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Alternative Name
Test Description

Probes: NTRK1 (1q23.1), NTRK2 (9q21.33), NTRK3 (15q25.3)

Disease(s): Various solid tumors.

Clinical Significance

The NTRK 1, 2, 3 FISH Panel provides simultaneous analysis of NTRK1, NTRK2, and NTRK3 for gene rearrangements (fusions) to identify TRK-inhibitor therapy and clinical trial options using break-apart probes. This panel is useful for screening solid tumors. Approximately 1% of solid tumors overall will have a positive FISH panel result. FISH-negative results in any tumor type may be confirmed with the NTRK NGS Fusion Profile. Pan-TRK IHC testing is also available to screen most tumors with low fusion frequencies. See also NTRK3 FISH for tumors with very high NTRK3 fusion frequencies. Fusion partners of the NTRK gene are not identified by this FISH panel but are identified by the NTRK NGS Fusion Profile.

Specimen Requirements
  • Bone marrow aspirate:  N/A
  • Peripheral blood: N/A
  • Fresh, unfixed tissue: N/A.
  • Fluids: N/A
  • Paraffin block: Send paraffin block. Also send circled H&E slide for tech-only (required).
  • Cut slides: H&E slide (required) plus 5 unstained slides cut at 4-5 microns. Circle H&E slide for tech-only.
Storage and Transportation

Use cold pack for transport, making sure cold pack is not in direct contact with specimen.

CPT Code(s)*
88377x3 manual or 88374x3 automated
Turnaround Time

3-5 days

  2. Cocco E, Scaltriti M, Drilon A. NTRK fusion-positive cancers and TRK inhibitor therapy. Nat Rev Clin Oncol. 2018;15:731-747.    
  3. Chen Y, Chi P. Basket trial of TRK inhibitors demonstrates efficacy in TRK fusion-positive cancers. J Hematol Oncol. 2018;11:78.
Level of Service

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.