Gastrointestinal Stromal Tumor Mutations
Also known as: GISTMUT
Use
The test is used to detect activating mutations in KIT and PDGFRA genes associated with gastrointestinal stromal tumors (GISTs). Identifying these mutations helps predict the response to tyrosine kinase inhibitor (TKI) therapy, an important aspect of personalized treatment planning for patients diagnosed with GIST.
Special Instructions
Include surgical pathology report with the specimen. If multiple specimens are sent, an order comment indicating the specimen choice by ARUP pathologist is required. A Pathologist Block Selection Fee (ARUP test code 3002076) will be added if the first option is used. Specimens from New York clients will be sent to a New York state-approved laboratory.
Limitations
This test will not detect mutations in other locations within the KIT or PDGFRA genes, in other genes, or below the limit of detection. The test evaluates variants in tumor tissue only and cannot distinguish between somatic and germline variants. Some large insertion/deletion mutations greater than 60bp may not be detected. Tissue samples yielding less than 50ng may yield suboptimal results. The limit of detection is 5% mutant allele frequency for single nucleotide variants and multi-nucleotide variants smaller than 60bp.
Methodology
NGS (Targeted)
Biomarkers
Result Turnaround Time
10-12 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Container
Tissue transport kit (ARUP supply #47808)
Collection Instructions
Formalin fix (10 percent neutral buffered formalin) and paraffin embed tissue. Transport block and/or slides in a tissue transport kit. Transport 8 unstained 5-micron slides for resections. Transport 15 unstained 5-micron slides for small biopsies.
Storage Instructions
Room temperature, also acceptable refrigerated.
Causes for Rejection
Less than 10 percent tumor. Specimens fixed in fixative other than 10 percent neutral buffered formalin. Decalcified specimens. FNA smears with less than 50 tumor cells.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Indefinitely |
| Refrigerated | Indefinitely |
| Frozen | Unacceptable |