Droplet Digital Polymerase Chain Reaction (ddPCR)
Epidermal growth factor receptor
KRAS codon 12
KRAS codon 13
KRAS codon 146
KRAS codon 61
Non-small cell lung cancer
Pathology report (final or preliminary) is required and must accompany specimen for testing to be performed. At minimum, it should contain the following information:
1. Patient name and second identifier
2. Fluid collection date
3. Source of the fluid
Container/Tube: 50-mL Falcon tube with fixative
Acceptable: CytoLyt solution, methanol:glacial acidic acid (3:1) fixative, or 50% or 80% ethanol
Specimen Volume: Two to four 50-mL Falcon tubes each containing fixed cells in equal volume to approved fixatives
Collection Instructions: Containers must be labeled with two unique patient identifiers.
Molecular Genetics: Inherited Cancer Syndromes Patient Information (T519)
100 mL of washing in acceptable fixative
|No fixative added||Reject|
|Specimen Type||Temperature||Time||Special Container|
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.
EGFR is a growth factor receptor that is activated by the binding of specific ligands (epiregulin and amphiregulin), resulting in activation of the RAS/MAPK (mitogen activated protein kinase) 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 alterations 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 mutant 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 mutant 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 mutation that is targetable with mutant-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.
An interpretive report will be provided.
An interpretative report will be provided.
Not all patients whose tumors have wild-type KRAS respond to epidermal growth factor receptor (EGFR)-targeted therapies.
Rare variants (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, 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 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.
Digital droplet polymerase chain reaction is used to test for the presence of KRAS codon 12, 13, 61, and 146 mutations.(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-KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene) (eg, carcinoma) gene analysis, variants in codons 12 and 13
81276-KRAS (v-Ki-ras2 Kirsten rat sarcoma viral oncogene) (eg, carcinoma) gene analysis, additional variants
|Test Id||Test Order Name||Order LOINC Value|
|KRASW||KRAS Mutation Analysis, Peritoneal||21702-6|
|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.