Characteristics of neck level VI lymph nodes in papillary thyroid carcinoma: correlation between nodal characteristics and primary tumor

NF-κB signaling activation and roles in thyroid cancers: implication of MAP3K14/NIK

Among follicular-derived thyroid cancers (TC), those with aggressive behavior and resistance to current treatments display poor prognosis. NF-κB signaling pathways are involved in tumor progression of various cancers. Here, we finely characterize the NF-κB pathways and their involvement in TC. By using immunoblot and gel shift assays, we demonstrated that both classical and alternative NF-κB pathways are activated in ten TC-derived cell lines, leading to activated RelA/p50 and RelB/p50 NF-κB dimers. By analyzing the RNAseq data of the large papillary thyroid carcinoma (PTC) cohort from The Cancer Genome Atlas (TCGA) project, we identified a tumor progression-related NF-κB signature in BRAFV600E mutated-PTCs. That corroborated with the role of RelA and RelB in cell migration and invasion processes that we demonstrated specifically in BRAFV600E mutated-cell lines, together with their role in the control of expression of genes implicated in invasiveness (MMP1, PLAU, LCN2 and LGALS3). We also identified NF-κB-inducing kinase (NIK) as a novel actor of the constitutive activation of the NF-κB pathways in TC-derived cell lines. Finally, its implication in invasiveness and its overexpression in PTC samples make NIK a potential therapeutic target for advanced TC treatment.

Diagnostic value of CD56 immunohistochemistry in thyroid lesions

PURPOSE

The present study aimed to evaluate the diagnostic roles of CD56 immunohistochemistry in differentiating various thyroid lesions.

METHODS

A meta-analysis was performed to evaluate the rate of loss of CD56 immunohistochemistry expression from 13 eligible studies regarding various thyroid lesions, including papillary thyroid carcinoma, follicular carcinoma, and follicular adenoma. To confirm the value of CD56 immunohistochemistry in differentiating various thyroid lesions, a diagnostic test accuracy review was conducted.

RESULTS

An 87.8%, 79.1%, 11.9%, 25.5%, and 19.6% loss of CD56 immunohistochemistry expression was identified in papillary thyroid carcinoma, follicular carcinoma, follicular adenoma, benign follicular nodule, and Hashimoto's thyroiditis, respectively. In the normal thyroid tissue, the rate of loss of CD56 expression was 1.6%. Classical, follicular, diffuse sclerosing, tall cell, and encapsulated variants of papillary thyroid carcinoma showed an 88.4%, 75.3%, 97.2%, 91.7%, and 91.7% loss of CD56 expression, respectively. In the comparison between the follicular variant of papillary thyroid carcinoma and follicular adenoma, the pooled sensitivity and specificity of CD56 immunohistochemistry was 0.82 (95% confidence interval (CI) 0.70, 0.90) and 0.94 (95% CI 0.83, 0.99), respectively. The diagnostic odds ratio and the area under curve on summary receiver operating characteristic curve was 51.43 (95% CI 5.83, 453.88) and 0.9387, respectively.

CONCLUSION

Collectively, these results indicate that the rate of loss of CD56 immunohistochemistry expression was significantly higher in malignant tumors, such as papillary thyroid carcinoma and follicular carcinoma, than in follicular adenoma, benign follicular nodule, and Hashimoto's thyroiditis. As such, CD56 immunohistochemistry can be useful in differentiating follicular variant papillary thyroid carcinoma from follicular adenoma.

Prognostic Role of Metastatic Lymph Node Ratio in Papillary Thyroid Carcinoma

Background

The aim of this study is to elucidate the clinicopathological significances, including the prognostic role, of metastatic lymph node ratio (mLNR) and tumor deposit diameter in papillary thyroid carcinoma (PTC) through a retrospective review and meta-analysis.

Methods

We categorized the cases into high (≥ 0.44) and low mLNR (< 0.44) and investigated the correlations with clinicopathological parameters in 64 PTCs with neck level VI lymph node (LN) metastasis. In addition, meta-analysis of seven eligible studies was used to investigate the correlation between mLNR and survival.

Results

Among 64 PTCs with neck level VI LN metastasis, high mLNR was found in 34 PTCs (53.1%). High mLNR was significantly correlated with macrometastasis (tumor deposit diameter ≥ 0.2 cm), extracapsular spread, and number of metastatic LNs. Based on linear regression test, mLNR was significantly increased by the largest LN size but not the largest metastatic LN (mLN) size. High mLNR was not correlated with nuclear factor κB or cyclin D1 immunohistochemical expression, Ki-67 labeling index, or other pathological parameters of primary tumor. Based on meta-analysis, high mLNR significantly correlated with worse disease-free survival at the 5-year and 10-year follow-up (hazard ratio [HR], 4.866; 95% confidence interval [CI], 3.527 to 6.714 and HR, 5.769; 95% CI, 2.951 to 11.275, respectively).

Conclusions

Our data showed that high mLNR significantly correlated with worse survival, macrometastasis, and extracapsular spread of mLNs. Further cumulative studies for more detailed criteria of mLNR are needed before application in daily practice.