Site Editors

Alexander Drilon, MD

Gregory J. Riely, MD, PhD


Singapore Task Force: When and How to Test for NTRK Gene Fusions in Select Cancers

By: Emily Rhode
Posted: Friday, January 28, 2022

An article published by a multidisciplinary task force of medical experts in Singapore recommended testing algorithms for NTRK gene fusions in a wide range of both select adult and pediatric malignancies. Kiat Hon Tony Lim, MBBS, FRCPA, FRCPath, of Singapore General Hospital, and colleagues explored algorithms for when and how oncologists and pathologists specializing in non–small cell lung cancer (NSCLC), colorectal cancer, adult sarcomas, and pediatric cancers should test for NTRK gene fusions. Their recommendations were published in the Asia-Pacific Journal of Clinical Oncology.

“The use of tumor-specific algorithms may provide guidance to the clinicians in deciding when and how to carry out NTRK gene fusion testing, and when to employ TRK inhibitors in the management of cancer patients,” stated the authors.

The authors created a framework of recommendations for each selected cancer type based on practice-oriented standards used in Singapore. For NSCLC, the consensus recommendation was to perform upfront testing for NTRK gene fusions as well as for key oncogenic drivers and then consider retesting upon disease progression. For colorectal cancer, testing should be performed for NTRK gene fusions via next-generation sequencing in all microsatellite instability–high colorectal cancers regardless of the RAS/RAF mutation status. A pan-TRK immunohistochemistry screening followed by next-generation sequencing to confirm NTRK gene fusions is recommended as a first step for testing in patients with adult sarcomas. In pediatric cancers, next-generation sequencing for NTRK gene fusions is recommended. If next-generation sequencing is not available, alternative tests should be fluorescence in situ hybridization, reverse transcriptase–polymerase chain reaction, and pan-TRK immunohistochemistry. If the tumor has a clear diagnosis and the type is not known to have NTRK gene fusions, then NTRK testing may be optional.

In the future, the authors suggest that development of an international registry for gene fusions could lead to improved detection of NTRK gene fusion partners as well as more specific and useful characterization of these cancers.

Disclosure: For full disclosures of the study authors, visit

By continuing to browse this site you permit us and our partners to place identification cookies on your browser and agree to our use of cookies to identify you for marketing. Read our Privacy Policy to learn more.