Test Id : T790M
Cell-Free DNA EGFR T790M Mutation Analysis, Blood
Useful For
Suggests clinical disorders or settings where the test may be helpful
Determination of EGFR T790M mutation status in blood specimens as an alternative to invasive tissue biopsies
Identification of patients with non-small cell lung cancer who harbor a T790M mutation and may benefit from specific EGFR-targeted therapies
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 peripheral blood for the presence of the EGFR T790M mutation in patients with non-small cell lung cancer (NSCLC) and can be used to assess eligibility for targeted therapies. Current data suggests that patients with metastatic NSCLC and the T790M mutation may benefit from T790M-targeted therapy (eg, osimertinib).
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.
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
NSCLC
Non-small cell lung cancer
Lung cancer
EGFR
Epidermal growth factor receptor
Cell free DNA
cfDNA
Circulating tumor DNA
Liquid biopsy
Circulating tumor cells
T790M
Cell-free DNA
Specimen Type
Describes the specimen type validated for testing
Whole blood
Ordering Guidance
This test is not a prenatal screening test.
This test detects only the T790M mutation in the EGFR gene. It does not detect other EGFR gene mutations in exons 18 through 21.
This test provides rapid detection of the EGFR T790M mutation in peripheral blood from non-small cell lung cancer patients as an alternative for EGFR analysis of tissue. For tissue testing, order EGFRS / EGFR Gene, Targeted Mutation Analysis, 51 Mutation Panel, Tumor.
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)
Specimen Volume: Two, 10-mL Streck cell-free DNA (cfDNA) blood collection tubes
Additional Information:
1. Only blood collected in Streck cfDNA tubes will be accepted for analysis.
2. 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 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
Determination of EGFR T790M mutation status in blood specimens as an alternative to invasive tissue biopsies
Identification of patients with non-small cell lung cancer who harbor a T790M mutation and may benefit from specific EGFR-targeted therapies
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 peripheral blood for the presence of the EGFR T790M mutation in patients with non-small cell lung cancer (NSCLC) and can be used to assess eligibility for targeted therapies. Current data suggests that patients with metastatic NSCLC and the T790M mutation may benefit from T790M-targeted therapy (eg, osimertinib).
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.
Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Epidermal growth factor receptor (EGFR)-targeted tyrosine kinase inhibitors (eg, gefitinib and erlotinib) have been approved by the US food and Drug Administration (FDA) for use in treating patients with non-small cell lung cancer (NSCLC) who previously failed to respond to traditional chemotherapy. However, the EGFR T790M mutation is associated with acquired resistance to tyrosine kinase inhibitor (TKI) therapy in about 60% of patients with disease progression after initial response to erlotinib, gefitinib, or afatinib. Recent data suggest that patients with metastatic NSCLC and the T790M mutation may benefit from osimertinib, an FDA-approved oral TKI that inhibits both EGFR-activating mutations and the T790M mutation.
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 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 the EGFR T790M mutation. Mutation testing of a tissue specimen for EGFR mutations should be considered for patients with a negative result with this test.
The limit of detection of this assay for the detection of EGFR mutations is influenced by the amount of cell-free DNA in the blood. This is a biological variable that cannot be controlled.
This assay was designed to detect the following T790M mutation in the EGFR gene.
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
Clinical Reference
Recommendations for in-depth reading of a clinical nature
1. Schwarzenbach H, Hoon DSB, Pantel K: Cell-free nucleic acids as biomarkers in cancer patients. Nat Rev Cancer. 2011 Jun;11(6):426-437
2. Ettinger DS, Wood DE, Aisner DL, et al: Non-Small Cell Lung Cancer, Version 5.2017, NCCN Clinical Practice Guidelines in Oncology. J Natl Compr Canc Netw. 2017 Apr;15(4):504-535
3. Janne PA, Yang JCH, Kim DW, et al: AZD9291 in EGFR inhibitor-resistant non-small-cell lung cancer. N Engl J Med. 2015 Apr 30;372(18):1689-1699
Method Description
Describes how the test is performed and provides a method-specific reference
Blood samples are collected in Streck Cell-Free DNA BC Tubes. Cell-free DNA is isolated from double-centrifuged plasma and assessed for the presence of the EGFR T790M mutation using droplet digital polymerase chain reaction analysis.(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.
81235
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 |
|---|---|---|
| T790M | cfDNA EGFR T790M Test, Blood | 55769-4 |
| 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.
|
|---|---|---|
| 113411 | Result Summary | 50397-9 |
| 113412 | Result | 55769-4 |
| 113413 | Interpretation | 69047-9 |
| 113414 | Additional Information | 48767-8 |
| 113415 | Specimen | 31208-2 |
| 113416 | Source | 31208-2 |
| 113417 | Released By | 18771-6 |