Test ID T790M Cell-Free DNA EGFR T790M Mutation Analysis, Blood
Advisory Information
This test is not a prenatal screening test. To evaluate for the presence of common fetal chromosome abnormalities using cell-free DNA, see NIPS / Cell-Free DNA Prenatal Screen.
This test detects only the T790M mutation in the EGFR gene. It does not detect other EGFR gene mutations in exons 18 through 21. For that purpose, order EGFRD / Cell-Free DNA EGFR Exon 18, 19, 20, 21, Mutation Analysis, Blood.
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 EGFRT / EGFR Gene, Mutation Analysis, 29 Mutation Panel, Tumor.
Shipping Instructions
1. Samples should be transported at ambient temperature or refrigerated (4° C)
2. Samples are viable for 7 days in the Streck Black/Tan Top Tube Kit (T715)
Specimen Required
Supplies: Streck Black/Tan Top Tube Kit (T-715)
Specimen Volume: Two 10-mL Streck Cell-Free DNA blood collection tubes
Additional Information:
1. 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.
2. Samples should be transported at room temperature or refrigerated (4° C)
3. Samples are viable for 7 days in the Streck Cell-Free DNA BCT tube.
Useful For
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
This test evaluates cell-free DNA (cfDNA) in the 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.
Highlights
Evaluates peripheral blood for the presence of the T790M mutation in the EGFR gene in cell-free DNA
Rapid detection of the EGFR T790M mutation in non-small cell lung cancer patients as an alternative for EGFR analysis of tissue
Current data suggests that patients with metastatic NSCLC and the T790M mutation may benefit from T790M-targeted therapy (eg, osimertinib)
Method Name
Digital Droplet Polymerase Chain Reaction (PCR) of Plasma Cell-Free DNA
Reporting Name
cfDNA EGFR T790M Test, BloodSpecimen Type
Whole bloodSpecimen Minimum Volume
One 10 mL Streck tube
Specimen Stability Information
Specimen Type | Temperature | Time | Special Container |
---|---|---|---|
Whole blood | Ambient (preferred) | 7 days | Streck Black/Tan top |
Refrigerated | 7 days | Streck Black/Tan top |
Day(s) and Time(s) Performed
Monday through Friday; Varies
Performing Laboratory

Test Classification
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 U.S. Food and Drug Administration.CPT Code Information
81235
LOINC Code Information
Test ID | Test Order Name | Order LOINC Value |
---|---|---|
T790M | cfDNA EGFR T790M Test, Blood | 55769-4 |
Result ID | Test Result Name | Result LOINC Value |
---|---|---|
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 |
NY State Approved
YesForms
If not ordering electronically, complete, print, and send an Oncology Test Request (T729) with the specimen.