0-9
A B C D E F G H I J K L M N O
P Q R S T U V W X Y Z
  • No FAQs found
  • No FAQs found
  • No FAQs found
  • No FAQs found
  • No FAQs found
  • No FAQs found
  • No FAQs found

FISH, MET Amplification

Test code(s) 91283

This is an outdated version of this FAQ. It was effective 10/15/2012 to 02/06/2017.

The current version is available here.

Question 1. What is the role of MET in lung cancer?

The MET protein is a receptor kinase that stimulates tyrosine-kinase activity, as does EGFR. Stimulated tyrosine kinase leads to activation of signaling pathways associated with cell growth and survival. Thus, MET gene amplification and MET protein overexpression lead to tumor growth and progression and unfavorable prognosis in patients with lung adenocarcinoma.

Patients with non-small cell lung cancer and EGFR-activating mutations, which increase sensitivity to tyrosine kinase inhibitor (TKI) therapy, may be resistant to TKI therapy in the presence of MET oncogene amplification.

Question 2. How do MET-activating mutations correlate with other mutations seen in lung cancer?

MET mutations may coexist with other oncogene mutations (eg, KRAS, EGFR, BRAF, ALK). Similar to mutations in these other oncogenes, MET overexpression and/or amplification is associated with a more aggressive disease.

Question 3. How does the FISH MET Amplification assay work?

The MET (7q31) FISH dual-color probe set is hybridized with a control probe (CEP7) to evaluate copy number gain (ie, polysomy) in interphase cells from the lesion of interest.

Question 4. What is the significance of the different patterns of increased MET signals, and how is the assay scored?

Normal tissues should have an average of two MET signals and two control probe (CEP7) signals. The over-representation of MET compared to the control is an indicator of copy number gain.

Scoring system is a combination of pattern and percentage (%) of cells positive.

Question 5. Which specimens can be tested?

Formalin-fixed, paraffin-embedded tissue and fresh tumor tissue can be tested.

Question 6. How does the MET FISH assay compare to the MET-phospho, IHC with Interpretation assay (test code 90169)?

The FISH assay determines the gene copy number (ie, MET amplification), while the IHC assay determines the level of gene expression (ie, MET overexpression). A direct comparison of the performance of these two assays is not available.

Question 7. What is the most common alias for MET?

The most common alias is c-MET.

This FAQ is provided for informational purposes only and is not intended as medical advice. A physician’s test selection and interpretation, diagnosis, and patient management decisions should be based on his/her education, clinical expertise, and assessment of the patient.

Document FAQS.84 Revision: 0