Immunohistochemistry, fluorescence in situ hybridization, and reverse transcription-polymerase chain reaction for the detection of anaplastic lymphoma kinase gene rearrangements in patients with non-small cell lung cancer: potential advantages and methodologic pitfalls.

Context: Echinoderm microtubule-associated protein-like 4 gene (EML4) and anaplastic lymphoma kinase gene (ALK) fusion was shown to be the driver of tumorigenesis in approximately 3% to 5% of patients with non-small cell lung cancer (NSCLC) and is associated with response to inhibition with crizotinib. However, no complete agreement regarding the best diagnostic test for identification of ALK rearrangements has been achieved yet.

Objective: To investigate the concordance, sensitivity, and specificity of immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and reverse transcription-polymerase chain reaction (RT-PCR) for detection of ALK rearrangements.