Methylation markers differentiate thyroid cancer from benign nodules

The role of epigenetic methylations in thyroid Cancer

Thyroid cancer (TC) represents one of the most prevalent endocrine malignancies, with a rising incidence worldwide. Epigenetic alterations, which modify gene expression without altering the underlying DNA sequence, have garnered significant attention in recent years. Increasing evidence underscores the pivotal role of epigenetic modifications, including DNA methylation, RNA methylation, and histone methylation, in the pathogenesis of TC. This review provides a comprehensive overview of these reversible and environmentally influenced epigenetic modifications, highlighting their molecular mechanisms and functional roles in TC. Additionally, the clinical implications, challenges associated with studying these epigenetic modifications, and potential future research directions are explored.

Inflammatory tumor microenvironment of thyroid cancer promotes cellular dedifferentiation and silencing of iodide-handling genes expression

BACKGROUND

Due to dedifferentiation of tumor cells, manifested by a decreased expression of iodide-handling genes in thyrocytes, some thyroid carcinomas lose their capability for radioiodine concentration and gradually develop radioactive iodine (RAI) resistance. This work aimed to investigate the role of tumor microenvironment (TME) in the process of tumor cell dedifferentiation.

MATERIALS AND METHODS

Bioinformatic analyses and subsequent immunohistochemistry (IHC) and western blot assays were performed in papillary thyroid carcinoma (PTC) and matched normal tissue. ELISA was used to assess the secretion of cytokines under the stimulation of pharmacological endoplasmic reticulum (ER) stress inducer.

RESULTS

Higher levels of pro-inflammatory cytokines, interleukin 6 (IL-6) and (C-X-C motif chemokine ligand 8 (CXCL8), were found in thyroid cancer tissues compared with matched normal tissues. ER stress, induced by stressful environmental stimuli, such as nutrient deprivation and hypoxia, occurred in thyroid tumors. Classic ER stress inducers, thapsigargin (Tg) and tunicamycin (Tm), promoted the expression of IL6 and CXCL8 in thyroid cancer cells at mRNA and protein levels. Of note, rIL-6 and rCXCL8 promoted the dedifferentiation of thyroid cancer cells or even non-transformed cells in an autocrine/paracrine manner, weakening radioiodine uptake ability of thyroid cancer cells. Intriguingly, sorafenib, a multiple kinase inhibitor (MKI), could potently suppress not only ER stress-induced but also basal expressions of IL-6 and CXCL8 in thyroid cancer cells.

CONCLUSIONS

The inflammatory TME could regulate cell dedifferentiation, leading to loss of thyroid-specific gene expressions, through reciprocal interaction between thyroid tumor cells and follicular cells. Our study provides a new perspective on the mechanisms of how inflammatory TME affects DTC dedifferentiation.

Association of DNA Promoter Methylation and BRAF Mutation in Thyroid Cancer

The BRAF V600E mutation and DNA promoter methylation play important roles in the pathogenesis of thyroid cancer (TC). However, the association of these genetic and epigenetic alterations is not clear. In this study, using paired tumor and surrounding normal tissue from the same patients, on a genome-wide scale we tried to identify (a) any association between BRAF mutation and DNA promoter methylation, and (b) if the molecular findings may provide a basis for therapeutic intervention. We included 40 patients with TC (female = 28, male = 12) without distant metastasis. BRAF mutation was present in 18 cases. We identified groups of differentially methylated loci (DML) that are found in (a) both BRAF mutant and wild type, (b) only in BRAF mutant tumors, and (c) only in BRAF wild type. BRAF mutation-specific promoter loci were more frequently hypomethylated, whereas BRAF wild-type-specific loci were more frequently hypermethylated. Common DML were enriched in cancer-related pathways, including the mismatch repair pathway and Wnt-signaling pathway. Wild-type-specific DML were enriched in RAS signaling. Methylation status of checkpoint signaling genes, as well as the T-cell inflamed genes, indicated an opportunity for the potential use of PDL1 inhibitors in BRAF mutant TC. Our study shows an association between BRAF mutation and methylation in TC that may have biological significance.

