Lymphocyte and immature dendritic cell infiltrates in differentiated, poorly differentiated, and undifferentiated thyroid carcinoma

Unravelling the Reasons Behind Limited Response to Anti-PD Therapy in ATC: A Comprehensive Evaluation of Tumor-Infiltrating Immune Cells and Checkpoints

Inhibiting the immune checkpoint (ICP) PD-1 based on PD-L1 expression status has revolutionized the treatment of various cancers, yet its efficacy in anaplastic thyroid carcinoma (ATC) remains limited. The therapeutic response depends upon multiple factors, particularly the conduciveness of the tumor's immune milieu. This study comprehensively evaluated and classified ATC's immune microenvironment (IME) to elucidate the factors behind suboptimal response to anti-PD therapy. Utilizing multiplex-immunofluorescence and immunohistochemistry, we retrospectively analyzed 26 cases of ATC for expression of ICPs PD-L1, PD-1, CTLA4, TIM3, and Galectin-9 and tumor-infiltrating cytotoxic T lymphocytes (CTL)-the effector cells, the anti-tumor NK cells, the immune-inhibitory myeloid-derived suppressor (MDSC) and regulatory T (Treg) cells, and B lymphocytes. Most ATCs (65%) exhibited PD-L1 positivity, but only 31%, in addition, had abundant CTL (type I IME), a combination associated with a better response to ICP inhibition. Additionally, PD-1 expression levels on CTL were low/absent in most cases-a "target-missing" situation-unfavorable for an adequate therapeutic response. All but one ATC showed nuclear Galectin-9 expression. The documentation of nuclear expression of Galectin-9 akin to benign thyroid is a first, and its role in ATC pathobiology needs further elucidation. In addition to less abundant PD-1 expression on CTL, the presence of MDSC, Treg, and exhausted cytotoxic T lymphocytes in the immune milieu of ATC can contribute to anti-PD resistance. TIM3, the most frequently expressed ICP on CTL, followed by CTLA4, provides alternate therapeutic targets in ATC. The co-expression of multiple immune checkpoints is of great interest for ATC since these data also open the avenue for combination therapies.

Th17/Treg cell balance in patients with papillary thyroid carcinoma: a new potential biomarker and therapeutic target

Papillary thyroid carcinoma (PTC) is the most common subtype of thyroid carcinoma. The most effective treatment for PTC is surgical resection, and patients who undergo surgery have good survival outcomes, but some patients have distant metastasis or even multiorgan metastases at the time of initial diagnosis. Distant metastasis is associated with poorer prognosis and a higher mortality rate. Helper T lymphocyte 17 (Th17) cells and regulatory T lymphocytes (Tregs) play different roles in PTC, and the Th17/Treg balance is closely related to the progression of PTC. Th17 cells play anticancer roles, whereas Tregs play cancer-promoting roles. A Th17/Treg imbalance promotes tumor progression and accelerates invasive behaviors such as tumor metastasis. Th17/Treg homeostasis can be regulated by the TGF-β/IL-2 and IL-6 cytokine axes. Immune checkpoint inhibitors contribute to Treg/Th17 cell homeostasis. For PTC, monoclonal antibodies against CTLA-4, PD-1 and PD-L1 inhibit the activation of Tregs, reversing the Th17/Treg cell imbalance and providing a new option for the prevention and treatment of PTC. This article reviews the role of Tregs and Th17 cells in PTC and their potential targets, aiming to provide better treatment options for PTC.

Emerging therapeutic options for follicular-derived thyroid cancer in the era of immunotherapy

Although most follicular-derived thyroid cancers are well differentiated and have an overall excellent prognosis following treatment with surgery and radioiodine, management of advanced thyroid cancers, including iodine refractory disease and poorly differentiated/undifferentiated subtypes, is more challenging. Over the past decade, better understanding of the genetic drivers and immune milieu of advanced thyroid cancers has led to significant progress in the management of these patients. Numerous targeted kinase inhibitors are now approved by the U.S Food and Drug administration (FDA) for the treatment of advanced, radioiodine refractory differentiated thyroid cancers (DTC) as well as anaplastic thyroid cancer (ATC). Immunotherapy has also been thoroughly studied and has shown promise in selected cases. In this review, we summarize the progress in the understanding of the genetic landscape and the cellular and molecular basis of radioiodine refractory-DTC and ATC, as well as discuss the current treatment options and future therapeutic avenues.

