Test Id : KRASP
KRAS Somatic Mutation Analysis, Tumor
Useful For
Suggests clinical disorders or settings where the test may be helpful
Detecting molecular markers associated with response or resistance to specific cancer
Additional Tests
Lists tests that are always performed, at an additional charge, with the initial tests.
| Test Id | Reporting Name | Available Separately | Always Performed |
|---|---|---|---|
| SLIRV | Slide Review in MG | No, (Bill Only) | Yes |
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, slide review will always be performed at an additional charge.
Method Name
A short description of the method used to perform the test
Droplet Digital Polymerase Chain Reaction (ddPCR)
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
Cetuximab (Erbitux)
Colorectal cancer
CRC
EGFR
Epidermal growth factor receptor
Erbitux (Cetuximab)
KRAS
KRAS codon 12
KRAS codon 13
KRAS codon 146
KRAS codon 61
KRAS G12C
KRAS WT
Non-small cell lung cancer
NSCLC
Patiumumab (Vectibix)
RAS
Vectibix (Patiumumab)
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, slide review will always be performed at an additional charge.
Specimen Type
Describes the specimen type validated for testing
Varies
Necessary Information
1. A pathology report (final or preliminary) is required and must accompany specimen for testing to be performed.
2. The following information must be included in the report provided.
-Patient name
-Block number-must be on all blocks, slides and paperwork (can be handwritten on the paperwork)
-Date of tissue collection
-Source of the tissue
Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing
Preferred:
Specimen Type: Tissue block
Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block.
Acceptable:
Specimen Type: Tissue slide
Slides: 1 Hematoxylin and eosin stained and 5 unstained
Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 5 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.
Specimen Type: Cytology slide (direct smears or ThinPrep)
Slides: 1 to 3 slides
Collection Instructions: Submit 1 to 3 slides stained and coverslipped with a preferred total of 5000 nucleated cells or a minimum of at least 3000 nucleated cells.
Note: Glass coverslips are preferred; plastic coverslips are acceptable but will result in longer turnaround times.
Additional Information: Cytology slides will not be returned.
Special Instructions
Library of PDFs including pertinent information and forms related to the test
Forms
1. Molecular Genetics: Inherited Cancer Syndromes Patient Information (T519).
2. If not ordering electronically, complete, print, and send a 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.
See Specimen Required
Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected
| Specimens that have been decalcified (all methods) Specimens that have not been formalin- fixed, paraffin-embedded | 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 |
|---|---|---|---|
| Varies | Ambient (preferred) | ||
| Refrigerated | |||
Useful For
Suggests clinical disorders or settings where the test may be helpful
Detecting molecular markers associated with response or resistance to specific cancer
Testing Algorithm
Delineates situations when tests are added to the initial order. This includes reflex and additional tests.
When this test is ordered, slide review will always be performed at an additional charge.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Strategies that focus on early detection and prevention effectively decrease the risk of mortality associated with cancer. In addition, an increase in survival rate for individuals with advanced stage disease has been observed as a result of advancements in standard chemotherapeutic agents and the development of specialized targeted therapies. Monoclonal antibodies against epidermal growth factor receptor (EGFR), such as cetuximab and panitumumab, represent an area of targeted therapy for patients with colorectal and non-small cell lung cancer (NSCLC). However, studies have shown that not all individuals with colorectal cancer or NSCLC respond to EGFR targeted molecules. Because the combination of targeted therapy and standard chemotherapy leads to an increase in toxicity and cost, strategies that help to identify the individuals most likely to benefit from such targeted therapies are desirable.
Epidermal growth factor receptor is a growth factor receptor that is activated by the binding of specific ligands (epiregulin and amphiregulin), resulting in activation of the RAS/MAPK pathway. Activation of this pathway induces a signaling cascade ultimately regulating a number of cellular processes including cell proliferation. Dysregulation of the RAS/MAPK pathway is a key factor in tumor progression. Targeted therapies directed to EGFR, which inhibit activation of the RAS/MAPK pathway, have demonstrated some success (increased progression-free and overall survival) in patients with cancer, in particular, colorectal cancer and NSCLC.
One of the most common somatic mutations in colon cancer and NSCLC is the presence of activating mutations in the protooncogene KRAS. KRAS is recruited by ligand-bound (active) 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 colon cancer and NSCLC is confined to patients with tumors lacking KRAS mutations. An exception is the KRAS G12C variant, which 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) mutations. A positive result indicates the presence of an activating KRAS mutation and can be a useful marker by which patients are selected for EGFR-targeted therapy.
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
Not all patients whose tumors have wildtype KRAS respond to epidermal growth factor receptor (EGFR)-targeted therapies.
Rare genetic alterations (ie, polymorphisms) exist that could lead to false-negative or false-positive results.
Test results should be interpreted in context of clinical findings, tumor sampling, and other laboratory data. If results obtained do not match other clinical or laboratory findings, please contact the laboratory for possible interpretation. Misinterpretation of results may occur if the information provided is inaccurate or incomplete.
This assay was designed to detect variants 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.
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1.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: ASCO Provisional Clinical Opinion update 2015. J Clin Oncol. 2016;34(2):179-185
2.Spano JP, Milano G, Vignot S, Khayat D. Potential predictive markers of response to EGFR-targeted therapies in colorectal cancer. Crit Rev Oncol Hematol. 2008;66(1)21-30
3.Lam DC: Clinical testing for molecular targets for personalized treatment in lung cancer. Respirology. 2013;18(2):233-237
4.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
A pathology review and macrodissection to enrich for tumor cells is performed prior to DNA extraction.
Droplet digital polymerase chain reaction is used to test for the presence of KRAS codon 12, 13, 61, and 146 variants.(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.
Monday through Friday
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-KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene) (eg, carcinoma) gene analysis, variants in codons 12 and 13
81276-KRAS additional variant(s)
88381-Microdissection, manual
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 |
|---|---|---|
| KRASP | KRAS Somatic Mutation Analysis | 103955-1 |
| 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.
|
|---|---|---|
| 610680 | Result Summary | 50397-9 |
| 610681 | Result | 82939-0 |
| 610682 | Interpretation | 69047-9 |
| 610683 | Specimen | 31208-2 |
| 610684 | Source | 31208-2 |
| 610685 | Tissue ID | 80398-1 |
| 610686 | Released By | 18771-6 |
| 610687 | Method | 85069-3 |
| 610688 | Disclaimer | 62364-5 |
| 614165 | Additional Information | 48767-8 |