CpG island status as an epigenetic alteration for NIS promoter in thyroid neoplasms; a cross-sectional study with a systematic review

BACKGROUND

Gene silence via methylation of the CpG islands is cancer's most common epigenetic modification. Given the highly significant role of NIS in thyroid cancer (TC) differentiation, this cross-sectional study aimed to investigate the DNA methylation pattern in seven CpG islands (CpG1-7 including +846, +918, +929, +947, +953, +955, and +963, respectively) of the NIS promoter in patients diagnosed with papillary (PTC), follicular (FTC), and multinodular goiter (MNG). Additionally, a systematic review of the literature was conducted to compare our results with studies concerning methylation of the NIS gene promoter.

METHODS

Thyroid specimens from 64 patients met the eligibility criteria, consisting of 28 PTC, 9 FTC, and 27 benign MNG cases. The mRNA of NIS was tested by qRT-PCR. The bisulfite sequencing PCR (BSP) technique was performed to evaluate the promoter methylation pattern of the NIS gene. Sequencing results were received in chromatograph, FASTA, SEQ, and pdf formats and were analyzed using Chromas. The methylation percentage at each position and for each sample was calculated by mC/(mC+C) formula for all examined CpGs; following that, the methylation percentage was also calculated at each CpG site. Besides, a literature search was conducted without restricting publication dates. Nine studies met the eligibility criteria after removing duplicates, unrelated articles, and reviews.

RESULTS

NIS mRNA levels decreased in tumoral tissues of PTC (P = 0.04) and FTC (P = 0.03) patients compared to their matched non-tumoral ones. The methylation of NIS promoter was not common in PTC samples, but it was frequent in FTC (P < 0.05). Significant differences were observed in the methylation levels in the 4th(+ 947), 6th(+ 955), and 7th(+ 963) CpGs sites in the forward strand of NIS promoter between FTC and MNG tissues (76.34 ± 3.12 vs 40.43 ± 8.42, P = 0.004, 69.63 ± 3.03 vs 23.29 ± 6.84, P = 0.001 and 50.33 ± 5.65 vs 24 ± 6.89, P = 0.030, respectively). There was no significant correlation between the expression and methylation status of NIS in PTC and FTC tissues.

CONCLUSION

Perturbation in NIS promoter's methylation individually may have a potential utility in differentiating MNG and FTC tissues. The absence of a distinct methylation pattern implies the importance of other epigenetic processes, which may alter the production of NIS mRNA. In addition, according to the reversibility of DNA methylation, it is anticipated that the design of particular targeted demethylation medicines will lead to a novel cancer therapeutic strategy.

The Role of TSHR, PTEN and RASSF1A Promoters' Methylation Status for Non-Invasive Detection of Papillary Thyroid Carcinoma

Aim: We investigated whether a difference exists between TSHR, PTEN and RASSF1A methylation status in plasma of subjects with papillary thyroid cancer (PTC). Methods: Peripheral blood samples were collected from 68 patients with PTC and 86 healthy controls (HC). Thyroid cancer tissue and corresponding adjacent normal tissue methylation levels were analyzed. DNA methylation level changes in TSHR, PTEN and RASSF1A genes were analyzed by quantitative methylation-sensitive polymerase chain reaction. Results: We observed that the methylation level of TSHR was significantly higher in the thyroid cancer tissue compared to adjacent normal tissue (p = 0.040). TSHR methylation levels in the PTC group plasma samples were significantly higher compared to HC (p = 0.022). After surgery, PTC plasma samples showed lower TSHR and PTEN methylation levels compared to the levels before surgery (p = 0.003, p = 0.031, respectively). The TSHR methylation level was significantly higher in PTC with larger tumor size (>2 cm) (p < 0.001), and lymph node metastases (p = 0.01), lymphovascular invasion (p = 0.02) and multifocality (p = 0.013) 0ROC analysis revealed that the TSHR methylation level provides high accuracy in distinguishing PTC from HC (p = 0.022, AUC of 0.616). Conclusion: TSHR methylation in peripheral blood samples is expected to be a sensitive and specific minimally invasive tool for the diagnosis of PTC, especially in combination with other diagnostic means.

Epigenetic modification and BRAF gene mutation in thyroid carcinoma

Thyroid cancer remains the most prevailing endocrine malignancy, and a progressively increasing incidence rate has been observed in recent years, with 95% of thyroid cancer represented by differentiated thyroid carcinomas. The genetics and epigenetics of thyroid cancer are gradually increasing, and gene mutations and methylation changes play an important roles in its occurrence and development. Although the role of RAS and BRAF mutations in thyroid cancer have been partially clarified,but the pathogenesis and molecular mechanisms of thyroid cancer remain to be elucidated. Epigenetic modification refer to genetic modification that does not change the DNA sequence of a gene but causes heritable phenotypic changes in its expression. Epigenetic modification mainly includes four aspects: DNA methylation, chromatin remodelling, noncoding RNA regulation, and histone modification. This article reviews the importance of thyroid cancer epigenetic modification and BRAF gene mutation in the treatment of thyroid cancer.

