As 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
Selection of patients with colorectal cancer who are most likely to benefit from epidermal growth factor receptor (EGFR)-targeted therapies
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 colorectal cancer and can be used to assess eligibility for targeted therapies.
This test is not validated for serial monitoring of patients with cancer. This test is also not intended as a screening test to identify cancer.
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.
Digital Droplet Polymerase Chain Reaction (PCR)
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
Whole blood
This test is not a prenatal screening test. To evaluate for the presence of common fetal chromosome abnormalities using cell-free DNA, order NIPS / Cell-Free DNA Prenatal Screen.
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).
Supplies: Streck Black/Tan Top Tube Kit (T715)
Container/Tube: Streck Cell-Free DNA blood collection kit (T715)
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.
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.
One 10 mL Streck tube
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Ambient (preferred) | 7 days | Streck Black/Tan top |
Refrigerated | 7 days | Streck Black/Tan top |
As 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
Selection of patients with colorectal cancer who are most likely to benefit from epidermal growth factor receptor (EGFR)-targeted therapies
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 colorectal cancer and can be used to assess eligibility for targeted therapies.
This test is not validated for serial monitoring of patients with cancer. This test is also not intended as a screening test to identify cancer.
Approximately 30% to 50% of colorectal cancers (CRC) have mutations in KRAS. Most occur in hotspot regions in codons 12, 13, 61, and 146. These mutations lead to constitutive activation of the RAS/MAPK pathway downstream of epidermal growth factor receptor (EGFR), limiting the effectiveness of anti-EGFR therapies, such as cetuximab and panitumumab, which inhibit ligand-mediated activation of EGFR. Therefore, identification and quantitation of these mutations is critical in selecting the appropriate therapy.
This test uses DNA extracted from peripheral blood 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 may be useful for guiding the treatment of individuals with colorectal cancer.
An interpretive report will be provided.
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.
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.
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-Epodermal Growth Factor Receptor Monoclonal Antibody Therapy: ASCO Provisional Clinical Opinion update 2015. J Clin Oncol 2016 Jan 10;34(2):179-185
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;17:484
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 digital droplet PCR.(Unpublished Mayo method)
Monday through Friday
This test was developed, and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.
81275
81276
81479 (if appropriate for government payers)
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 |