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Date Published: 15/12/2025
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DOI: https://doi.org/10.51298/vmj.v556i3.16532
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Vol. 556 No. 3 (2025)
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Dương, T. A., Phạm, Q. T., Nguyễn, T. T., Trần, Q. V., Cao, N. T. N., Thái, A. T., & Ngô, Q. Đạt. (2025). OPTIMIZATION OF THE IMMUNOHISTOCHEMISTRY PROTOCOL FOR THE PAN-TRK (EPR17341) MARKER IN COLORECTAL CANCER. Vietnam Medical Journal, 556(3). https://doi.org/10.51298/vmj.v556i3.16532

OPTIMIZATION OF THE IMMUNOHISTOCHEMISTRY PROTOCOL FOR THE PAN-TRK (EPR17341) MARKER IN COLORECTAL CANCER

Thu Anh Dương, Quốc Thắng Phạm, Thanh Toàn Nguyễn, Quang Vũ Trần, Ngọc Tuyết Nga Cao, Anh Tú Thái, Quốc Đạt Ngô

Main Article Content

Abstract

Introduction: NTRK gene fusions have been identified as oncogenic alterations in a variety of tumor types. The detection of NTRK fusions is of significant diagnostic and therapeutic importance, as affected patients may benefit from targeted tyrosine kinase inhibitors such as larotrectinib and entrectinib, which achieve high response rates (>75%) irrespective of tumor histology. According to the 2019 ESMO guidelines, immunohistochemistry with pan-TRK antibodies represents an effective screening approach for identifying NTRK fusions. Objective: This study aimed to standardize the immunohistochemistry (IHC) protocol for pan-TRK (EPR17341)  staining at our institution by optimizing specific technical parameters based on the manufacturer’s recommendations, thereby establishing an optimized protocol applicable to routine diagnostic practice. Materials and Methods: We conducted a retrospective analysis of 163 formalin-fixed paraffin-embedded (FFPE) colorectal carcinoma specimens with microsatellite instability, retrieved from the Department of Pathology, Ho Chi Minh City Oncology Hospital. Results: Through five trial procedures, we successfully optimized the IHC protocol for pan-TRK. Application of the optimized protocol to 163 microsatellite-instable colorectal carcinoma cases revealed a pan-TRK positivity rate of 6.7%, predominantly localized to the membrane and cytoplasm. Conclusion: The optimized IHC protocol using the VENTANA pan-TRK (EPR17341) antibody demonstrated reliable performance and holds promise for broad application in the diagnosis and potential management of NTRK fusion–positive cancers.

Article Details

Keywords

NTRK, pan-TRK (EPR17341), optimized, immunohistochemistry, microsatellite instability colorectal carcinoma, FFPE.

References

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