Identification of 4-methylation driven genes based prognostic signature in thyroid cancer: an integrative analysis based on the methylmix algorithm

Thyroid cancer (TC) is known with a high rate of persistence and recurrence. We aimed to develop a prognostic signature to monitor and assess the survival of TC patients. mRNA expression and methylation data were downloaded from the TCGA database. Then, R package methylmix was applied to construct a mixed model was used to identify methylation-driven genes (MDGs) according to the methylation levels. Furthermore, an MDGs based prognostic signature and predictive nomogram were constructed according to the analysis of univariate and multivariate Cox regression. Totally 62 methylation-driven genes that were mainly enriched in substrate-dependent cell migration, cellular response to mechanical stimulus, et al. were found in TC tissues. aldolase C (AldoC), C14orf62, dishevelled 1 (DVL1), and protein tyrosine phosphatase receptor type C (PTPRC) were identified to be significantly related to patients' survival, and may serve as independent prognostic biomarkers for TC. Additionally, the prognostic methylation signature and a novel prognostic, predictive nomogram was established based on the methylation level of 4 MDGs. In this study, we developed a 4-MDGs based prognostic model, which might be the potential predictors for the survival rate of TC patients, and this findings might provide a novel sight for accurate monitoring and prognosis assessment.

Clinical implications of TPO and AOX1 in pediatric papillary thyroid carcinoma

BACKGROUND

Thyroid carcinoma is a common pediatric head and neck cancer, of which papillary thyroid cancer (PTC) is the most common type. Previously, we found that thyroid peroxidase (TPO) and aldehyde oxidase 1 (AOX1) were differentially expressed in PTC. This study explored the clinical importance of TPO and AOX1 in the diagnosis and prognosis of PTC in children.

METHODS

Both TPO and AOX1 expression in PTC were analyzed using datasets from Gene Expression Omnibus (GEO). TPO and AOX1 protein levels in plasma from patients with PTC and non-tumor controls were detected via enzyme-linked immunosorbent assay (ELISA). The diagnostic accuracy of TPO and AOX1 was assessed using receiver operating characteristic (ROC) curve analysis. The association between gene expression levels and patient survival was explored using the Kaplan-Meier plotter online database.

RESULTS

The results revealed that TPO and AOX1 expression was significantly downregulated in four independent datasets (GSE33630, GSE27155, GSE3678, and GSE3467). TPO and AOX1 protein levels in blood plasma were significantly decreased in patients with PTC. Quantitative analysis demonstrated that TPO and AOX1 levels in plasma had satisfactory predictive performance and the ability to discriminate PTC from healthy samples. Prognostic analysis demonstrated that low levels of TPO and AOX1 were markedly associated with poor survival in patients with PTC.

CONCLUSIONS

In summary, these results implied that TPO and AOX1 could serve as novel biomarkers for the diagnosis and prognosis of pediatric PTC.

DNA Methylation Haplotype Block Markers Efficiently Discriminate Follicular Thyroid Carcinoma from Follicular Adenoma

CONTEXT

Follicular thyroid carcinoma (FTC) is the second most common type of thyroid carcinoma and must be pathologically distinguished from benign follicular adenoma (FA). Additionally, the clinical assessment of thyroid tumors with uncertain malignant potential (TT-UMP) demands effective indicators.

OBJECTIVE

We aimed to identify discriminating DNA methylation markers between FA and FTC.

METHODS

DNA methylation patterns were investigated in 33 FTC and 33 FA samples using reduced representation bisulfite sequencing and methylation haplotype block-based analysis. A prediction model was constructed and validated in an independent cohort of 13 FTC and 13 FA samples. Moreover, 36 TT-UMP samples were assessed using this model.

RESULTS

A total of 70 DNA methylation markers, approximately half of which were located within promoters, were identified to be significantly different between the FTC and FA samples. All the Gene Ontology terms enriched among the marker-associated genes were related to "DNA binding," implying that the inactivation of DNA binding played a role in FTC development. A random forest model with an area under the curve of 0.994 was constructed using those markers for discriminating FTC from FA in the validation cohort. When the TT-UMP samples were scored using this model, those with fewer driver mutations also exhibited lower scores.

