BRAF Mutations

Interpretation

Guidelines

• Genetics and Solid Tumor Diagnostic Testing
• Gynecologic Oncology (GYNPTH) Pathways
• Thoracic Oncology Reflex (THOR) Panel

Method

Next-generation sequencing. Exon 15 of the BRAF gene is captured and sequenced using next-generation sequencing to detect the V600E (GTG to GAG), V600K (GTG to AAG), and other clincally significant BRAF mutations. The test can normally detect a heterozygous mutation if it is present in more than about 5% of the cells in the sample. This test was developed and its performance characteristics determined by the Department of Laboratory Medicine at the University of Washington.

Reference Range

See individual components

Ref. Range Notes

No mutations detected.

References

• Di Nicolantonio F, et al. Wild-type BRAF is required for response to panitumumab or cetuximab in metastatic colorectal cancer. J Clin Oncol 2008, 26:5705-12. 19001320
• Pritchard CC and Grady WM. Colorectal cancer molecular biology moves into clinical practice. Gut 2011, 60:116-29. 20921207
• Sharma SG and Gulley ML. BRAF mutation testing in colorectal cancer. Arch Pathol Lab Med 2010, 134:1225-8. 20670148
• Flaherty KT, et al. Inhibition of mutated, activated BRAF in metastatic melanoma. N Engl J Med 2010, 363:809-19. 20818844
• Rubinstein JC, et al. Incidence of the V600K mutation among melanoma patients with BRAF mutations, and potential therapeutic response to the specific BRAF inhibitor PLX4032. J Transl Med 2010, 8:67. 20630094

Ordering & Collection

Specimen Type

Tumor Tissue, Purified DNA, accompanied by a PATHOLOGY REPORT for the tested tissue.

Collection

Requirements for Specimen Selection

• To ensure clinically relevant results, the most recent and/or metastatic sample is preferred to older specimens, provided sufficient tumor is present (see point 2).
• To ensure detection of all types of mutations there should be at least 10% tumor cells in the tissue area processed for DNA for mutation detection and 20% tumor cells for microsatellite instability evaluation. If there is more than one tissue block, please provide the block that has the greatest percentage of neoplastic nuclei.
• Tissue samples and pathology reports will be reviewed by directors upon receipt for acceptability prior to testing. Director consultation for tissue selection is available if needed (contact Genetics lab).

Specimen Types

Tissue samples

Send one of the following:

1. Slides: 1 slide at 4-micron thickness stained with hematoxylin-and-eosin (H&E) AND 10 unstained, non-baked slides at 10-micron thickness (a minimum of 5 unstained slides is acceptable). Unstained slides can be on charged or uncharged slides.
2. Tissue Blocks: Provide complete formalin-fixed tissue block containing tumor tissue. Tissue block will be returned at completion of testing.
3. Fresh/frozen tissue: 5 microgram tissue in cell culture medium or frozen tissue stored at -20C. Tumor percentage will not be determined prior to sequencing studies.

NOTE: In order to ensure that enough DNA is obtained, the minimum acceptable tissue area is 10 square millimeters when ten 10-micron slides are supplied (1 cubic millimeter of tissue).

Purified DNA

5 micrograms ANDa reference hematoxylin-and-eosin (H&E) stained slide and pathology report required.

Bone Marrow

1 to 2 mL Bone Marrow in LAVENDER TOP (EDTA) tube

Blood

6 mL blood in LAVENDER TOP (EDTA) tube.

Alternative specimens may be acceptable with approval (contact: 206-598-1149).

For ADD-ON after prior testing, contact Genetics lab.

Unacceptable samples

We cannot accept decalcified samples or tissue samples treated with fixatives other than formalin.

Quantity:

Requested:

• Tissue: 10 unstained slides (10-micron thickness) plus one H&E-stained slide.
• Extracted DNA: 5 microgram Bone Marrow: 2 mL
• Blood: 6 mL

Minimum:

• Tissue: 5 unstained slides (10-micron thickness) plus one H&E-stained slide.
• Extracted DNA: 100-250 nanograms Bone Marrow: 1 mL
• Blood: 3 mL

Forms & Requisitions

Genetics Requisition

Providers with access to the UW implementation of Epic (i.e., FHCC, HMC, SCCA, UWMC, UWNW) may order this test using the order "UW Genetics and Solid Tumor Test Request." See tip sheet for more information.

Handling Instructions

Attach a copy of the pathology report for the tumor sample being submitted.

Hold slides or tissue blocks at room temperature.

Outside Laboratories: Ship at room temperature.

Stability: unstained slides or tissue blocks stable at room temperature for at least 2 years.

Quantity

Requested: Amounts as noted above
Minimum: Amounts as noted above

Processing

Receiving Instructions

Hold slides or tissue blocks at room temperature.

Outside Laboratory: Ship at room temperature.

Stability: unstained slides or tissue blocks stable at room temperature for at least 2 years

Misc Sendout

Performance

Lab Department

Genetics(GEN)

Frequency

Run at least once a week; Typical Turnaround: 3 weeks *Turn around times may vary based on factors such as tissue acquisition and insurance preauthorization.

Available STAT?

No

Performing Location(s)

UW-MT	Genetics Attention: Genetics Lab Clinical lab, Room NW220 University of Washington Medical Center 1959 NE Pacific Street Seattle, WA 98195 Tel: 206-598–6429 M–F (7:30 AM–4:00 PM) Fax: 206-616-4584 Lab email: cgateam@uw.edu Tel (EXOME only): 206-543-0459	Faculty Jillian Buchan, PhD, FACMG Runjun Kumar, MD, PhD Regina Kwon, MD, MPH Christina Lockwood, PhD, DABCC, DABMGG Abbye McEwen, MD, PhD Colin Pritchard, MD, PhD Vera Paulson, MD, PhD Eric Konnick, MD, MS He Fang, PhD

Billing & Coding

CPT Codes

81210

LOINC

58483-9

Interfaced Order Code

UOW2181

Billing Comments

For pricing information, contact Client Support Services 206-520-4600 or 800-713-5198.