Gastrointestinal Stromal Tumors (GISTs), c-KIT Mutation Analysis
Also known as: Tyrosine Kinase Inhibitor (TKI, Imatinib) Responsiveness
Use
c-KIT is a proto-oncogene that encodes a type III transmembrane tyrosine kinase. c-KIT and its ligand stem cell factor have a key role in survival, proliferation, differentiation, and functional activation of cells.
Special Instructions
Not provided.
Limitations
Genomic DNA is purified from the specimen provided. Exons 9, 11, 13, and 17 of c-KIT gene coding are subjected to PCR amplification and bidirectional sequencing in duplicate to identify sequence variations. The assay has a sensitivity to detect approximately 10% of cells containing the c-KIT mutations in a background of nonmutant cells but will not detect mutations below this sensitivity level. Secondary mutations often occur in c-KIT kinase domains following imatinib treatment, leading to resistance. The test was developed by LabCorp and has not been cleared or approved by the FDA; however, the FDA has determined such clearance is unnecessary.
Methodology
PCR-based (PCR)
Biomarkers
No genes
Gene
LOINC Codes
- 55201-8
- 48004-6
- 48005-3
- 77202-0
- 49549-9
- 72486-4
- 8100-0
Result Turnaround Time
10-14 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Formalin-fixed, paraffin-embedded (FFPE) block or five unstained slides from paraffin block in 10-μM sections
Minimum Volume
2 mm x 2 mm tumor area with ≥50% tumor
Container
Slides or blocks
Collection Instructions
Provide a copy of the pathology report. Direct any questions to oncology customer service at 800-345-4363.
Storage Instructions
Maintain blocks and slides at room temperature.
Causes for Rejection
Tumor block containing insufficient tumor tissue or tumor fixed in a heavy metal fixative; broken or stained slides
Other tests from different labs that may be relevant