CONCLUSION

An FTC-predicting model was constructed using DNA methylation markers, which distinguished between FA and FTC tissues with a high degree of accuracy. This model can also be used to help determine the potential of malignancy in TT-UMP.

Urinary phthalate metabolite concentrations, oxidative stress and thyroid function biomarkers among patients with thyroid nodules

Prior human studies have explored effects of phthalate exposures on thyroid function, but the underlying biological mechanisms remain poorly unclear. We aimed to explore the associations between phthalate exposures and thyroid function among a potentially susceptible population such as patients with thyroid nodules, and further to assess the mediating role of oxidative stress. We measured eight phthalate metabolites, three oxidative stress biomarkers [8-hydroxy-2-deoxyguanosine (8-OHdG), 8-iso-prostaglandin F_2α (8-isoPGF_2α) and 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA)] in urine and three thyroid function biomarkers [thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4)] in serum among 214 patients with thyroid nodules. Multivariate regression models were applied to assess the associations among urinary phthalate metabolites, oxidative stress and thyroid function biomarkers. The potential mediating role of oxidative stress was explored by mediation analysis. We observed that multiple urinary phthalate metabolites were associated with altered FT4 and increased oxidative stress biomarkers (all FDR-adjusted P ≤ 0.05). Meanwhile, we found that 8-isoPGF_2α was negatively associated with FT3/FT4 among patients with benign thyroid nodules (FDR-adjusted P = 0.08). The mediation analysis indicated that 8-isoPGF_2α mediated the associations of urinary MEHHP and %MEHP with FT3/FT4, with 55.6% and 32.6% proportion of the mediating effects, respectively. Our data suggest that lipid peroxidation may be an intermediate mechanism involved in the effects of certain phthalate exposures on altered thyroid function among patients with benign thyroid nodules.

Association between TSHR gene methylation and papillary thyroid cancer: a meta-analysis

PURPOSE

To explore the association between the thyroid stimulating hormone receptor (TSHR) gene methylation and human papillary thyroid cancer (PTC), as well as PTC related clinicopathological indicators.

METHODS

We searched PubMed, Embase, Medline, and Web of Science databases through computer for articles published in English on association between methylation of TSHR gene and PTC. Articles published in Chinese were searched in China National Knowledge Infrastructure (CNKI), WanFang, China Biology Medicine (CBM) disc, and WeiPu databases. Database search took place in the 4th week of October.

RESULTS

Totally 914 samples from 14 case-control studies were included in our meta-analysis. The methylation rate of TSHR gene in PTC group was significantly greater than that in control group (OR = 6.45, 95% CI 3.03, 13.71, P < 0.001). The subgroup analysis results showed the incidence of TSHR gene methylation was higher in autologous controls (OR = 16.39, 95% CI 8.83, 30.42, P < 0.001), Asian races (OR = 8.26, 95% CI 3.54, 19.23, P < 0.001), and Chinese (OR = 11.40, 95% CI 5.56, 23.39, P < 0.001). Hierarchical analysis of PTC related clinicopathological indicators showed that TSHR gene methylation rate are higher in PTC patients over 45 years (OR = 1.65, 95% CI 1.07, 2.55, P < 0.05) and lymph node metastasis (OR = 5.36, 95% CI 1.54, 18.67, P < 0.01). In addition, the occurrence of TSHR gene methylation had also been shown to be related to the clinical stage (OR = 0.23, 95% CI 0.07, 0.70, P < 0.05) and size (OR = 0.19, 95% CI 0.11, 0.32, P < 0.01) of tumors. The result of sensitivity analysis showed the combined results of the studies included in the meta-analysis were fairly stable. Begg's and Egger's tests also suggested that there was no significance publication bias (P > 0.1).

CONCLUSIONS

The rate of TSHR gene methylation is higher in PTC and it may be associated with the pathogenesis of human PTC, suggesting that TSHR gene may be a candidate marker for PTC diagnosis. In addition, the occurrence of TSHR gene methylation in PTC patients is closely related to age, lymph node metastasis, clinical stage, and tumor size, suggesting that TSHR gene may be used as an index to judge the severity of PTC.

