Mitotically associated long non-coding RNA is a tumor promoter in anaplastic thyroid cancer.

BACKGROUND: Patients with anaplastic thyroid cancer (ATC), which is among the deadliest of all cancers, often have a poor response to traditional therapies. Currently, the role of long non-coding RNAs (lncRNAs) in ATC carcinogenesis is unclear. In this study, we analyzed the lncRNA expression profile of ATC with the aim of identifying potential molecular targets for treatment of the disease. METHODS: Whole transcriptome sequencing of three ATC and two normal thyroid (NT) samples was performed, and the lncRNA expression profile of ATC was analyzed. Original data as well as datasets deposited in the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) were used for clinical validation. Cell proliferation, Transwell, and apoptosis assays were performed using ATC cell lines. Gene Ontology (GO) and gene set enrichment analyses (GSEA) were performed to determine the dysregulated pathways. RESULTS: Whole transcriptome sequencing revealed 182 lncRNAs to be differentially expressed in ATC. One of the lncRNAs, mitotically associated long non-coding RNA (MANCR; LINC00704), was significantly overexpressed in ATC cell lines and patient samples compared with NT and papillary thyroid cancer (PTC). MANCR depletion in ATC cells significantly inhibited cancer cell proliferation and invasion, and induced apoptosis. By further analyzing the transcriptome data, we identified 451 genes co-expressed with MANCR. GO and GSEA showed that the top dysregulated pathways were related to mitosis and cell cycle. CONCLUSIONS: MANCR is a tumor promoter in ATC, and its role in carcinogenesis is possibly associated with cell cycle regulation. Because MANCR expression is minimal in most normal tissues, it may serve as a potential target in the future treatment of ATC.

IL-2 enhanced MHC class I expression in papillary thyroid cancer with Hashimoto's thyroiditis overcomes immune escape in vitro.

The impact of Hashimoto's thyroiditis (HT) on the progression of papillary thyroid cancer (PTC) is still unclear. Interleukin-2 (IL-2) is a growth factor and crucial for HT development. This study aimed at investigating the effect of IL-2 on MHC class I expression in PTC cells and immune activation with experimental treatment for PTC using PTC cell lines. We assessed the expression of IL-2, HLA class I, PD-L1, CD3, CD8 and CD16 molecules in paired PTC tissues and HLA-ABC and PD-L1 expression in IL-2 pre-treated K1, TPC-1 and BCPAP cells by immunohistochemistry, qPCR, flow cytometry and Western blotting. The effect of IL-2 on immunogenicity of PTC cells to stimulate activated human T cells was determined for the percentages of activated CD8+ T cells and their cytokine production as well as PD-1 and PD-L1 expression. Compared with non-tumor tissues, we found that IL-2 expression was up-regulated in PTC tissues, particularly in PTC+HT tissues and correlated positively with HLA-class I, CD3 and CD8 expression in PTC+HT tissues. Conversely, PD-L1 expression decreased in PTC+HT tissues. Treatment with IL-2 significantly up-regulated HLA-class I expression, but down-regulated PD-L1 expression in PTC cells. Co-culture with IL-2-pre-treated PTC cells significantly promoted the proliferation of activated CD8+ T cells and their IL-2 secretion, but decreased their PD-1 expression, accompanied by decreased PD-L1 expression in IL-2-treated PTC cells in vitro. In conclusion, IL-2 up-regulated HLA-class I expression and enhanced anti-tumor T cell immunity during the development of PTC and HT. IL-2 may be a promising immunotherapy for PTC.

Lymph node ratio (LNR) as a complementary staging system to TNM staging in salivary gland cancer.

PURPOSE: The role of lymph node ratio (LNR, ratio of metastatic to examined nodes) in the staging of multiple human malignancies has been reported. We aim to evaluate its value in salivary gland cancer (SGC). METHODS: Records of SGC patients from Surveillance, Epidemiology, and End Results database (SEER, training set, N = 4262) and Fudan University Shanghai Cancer Center (FUSCC, validating set, N = 154) were analyzed for the prognostic value of LNR. Kaplan-Meier survival estimates, the Log-rank χ2 test and Cox proportional hazards model were used for univariate and multivariate analysis. Optimal LNR cutoff points were identified by X-tile. RESULTS: Optimal LNR cutoff points classified patients into four risk groups, R0, R1 (≤ 0.17), R2 (0.17-0.56) and R3 (> 0.56), corresponding to 5-year cause-specific survival in SEER patients of 88.6%, 57.2%, 53.1% and 39.7%, disease-free survival in FUSCC patients of 69.2%, 63.3%, 34.6% and 0%, and disease-specific survival in FUSCC patients of 92.3%, 90.0%, 71.4% and 0%, respectively. Compared with TNM staging, TNM + R staging showed smaller AIC values and higher C-index values in the Cox regression model in both patient sets. CONCLUSIONS: LNR classification should be considered as a complementary system to TNM staging and LNR classification based clinical trials deserve further research.