Research progress of immunotherapy against anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is the most aggressive type of thyroid cancer. While ATC is rare, its mortality is high. Standard treatments, such as surgery, radiotherapy, and chemotherapy, have demonstrated limited efficacy in managing ATC. However, the advent of immunotherapy has significantly improved the prognosis for patients with ATC. Immunotherapy effectively targets and eliminates tumor cells by using the power of the body's immune cells. The neoantigen is an atypical protein generated by somatic mutation, is exclusively observed in neoplastic cells, and is devoid of central tolerance. Neoantigens exhibit enhanced specificity towards tumor cells and display robust immunogenic properties. Currently, neoantigen therapy is primarily applied in immune checkpoint inhibitors and cellular immunotherapy, encompassing adoptive immunotherapy and tumor vaccines. This study discusses the mechanism, tumor microenvironment, clinical trials, adverse events, limitations and future directions associated with ATC immunotherapy.

Harnessing Immunity to Treat Advanced Thyroid Cancer

The incidence of thyroid cancer (TC) has increased over the past 30 years. Although differentiated thyroid cancer (DTC) has a good prognosis in most patients undergoing total thyroidectomy followed by radioiodine therapy (RAI), 5-10% of patients develop metastasis. Anaplastic thyroid cancer (ATC) has a low survival rate and few effective treatments have been available to date. Recently, tyrosine kinase inhibitors (TKIs) have been successfully applied to RAI-resistant or non-responsive TC to suppress the disease. However, TC eventually develops resistance to TKIs. Immunotherapy is a promising treatment for TC, the majority of which is considered an immune-hot malignancy. Immune suppression by TC cells and immune-suppressing cells, including tumor-associated macrophages, myeloid-derived suppressor cells, and regulatory T cells, is complex and dynamic. Negative immune checkpoints, cytokines, vascular endothelial growth factors (VEGF), and indoleamine 2,3-dioxygenase 1 (IDO1) suppress antitumor T cells. Basic and translational advances in immune checkpoint inhibitors (ICIs), molecule-targeted therapy, tumor-specific immunotherapy, and their combinations have enabled us to overcome immune suppression and activate antitumor immune cells. This review summarizes current findings regarding the immune microenvironment, immunosuppression, immunological targets, and immunotherapy for TC and highlights the potential efficacy of immunotherapy.

Integrative single-cell transcriptome analysis reveals immune suppressive landscape in the anaplastic thyroid cancer

The tumor immune microenvironment (TIME) in ATC is a complex and diverse ecosystem. It is essential to have a comprehensive understanding to improve cancer treatment and prognosis. However, TIME of ATC and the dynamic changes with PTC has not been revealed at the single-cell level. Here, we performed an integrative single-cell analysis of PTC and ATC primary tumor samples. We found that immunosuppressive cells and molecules dominated the TIME in ATC. Specifically, the level of infiltration of exhausted CD8+ T cells, and M2 macrophages was increased, and that of NK cells, B cells, and M1 macrophages was decreased. The cytotoxicity of CD8+ T cells, γδT cells, and NK cells was decreased, and immune checkpoint molecules, such as LAG3, PD1, HAVCR2, and TIGIT were highly expressed in ATC. Our findings contribute to the comprehension of TIME in both PTC and ATC, offering insights into the immunosuppressive factors specifically associated with ATC. Targeting these immunosuppressive factors may activate the anti-tumor immune response in ATC.

Prevalence and Impact of BRAF mutation in patients with concomitant papillary thyroid carcinoma and Hashimoto's thyroiditis: a systematic review with meta-analysis

Background

Evidence suggests that patients with Hashimoto thyroiditis (HT) are at significantly higher risk of developing papillary thyroid cancer (PTC). However, the course of PTC in patients with both diseases concomitantly has been found to be more indolent than conventional PTC. Additionally, it has been well proven that BRAF mutation results in an aggressive course of PTC. The aims of this meta-analysis were to identify prevalence of BRAF mutation and its impact on clinicopathological features in patients with concomitant PTC-HT.

Methods

Medline, Cochrane Library, Scopus, and Web of Science were searched until 16.09.2022, resulting in 227 articles, of which nine studies were included. Summary estimates, comparing patients with (A) BRAF (+) PTC-HT versus BRAF (+) PTC, and (B) BRAF (+) PTC-HT versus BRAF (-) PTC-HT, were generated with Review Manager 5.0.

