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Test Code NTRKM NTRK Genes Mutation Analysis, Next-Generation Sequencing, Tumor


Ordering Guidance


Multiple oncology (cancer) gene panels are available. For more information see Oncology Somatic NGS Testing Guide.



Necessary Information


A pathology report (final or preliminary), at minimum containing the following information, must accompany specimen for testing to be performed:

1. Patient name

2. Block number-must be on all blocks, slides, and paperwork (can be handwritten on the paperwork)

3. Tissue collection date

4. Source of the tissue



Specimen Required


This assay requires at least 20% tumor nuclei.

-Preferred amount of tumor area with sufficient percent tumor nuclei: tissue 216 mm(2)

-Minimum amount of tumor area: tissue 36 mm(2)

-These amounts are cumulative over up to 10 unstained slides and must have adequate percent tumor nuclei.

-Tissue fixation: 10% neutral buffered formalin, not decalcified

-For specimen preparation guidance, see Tissue Requirement for Solid Tumor Next-Generation Sequencing. In this document, the sizes are given as 4 mm x 4 mm x 10 slides as preferred: approximate/equivalent to 144 mm(2) and the minimum as 3 mm x 1 mm x 10 slides: approximate/equivalent to 36 mm(2).

 

Preferred:

Specimen Type: Tissue block

Collection Instructions: Submit a formalin-fixed, paraffin-embedded tissue block with acceptable amount of tumor tissue.

 

Acceptable:

Specimen Type: Tissue slide

Slides: 1 Stained and 10 unstained

Collection Instructions: Submit 1 slide stained with hematoxylin and eosin and 10 unstained, nonbaked slides with 5-micron thick sections of the tumor tissue.

Note: The total amount of required tumor nuclei can be obtained by scraping up to 10 slides from the same block.

Additional Information: Unused unstained slides will not be returned.

 

Specimen Type: Cytology slide (direct smears or ThinPrep)

Slides: 1 to 3 Slides

Collection Instructions: Submit 1 to 3 slides stained and coverslipped with a preferred total of 5000 nucleated cells or a minimum of at least 3000 nucleated cells.

Note: Glass coverslips are preferred; plastic coverslips are acceptable but will result in longer turnaround times.

Additional Information: Cytology slides will not be returned.


Useful For

Identifying NTRK mutations that may predict resistance to Trk inhibitors

Method Name

Sequence Capture Next-Generation Sequencing (NGS)

Reporting Name

NTRK Genes Mutation Analysis, Tumor

Specimen Type

Varies

Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Varies Ambient (preferred)
  Refrigerated 

Reject Due To

Specimens that have been decalcified (all methods)
Specimens that have not been formalin-fixed, paraffin-embedded, except for cytology slides
Extracted nucleic acid (DNA/RNA)
Reject

Clinical Information

The NTRK1, NTRK2, and NTRK3 genes encode the tropomyosin receptor kinases TrkA, TrkB, and TrkC, respectively. Fusions of the NTRK genes with a variety of 5' (upstream) partner genes upregulate Trk kinase activity and contribute to tumorigenesis. NTRK gene fusions have been reported in diverse tumor types. Numerous US Food and Drug Administration approved pan-Trk inhibitors have been developed for the treatment of tumors with NTRK gene fusions. However, resistance to Trk inhibition can occur through the development of NTRK gene mutations. This test can be used to identify NTRK resistance mutations to aid in the management of these patients. Second generation Trk inhibitors have been developed to overcome resistance to the first-generation inhibitors.

Reference Values

An interpretive report will be provided.

Day(s) Performed

Monday through Friday

Report Available

12 to 20 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. It has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

88381-Microdissection, manual

81479

Forms

If not ordering electronically, complete, print, and send a Oncology Test Request (T729) with the specimen.