Test Code BRAFB Cell-Free DNA BRAF V600, Blood
Useful For
An alternative to invasive tissue biopsies for the determination of BRAF V600E and V600K alterations
Identification of patients with cancer who are most likely to benefit from targeted therapies
This test is not intended for serial monitoring of patients with cancer or as a screening test to identify cancer.
Genetics Test Information
This test evaluates cell-free DNA (cfDNA) in the peripheral blood for the presence of BRAF V600E or V600K alterations in patients with cancer and can be used to determine if these patients are candidates for targeted therapies.
Method Name
Digital Droplet Polymerase Chain Reaction (ddPCR)
Reporting Name
cfDNA BRAF V600 Test, BloodSpecimen Type
Whole bloodOrdering Guidance
This test is not a prenatal screening test.
Shipping Instructions
1. Samples should be transported at ambient temperature or refrigerated (4° C)
2. Samples are viable for 7 days in the Streck Black/Tan Top Tube Kit (T715)
Specimen Required
Supplies: Streck Black/Tan Top Tube Kit (T715)
Container/Tube: Streck Cell-Free DNA blood collection kit
Specimen Volume: Two 10-mL Streck Cell-Free DNA blood collection tubes
Additional Information: Only blood collected in Streck Cell-Free DNA tubes will be accepted for analysis. Whole blood will be processed to produce platelet-poor plasma before cfDNA isolation.
Specimen Minimum Volume
One 10 mL Streck cell-free DNA blood collection tube
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Ambient (preferred) | 7 days | |
Refrigerated | 7 days |
Reject Due To
All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.Clinical Information
This test uses DNA extracted from the peripheral blood to evaluate for the presence of BRAF V600E and V600K alterations. The BRAF gene is a member of the mitogen-activated protein/extracellular signal-regulated (MAP/ERK) kinase pathway, which plays a role in cell proliferation and differentiation. Dysregulation of this pathway is a key factor in tumor progression and BRAF alterations occur frequently in many different tumor types. BRAF variant analysis aids in the diagnosis of cancer types including anaplastic and papillary thyroid carcinoma, hairy cell leukemia, and papillary craniopharyngioma.
BRAF V600E and V600K alterations are associated with response or resistance to specific targeted therapies in cancer. Targeted cancer therapies are defined as antibody or small molecule drugs that block the growth and spread of cancer by interfering with specific cell molecules involved in tumor growth and progression. Multiple targeted therapies have been approved by the FDA for treatment of specific cancers. Molecular genetic profiling is often needed to identify targets amenable to targeted therapies and to minimize treatment costs and therapy-associated risks.
Interpretation
The interpretation of molecular biomarker analysis includes an overview of the results and the associated diagnostic, prognostic, and therapeutic implications.
Cautions
Patients with a negative test result may still harbor a V600E or V600K alteration. Variant testing of a tissue specimen for BRAF alterations should be considered for patients with a negative result with this test.
The limit of detection of this assay for the detection of BRAF V600E and V600K alterations is influenced by the amount of cell-free DNA (cfDNA) in the blood. This is a biological variable that cannot be controlled.
This assay was designed to detect V600E and V600K alterations. The sensitivity for rarer V600 alterations has not been established.
This test has not been clinically validated for use as a tool to monitor response to therapy or for early detection of tumors.
This test cannot differentiate between somatic and germline alterations. Additional testing may be necessary to clarify the significance of results if there is a potential hereditary risk.
Supportive Data
This test has been evaluated by our laboratory as an alternative to assessing paraffin embedded tumor specimens for BRAF alterations in patients with advanced melanoma. Those studies revealed that this assay has a high positive predictive value (100% in our study) for the presence of a BRAF V600 alteration in a patient's tumor and high concordance between the specific alteration type observed in the patient's plasma and tumor.
While the positive predictive value of this assay was very high, the negative predictive value of the assay in this study (using BRAF tissue result as the gold standard) was only 71%.
Method Description
Blood samples are collected in Streck Cell-Free DNA blood collection tubes. Cell-free DNA (cfDNA) is isolated from double-centrifuged plasma and assessed for the presence of the BRAF V600E and BRAF V600K alterations using digital droplet polymerase chain reaction (ddPCR).(Unpublished Mayo method)
Day(s) Performed
Varies
Report Available
5 to 10 daysPerforming Laboratory
Mayo Clinic Laboratories in RochesterTest Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.CPT Code Information
81210
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
BRAFB | cfDNA BRAF V600 Test, Blood | 93690-6 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
48044 | Result Summary | 50397-9 |
48045 | Result | 93690-6 |
48046 | Interpretation | 69047-9 |
48047 | Additional Information | 48767-8 |
48048 | Specimen | 31208-2 |
48049 | Source | 31208-2 |
48050 | Released By | 18771-6 |
606201 | Method | 85069-3 |
606202 | Disclaimer | 62364-5 |
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Reference Values
An interpretive report will be provided.