Relationship between genetic alterations and clinicopathological characteristics of papillary thyroid carcinoma

Clinicopathological Features of CCDC6-RET and NCOA4-RET Fusions in Thyroid Cancer: A Single-Center Retrospective Cohort Study in a Chinese Population

Background: The rearranged during transfection (RET) proto-oncogene fusion is common in papillary thyroid cancer (PTC), varying across ethnic groups. However, comprehensive comparisons of RET fusion types are limited. This study aims to identify predominant RET fusions and analyze their clinicopathological characteristics in a cohort of Chinese thyroid cancer cases. Methods: This single-center retrospective cohort study analyzed thyroid cancer data, utilizing next-generation sequencing on formalin-fixed, paraffin-embedded tissue samples. Detailed clinicopathological data of thyroid cancer cases with RET fusions were collected. Results: Among 2300 thyroid cancer cases, RET fusions were exclusively found in PTC or differentiated high-grade thyroid carcinoma (DHGTC) cases (2234 cases), absent in other types (66 cases). Of the 2234 PTC or DHGTC cases, 113 (5.06%) exhibited RET fusions, including 100 primary cases. Coiled-coil domain containing 6 (CCDC6)-RET fusions predominated (78.0%, 78/100), with nuclear receptor coactivator 4 (NCOA4)-RET fusions representing 22.0% (22/100). NCOA4-RET fusions were more prevalent in patients aged 45 years and older (54.5% vs. 28.2%, p = 0.021) and DHGTC cases (p < 0.05) and associated with higher rates of lymph node metastases (90.9% vs. 67.9%, p = 0.032). CCDC6-RET fusion exhibited a higher prevalence of Hashimoto's thyroiditis (HT) (67.9% vs. 22.7%, p < 0.001) and elevated thyroglobulin antibody levels (14.11 [1.86-174.32] IU/mL vs. 2.01 [1.14-15.41] IU/mL, p = 0.018). Moreover, CCDC6-RET fusion predominantly occurred in classical PTC (56.4%, 44/78) and infiltrative follicular PTC (17.9%, 14/78), whereas NCOA4-RET fusion was more frequent in classical PTC (36.4%, 8/22), solid PTC (27.3%, 6/22), and DHGTC (27.3%, 6/22). RET fusions with compound mutations were associated with older age (≥45 years) and bilateral thyroid involvement. Follow-up data showed a higher recurrence rate in the RET fusion group compared with the BRAFV600E mutation group (5.0% vs. 0.0%, p = 0.018). Although the NCOA4-RET group showed a numerically higher recurrence rate compared with CCDC6-RET (9.1% vs. 3.8%), this difference was not statistically significant (p = 0.559). Conclusions: RET fusions are specific to PTC or DHGTC cases among Chinese thyroid cancer cases. CCDC6-RET and NCOA4-RET fusions exhibited distinct clinicopathological features, with NCOA4-RET being more aggressive.

TPO as an indicator of lymph node metastasis and recurrence in papillary thyroid carcinoma

The objective of this study was to investigate the expression of thyroid peroxidase (TPO) in papillary thyroid carcinoma (PTC) and to preliminarily investigate its value as a marker of lymph node metastasis and recurrence in patients with PTC. Clinical data of PTC patients and TPO expression were collected from The Cancer Genome Atlas (TCGA) database for analysis. We recruited 230 consecutive PTC patients from the Department of Thyroid Surgery of the First Affiliated Hospital of Kunming Medical University, collected their clinicopathological data, and also performed immunohistochemical analysis of TPO expression on their thyroid specimens to validate the results of bioinformatics analysis. In addition, the construction of protein-protein interaction networks was performed too. Functional enrichment analysis and immuno-infiltration analysis characterized the pathways in which TPO genes may be involved. Data mining based on the TCGA database showed that TPO expression in PTC tissues was significantly lower than in paired normal thyroid tissues. The expression level of TPO in PTC tissues correlated with tumor lymph node metastasis and recurrence. Follow-up data from our center also validated the difference in TPO expression and its relationship with lymph node metastasis in PTC patients. Functional enrichment analysis showed that TPO function was significantly associated with signaling pathways related to amino acid metabolism, gene expression regulation and tumorigenesis. TPO expression was also significantly associated with immune infiltration. Our study showed that reduced TPO expression was significantly associated with lymph node metastasis and recurrence in patients with PTC, and we validated this result in our central cohort. These data suggest that TPO may serve as a prognostic indicator for PTC.

