Test Id : KRASD
Cell-Free DNA KRAS 12, 13, 61,146, Blood
Useful For
Suggests clinical disorders or settings where the test may be helpful
An alternative to invasive tissue biopsies for the determination of KRAS 12, 13, 61,146 (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T) mutation status
Detecting molecular markers associated with response or resistance to specific therapy
This test is not intended as a screening test to identify cancer.
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
This test evaluates cell-free DNA (cfDNA) in the peripheral blood for the presence of KRAS mutations at codons 12, 13, 61, and 146 (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T) in patients with cancer and can be used to assess eligibility for targeted therapies.
Highlights
This test provides rapid detection of KRAS mutations in colorectal cancer patients as an alternative for KRAS analysis of tissue.
Current data suggests that the efficacy of epidermal growth factor receptor (EGFR)-targeted therapy in colorectal cancer patients is limited to patients whose tumors do not harbor mutations in the KRAS gene.
Method Name
A short description of the method used to perform the test
Digital Droplet Polymerase Chain Reaction (PCR)
NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.
Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test
Aliases
Lists additional common names for a test, as an aid in searching
CRC
Colorectal cancer
EGFR
Epidermal growth factor receptor
Cell free DNA
cfDNA
cell-free DNA
circulating tumor DNA
liquid biopsy
KRAS WT
KRAS codon 12
KRAS codon 13
KRAS codon 61
KRAS codon 146
Circulating tumor cells
KRAS
RAS
Specimen Type
Describes the specimen type validated for testing
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 degrees C).
2. Samples are viable for 7 days in the Streck Black/Tan Top Tube Kit (T715).
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
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 BCT tubes will be accepted for analysis. Whole blood will be processed to produce platelet-poor plasma before cfDNA isolation.
Forms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.
One 10 mL Streck tube
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Specimen collected in tube other than Streck Cell-Free DNA collection tube | Reject |
Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Whole blood | Ambient (preferred) | 7 days | Streck Black/Tan top |
| Refrigerated | 7 days | Streck Black/Tan top |
Useful For
Suggests clinical disorders or settings where the test may be helpful
An alternative to invasive tissue biopsies for the determination of KRAS 12, 13, 61,146 (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T) mutation status
Detecting molecular markers associated with response or resistance to specific therapy
This test is not intended as a screening test to identify cancer.
Genetics Test Information
Provides information that may help with selection of the correct genetic test or proper submission of the test request
This test evaluates cell-free DNA (cfDNA) in the peripheral blood for the presence of KRAS mutations at codons 12, 13, 61, and 146 (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T) in patients with cancer and can be used to assess eligibility for targeted therapies.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
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 US Food and Drug Administration for treatment of solid tumor malignancies. Molecular genetic profiling is often needed to identify targets amenable to targeted therapies and to minimize treatment costs and therapy-associated risks.
One of the most common somatic alterations in colorectal cancer (CRC) and non-small cell lung cancer (NSCLC) is the presence of activating variants in the protooncogene KRAS. KRAS is recruited by ligand-bound (active) epidermal growth factor receptor (EGFR) to initiate the signaling cascade induced by the RAS/MAPK pathway. Because altered KRAS constitutively activates the RAS/MAPK pathway downstream of EGFR, agents such as cetuximab and panitumumab, which prevent ligand-binding to EGFR, do not appear to have any meaningful inhibitor activity on cell proliferation in the presence of altered KRAS. Current data suggest that the efficacy of EGFR-targeted therapies in CRC and NSCLC is confined to patients with tumors lacking KRAS mutations. An exception is the KRAS G12C variant that is targetable with variant-specific inhibitors.
This test uses DNA extracted from tumor tissue to evaluate for the presence of KRAS (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T) variants. A positive result indicates the presence of an activating KRAS mutation and can be useful for guiding the treatment of patients with CRC and NSCLC.
Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided
Interpretation
Provides information to assist in interpretation of the test results
The interpretation of molecular biomarker analysis includes an overview of the results and the associated diagnostic, prognostic, and therapeutic implications.
Cautions
Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
Patients with a negative test result may still harbor a KRAS mutation. Mutation testing of a tissue specimen for KRAS mutations should be considered for patients with who have a negative result with this test.
The limit of detection of this assay for the detection of KRAS mutations 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 mutations in KRAS codons 12, 13, 61, and 146 (G12A, G12C, G12D, G12R, G12S, G12V, G13D, Q61K, Q61L, Q61R, Q61H, and A146T).
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 KRAS mutations in patients with colorectal cancer.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Schwarzenbach H, Hoon DS, Pantel K. Cell-free nucleic acids as biomarkers in cancer patients. Nat Rev Cancer. 2011;11(6):426-437
2. Allegra CJ, Rumble BR, Hamilton SR, et al. Extended RAS gene mutation testing in metastatic colorectal carcinoma to predict response to anti-epidermal growth factor receptor monoclonal antibody therapy: American Society of Clinical Oncology Provisional Clinical Opinion Update 2015. J Clin Oncol. 2016;34(2):179-185. doi:10.1200/JCO.2015.63.967
3. Olmedillas Lopez S, Garcia-Olmo DC, Garcia-Arranz M, et al. KRAS G12V mutation detection by droplet digital PCR in circulating cell-free DNA of colorectal cancer patients. Int J Mol Sci. 2016;17(4):484
4.Lam DC. Clinical testing for molecular targets for personalized treatment in lung cancer. Respirology. 2013 Feb;18(2):233-237
5.Hong DS, Fakih MG, Strickler JH, et al. KRAS G12C inhibition with sotorasib in advanced solid tumors. N Engl J Med. 2020;383(13):1207-1217
Method Description
Describes how the test is performed and provides a method-specific reference
Blood samples are collected in Streck Cell-Free DNA BCT tubes. Cell-free DNA (cfDNA) is isolated from double-spun plasma and assessed for the presence of KRAS codon 12, 13, 61, and 146 mutations using droplet digital polymerase chain reaction.(Unpublished Mayo method)
PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information
Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.
Varies
Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.
Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location
Indicates the location of the laboratory that performs the test
Fees :
Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.
- Authorized users can sign in to Test Prices for detailed fee information.
- Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
- Prospective clients should contact their account representative. For assistance, contact Customer Service.
Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.
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
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
CPT codes are provided by the performing laboratory.
CPT codes are provided by the performing laboratory.
81275
81276
LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.
| Test Id | Test Order Name | Order LOINC Value |
|---|---|---|
| KRASD | cfDNA KRAS 12, 13, 61, 146 Blood | In Process |
| Result Id | Test Result Name |
Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
|
|---|---|---|
| 113123 | Result Summary | 50397-9 |
| 113125 | Interpretation | 69047-9 |
| 113126 | Additional Information | 48767-8 |
| 113127 | Specimen | 31208-2 |
| 113128 | Source | 31208-2 |
| 113129 | Released By | 18771-6 |
| 113508 | Result | 75974-6 |