Results

In total, 6395 patients were included in this review. PTC-HT patients had significantly less BRAF mutation than PTC patients (Odds Ratio (OR) (95% Confidence Interval (CI))=0.45 (0.35-0.58), P<0.001). BRAF (+) PTC-HT patients were significantly more likely to have multifocal lesions (OR (95% CI)=1.22 (1.04-1.44), P=0.01) but less likely to have lymph node metastasis (OR (95% CI)=0.65 (0.46-0.91), P=0.01) and extrathyroidal extension (OR (95% CI)=0.55 (0.32-0.96), P=0.03) compared to BRAF (+) PTC patients. BRAF (+) PTC-HT patients were more likely to have multifocal lesions (OR (95% CI)=0.71 (0.53-0.95), P=0.02), lymph node metastasis (OR (95% CI)=0.59 (0.44-0.78), P<0.001) and extrathyroidal extension (OR (95% CI)=0.72 (0.56-0.92), P=0.01) compared to BRAF (-) PTC-HT patients.

Conclusion

This meta-analysis highlights that the lower prevalence of BRAF mutation in patients with PTC-HT than conventional PTC may explain the indolent clinicopathological course in this cohort.

New Insights into Immune Cells and Immunotherapy for Thyroid Cancer

Thyroid cancer (TC) is the most common endocrine malignancy worldwide, and the incidence of TC has gradually increased in recent decades. Differentiated thyroid cancer (DTC) is the most common subtype and has a good prognosis. However, advanced DTC patients with recurrence, metastasis and iodine refractoriness, as well as more aggressive subtypes such as poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC), still pose a great challenge for clinical management. Therefore, it is necessary to continue to explore the inherent molecular heterogeneity of different TC subtypes and the global landscape of the tumor immune microenvironment (TIME) to find new potential therapeutic targets. Immunotherapy is a promising therapeutic strategy that can be used alone or in combination with drugs targeting tumor-driven genes. This article focuses on the genomic characteristics, tumor-associated immune cell infiltration and immune checkpoint expression of different subtypes of TC patients to provide guidance for immunotherapy.

The Incidence Trend and Management of Thyroid Cancer-What Has Changed in the Past Years: Own Experience and Literature Review

Because of ambiguous and widely debated observations concerning the incidence, trend, and management of TC, we performed this analysis. We drew attention to some events, such as "cancer screening activity", introduction of noninvasive follicular neoplasm with papillary-like nuclear features (NIFTP) to TC types, possibility of papillary thyroid microcarcinoma (PTMC) active surveillance (AS), occurrence of personalized medicine in TC management, and, finally, COVID-19 pandemic time. Because of the opinion that all changes have been made mostly by PTC, we compared it to the remaining types of TC in terms of incidence, clinical and pathological characteristics, and treatment. We analyzed patients treated in a single surgical center in eastern Europe (Poland). The prevalence of TC significantly increased from 5.15% in 2008 to 13.84% in 2015, and then significantly decreased to 1.33% in 2022 when the COVID-19 pandemic lasted (p < 0.0001). A similar trend was observed for PTC, when the incidence significantly increased to 13.99% in 2015 and then decreased to 1.38% in 2022 (p < 0.0001). At that time, the NIFTP category was introduced, and observation of PTMC began. The prevalence of FTC and MTC also increased until 2015 and then decreased. Significant differences in age, types of surgery, necessity of reoperation, and pTNM between PTCs and other types of TCs were observed. The average age was significantly lower in PTC patients than in patients with the remaining types of TC (p < 0.0001). Four milestones, including NIFTP introduction, the possibility of PTMC AS, personalized cancer medicine, and the COVID-19 pandemic, may have influenced the general statistics of TC.

Upregulation of dendrocyte-expressed seven transmembrane protein is associated with unfavorable outcomes in differentiated thyroid cancer

PURPOSE

Dendritic cell infiltrates are increased in thyroid cancer but may have a defective ability to provoke effective immune responses. In this study, we aimed to identify potential thyroid cancer biomarkers linked to dendritic cell development and evaluate their prognostic relevance.

METHODS

Through a bioinformatics search, we identified the dendrocyte-expressed seven transmembrane protein (DCSTAMP) as a prognostic gene involved in dendritic cell differentiation for thyroid cancer. Immunohistochemical analyses of DCSTAMP expression were performed and correlated with clinical outcomes.

RESULTS

DCSTAMP was overexpressed in a variety of types of thyroid cancers, while normal thyroid tissue or benign thyroid lesions exhibited low or undetectable DCSTAMP immunoreactivity. The results of automated quantification were consistent with subjective semiquantitative scoring. Among 144 patients with differentiated thyroid cancer, high DCSTAMP expression was associated with papillary tumor type (p < 0.001), extrathyroidal extension (p = 0.007), lymph node metastasis (p < 0.001), and BRAF V600E mutation (p = 0.029). Patients with tumors showing high DCSTAMP expression had shorter overall (p = 0.027) and recurrence-free (p = 0.042) survival.

