ALK Gene Rearrangements by FISH

Casandra

Casandra Test Code AR21891Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 3001302CPT Code 88366

ALK Gene Rearrangements by FISH

Also known as: ALK_FISH

Clinical Use

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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.

Test Details

New York Approved