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AACR 2023: Finnish Population–Based Study of NTRK Gene Fusions in Solid Tumors

By: Emily Rhode
Posted: Tuesday, April 25, 2023

Merja Perälä, MD, of the University of Turku and Turku University Hospital, Finland, and colleagues conducted a retrospective cohort study to investigate the frequency of NTRK gene fusions in patients with solid tumors from a population-based setting in the Turku region of Finland. Their results, which were presented at the American Association for Cancer Research (AACR) Annual Meeting 2023 (Abstract 925/8), indicated that NTRK gene fusions were rare in adults with colorectal cancer, non–small cell lung cancer (NSCLC), parotid or salivary tumors, and sarcoma and in pediatric solid tumors.

Researchers used archival tissue samples from 2,059 patients with solid tumors identified from the Auria Biobank between January 2005 and December 2019. Electronic health records and the national vital statistics database were used to obtain patients’ demographics, clinical characteristics, and survival status and followed patients from 1 year before their cancer diagnosis until the end of follow-up or death. The study included all solid tumors in pediatrics and selected solid tumors in adults (including colorectal cancer, NSCLC, sarcoma, and salivary or parotid cancer.)

Pan-TRK immunohistochemistry staining was used to determine the expression of TRK proteins, and NTRK gene fusion was confirmed through next-generation sequencing. The numbers of patients found to have NTRK gene fusion–positive disease were 8 of 1,151 (0.7%) for colorectal cancer, 1 of 288 (0.3%) for NSCLC, 1 of 114 (0.9%) for salivary or parotid cancer, 0 of 379 (0.0%) for sarcoma, and 4 of 127 (3.1%) for pediatric solid tumors. Researchers then identified the number of patients confirmed as NTRK-positive after next-generation sequencing as a proportion of those identified as NTRK-positive after immunohistochemistry staining. The resulting proportions were 80% for colorectal cancer, 5% for NSCLC, 6% for salivary or parotid cancer, 0% for sarcoma, and 25% for pediatric solid tumors.

The findings have clinical implications for the identification of patients who may benefit from selective TRK inhibitors as targeted therapies for solid tumors harboring NTRK gene fusions.

Disclosure: For full disclosures of the study authors, visit

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