CONCLUSION

This study provides the first evidence of DCSTAMP overexpression in thyroid cancer. Apart from the prognostic implications, studies are needed to explore its potential immunomodulatory role in thyroid cancer.

Identification of key immune genes related to lymphatic metastasis of papillary thyroid cancer via bioinformatics analysis and experimental validation

Objective

The current research aimed to development and validation in signature immune genes for lymphatic metastasis in papillary thyroid cancer (PTC).

Method

Weighted correlation network analysis (WGCNA) was performed to identify genes closely correlated with lymphatic metastasis in PTC from TCGA database. Information on immune-related genes (IRGs) was obtained from the ImmPort database. Crossover genes were used with the R package clusterProfiler for Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment. Key genes in the protein-protein interaction network of cross-targets were obtained using Cytoscape. Lasso and Random Forest (RF) models were utilized to identify pivotal genes. We constructed a nomogram based on the hub genes. The correlation between hub genes and immune cell infiltration was explored. We collected and assessed clinical samples via immunohistochemistry to detect the expression of hub genes.

Result

In total, 122 IRGs were correlated with lymphatic metastases from PTC. There are 10 key IRGs in the protein-protein interaction network. Then, three hub genes including PTGS2, MET, and ICAM1 were established using the LASSO and RF models. The expression of these hub genes was upregulated in samples collected from patients with lymphatic metastases. The average area under the curve of the model reached 0.83 after a 10-fold and 200-time cross-validation, which had a good prediction ability. Immuno-infiltration analysis showed that the three hub genes were significantly positively correlated with resting dendritic cells and were negatively correlated with activated natural cells, monocytes, and eosinophils. Immunohistochemistry results revealed that lymph node metastasis samples had a higher expression of the three hub genes than non-metastasis samples.

Conclusion

Via bioinformatics analysis and experimental validation, MET and ICAM1 were found to be upregulated in lymph node metastasis from papillary thyroid carcinoma. Further, the two hub genes were closely correlated with activated natural killer cells, monocytes, resting dendritic cells, and eosinophils. Therefore, these two genes may be novel molecular biomarkers and therapeutic targets in lymph node metastasis from papillary thyroid carcinoma.

Ferroptosis-related gene signature predicts the prognosis of papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer (TC), accounting for more than 80% of all cases. Ferroptosis is a novel iron-dependent and Reactive oxygen species (ROS) reliant type of cell death which is distinct from the apoptosis, necroptosis and pyroptosis. Considerable studies have demonstrated that ferroptosis is involved in the biological process of various cancers. However, the role of ferroptosis in PTC remains unclear. This study aims at exploring the expression of ferroptosis-related genes (FRG) and their prognostic values in PTC.

METHODS

A ferroptosis-related gene signature was constructed using lasso regression analysis through the PTC datasets of the Cancer Genome Atlas (TCGA). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to investigate the bioinformatics functions of significantly different genes (SDG) of ferroptosis. Additionally, the correlations of ferroptosis and immune cells were assessed through the single-sample gene set enrichment analysis (ssGSEA) and CIBERSORT database. Finally, SDG were test in clinical PTC specimens and normal thyroid tissues.

RESULTS

LASSO regression model was utilized to establish a novel FRG signature with 10 genes (ANGPTL7, CDKN2A, DPP4, DRD4, ISCU, PGD, SRXN1, TF, TFRC, TXNRD1) to predicts the prognosis of PTC, and the patients were separated into high-risk and low-risk groups by the risk score. The high-risk group had poorer survival than the low-risk group (p < 0.001). Receiver operating characteristic (ROC) curve analysis confirmed the signature's predictive capacity. Multivariate regression analysis identified the prognostic signature-based risk score was an independent prognostic indicator for PTC. The functional roles of the DEGs in the TGCA PTC cohort were explored using GO enrichment and KEGG pathway analyses. Immune related analysis demonstrated that the most types of immune cells and immunological function in the high-risk group were significant different with those in the low-risk group. Quantitative Real-Time Polymerase Chain Reaction (qRT-PCR) verified the SDG have differences in expression between tumor tissue and normal thyroid tissue. In addition, cell experiments were conducted to observe the changes in cell morphology and expression of signature's genes with the influence of ferroptosis induced by sorafenib.

CONCLUSIONS

We identified differently expressed FRG that may involve in PTC. A ferroptosis-related gene signature has significant values in predicting the patients' prognoses and targeting ferroptosis may be an alternative for PTC's therapy.