The predictive value of coexisting BRAFV600E and TERT promoter mutations on poor outcomes and high tumour aggressiveness in papillary thyroid carcinoma: A systematic review and meta-analysis

BRAFV600E mutation is highly prevalent in patients with papillary thyroid carcinoma (PTC), and TERT promoter (TERTp) mutation is strongly associated with cancer-related mortality. However, predictive power of the two mutations remains inconclusive. We aimed to verify the prognostic effects of both mutations to assess the value of mutation detection for risk stratification in terms of PTC prognosis and tumour invasion, to guide PTC diagnosis and treatment. We conducted a literature search in the MEDLINE (PubMed), EMBASE, Web of Science and CENTRAL (Cochrane library) databases, from inception to February 2020. Basic characteristics, prognoses and clinicopathological features were collected from the included studies for further analysis. Twelve studies involving 4184 PTC patients were enrolled in our analysis. In total, 2412 (57.6%) of the patients carried either BRAFV600E or TERTp mutation, and 290 (6.9%) patients had both mutations. TERTp mutation was more common in patients with BRAFV600E mutation (RR = 1.75 [95% CI 1.44-2.13]). Patients with both mutations had a worse prognosis compared with those with a single mutation (vs BRAFV600E only: RR = 5.34 [4.20-6.78] vs TERTp only: RR = 2.12 [1.41-3.19]). TERTp mutation alone independently increased the risk of a poor prognosis (RR = 2.90 [1.93-4.35]) in terms of mortality (RR = 15.09 [7.75-29.37]), disease persistence (RR = 4.00 [2.03-7.90]), recurrence (RR = 4.34 [4.20-6.78]), lymph node metastasis (RR = 1.57 [1.24-1.99]) and distant metastasis (RR = 2.94 [1.13-7.65]). We found that PTC patients with BRAFV600E mutation were more likely to have TERTp mutation. TERTp mutation was an independent predictive factor for poor prognosis of PTC patients, but the predictive value of BRAFV600E mutation remains inconclusive. Patients with both mutations have remarkably higher risks of adverse outcomes compared with those with a single mutation. PTC patients could benefit from mutation detection for aiding risk stratification (BRAF + TERT+ > BRAF - TERT+ > BRAF + TERT-).

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.

Incidence of BRAF V600E mutation in patients with papillary thyroid carcinoma: a single-institution experience

Objective

Papillary thyroid carcinoma (PTC) accounts for 95% of all thyroid carcinomas. PTC is an epithelial tumor characterized by the proliferation of follicular cells with distinctive nuclear features, and is heterogeneous in terms of its carcinogenesis and behavior. PTC has been associated with several genetic abnormalities, of which the BRAF V600E mutation is the most common. However, reported incidences of this mutation have varied depending on the patient background, population size, or methods. In this study, we investigated the incidence of BRAF V600E mutation and its relationships with clinicopathological characteristics in patients with PTC.

Methods

Surgical specimens were obtained from 40 patients with PTC who underwent surgery at Nippon Medical School Hospital between 2009 and 2017. DNA from exon 15 of the BRAF gene was extracted and amplified by polymerase chain reaction, followed by direct sequencing.

Results

The frequency of BRAF V600E mutation increased with age. However, there were no correlations between BRAF V600E mutation and other clinicopathological features including sex, Hashimoto disease, family history of thyroid disease, tumor size, pathological T stage, pathological N stage, lymphovascular invasion, extrathyroidal extension, and metastasis.

Conclusions

This study demonstrated that PTCs harboring the BRAF V600E mutation increased in an age-dependent manner.