Methodology: PCR

Clinical Significance:
PhenoPath’s real-time PCR assay utilizes allele-specific PCR to detect BRAF V600 mutations, including the V600E BRAF mutation (c.1799T>A) as well as a subset of other less common activating BRAF V600 mutations (such as V600K, V600D, etc); however, these mutations cannot be distinguished by this assay.

BRAF V600 mutations occur in a variety of human malignancies, including (but not limited to) subsets of colorectal carcinomas, papillary thyroid carcinomas, melanomas*, gastrointestinal stromal tumors (GIST) that are negative for KIT and PDGFRA mutations, CNS neoplasms, malignant peripheral nerve sheath tumors, Langerhans cell histiocytoses, and Erdheim-Chester disease; and in virtually all cases of hairy cell leukemia.

In colorectal carcinomas, the V600E mutation has been associated with a lack of response to epidermal growth factor receptor (EGFR) targeted therapies (cetuximab or panitumumab). When evaluated in conjunction with KRAS/NRAS mutation testing, BRAF V600 mutation analysis may predict response to these therapies. Determination of BRAF mutation status can also be useful in the work-up hereditary non-polyposis colorectal carcinomas (HNPCC), as BRAF V600 mutations are found in non-hereditary/sporadic CRC cases exhibiting microsatellite instability, but not in HNPCC.

*For BRAF V600 testing in melanomas, please see BRAF IVD cobas v600.

Organ: Blood/Bone Marrow, Brain/CNS, Colon & Other GI, Lung, Lymph Node / Spleen, Skin & Mucosa, Thyroid

Disease State: Adenocarcinoma, Astrocytoma, Hairy Cell Leukemia, Langerhans Cell Histiocytosis, Lynch Syndrome / HNPCC, Oligodendroglioma

CPT Code(s): 81210; 88381 may apply (reference only; CPTs may vary)

Turnaround Time: Within 3-6 business days of receipt

Schedule: Tuesday and Friday

Specimen Requirements:
Formalin-fixed, paraffin-embedded (FFPE) tissue block, 10 FFPE tissue slides, or peripheral blood or bone marrow in EDTA or heparin.