The Association Between Hyperhomocysteinemia and Thyroid Nodule Prevalence in an Adult Population

Background: Thyroid nodule is the most common disorder of thyroid. Metabolic syndrome was regarded as an important factor for the prevalence of thyroid nodule. Homocysteine has been shown to be related to metabolic syndrome, inflammation, and several common cancers. In this study, we aimed to investigate the relationship between serum homocysteine and the prevalence of thyroid nodule. Materials and Methods: This was a cross-sectional study that included 2040 adults in a health checkup population in Beijing Chao-yang hospital. Thyroid ultrasound data, together with anthropometric characteristics, metabolic parameters, and serum homocysteine, were recorded respectively. Results: Hyperhomocysteinemia (defined as serum homocysteine ≥15 μmol/L) was detected in 452 participants (21.91%). Thyroid nodule prevalence was significantly higher in hyperhomocysteinemia participants than in normal homocysteine participants (52.57% vs. 45.16%, P = 0.006). Logistic regression analysis revealed that age [odds ratio (OR) 1.054; P < 0.001], female gender (OR 2.242; P < 0.001), body mass index (OR 1.050; P < 0.001), and serum homocysteine level (OR 1.022; P = 0.001) were the independent risk factors for thyroid nodule. Conclusions: Subjects with hyperhomocysteinemia have significantly higher thyroid nodule prevalence. Homocysteine is an independent risk factor for thyroid nodule. It implies that individuals with hyperhomocysteinemia have higher susceptibility to thyroid nodule.

Bioinformatics analysis to screen key genes in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common type of thyroid carcinoma, and its incidence has been on the increase in recent years. However, the molecular mechanism of PTC is unclear and misdiagnosis remains a major issue. Therefore, the present study aimed to investigate this mechanism, and to identify key prognostic biomarkers. Integrated analysis was used to explore differentially expressed genes (DEGs) between PTC and healthy thyroid tissue. To investigate the functions and pathways associated with DEGs, Gene Ontology, pathway and protein-protein interaction (PPI) network analyses were performed. The predictive accuracy of DEGs was evaluated using the receiver operating characteristic (ROC) curve. Based on the four microarray datasets obtained from the Gene Expression Omnibus database, namely GSE33630, GSE27155, GSE3467 and GSE3678, a total of 153 DEGs were identified, including 66 upregulated and 87 downregulated DEGs in PTC compared with controls. These DEGs were significantly enriched in cancer-related pathways and the phosphoinositide 3-kinase-AKT signaling pathway. PPI network analysis screened out key genes, including acetyl-CoA carboxylase beta, cyclin D1, BCL2, and serpin peptidase inhibitor clade A member 1, which may serve important roles in PTC pathogenesis. ROC analysis revealed that these DEGs had excellent predictive performance, thus verifying their potential for clinical diagnosis. Taken together, the findings of the present study suggest that these genes and related pathways are involved in key events of PTC progression and facilitate the identification of prognostic biomarkers.

Promoter Methylation of Four Tumor Suppressor Genes in Human Papillary Thyroid Carcinoma

BACKGROUND & OBJECTIVE

Papillary thyroid cancer (PTC) is considered to be the most common type of thyroid malignancies. Epigenetic alteration, in which the chromatin conformation and gene expression change without changing the sequence of DNA, can occur in some tumor suppressor genes and oncogenes. Methylation is the most common type of epigenetic alterations that can be an excellent indicator of PTC invasive behavior.

METHODS

In this research, we determined the promoter methylation status of four tumor suppressor genes (SLC5A8, RASSF1, MGMT, and DNMT1) and compared the results of 55 PTC cases with 40 goiter patients. For methylation, we used the methylation-sensitive high resolution melting (MS-HRM) assay technique. The resulting graphs of each run were compared with those of 0%, 50%, and 100% methylated controls.

RESULTS

Our data showed that the promoter methylation of SLC5A8, Ras association domain family member 1(RASSF1), and MGMT were significantly different between PTC tissue and goiter with P-value less than 0.05. The most significant differences were observed in RASSF1; 77.2% of hyper-methylated PTC patients versus 15.6% hyper-methylated goiter samples (P<0.001).

CONCLUSION

RASSF1 promoter methylation can be a PTC genetic marker. RASSF1 promoter methylation is under the impact of the methyltransferase genes (DNMT1 and MGMT), protein expression, and promoter methylation.

