BIOMARKER RESULTS (IHC)

Original block:

panTRK IHC result: Positive Negative

Proportion	Stain intensity	Subtotal
Nuclear staining	{0 to 3}	{0 to 2}	{}
Cytoplasmic staining	{0 to 3}	{0 to 2}	{}
Membranous staining	{0 to 3}	{0 to 2}	{}
CANTRK Total	{}

panTRK Interpretation:

Proportion of staining: 0 = < 10%; 1 = [10% - 30%]; 2 = [30% - 70%] and 3 [70% - 100%]

Intensity of staining: 0 less than 10% of cells stained; 1 stain not detected at 100X; 2 stain detected at 100X

Definition of POSITIVE panTRK IHC: CANTRK score total must be >= 6 or any single cellular compartment = 5

APL meets accreditation and ASCO-CAP Guidelines including tissue fixation standards. Refer to original surgical report for fixation data.

If the result is insufficient, please submit if possible a new sample. If the result is negative, it supports absence of NTRK gene rearrangement. No additional NTRK testing required except if the tumour is associated with high frequency NTRK fusion. If the result is positive, it may indicate NTRK gene rearrangement but IHC triage is at this point highly sensitive but lack specificity and Next-Generation Sequencing (NGS) is mandatory to confirm gene rearrangement. When IHC positive, NGS test will be automatically ordered.

Disclaimer: VENTANA pan-TRK (EPR17341) assay is utilized in the Edmonton Zone IHC Laboratory to screen tumours with NTRK gene fusions for which a tyrosine kinase inhibitor therapy is available. The assay detects the C-terminal region of the tropomyosin receptor kinase (TRK) proteins A, B and C, in formalin-fixed, paraffin-embedded (FFPE) neoplastic tissues. This assay has been optimized through the Canadian ring study CANTRK.

Test ID: PANTRK