Prognostic Nomograms for Predicting Overall Survival and Cancer-Specific Survival of Patients with Major Salivary Gland Mucoepidermoid Carcinoma.

Background: The aim of this study was to develop and validate prognostic nomograms predicting overall (OS) and cancer-specific survival (CSS) of patients with major salivary gland (MaSG) mucoepidermoid carcinoma (MEC). Methods: 1398 MaSG-MEC patients were identified from the Surveillance, Epidemiology and End Results (SEER) database. They were randomly and equally divided into a training cohort (n=699) and a validation cohort (n=699). The best subsets of covariates were identified to develop nomograms predicting OS and CSS based on the smallest Akaike Information Criterion (AIC) value in the multivariate Cox models. The nomograms were internally and externally validated by the bootstrap resampling method. The predictive ability was evaluated by Harrell's Concordance Index (C-index). Results: For the training cohort, eight (age at diagnosis, tumor grade, primary site, surgery, radiation, T, N and M classification) and seven predictors (all the above factors except primary site) were selected to create the nomograms estimating the 3- and 5- year OS and CSS, respectively. C-index indicated better predictive performance of the nomograms than the 7th AJCC staging system, which was confirmed by both internal (via the training cohort: OS: 0.888 vs 0.785, CSS: 0.938 vs 0.821) and external validation (via the validation cohort: OS: 0.844 vs 0.743, CSS: 0.882 vs 0.787). The calibration plots also revealed good agreements between the nomogram-based prediction and observed survival. Conclusions: We have proposed and validated the nomograms predicting OS and CSS of MaSG-MEC. They are proved to be of higher predictive value than the AJCC staging system and may be adopted in future clinical practice.

Association Between Programmed Death-Ligand 1 Expression and Clinicopathological Characteristics, Structural Recurrence, and Biochemical Recurrence/Persistent Disease in Medullary Thyroid Carcinoma.

Background: Expression of the programmed death-ligand 1 (PD-L1) in medullary thyroid carcinoma (MTC) has been rarely reported. In this study, we evaluated PD-L1 positivity in MTC and analyzed its correlation with clinicopathological characteristics, structural recurrence (SR), and biochemical recurrence/persistent disease (BcR/BcPD). We also evaluated the prevalence of PD-L1 expression in patients developing distant or unresectable locoregional recurrence. Methods: In total, 201 consecutive MTC patients who underwent initial surgery in our institution from January 2006 to December 2015 were included. PD-L1 expression was evaluated by immunohistochemical staining and was considered positive in case of a combined positive score ≥1. The association of PD-L1 positivity with clinicopathological characteristics, structural recurrence-free survival (SRFS), and BcR/BcPD was retrospectively investigated. Results: The median follow-up length of the entire cohort was 73 months. We observed positive PD-L1 staining in 29 (14.4%) patients who were more likely to have a larger tumor size (p = 0.002), lymph node metastases (p = 0.036), and advanced TNM staging (p = 0.019). The five-year SRFS of the PD-L1-negative and PD-L1-positive groups was 85.4% and 57.9% (p = 0.001). Multivariate Cox analysis showed that PD-L1 positivity was independently associated with SR (hazard ratio = 2.19 [95% confidence interval (CI) 1.01-4.77], p = 0.047). Furthermore, multivariate logistic analysis showed that PD-L1 positivity was significantly associated with BcR/BcPD (odds ratio = 3.16 [CI 1.16-8.66], p = 0.025). During the study period, 20 patients developed distant or unresectable locoregional recurrence, among whom 8 (40%) were PD-L1 positive, which was much higher than in the entire MTC population. Conclusions: Using a large cohort of MTC patients, we demonstrate that PD-L1 positivity is associated with aggressive clinicopathological features and is independently predictive of SR and BcR/BcPD. Furthermore, a higher rate of PD-L1 expression in patients with incurable recurrence has been observed. Therefore, immune checkpoint inhibitors targeting the programmed cell death-1 (PD-1)/PD-L1 pathway may be a potential therapeutic strategy to treat advanced MTC.

Anatomic extent of lymph node metastases as an independent prognosticator in node-positive major salivary gland carcinoma: A study of the US SEER database and a Chinese multicenter cohort.

BACKGROUND: We aimed to explore whether the anatomic extent of lymph node metastases (AE-LNM) could independently predict prognosis of node-positive major salivary gland carcinoma (MaSGC). METHODS: A total of 376 pathologically node-positive MaSGC patients were identified from the Surveillance, Epidemiology and End Results database and constituted the training cohort. Using the X-Tile program, these patients were divided into three groups based on AE-LNM degrees. Discrimination of overall survival (OS) and disease-specific survival (DSS) was evaluated and compared with the 8th American Joint Committee on Cancer (AJCC) pN classification. The results were externally validated by 220 patients in a Chinese multicenter cohort (Validation cohort). RESULTS: Using the training cohort, AE-LNM was divided into Extent 1 (spread to parotid LNs or level I), Extent 2 (spread to level II-IV) and Extent 3 (spread to level V or bilateral LNs or rare LNs). Regarding both OS and DSS, the AE-LNM model revealed clear separation of survival curves, while the pN classification failed to discriminate the prognosis of pN1 and pN2 patients. When we incorporated both the AE-LNM model and AJCC pN classification into the same multivariate Cox analyses, AE-LNM was still an independent prognostic factor, while the AJCC pN classification lost its significance. These results were externally validated by the validation cohort. CONCLUSION: AE-LNM is an independent nodal prognosticator for node-positive MaSGC and may have improved discriminative ability over the current AJCC pN classification. Integration of anatomic extent of LNM into the current AJCC N classification could be considered.

