2 years DNA and raw data, 10 years FFPE
Comments
Only tissue that is clearly invasive carcinoma (established by histopathologic criteria) should be tested. Selection of tissue for the PCR assay should be performed by a pathologist.
This test was developed and its performance characteristics determined by CellNetix Labs LLC. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test. However, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. CellNetix is authorized under Clinical Laboratory Improvement Amendments (CLIA) to perform high-complexity testing.
FISH testing will only proceed following a negative EGFR result.