EPIDERMAL GROWTH FACTOR RECEPTOR - EGFR
Gene Symbol: EGFR
Chromosomal Locus: 7p11.2
Protein: epidermal growth factor receptor
TURNAROUND TIME: 10 days
TESTING METHODOLOGY: Polymerase chain reaction (PCR) and DNA Sequencing of exons 19 and 21.
Collect: Tumor specimen containing at least 30% tumor mass. 5 to 6 unsustained slides with 3-4 um thick tissue sections. Must be accompanied by a pathology report and an H&E slide with the tumor regions clearly identified.
- Transport: Specimen should be shipped at Room Temperature (No Saturday delivery)
- Unacceptable Conditions: Stained slides.
Counseling and informed consent are recommended for genetic testing. A consent form
is available as a resource but not required.
Incidence: About 85% of lung cancers are nonsmall cell lung cancers (NSCLC); and of them, about 10% of those individuals have EGFR mutations. These individuals respond rapidly and dramatically to therapy with Gefitinib.
Molecular Genetic Mechanism: Somatic mutations can be point mutations or insertions and deletions.
Clinical Sensitivity: The tissue sample submitted for testing must contain at least 30% tumor. The assay will detect a 25% population of mutant cells.
Analytical Sensitivity: 75%
Test Limitations: Mutations located outside of the exons examined by sequencing. This test is only for somatic EGFR mutation in cancer tissue. Rare diagnostic errors can occur due to primer / probe site mutations or rare polymorphisms.
INDICATIONS FOR USE:
- To determine whether a nonsmall cell lung cancer in a patient may be responsive to therapy.
- To assess whether additional tumors may be the result of metastasis.