Identification of a Five-CpG Signature with Diagnostic Value in Thyroid Cancer

Thyroid cancer (TC) ranks as the most common endocrine malignancy, and its incidence and mortality rates continue to rise annually. Increasing evidence have shown that DNA methylation, a kind of stable epigenetic modification, is associated with carcinogenesis, suggesting its potential as biomarkers for the early detection of tumors. With the aim of exploring likely DNA methylation biomarkers for TC diagnosis, we conducted a synthetic analysis of DNA methylation profiles based on 789 samples from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. In the discovery phase, we identified five CpG probes (cg11228682, cg01291854, cg06778183, cg01668008, and cg01702055) on the condition of DNA methylation data from GSE86961 (n = 82) and constructed a five-CpG signature-based diagnostic model for TC. In addition, we validated the diagnostic score formula in two independent training cohorts, GSE97466 (n = 141) and TCGA (n = 566), as well as the previous developing cohort GSE86961. Receiver operating characteristic analysis revealed that the five-CpG signature had a good diagnostic performance to distinguish TC samples from benign samples. In conclusion, our findings suggest that the five-CpG signature could provide a novel biomarker with useful applications in TC diagnosis.

DNA methylation in thyroid cancer

In recent years, cancer genomics has provided new insights into genetic alterations and signaling pathways involved in thyroid cancer. However, the picture of the molecular landscape is not yet complete. DNA methylation, the most widely studied epigenetic mechanism, is altered in thyroid cancer. Recent technological advances have allowed the identification of novel differentially methylated regions, methylation signatures and potential biomarkers. However, despite recent progress in cataloging methylation alterations in thyroid cancer, many questions remain unanswered. The aim of this review is to comprehensively examine the current knowledge on DNA methylation in thyroid cancer and discuss its potential clinical applications. After providing a general overview of DNA methylation and its dysregulation in cancer, we carefully describe the aberrant methylation changes in thyroid cancer and relate them to methylation patterns, global hypomethylation and gene-specific alterations. We hope this review helps to accelerate the use of the diagnostic, prognostic and therapeutic potential of DNA methylation for the benefit of thyroid cancer patients.

Subcellular expression of maspin – from normal tissue to tumor cells

Maspin or SerpinB5, a member of the serine protease inhibitor family, was shown to function as a tumor suppressor, especially in carcinomas. It seems to inhibit invasion, tumor cells motility and angiogenesis, and promotes apoptosis. Maspin can also induce epigenetic changes such as cytosine methylation, de-acetylation, chromatin condensation, and histone modulation. In this review, a comprehensive synthesis of the literature was done to present maspin function from normal tissues to pathologic conditions. Data was sourced from MEDLINE and PubMed. Study eligibility criteria included: Published in English, between 1994 and 2019, specific to humans, and with full-text availability. Most of the 118 studies included in the present review focused on maspin immunostaining and mRNA levels. It was shown that maspin function is organ-related and depends on its subcellular localization. In malignant tumors, it might be downregulated or negative (e.g., carcinoma of prostate, stomach, and breast) or upregulated (e.g., colorectal and pancreatic tumors). Its subcellular localization (nuclear vs cytoplasm), which can be proved using immunohistochemical methods, was shown to influence both tumor behavior and response to chemotherapy. Although the number of maspin-related papers increased, the exact role of this protein remains unknown, and its interpretation should be done with extremely high caution.

DNA methylation alterations as therapeutic prospects in thyroid cancer

BACKGROUND

Thyroid cancer is one of the most common endocrine malignancies. Although the 10-year survival rate of differentiated thyroid cancer (DTC) is about 90% after conventional treatments, a small proportion of patients still suffer from tumor recurrence or drug resistance.

OBJECTIVE

This review article summarizes recent researches and clinical trials related to target drugs that reduce mortality in thyroid cancer.

METHODS

This is a review of the recent literature and clinical trials on the three main aspects including methylation genes in thyroid cancers, the relationship between BRAF mutation and gene methylation, target and dehypermethylation drugs in clinical trials.

RESULTS

We propose new approaches to treating malignant thyroid cancer, based on advances in understanding the relationship between genetic and epigenetic changes in thyroid cancer. Although the effect of traditional treatment for thyroid cancer is relatively good, a small proportion of patients still suffer from tumor recurrence or drug resistance. Molecular targeted drugs and dehypermethylation drugs have more promising outcomes in aggressive thyroid cancer compared with conventional treatments.

CONCLUSION

Based on what was discussed in this review, we suggest that integration of epigenetic and targeted therapies into conventional treatments will reduce the occurrence of refractory radioiodine differentiated thyroid cancer and improve the outcomes in aggressive thyroid cancer patients.