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UW Health SMPH
American Family Children's Hospital

UW Hospital and Clinics Lab Test Directory

Test Name: EGFR Mutation Analysis

Test Code(s): Orderable through Surgical Pathology

CPT Code(s): 81235

Methodology: Real-Time PCR followed by Direct Sequencing

Clinical Significance: Based on current guidelines endorsed by the National Comprehensive Cancer Network (NCCN), College of American Pathologists (CAP), International Association for the Study of Lung Cancer (IASLC) and the Association of Molecular Pathology (AMP), EGFR molecular testing is highly recommended to select patients for EGFR-targeted tyrosine kinase inhibitor (TKI) therapy. Patients with lung adenocarcinoma should not be excluded from testing on the basis of clinical characteristics (age, sex, ethnicity and smoking history).

The EGFR-Kras-Braf signaling pathway is aberrantly activated in several types of cancer, including colorectal cancer (CRC) and lung adenocarcinoma. EGFR mutation testing is useful in tumor specimens from patients diagnosed with colorectal cancer or lung adenocarcinoma who are being considered for TKI therapy such as erlotinib, gefitinib or afatinib. Over 100 mutations within the EGFR gene have been identified, mainly in exons 18-21. Some have been shown to be associated with TKI resistance (primarily T790M), and others with TKI sensitivity. In order to determine if a TKI targeting EGFR would be beneficial, EGFR exons 18-21 should be assessed for mutations.

Days Performed: Once a week.

Turnaround Time: Routine: 10 days.


Specimen Requirements

Specimen: Formalin-fixed, paraffin embedded tissue.

Sample Analyzed: Tissue

Specimen Processing: FFPE tissue should be cut in 10 or 20 micron sections (minimum 5 sections) and placed into a 1.5 mL tube. Unstained sections on slides are also acceptable (minimum 5 slides, 10 micron each.)

If an add-on order is needed, please contact UWHC Surgical Pathology at (608)263-8443. A Surgical Pathology Tissue Examination Request form will need to be completed and faxed to (608)262-7174.

Many insurers require a prior authorization (PA) for this test. Please check patient coverage and send copy of PA to lab with the add-on test request.

Specimen Transport: Transport at room temperature.

Outreach Specimen Transport: Transport with a cold pack. Avoid excessive heat.

Stability: Ambient: Indefinitely.
Refrigerated: Indefinitely.
Frozen: Do not Freeze.


Interpretation

Expected result: Not detected. A written interpretive report is provided by the laboratory.

Test Limitations:

A "Not Detected" results may be due to insufficient tissue or tumor present or to the presence of PCR inhibitors. The detection limit is 15% mutated DNA in a non-mutated background.

Additional Information:

A "Detected" results indicates the presence of a EGFR mutation. A "Not detected" result does not rule out the presence of a EGFR mutation. Inadequate specimen collection, processing and storage may invalidate test results. This test should not be used as the only criterion to form a clinical conclusion, instead, results should be correlated with other test results, patient symptoms and clinical presentation. 

 

The performance characteristics of this test were validated by UWHC Clinical Laboratories. The U.S. Food and Drug Administration (FDA) has not approved or cleared this test; however, FDA approval or clearance is currently not required for clinical use of this test. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions. The UWHC Clinical Laboratories is authorized under Clinical Laboratory Improvement Amendments (CLIA) to perform high-complexity testing.

 

A professional fee is associated with this test.

Epidermal Growth Factor Receptor Mutation. Note this is not e-GFR - Estimated Glomerular Filtration Rate for this test see creatinine.

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