ALK Rearrangement by FISH

Methodology

Specimen Requirements

CPT Code

Highlights

• Detection of ALK gene rearrangements by fluorescence in situ hybridization (FISH) may be demonstrated in different types of cancers.
• Recent studies have demonstrated that the determination of the presence of ALK gene rearrangements may help treating physicians select more effective therapies for patients with non-small cell lung cancer (NSCLC).
• Based on current literature, the determination of ALK gene arrangements identify patients who may not benefit from targeted therapeutics like epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), such as Tarceva (Erlotinib).
• ALK gene rearrangements define a distinct molecular subset of NSCLC that is mutually exclusive from EGFR and KRAS mutations.
• The FISH test results should be used in conjunction with other clinical information. The probe used is an ALK Dual Color, Break Apart Rearrangement Probe (Vysis®). 

Indications for Use

• ALK mutations have been recently identified in 3%-7% of NSCLC patients.
• The NSCLC patients most likely to harbor EML4-ALK are young patients with adenocarcinoma with no smoking history.
• Patients with EML4-ALK-positive NSCLC responded poorly to standard therapies, including platinum-based chemotherapy combinations and EGFR TKIs.
• Crizotinib demonstrated marked activity in patients with advanced NSCLC harboring ALK translocations.
• Patients with metastatic, EML4-ALK positive NSCLC should be directed to clinical trials of agents targeting ALK-targeted agents.^1,2