Aims In thyroid cytopathology, the undetermined diagnostic categories still pose diagnostic challenges. Although next-generation sequencing (NGS) is a promising technique for the molecular testing of thyroid fine-needle aspiration (FNA) specimens, access to such technology can be difficult because of its prohibitive cost and lack of reimbursement in countries with universal health coverage. To overcome these issues, we developed and validated a novel custom NGS panel, Nexthyro, specifically designed to target 264 clinically relevant mutations involved in thyroid tumourigenesis. Moreover, in this study, we compared its analytical performance with that of our previous molecular testing strategy.
Methods The panel, which includes 15 genes (BRAF, EIF1AX, GNAS, HRAS, IDH1, KRAS, NF2, NRAS, PIK3CA, PPM1D, PTEN, RET, DICER1, CHEK2, TERT promoter), was validated with a cell-line derived reference standard and 72 FNA archival samples previously tested with the 7-gene test.
Results Nexthyro yielded 100% specificity and detected mutant alleles at levels as low as 2%. Moreover, in 5/72 (7%) FNAs, it detected more clinically relevant mutations in BRAF and RAS genes compared with the 7-gene test. Nexthyro also revealed better postsequencing metrics than the previously adopted commercial ‘generic’ NGS panel.
Conclusion Our comparative analysis indicates that Nexthyro is a reliable NGS panel. The study also implies that a custom-based solution for routine thyroid FNA is sustainable at the local level, allowing patients with undetermined thyroid nodules affordable access to NGS.
- thyroid neoplasms
- cytological techniques
Data availability statement
All data relevant to the study are included in the article or uploaded as online supplemental information.
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Handling editor Runjan Chetty.
Twitter @UmbertoMalapel1, @PasqualePisapia
RS and MN contributed equally.
Contributors Conceptualisation, RS, MN, GT and CB; methodology, all authors; software, all authors; validation, all authors; formal analysis, all authors; investigation, all authors; resources, all authors; data curation, all authors; writing—original draft preparation, RS, MN, CB; writing—review and editing, all authors; visualisation, all authors; supervision, GT and CB; project administration, RS, MN, GT and CB; funding acquisition, GT and CB.
Funding Regione Campania for the investigation of the molecular biology of thyroid cancer. Grant number: LR n.24 29/12/2005.
Competing interests EV has received personal fees (as consultant and/or speaker bureau) from Diaceutics, unrelated to the current work. UM has received personal fees (as consultant and/or speaker bureau) from Boehringer Ingelheim, Roche, MSD, Amgen, Thermo Fisher Scientifics, Diaceutics, GSK, Merck and AstraZeneca, unrelated to the current work. GT reports personal fees (as speaker bureau or advisor) from Roche, MSD, Pfizer and Bayer, unrelated to the current work.
Provenance and peer review Not commissioned; externally peer reviewed.
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