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
Provide a copy of the pathology report. Direct any questions regarding this test to oncology customer service at 800-345-4363. This assay currently is not available in New York state.
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
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