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BRAF Mutation Analysis
Test Code16767
CPT Codes
81210<br />
Preferred Specimen
Formalin-fixed, paraffin-embedded tissue
Minimum Volume
3 mL whole blood • 1 mL bone marrow aspirate • 4 unstained charged (+) slides
Other Acceptable Specimens
5 mL whole blood or 3 mL bone marrow aspirate collected in an EDTA (lavender-top) tube or sodium heparin (green-top) tube • 8 unstained charged (+) slides
Instructions
Do not reject specimens, send to laboratory for screening.
For submission of paraffin block, tissue source and block ID are required on the requisition form. A pathology report must be submitted.
For whole blood in EDTA specimens, sample type, collection time and date should be entered on tube and requisition form. Ship samples immediately to maintain stability. Ship samples room temperature or on ice pack in summer.
For submission of paraffin block, tissue source and block ID are required on the requisition form. A pathology report must be submitted.
For whole blood in EDTA specimens, sample type, collection time and date should be entered on tube and requisition form. Ship samples immediately to maintain stability. Ship samples room temperature or on ice pack in summer.
Transport Temperature
FFPE and slides: Room temperature
Whole blood and bone marrow: Refrigerated (cold packs)
Whole blood and bone marrow: Refrigerated (cold packs)
Specimen Stability
Room temperature: Preferred
Refrigerated: Acceptable
Frozen: Unacceptable
Refrigerated: Acceptable
Frozen: Unacceptable
Methodology
Next Generation Sequencing
FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.
Setup Schedule
Set up: Daily; Report available: 7 days
Reference Range
Not detected
Clinical Significance
BRAF encodes a serine/threonine protein kinase downstream of the epidermal growth factor receptor (EGFR) and the RAS family of small G-proteins (KRAS, HRAS and NRAS) in the MAPK pathway. BRAF is mutated in a variety of human tumors, most frequently in melanoma and in papillary thyroid cancer. BRAF mutations are also found in lower frequency in colorectal cancer, non-small cell lung cancer (NSCLC), acute myeloid leukemia (AML), hairy cell leukemia, glioma, sarcomas, breast cancer, hepatoma and ovarian cancer.
BRAF mutations are found clustered within the P-loop (exons 11&12) and activation domain (exon 15) of the kinase domain. A single glutamic acid for valine substitution at codon 600 (V600E) in exon 15 comprises approximately 90% of BRAF somatic mutations in cancer. In general, BRAF V600E mutations do not coexist with RAS mutations in the same tumor cells, suggesting that each of these genetic alterations is sufficient for activating downstream effectors that initiate or promote tumorigenesis.
The BRAF V600E mutation is also associated with significantly poor prognosis and higher recurrent and persistent disease in patients with melanomas, colorectal carcinoma, and papillary thyroid cancers. In patients with metastatic colorectal cancer, the presence of the BRAF V600E mutation in tumors with wild-type KRAS is associated with resistance to EGFR inhibitor therapy. In contrast, in patients with metastatic melanoma, BRAF V600E mutation may predict for response to BRAF inhibitors. Therefore, BRAF mutation analysis may be used either as a standalone test for the selection of cancer patients who might benefit from BRAF inhibitor therapies, or as an additional tool (along with RAS mutation analysis) for the selection of metastatic colorectal cancer patients that might benefit from EGFR-targeted therapies.
BRAF mutations are found clustered within the P-loop (exons 11&12) and activation domain (exon 15) of the kinase domain. A single glutamic acid for valine substitution at codon 600 (V600E) in exon 15 comprises approximately 90% of BRAF somatic mutations in cancer. In general, BRAF V600E mutations do not coexist with RAS mutations in the same tumor cells, suggesting that each of these genetic alterations is sufficient for activating downstream effectors that initiate or promote tumorigenesis.
The BRAF V600E mutation is also associated with significantly poor prognosis and higher recurrent and persistent disease in patients with melanomas, colorectal carcinoma, and papillary thyroid cancers. In patients with metastatic colorectal cancer, the presence of the BRAF V600E mutation in tumors with wild-type KRAS is associated with resistance to EGFR inhibitor therapy. In contrast, in patients with metastatic melanoma, BRAF V600E mutation may predict for response to BRAF inhibitors. Therefore, BRAF mutation analysis may be used either as a standalone test for the selection of cancer patients who might benefit from BRAF inhibitor therapies, or as an additional tool (along with RAS mutation analysis) for the selection of metastatic colorectal cancer patients that might benefit from EGFR-targeted therapies.
Performing Laboratory
Quest Diagnostics Nichols Institute
14225 Newbrook Drive
Chantilly, VA 20153