Inflammatory Components of the Thyroid Cancer Microenvironment: An Avenue for Identification of Novel Biomarkers

The incidence of thyroid cancer in the United States is on the rise with an appreciably high disease recurrence rate of 20-30%. Anaplastic thyroid cancer (ATC), although rare in occurrence, is an aggressive form of cancer with limited treatment options and bleak cure rates. This chapter uses discussions of in vitro models that are representative of papillary, anaplastic, and follicular thyroid cancer to evaluate the crosstalk between specific cells of the tumor microenvironment (TME), which serves as a highly heterogeneous realm of signaling cascades and metabolism that are associated with tumorigenesis. The cellular constituents of the TME carry out varying characteristic immunomodulatory functions that are discussed throughout this chapter. The aforementioned cell types include cancer-associated fibroblasts (CAFs), endothelial cells (ECs), and cancer stem cells (CSCs), as well as specific immune cells, including natural killer (NK) cells, dendritic cells (DCs), mast cells, T regulatory (Treg) cells, CD8+ T cells, and tumor-associated macrophages (TAMs). TAM-mediated inflammation is associated with a poor prognosis of thyroid cancer, and the molecular basis of the cellular crosstalk between macrophages and thyroid cancer cells with respect to inducing a metastatic phenotype is not yet known. The dynamic nature of the physiological transition to pathological metastatic phenotypes when establishing the TME encompasses a wide range of characteristics that are further explored within this chapter, including the roles of somatic mutations and epigenetic alterations that drive the genetic heterogeneity of cancer cells, allowing for selective advantages that aid in their proliferation. Induction of these proliferating cells is typically accomplished through inflammatory induction, whereby chronic inflammation sets up a constant physiological state of inflammatory cell recruitment. The secretions of these inflammatory cells can alter the genetic makeup of proliferating cells, which can in turn, promote tumor growth.This chapter also presents an in-depth analysis of molecular interactions within the TME, including secretory cytokines and exosomes. Since the exosomal cargo of a cell is a reflection and fingerprint of the originating parental cells, the profiling of exosomal miRNA derived from thyroid cancer cells and macrophages in the TME may serve as an important step in biomarker discovery. Identification of a distinct set of tumor suppressive miRNAs downregulated in ATC-secreted exosomes indicates their role in the regulation of tumor suppressive genes that may increase the metastatic propensity of ATC. Additionally, the high expression of pro-inflammatory cytokines in studies looking at thyroid cancer and activated macrophage conditioned media suggests the existence of an inflammatory TME in thyroid cancer. New findings are suggestive of the presence of a metastatic niche in ATC tissues that is influenced by thyroid tumor microenvironment secretome-induced epithelial to mesenchymal transition (EMT), mediated by a reciprocal interaction between the pro-inflammatory M1 macrophages and the thyroid cancer cells. Thus, targeting the metastatic thyroid carcinoma microenvironment could offer potential therapeutic benefits and should be explored further in preclinical and translational models of human metastatic thyroid cancer.

Prognostic Value of the Neutrophil-to-Lymphocyte Ratio before and after Radiotherapy for Anaplastic Thyroid Carcinoma

Simple Summary

Systemic hematologic markers such as the neutrophil–lymphocyte ratio (NLR) are attracting attention in a simple blood test predicting survival and treatment outcomes in various solid cancers. In our study including 40 patients with anaplastic thyroid cancer (ATC) who underwent radiotherapy, we found that high NLR before and after radiotherapy was associated with poor survival. This study result means that host immunity has an important role in patients with ATC, which can be important information for designing future investigations on the impact of immune system modulating therapy in ATC.

Abstract

The neutrophil–lymphocyte ratio (NLR) is a marker of systemic inflammation, and its elevation has recently been associated with poor survival in many solid cancers. Leukocyte elevation and lymphocyte reduction are associated with a poor response to radiotherapy (RT). This study aimed to assess the prognostic value of NLR before and after RT for anaplastic thyroid carcinoma (ATC). This retrospective study analyzed 40 patients with ATC who received RT with available complete blood cell count data from November 1995 through May 2020 at Samsung Medical Center (Seoul, Korea). Patients were classified into two groups according to the NLR before and after RT. The median overall survival (OS) was 8.9 months (range, 3.5–18.2) in the low NLR group (<3.47) and 5.2 months (range, 2.7–7.5) months in the high NLR group (≥3.47). The association between NLR and OS was also observed in multivariable Cox regression analysis (hazard ratio, 3.18; 95% confidence interval, 1.15–8.85; p = 0.026). The OS curves differed significantly according to post-RT NLR (p = 0.036). A high NLR before and after RT may be significantly associated with poor OS in patients with ATC who receive RT.

