MeIS: DNA methylation-based immune response signatures for thyroid nodule diagnostics

Abstract

Context: Accurately distinguishing between benign thyroid nodules (BTNs) and papillary thyroid cancers (PTCs) with current conventional methods poses a significant challenge.

Objective: We identify DNA methylation markers of immune response-related genes for distinguishing BTNs and PTCs.

Methods: In this study, we analyzed a public reduced representative bisulfite sequencing (RRBS) dataset and revealed distinct methylation patterns associated with immune signals in PTCs and BTNs. Based on these findings, we developed a diagnostic classifier named as the Methylation-based Immune Response Signature (MeIS), which was composed of fifteen DNA methylation markers associated with immune response-related genes. We validated the MeIS's performance in two independent cohorts: ZS's retrospective cohort (50 PTC and 18 BTN surgery-leftover samples) and ZS's preoperative cohort (31 PTC and 30 BTN fine-needle aspiration (FNA) samples).

Results: The MeIS classifier demonstrated significant clinical promise, achieving AUCs of 0.96, 0.98, 0.89 and 0.90 in the training set, validation set, ZS's retrospective cohort, and ZS's preoperative cohort, respectively. For the cytologically indeterminate thyroid nodules, in the ZS's retrospective cohort, MeIS exhibited a sensitivity of 91% and a specificity of 82%; in the ZS's preoperative cohort, MeIS achieved a sensitivity of 84% and a specificity of 74%. Additionally, combining MeIS and BRAFV600E detection improved the detecting performance of cytologically indeterminate thyroid nodules, yielding sensitivities of 98% and 87%, and specificities of 82% and 74% in the ZS's retrospective cohort and ZS's preoperative cohort, respectively.

Conclusions: The fifteen markers we identified can be employed to improve the diagnostic of cytologically indeterminate thyroid nodules.

Keywords: DNA methylation; Immune response signatures; Neutrophil activation; Thyroid nodule diagnostics.