Multicenter collaborative study on the development of a Japanese NGS panel for thyroid tumors: One of the JTA Key Clinical Issues (2022–2025)

Background Genetic testing has been shown to play a significant role in thyroid cytopathology. We developed a Japanese targeted NGS panel, ThyroGene TM , specifically designed for thyroid tumors. This study conducted as one of the Japan Thyroid Association (JTA) Key Clinical Issues (2022–2025), aimed at determining the feasibility of ThyroGene TM V2 in improving the diagnostic accuracy of FNA for thyroid nodules. Methods Multicenter collaborative research was performed using FNA samples. Ninety specimens were subjected to DNA and RNA extraction and genetic testing using ThyroGene TM V2. Results The ThyroGene™ V2 panel detected at least one genetic alteration in 49 of the 90 specimens. In the Bethesda II, 13 of 30 samples harbored mutations, comprising N/H/KRAS , PTEN , EIF1AX and DICER1 ; no TERT promoter ( TERT p) mutations were detected. In the Bethesda III, one of two samples showed BRAF (p.V600E) with mutations of PTEN and TERT p. In the Bethesda IV, 18 of 40 samples showed various mutations, consisting of N/H/KRAS , PTEN , EIF1AX , DICER1 , TSHR and GNAS , and one of 40 showed an NRAS co-mutation with EIF1AX . In the Bethesda VI, all papillary thyroid carcinoma cases showed BRAF (p.V600E) mutations. One of the two ATC cases had an NRAS mutation coexisting with TERT p and EIF1AX . The other ATC case did not show detectable mutations. Conclusion ThyroGene TM V2 provides molecular evidence that complements cytological diagnosis, including assessment of the genetic risk of malignant thyroid nodules. ThyroGene TM V2 demonstrates the potential to refine the FNA diagnosis of thyroid nodules and for preoperative decision-making in patient management.