OGDHL closely associates with tumor microenvironment and can serve as a prognostic biomarker for papillary thyroid cancer

Background

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer. However, due to the lack of reliable prognostic biomarkers for PTC, overtreatment has been on the rise. Therefore, our research aims to identify new and promising prognostic biomarkers and provide fresh perspectives for clinical decision making.

Methods

The RNA‐seq data and clinical data of PTC samples were obtained from The Cancer Genome Atlas data portal. GSE64912 and GSE83520 datasets were downloaded through the GEOquery R package. The difference in the expression of oxoglutarate dehydrogenase like (OGDHL) between PTC and normal tissues was explored by the Wilcoxon test. Kaplan–Meier (KM) and Cox regression analyses were used to further explore the prognostic value of OGDHL. The tumor microenvironments of PTC patients were explored based on ssGSEA and Tumor Immune Estimation Resource online database. Gene Set Enrichment Analysis (GSEA) was performed to explore the biological processes associated with OGDHL.

Results

The expression level of OGDHL in PTC was significantly altered compared to that in normal tissues (p < 0.05). Various biological processes associated with OGDHL were also explored through GSEA. KM analysis suggested that the low‐OGDHL group had a better overall survival [OS, p = 3.49e‐03, hazard ratio (HR) = 4.567]. The receiver operating characteristic curve also indicated the favorable prognostic potential of OGDHL. Moreover, OGDHL was proved to be an independent prognostic indicator in Cox analysis (p = 1.33e‐02, HR = 0.152). In the analysis of the tumor microenvironment, the low‐OGDHL group showed a lower immune score and stromal score, while tumor purity was higher. The expression of OGDHL was also closely correlated with the infiltration of immune cells.

Conclusion

Our study elucidated the influence of OGDHL on the prognosis of PTC and demonstrated its potential as a novel biomarker, which would provide new insights into the prognosis monitoring and clinical decision making in PTC patients.

The Thyroid Tumor Microenvironment: Potential Targets for Therapeutic Intervention and Prognostication

Thyroid cancer is the most common endocrine malignancy and incidences are rising rapidly, in both pediatric and adult populations. Many thyroid tumors are successfully treated which results in low mortality rates, but there is often a significant morbidity associated with thyroid cancer treatments. For patients with tumors that are not successfully treated with surgical resection or radioactive iodine treatment, prognosis is dramatically reduced. Patients diagnosed with anaplastic thyroid cancer face a very grim prognosis with a median survival of 6 months post-diagnosis. There is a critical need to identify patients who are at greatest risk of developing persistent disease and progressing to poorly differentiated or anaplastic disease. Furthermore, development of treatments associated with less morbidity would represent a significant improvement for thyroid cancer survivors. It is well established the stromal cells and components of the tumor microenvironment can drive tumor progression and resistance to therapy. Here we review the current state of what is known regarding the thyroid tumor microenvironment and how these factors may contribute to thyroid tumor pathogenesis. Study of the tumor microenvironment within thyroid cancer is a relatively new field, and more studies are needed to dissect the complex and dynamic crosstalk between thyroid tumor cells and its tumor niche.

Clinical and prognostic value of neutrophil-lymphocyte ratio for patients with thyroid cancer: A meta-analysis

BACKGROUND

Although the malignant degree is relatively low and overall prognosis is excellent, some patients with thyroid cancer still experience metastasis during the follow-up, which leads to their possible death. Pretreatment neutrophil-to-lymphocyte ratio (NLR) has been recommended as a biomarker for the prediction of metastasis and prognosis in patients with cancers. However, its value in thyroid cancer remains inconclusive. This study aimed to comprehensively evaluate the prognostic and clinicopathological significance of NLR for thyroid cancer by a meta-analysis.

METHODS

Eligible studies were identified by searching PubMed, EMBASE, and Cochrane Library databases. The associations between NLR level and disease-free survival (DFS) or clinicopathological parameters were estimated by calculating hazard ratio (HR) or effect size with 95% confidence interval (CI).

RESULTS

Nine studies consisting of 3081 patients were enrolled. Results of meta-analysis showed that elevated NLR was not significantly associated with unfavorable DFS overall, but subgroup analysis of multivariate-adjusted studies demonstrated an elevation in pretreatment NLR predicted poor DFS (HR = 3.51, 95%CI = 1.42-8.70). Overall, a high level of NLR was significantly correlated with larger tumor size (standardized mean difference [SMD] = 0.49, 95%CI = 0.33-0.64), and metastasis status (risk ratio [RR] = 1.70, 95%CI = 1.10-2.64). The association with tumor size was still significant in the stratified analyses by country and histology type (Asian: SMD = 0.719, 95%CI = 0.44-0.98; non-Asian: SMD = 0.36, 95%CI = 0.17-0.56; medullary thyroid carcinoma: SMD = 0.57, 95%CI = 0.09-1.05; papillary thyroid carcinoma: SMD = 0.48, 95%CI = 0.31-0.64). The association between NLR and metastasis was only significant for papillary thyroid carcinoma subtype (RR = 1.82, 95%CI = 1.04-3.20).

