Rearrangement of the ROS1 gene is detected by fluorescence in situ hybridization (FISH).

disease state indication(s)
Non-Small Cell Lung Cancer (NSCLC)

clinical use
Predictive ROS1 rearrangements occur in 1-2% of patients with NSCLC. The in-frame fusion of an upstream partner gene and the downstream ROS1 kinase domain results in production of a chimeric protein with increased kinase activity. The presence of ROS1 gene rearrangement determines eligibility for targeted therapies (such as crizotinib).

methodology/product platform
Fluorescence in situ hybridization (FISH)

specimen type and requirements
Preferred: One (1) or two (2) formalin-fixed, paraffin-embedded (FFPE) blocks containing tumor tissue from the most recent surgery or biopsy.
Acceptable Alternative: Two (2) to three (3) unstained FFPE tissue sections recently cut at 4 µm thickness on glass slides, plus accompanying H&E stained slide.
Unacceptable: Specimens preserved in alternative (non-formalin) fixatives, decalcified specimens, fresh or frozen tissue.
Note: Use refrigerated cold pack for transport. Make sure cold pack is not in direct contact with specimen.

turnaround time
Tech-only (TC): 3 days
Global (TC & PC): 7 days

cpt code(s)
88377 (x1)

medicare moldx cpt code
Not applicable

regulatory classification
Laboratory developed test (LDT)

ordering option
Global (TC & PC) or Tech-only (TC)