Abstract
OBJECTIVE: This study aims to evaluate the changes in the expression levels of METTL3 and METTL14 in patients with differentiated thyroid cancer (DTC) and their association with thyroid function indicators, as well as to explore the potential value of these genes in predicting the risk of DTC recurrence. METHODS: This cohort study included 189 DTC patients treated at Shidong Hospital between April 2016 and February 2021. Patients were divided into an experimental group, which received combined radioactive iodine ((131)I) therapy and thyroid-stimulating hormone (TSH) suppression therapy (n = 119), and a control group, which received only TSH suppression therapy (n = 70). Messenger RNA (mRNA) expression levels of METTL3 and METTL14 in patients' serum were measured before and six months after treatment using quantitative real-time polymerase chain reaction (qRT-PCR). Thyroid function indicators, including free triiodothyronine (FT3), free thyroxine (FT4), TSH, and thyroglobulin (Tg), were assessed using electrochemiluminescence immunoassay. Disease-free survival (DFS) was analyzed using Cox regression analysis, and data visualization was performed with the ggplot2 package in R. RESULTS: Both METTL3 and METTL14 expression levels significantly decreased after treatment in both the experimental and control groups (P < 0.001). Regarding thyroid function indicators, FT3 and FT4 levels significantly increased, while TSH and Tg levels significantly decreased post-treatment (P < 0.001). Lower post-treatment expression levels of METTL3 and METTL14 were significantly associated with a higher risk of recurrence. Cox regression analysis further indicated that post-treatment METTL3, METTL14, TSH, and Tg levels were independent predictors of DFS (P < 0.05). CONCLUSION: Low expression levels of METTL3 and METTL14 are closely associated with malignant progression and an increased risk of recurrence in DTC. Patients receiving combined (131)I and TSH suppression therapy demonstrated longer DFS. These findings suggest that METTL3 and METTL14 could serve as potential biomarkers for prognosis evaluation in DTC patients.