Methodology: FISH

Clinical Significance:
ROS-1 is a an orphan receptor tyrosine kinase that is phylogenetically related to the ALK tyrosine kinase gene. ROS-1 rearrangements have been found to occur in approximately 2% of lung adenocarcinomas and several gene fusion partners have been identified including CD74, LRIG3, SDC4, TPM3, and FIG. Tumors that harbor a ROS-1 gene rearrangement have been found to be responsive to treatment with the ALK inhibitor drug crizotinib (Xalkori). Recent studies have demonstrated that FISH can be used to identify ROS-1 rearrangements in lung adenocarcinoma. A positive result with this test would therefore indicate that the patient may respond to treatment with crizotinib*. *NOTE: Determining insurance eligibility is the responsibility of the patient and their physician.

Organ: Lung

Disease State: Mesothelioma vs. Adenocarcinoma

CPT Code(s): 88374. The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Turnaround Time: Within 4-6 business days of receipt

Schedule: Monday - Friday

Specimen Requirements:
• Formalin-fixed, paraffin-embedded tissue block or cell block - OR - • Minimum of 5 unstained slide cut at 4µm for each test requested