EML4-ALK Gene Fusion
Order Name
EML4-ALK
Test Number: 9100775
Revision Date 12/14/2012
Test Number: 9100775
Revision Date 12/14/2012
| Test Name | Methodology | LOINC Code |
|---|---|---|
|
EML4-ALK Gene Fusion
|
Polymerase Chain Reaction |
| SPECIMEN REQUIREMENTS | ||||
|---|---|---|---|---|
| Specimen | Specimen Volume (min) | Specimen Type | Specimen Container | Transport Environment |
| Preferred | See Below | Tissue | Paraffin Block | Room Temperature |
| Instructions | Formalin fixed paraffin embedded tissue. Tissue source and block ID containing tumor are required on the requisition form. Pathology permission is required for any alternate sample types. |
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| GENERAL INFORMATION | |
|---|---|
| Testing Schedule | Sets up on Mondays and Reports the following Monday. |
| Expected TAT | Mon |
| Clinical Use | The introduction of targeted therapies for cancer has provided physicians with a personalized approach to cancer treatment. In non-small cell lung cancer (NSCLC), EGFR and KRAS mutations have been the most widely studied in terms of the use of tyrosine kinase inhibitors (TKI) such as gefitinib and erlotinib. It is crucial to define the gene mutations harbored by the tumor before treating with targeted therapy. For example, use of tyrosine kinase inhibitors (TKIs) in patients harboring EGFR mutations is much more effective than in patients harboring KRAS mutations, which are non-responsive to these drugs. Clinical EGFR and KRAS mutation testing provide a means to identify patients who are most likely to respond to such therapies. |
| Notes | Recently, inhibitors of anaplastic lymphoma kinase (ALK) have been used successfully in patients harboring gene fusions between echinoderm microtubule-associated protein-like 4 (EML4) and ALK9. These fusions result from a paracentric inversion on chromosome 2 [inv(2)(p21;p23)] and have been identified in 3-7% of all non-small cell lung cancer (NSCLC) cases. To date, 13 variants have been published involving 8 different EML4 exons (exon 2, 6, 13, 14, 15, 17, 18. and 20) and invariably involving exon 20 of ALK. With such a plethora of fusion variants, we developed an RT-PCR based exon scanning approach to encompass fusion variants spanning nearly the entire EML4 gene. This method enabled us to identify an additional two novel EML4-ALK variants (8a and 8b) from the tumor tissue of an NSCLC patient and will likely detect many more positive patients than simply detecting the known EML4-ALK fusion variants. |
| CPT Code(s) | 83891, 83900; 83901x2, 83909, 83904x4, 83912 |
| Service Provided By |  |
| Lab Section | Reference Lab |