CONCLUSION

Pretreatment NLR may serve as an excellent biomarker for prediction of tumor growth, metastasis, and prognosis in patients with thyroid cancer.

Role of kif2c, A Gene Related to ALL Relapse, in Embryonic Hematopoiesis in Zebrafish

Relapse of acute lymphoblastic leukemia (ALL) is dangerous and it worsens the prognosis of patients; however, prognostic markers or therapeutic targets for ALL remain unknown. In the present study, using databases such as TARGET, GSE60926 and GSE28460, we determined that KIF2C and its binding partner, KIF18B are overexpressed in patients with relapsed ALL compared to that in patients diagnosed with ALL for the first time. As 50% of the residues are exactly the same and the signature domain of KIF2C is highly conserved between human and zebrafish, we used zebrafish embryos as a model to investigate the function of kif2c in vivo. We determined that kif2c is necessary for lymphopoiesis in zebrafish embryos. Additionally, we observed that kif2c is not related to differentiation of HSCs; however, it is important for the maintenance of HSCs as it provides survival signals to HSCs. These results imply that the ALL relapse-related gene KIF2C is linked to the survival of HSCs. In conclusion, we suggest that KIF2C can serve as a novel therapeutic target for relapsed ALL.

Dynamics of serum antithyroglobulin antibodies in patients with differentiated thyroid cancer

PURPOSE

Serum antithyroglobulin antibodies (sTgAb) affect the reliability of Tg measurement in patients with thyroid cancer. We compared the outcome of patients with detectable and undetectable sTgAb, stratified according to the initial risk of recurrence (RR); also the response to treatment in patients with detectable sTgAb treated with total thyroidectomy (TT) with and without radioiodine remnant ablation (RA) and the sTgAb trend in the long-term follow-up according to the initial response.

METHODS

We included 432 patients submitted to TT, with or without RA; 106 patients had detectable sTgAb levels. Median follow-up was 53 months.

RESULTS

There were no statistically significant differences considering presentation between negative or positive sTgAb subjects. The frequency of structural incomplete response (SIR) in low, intermediate, and high RR was similar. Undetectable sTgAb in patients was achieved in a median of 16 months in ablated patients compared with 11 months in those without RA (p = 0.0232). Patients without RA had a higher rate of undetectable sTgAb during the first 12 months. A SIR was observed in 3% of patients with declining sTgAb, in 19% of those with stable levels, and in 43% with increasing sTgAb (p = 0.004). The status of no evidence of disease was achieved more frequently in patients with initial sTgAb levels < 200 mUI/l, independently of the initial RR.

CONCLUSIONS

There was no impact of sTgAb on the initial clinical presentation and the response to therapy in low-risk patients treated with or without RA. sTgAb trend is more useful than an absolute value to predict a SIR.

Prognostic role of the lymphocyte-to-monocyte ratio for clinical outcomes of patients with progressive radioiodine-refractory differentiated thyroid carcinoma treated by sorafenib

OBJECTIVES

The lymphocyte-to-monocyte ratio (LMR) reflects the status of tumour-infiltrating immune cells and host immunity. The LMR has been reported as a prognostic marker in various cancers. The present study evaluated the role of the LMR as a prognostic marker in patients with progressive radioiodine-refractory (RAIR) differentiated thyroid carcinoma (DTC).

DESIGN

Retrospective cohort study.

PATIENTS

Forty patients with progressive RAIR DTC who were treated by sorafenib with available baseline complete blood cell count data.

MEASUREMENTS

We assessed the response rate, progression-free survival (PFS) and overall survival (OS).

RESULTS

The patients were divided into low and high LMR groups based on their baseline LMRs (<4, n = 22, 55% and ≥4, n = 18, 45%, respectively). There were no significant differences in baseline characteristics between the groups. The OS curves differed significantly based on the LMR. The median OS of the low LMR group was 24.3 months and that of the high LMR group was not reached until the end of observation period (P = .015). The PFS curves and median PFS also differed significantly based on the LMR values (P = .019). In multivariate analysis, low LMR was an independent risk factor for all-cause mortality in patients with progressive RAIR DTC (hazard ratio, 2.64; 95% confidence interval: 1.04-6.72, P = .041).

