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Test Code BRAFB Cell-Free DNA BRAF V600, Blood

Secondary ID

65100

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.

Highlights

This test evaluates peripheral blood for BRAF alterations in cell-free DNA.

 

Detection of BRAF alterations in melanoma patients can be used as an alternative for BRAF analysis of tissue.

 

Current data suggests that the efficacy of BRAF-targeted therapy and anti-MEK therapy in melanoma is limited to patients whose tumors harbor a V600E or V600K alteration.

Method Name

Digital Droplet Polymerase Chain Reaction (ddPCR)

Reporting Name

cfDNA BRAF V600 Test, Blood

Specimen Type

Whole blood


Ordering 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%.

Clinical Reference

1. Sanmamed MJ, Fernandez-Landazuri S, Rodriguez C, et al: Quantitative cell-free circulating BRAFV600E mutation analysis by use of droplet digital PCR in the follow-up of patients with melanoma being treated with BRAF inhibitors. Clin Chem. 2015;61(1):297-304

2. Schwarzenbach H, Hoon DS, Pantel K: Cell-free nucleic acids as biomarkers in cancer patients. Nat Rev Cancer. 2011 Jun;11(6):426-437

3. Johnson DB, Sosman JA: Update on the targeted therapy of melanoma. Curr Treat Options Oncol. 2013 Jun 14;(2):280-292

4. McArthur GA, Chapman PB, Robert C, et al: Safety and efficacy of vemurafenib in BRAF (V600E) and BRAF (V600K) mutation-positive melanoma (BRIM-3): extended follow-up of a phase 3, randomized, open-label study. Lancet Oncol. 2014 Mar;15(3):323-332

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 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test 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.

Specimen Retention Time

Whole Blood: 2 weeks (if available); Extracted DNA: 3 months