ALK Gene Rearrangements by FISH
Also known as: ALK_FISH
Use
This test is designed to detect rearrangements involving the ALK gene, which are useful for predicting tumor response to targeted therapy in non-small cell lung cancer. ALK rearrangements occur in approximately 4-6 percent of lung adenocarcinomas, and the detection of such an alteration is critical for therapeutic decisions, specifically concerning the use of ALK inhibitors like crizotinib.
Special Instructions
The test does not identify the translocation partner or variant of the ALK gene rearrangement. It is important for specimens to be formalin-fixed and paraffin-embedded according to specified guidelines, and surgical pathology reports should accompany submissions. If multiple samples are submitted, clear instructions for block selection should be included.
Limitations
The assay is expected to detect 100 percent of ALK rearrangements in patients with ALK-rearranged carcinomas, except for rare instances of cryptic rearrangements. The test does not identify the specific partner gene involved in the ALK fusion, and only abnormalities present in 15 percent or more of tumor cells are considered positive. Results are contingent on proper specimen handling and adherence to defined preparatory steps.
New York Approved
Methodology
Chromosomal / Cytogenetics (FISH)
Biomarkers
LOINC Codes
- 31208-2
- 78205-2
- 81304-8
- 78236-7
Result Turnaround Time
3-7 days
Related Documents
For more information, please review the documents below
Specimen
Tumor Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Container
Tissue block or 4 unstained, consecutively cut, 4-micron thick sections, mounted on positively charged glass slides
Collection Instructions
Formalin fix (10 percent neutral buffered formalin) and paraffin embed tumor tissue. Transport in a tissue transport kit.
Storage Instructions
Protect paraffin block and/or slides from excessive heat.
Causes for Rejection
Specimens fixed or processed in alternative fixatives or heavy metal fixatives; no tumor in tissue; decalcified specimens.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Indefinitely |
| Refrigerated | Indefinitely |
| Frozen | Unacceptable |