Alternate Test Names:
cobas EGFR PLASMA
The Roche cobas® EGFR Mutation Test v2 is an FDA-approved assay for identifying EGFR T790M, exon 19 deletions, and exon 21 L858R substitution mutations in circulating tumor DNA obtained from patients with non-small cell lung carcinoma. The identification of other clinically relevant EGFR mutations has been validated by PhenoPath Laboratories. Circulating tumor / “cell-free” DNA is isolated from plasma using the cobas® cfDNA Sample Preparation Kit; followed by amplification and detection of target DNA sequences using the cobas® z 480 analyzer.
Please note that tumor samples (such as cytology preparations, biopsies and resection specimens) are the most robust method for determining EGFR mutation status. EGFR mutation testing of circulating tumor DNA in plasma is inherently more likely to produce a false negative result. When detected, EGFR mutations identified in circulating tumor DNA are associated with EGFR mutation-positive tumors; however, testing of tumor samples is recommended whenever possible.
CPT Code(s): 81235 (reference only; CPTs may vary)
Turnaround Time: Within 3-5 business days of receipt
Schedule: Once per week
--Minimum of 2 mL of plasma (following collection instructions below)
--Recommend 4-6 mL of plasma for testing
--Venipuncture into K2-EDTA/plasma separator tube (ideally collect two to three 5 mL tubes; minimum of one 5 mL tube needed)
--Within 4 hours of collection; separate plasma by centrifugation
--Transfer plasma into transport tube
--Immediately ship to PhenoPath frozen on dry ice