# NTRK and RET fusion-directed therapy in pediatric thyroid cancer yields a tumor response and radioiodine uptake

Source: https://onco.cc/key-papers/paper-navigate-j-clin-invest-2021/  
OnCo record `paper-navigate-j-clin-invest-2021` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Published report from the NAVIGATE trial registered as NCT02576431, in Journal of Clinical Investigation (2021), chosen as the most cited paper whose own text cites the registry id.

## Summary

BACKGROUNDMolecular characterization in pediatric papillary thyroid cancer (PTC), distinct from adult PTC, is important for developing molecularly targeted therapies for progressive radioiodine-refractory (131I-refractory) PTC.METHODSPTC samples from 106 pediatric patients (age range: 4.3-19.8 years; n = 84 girls, n = 22 boys) who were admitted to SNUH (January 1983-March 2020) were available for genomic profiling. Previous transcriptomic data from 125 adult PTC samples were used for comparison.RESULTSWe identified genetic drivers in 80 tumors: 31 with fusion oncogenes (RET in 21 patients, ALK in 6 patients, and NTRK1/3 in 4 patients); 47 with point mutations (BRAFV600E in 41 patients, TERTC228T in 2 patients [1 of whom had a coexisting BRAFV600E], and DICER1 variants in 5 patients); and 2 with amplifications. Fusion oncogene PTCs, which are predominantly detected in younger patients, were at a more advanced stage and showed more recurrent or persistent disease compared with BRAFV600E PTCs, which are detected mostly in adolescents. Pediatric fusion PTCs (in patients <10 years of age) had lower expression of thyroid differentiation genes, including SLC5A5, than did adult fusion PTCs. Two girls with progressive 131I-refractory lung metastases harboring a TPR-NTRK1 or CCDC6-RET fusion oncogene received fusion-targeted therapy; larotrectinib and selpercatinib decreased the size of the tumor and restored 125I radioiodine uptake. The girl with the CCDC6-RET fusion oncogene received 131I therapy combined with selpercatinib, resulting in a tumor response. In vitro 125I uptake and 131I clonogenic assays showed that larotrectinib inhibited tumor growth and restored radioiodine avidity.CONCLUSIONSIn pediatric patients with fusion oncogene PTC who have 131I-refractory advanced disease, selective fusion-directed therapy may restore radioiodine avidity and lead to a dramatic tumor response, underscoring the importance of molecular testing in pediatric patients with PTC.FUNDINGThe Ministry of Science, ICT and Future Planning (NRF-2016R1A2B4012417 and 2019R1A2C2084332); the Korean Ministry of Health and Welfare (H14C1277); the Ministry of Education (2020R1A6A1A03047972); and the SNUH Research Fund (04-2015-0830).TRIAL REGISTRATIONTwo patients received fusion-targeted therapy with larotrectinib (NCT02576431; NAVIGATE) or selpercatinib (LOXO-RET-18018).

Indexed on Europe PMC as PubMed record 34237031 (DOI 10.1172/jci144847). Its abstract cites the registry id NCT02576431, which is how it was matched to this trial; no figure has been checked by an editor.

## Fields

- Kind: Key paper
- Last checked: 2026-09-22
- Tags: europepmc-ingest
- Journal: Journal of Clinical Investigation
- Year: 2021
- DOI: 10.1172/jci144847
- Authors: Lee YA, Lee H, Im SW, et al.
- What it means: This is the paper Europe PMC returns for registry id NCT02576431 with the most citations, so it is the natural first reading for anyone following the NAVIGATE trial. Read the abstract above alongside the trial page and the registry entry; the record was linked automatically and its figures have not been checked by hand.
- Caveats: Matched to the trial by the registry id cited in the Europe PMC record; the summary reproduces the record's abstract and no figure has been verified against the full paper.

## Sources

- J Clin Invest 2021: https://doi.org/10.1172/jci144847
- PubMed: https://pubmed.ncbi.nlm.nih.gov/34237031/
- Europe PMC: https://europepmc.org/article/MED/34237031
- ClinicalTrials.gov NCT02576431: https://clinicaltrials.gov/study/NCT02576431

## Connected records

- trials: [NAVIGATE](https://onco.cc/trials/navigate/)
- journals: [Journal of Clinical Investigation](https://onco.cc/journals/jci/)

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