KRAS Mutation Analysis

Test Code

AP KRAS

Quest Code

16510

Alias/See Also

16510

CPT Codes
81275, 81276 (per DEX 81479 ZBY96)

Preferred Specimen

Formalin-fixed, paraffin-embedded tissue block

Minimum Volume

3 mL whole blood • 1 mL bone marrow aspirate • 4 unstained charged (+) slides

Other Acceptable Specimens

5 mL whole blood collected in an EDTA (lavender-top) tube or sodium heparin (green-top) tube • 3 mL bone marrow aspirate submitted in an EDTA (lavender-top) tube or sodium heparin (green-top) tube • 8 unstained charged (+) slides

Instructions

Submission of formalin-fixed, paraffin-embedded tissue is the preferred sample type. Other sample types listed are acceptable for testing. For submission of paraffin block, another preferred specimen type, tissue source and block ID are required on the requisition form. A pathology report must be submitted.

Whole blood: Follow standard whole blood collection procedures. Collect 3-5 mL whole blood in an EDTA tube. Record sample type, collection time and date onto tube and requisition form.

Bone marrow collection: The notation of sample type, collection time and date onto the tube and requisition form is required. Ship sample at refrigerated temperature or room temperature. Ship immediately to maintain stability.

Do not reject specimens. Send to laboratory for screening.

Transport Temperature

Room temperature

Specimen Stability

Formalin-fixed paraffin embedded tissue/slides
Room temperature: 5 years
Refrigerated: 5 years
Frozen: Unacceptable

Whole blood and bone marrow
Room temperature: 72 hours
Refrigerated: 72 hours
Frozen: Unacceptable

Methodology
Next Generation Sequencing

FDA Status
This test was developed and its analytical performance characteristics have been determined by Quest Diagnostics. It has not been cleared or approved by FDA. This assay has been validated pursuant to the CLIA regulations and is used for clinical purposes.

Setup Schedule

Set up: Daily; Report available: 7 days

Reference Range

Not detected

Clinical Significance

Activating KRAS mutations can be found in human malignancies with an overall frequency of 15-20%, including 25-35% of lung adenocarcinomas, 60-90% of malignant tumors of the pancreas, 30-45% of colorectal carcinomas, and 18-30% of hematopoietic neoplasms of myeloid origin. KRAS proteins have been shown to influence proliferation, differentiation, transformation, and apoptosis by relaying mitogenic and growth signals into the cytoplasm and the nucleus. Mutations leading to an amino acid substitution at positions 12, 13, 61 and 146 of KRAS are the most common in naturally occurring neoplasms. The presence of KRAS mutation in most tumor types is associated with adverse prognosis as well as resistance to receptor tyrosine kinase-directed targeted therapies, including against EGFR. KRAS, along with others, is an emerging biomarkers in NSCLC (non-small cell lung cancer) and other tumor types. Currently, in NSCLC the KRAS G12C mutation is prevalent in approximately 13% of patients and represents nearly half (44%) of all KRAS mutations. Investigational agents targeting KRAS G12C are currently in clinical trials.

Performing Laboratory
Quest Diagnostics Nichols Institute
33608 Ortega Highway
San Juan Capistrano, CA 92690-6130

The CPT Codes provided in this document are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed. Any Profile/panel component may be ordered separately. Reflex tests are performed at an additional charge.