NRAS Mutations

Interpretation

Guidelines

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

Method

Next-generation sequencing. The NRAS gene is captured, sequenced, and analyzed. For additional method details see methods for UW Oncoplex. 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

• De Mattos-Arruda L, Dienstmann R, and Tabernero J. Development of molecular biomarkers in individualized treatment of colorectal cancer. Clin Colorectal Cancer 2011, 10:279-89. 21729679
• De Roock W, et al. Effects of KRAS, BRAF, NRAS, and PIK3CA mutations on the efficacy of cetuximab plus chemotherapy in chemotherapy-refractory metastatic colorectal cancer: a retrospective consortium analysis. Lancet Oncol 2010, 11:753-62. 20619739
• Schirripa M, et al. Role of NRAS mutations as prognostic and predictive markers in metastatic colorectal cancer. Int J Cancer 2015, 136:83-90. 24806288
• Irahara N, et al. NRAS mutations are rare in colorectal cancer. Diagn Mol Pathol 2010, 19:157-63. 20736745
• Janku F, et al. PIK3CA mutations frequently coexist with RAS and BRAF mutations in patients with advanced cancers. PLoS One 2011, 6:e22769. 21829508
• Johnson DB, Smalley KS, and Sosman JA. Molecular pathways: targeting NRAS in melanoma and acute myelogenous leukemia. Clin Cancer Res 2014, 20:4186-92. 24895460
• Zhao Y and Adjei AA. The clinical development of MEK inhibitors. Nat Rev Clin Oncol 2014, 11:385-400. 24840079

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 (internal link).

Handling Instructions

Outside Laboratories: Ship at room temperature. Refrigerate blood, bone marrow and purified DNA for AML patients only.

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

Quantity

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

Processing

Receiving Instructions

Hold slides or tissue blocks at room temperature.

For AML patients only, Refrigerate blood, bone marrow and purified DNA.

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

81311, 81479

LOINC

21720-8

Interfaced Order Code

UOW2883

Billing Comments

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