Evaluation of the genetic alterations landscape of differentiated thyroid cancer in children.

[OBJECTIVES] Studies investigating the underlying genetic profile in pediatric patients diagnosed with differentiated thyroid cancer (DTC) are quite limited. This study aimed to identify genetic alterations in patients diagnosed with DTC.

[METHODS] A total of 20 patients with confirmed DTC were included in the study; however, five were excluded due to the unavailability of thyroid tumor samples. Somatic mutation analysis of the DICER1, BRAF, KRAS, NRAS, and HRAS genes was performed using next-generation sequencing. In addition, gene fusions involving ALK, RET, PTC, ETV6, and NTRK3 were assessed using fluorescence hybridization. A family screening was also conducted, and thyroid ultrasonography was performed. Fine-needle aspiration biopsy was carried out for family members when deemed necessary.

[RESULTS] The mean age at diagnosis was 14.42 ± 2.88 years. Somatic mutations were identified in nine patients (60 %). The detected mutations were as follows: RET/PTC fusion (n=3), BRAF V600E (n=2), NRAS Q61R (n=1), NRAS A59D (n=1), DICER1 E1705K (n=1), and ETV6/NTRK3 fusion (n=1). No statistically significant differences in prognostic factors were observed between patients with and without somatic mutations. As part of the family screening, suspicious thyroid nodules were detected in four parents. One parent underwent hemithyroidectomy, and final pathology revealed papillary thyroid carcinoma.

[CONCLUSIONS] Considering the limited number of similar studies on childhood thyroid cancer, these findings provide a valuable contribution to the existing literature. In particular, the results obtained from family screening may support advancements in early diagnosis, risk stratification, and the development of targeted therapeutic approaches.