An Update of the Appropriate Treatment Strategies in Anaplastic Thyroid Cancer: A Population-Based Study of 735 Patients.

BACKGROUND: Anaplastic thyroid cancer (ATC) responds poorly to conventional therapies and requires a multidisciplinary approach to manage. The aim of the current study is to explore whether aggressive treatment is beneficial, especially the appropriate extent of surgery in ATC. METHODS: Patients diagnosed with ATC from 2004 to 2014 were identified from the Surveillance, Epidemiology, and End Results (SEER) database and included in our study. RESULTS: A total of 735 ATC patients were identified. The two-year overall survival (OS) rates for stage IVA, IVB, and IVC patients were 36.5%, 15.6%, and 1.4%, respectively. By directly comparing eight treatment modalities, we found that surgery + radiotherapy (RT) ± chemotherapy was the most effective treatment strategy. surgery + chemotherapy and RT + chemotherapy had comparable results (hazard ratio (HR) = 1.461, 95% confidential interval (CI): 0.843-2.531, P = 0.177). Multivariate Cox regression analysis also showed increased mortality risk in patients with increased age (HR = 1.022, P < 0.001), tumor extension to adjacent structures (HR = 1.649, P = 0.013), and distant metastasis (HR = 2.041, P < 0.001), while surgery + RT (HR = 0.600, P = 0.004) and chemotherapy (HR = 0.692, P = 0.010) were independently associated with improved OS. Further analysis revealed that patients undergoing total/near-total thyroidectomy (TT) had superior OS to those receiving less than TT (P < 0.001). In subgroup analysis, the benefit of TT remained significant in patients with tumors larger than 4.0 cm (HR = 0.776, 95% CI: 0.469-0.887, P = 0.007), with adjacent structure extension (HR = 0.642, 95% CI: 0.472-0.877, P = 0.005), including trachea and major vessels, but not in patients with early phase local disease such as tumor ≤ 4.0 cm or tumor within the thyroid or with minimal extrathyroidal extension. Patients with very locally advanced disease or distant metastasis could not benefit from TT as well. CONCLUSIONS: In operable cases, surgery + RT ± chemotherapy was the optimal treatment modality. Otherwise, RT + chemotherapy was the appropriate strategy. However, TT was not beneficial for very early stage or metastatic ATC.

Central Lymph Node Status has Significant Prognostic Value in the Clinically Node-Negative Tall-Cell Variant of Papillary Thyroid Cancer Regardless of T-Staging and Radioactive Iodine Administration: First Evidence From a Population-Based Study.

BACKGROUND: The prognostic value of central lymph node (CLN) status in papillary thyroid cancer (PTC) remains controversial. This study aimed to provide the first evidence on this issue for the aggressive tall-cell variant (TCV) subtype. METHODS: The study identified TCV patients from the Surveillance, Epidemiology, and End Results database. The Kaplan-Meier method, log-rank test, and multivariate Cox regression models were used for analysis. RESULTS: Of the 744 patients included, 404 were recorded as N0, which were pathologically or only clinically confirmed. Overall survival (OS) and cancer-specific survival (CSS) did not differ significantly between the N0 and pN1a patients (p > 0.05). To investigate the reason, the N0 patients were subdivided according to the number of examined lymph nodes (ELN). The patients with a N0 diagnosis confirmed by two or more ELNs (N0-e2+) showed significantly better outcomes than the pN1a patients and their N0 counterparts without ELN (N0-e0) (p < 0.05), whereas the N0-e0 and pN1a groups demonstrated comparable outcomes in both the log-rank and multivariate analyses (p > 0.05). Moreover, the subgroup analyses showed that even among the patients with early T-staging (T1-T2) or receipt of radioactive iodine (RAI) therapy, the N0-e0 patients still demonstrated compromised OS compared with the N0-e2+ group (p < 0.05). CONCLUSION: The cN0 patients without ELN (N0-e0) had outcomes similar to those of the pN1a patients, but showed a poorer OS than the N0-e2+ group regardless of T-staging and RAI administration, suggesting that occult CLN metastases might act as a negative prognosticator in cN0 TCV. Therefore, prophylactic central neck dissection might be considered for biopsy-proven cN0 TCV patients. Prospective studies are expected to further validate our conclusions.