Braf - Melanoma

 


BRAF - MELANOMA
 
Gene Symbol: BRAF                            
Chromosomal Locus: 7q34
 
Protein: v-raf Murine Sarcoma Virus Oncogene Homolog B1      
 
TURNAROUND TIME: 8 days.
 
TESTING METHODOLOGY:  Polymerase chain reaction (PCR) and Shifted Termination Assay for detection of specific mutations.  Mutations detected are V600E (GTGGCG), and V600G (GTG>GGG).
 
SPECIMEN REQUIREMENTS:
 
Collect:  FFPE tumor specimen containing at least 30% tumor mass. 5 to 6 unsustained slides with 3-4 um thick tissue sections.  Must be accompanied by a pathology report and an H&E slide with the tumor regions identified.
  • Transport: Specimen should be shipped at Room Temperature (No Saturday delivery)
  • Unacceptable Conditions: Stained slides.        
A Molecular Genetics Laboratory Test Requisition must accompany the specimen. Contact the Molecular Laboratory at 918-502-1721 to obtain further information.
 
Note: Counseling and informed consent are recommended for genetic testing. A consent form is available as a resource but not required.
 
INTERPRETATIVE DATA:
 
Incidence:  Found in 40-80% of all malignant melanomas.
 
Disease Characteristics: In 2011, Zelboraf (BRAF kinase inhibitor) was FDA approved for inoperable or metastatic melanoma with a BRAF V600E mutation. These tumors have an 80% response rate to this drug.
 
Molecular Genetic Mechanism:  The BRAF V600E mutation enhances the proliferation and metastasis of tumor cells.
 
Clinical Sensitivity: The tissue sample submitted for testing must contain at least 30% tumor.  The assay will detect as low as a 5% population of mutant cells.
 
Analytical Sensitvitity:  95%
 
Test Limitations: Mutations not listed in the methodology will not be detected.   This test is only for somatic BRAF changes in cancer tissues. Rare diagnostic errors can occur due to primer / probe site mutations or rare polymorphisms.
 
INDICATIONS FOR USE:   
  • To determine whether a melanoma patient is a good candidate for Zelboraf.
ADDITIONAL REFERENCES: