TEST CATALOG ORDERING & RESULTS SPECIMEN HANDLING CUSTOMER SERVICE EDUCATION & INSIGHTS
Test Catalog

Test ID: METF    
MET (7q31), FISH, Tissue

Useful For Suggests clinical disorders or settings where the test may be helpful

Providing prognostic information and guiding treatment primarily for patients with lung, gastric, and renal tumors as well as other tumor types

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

This test does not include a pathology consult. If a pathology consultation is requested, PATHC / Pathology Consultation should be ordered and the appropriate FISH test will be ordered and performed at an additional charge.

 

This test includes a charge for application of the first probe set (2 FISH probes) and professional interpretation of results.

 

Additional charges will be incurred for all reflex probes performed. Analysis charges will be incurred based on the number of cells analyzed per probe set. If no cells are available for analysis, no analysis charges will be incurred.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

MET is a proto-oncogene and its overexpression is associated with disease progression. Recent studies have shown MET amplification to be a major mechanism of acquired resistance to epidermal growth factor receptor tyrosine kinase domain inhibitor (EGFR-TKI). MET amplification has been reported in approximately 5% of patients not treated with EGFR-TKI and up to 20% of patients with acquired resistance to gefitinib or erlotinib.

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

A positive result is detected when the MET:D7Z1 ratio is > or =2.0.

 

The MET locus is reported as amplified when the MET:D7Z1 ratio of 2.0 or greater.

 

Patients with 5 or more copies of MET have a poor prognosis.

 

The absence of an abnormal clone does not rule out the presence of a neoplastic disorder.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

This test is not approved by the US Food and Drug Administration and is best used as an adjunct to existing clinical and pathologic information.

                                                                                       

Fixatives other than formalin (eg, Prefer, Bouin) may not be successful for FISH assays, however nonformalin-fixed samples will not be rejected.

 

Paraffin-embedded tissues that have been decalcified are generally unsuccessful for FISH analysis. The pathologist reviewing the hematoxylin and eosin-stained slide may find it necessary to cancel testing.

Supportive Data

The probe set was independently validated in a blinded study on 29 paraffin-embedded tissue samples from patients with various tumors. A series of normal control samples were used to generate the normal cutoffs. The probe performed as intended and abnormalities including aneusomy, duplication and deletion of MET were identified, and may be observed in addition to MET amplification in tumor samples.

Clinical Reference Recommendations for in-depth reading of a clinical nature

1. Cappuzzo F, Marchetti A, Skokan M, et al: Increased MET gene copy number negatively affects survival of surgically resected non-small-cell lung cancer patients. J Clin Oncol 2009;27(10):1667-1674

2. Go H, Jeon YK, Park HJ, et al: High MET gene copy number leads to shorter survival in patients with non-small cell lung cancer. J Thorac Oncol 2010;5(3):305-313

3. Okuda K, Sasaki H, Yukiue H, et al: MET gene copy number predicts the prognosis for completely resected non-small cell lung cancer. Cancer Sci 2008;99(11):2280-2285

4. Karamouzis MV, Konstantinopoulos PA, Papavassiliou AG: Targeting MET as a strategy to overcome crosstalk-related resistance to EGFR inhibitors. Lancet Oncol 2009;10:709-717

5. Engelman JA, Zejnullahu K, Mistudomi T, et al: MET amplification leads to gefitinib resistance in lung cancer by activating ERBB3 signaling. Science 2007;316:1039-1043