CONCLUSION

A low LMR was associated with poor response rate, PFS and OS in patients with progressive RAIR DTC treated with sorafenib. Thus, LMR could be a simple prognostic biomarker in patients with progressive RAIR DTC.

The Immune Landscape of Thyroid Cancer in the Context of Immune Checkpoint Inhibition

Immune cells play critical roles in tumor prevention as well as initiation and progression. However, immune-resistant cancer cells can evade the immune system and proceed to form tumors. The normal microenvironment (immune cells, fibroblasts, blood and lymphatic vessels, and interstitial extracellular matrix (ECM)) maintains tissue homeostasis and prevents tumor initiation. Inflammatory mediators, reactive oxygen species, cytokines, and chemokines from an altered microenvironment promote tumor growth. During the last decade, thyroid cancer, the most frequent cancer of the endocrine system, has emerged as the fifth most incident cancer in the United States (USA), and its incidence is steadily growing. Inflammation has long been associated with thyroid cancer, raising critical questions about the role of immune cells in its pathogenesis. A plethora of immune cells and their mediators are present in the thyroid cancer ecosystem. Monoclonal antibodies (mAbs) targeting immune checkpoints, such as mAbs anti-cytotoxic T lymphocyte antigen 4 (anti-CTLA-4) and anti-programmed cell death protein-1/programmed cell death ligand-1 (anti-PD-1/PD-L1), have revolutionized the treatment of many malignancies, but they induce thyroid dysfunction in up to 10% of patients, presumably by enhancing autoimmunity. Combination strategies involving immune checkpoint inhibitors (ICIs) with tyrosine kinase (TK) or serine/threonine protein kinase B-raf (BRAF) inhibitors are showing considerable promise in the treatment of advanced thyroid cancer. This review illustrates how different immune cells contribute to thyroid cancer development and the rationale for the antitumor effects of ICIs in combination with BRAF/TK inhibitors.

Recent advances in understanding immune phenotypes of thyroid carcinomas: prognostication and emerging therapies

Tumors modulate the host immune cells within their microenvironment to avoid recognition and elimination by our immune system, a phenotype called cancer immune escape. Different mechanisms responsible for cancer immune escape that result either in decreased tumor immunogenicity or in increased tumor immunosuppressive activity have been identified. Recently, various immunotherapeutic approaches have been developed with the aim to revert tumor immune escape. The aims of this review are to explore the immunological aspects of thyroid cancer and to assess whether these features can be exploited in the prognosis and treatment of advanced forms of this disease. Therefore, we will describe the immune landscape and phenotypes of thyroid cancer, summarize studies investigating the expression of immunomodulatory molecules, and finally describe the preclinical and clinical trials investigating the utility of immunotherapies in the management of thyroid cancer. The aim of this review is to explore the immunological aspects of thyroid cancer and to assess whether these features can be exploited in the prognosis and treatment of advanced forms of this disease. Therefore, we will describe the immune-landscape and phenotypes of thyroid cancer, we will summarize studies investigating the expression of immunomodulatory molecules, and we will finally describe the preclinical and clinical trials investigating the utility of immunotherapies in the management of thyroid cancer.

Novel targeted therapies and immunotherapy for advanced thyroid cancers

Thyroid cancer is a frequently encountered endocrine malignancy. Despite the favorable prognosis of this disease, 15–20% of differentiated thyroid cancer (DTC) cases and most anaplastic types, remain resistant to standard treatment options, including radioactive iodine (RAI). In addition, around 30% of medullary thyroid cancer (MTC) cases show resistance after surgery. The evolving understanding of disease-specific molecular therapeutic targets has led to the approval of two targeted therapies (Sorafenib and Lenvatinib) for RAI refractory DTC and another two drugs (Vandetanib and Cabozantinib) for MTC. These advanced therapies exert their effects by blocking the MAPK pathway, which has been widely correlated to different types of thyroid cancers. While these drugs remain reserved for thyroid cancer patients who failed all treatment options, their ability to improve patients’ overall survival remain hindered by their low efficacy and other molecular factors. Among these factors is the tumor’s ability to activate parallel proliferative signaling pathways other than the cascades blocked by these drugs, along with overexpression of some tyrosine kinase receptors (TKR). These facts urge the search for novel different treatment strategies for advanced thyroid cases beyond these drugs. Furthermore, the growing knowledge of the dynamic immune system interaction with tumor microenvironment has revolutionized the cancer immune therapy field. In this review, we aim to discuss the molecular escape mechanisms of thyroid tumors from these drugs. We also highlight novel therapeutic options targeting other pathways than MAPK, including PI3K pathway, ALK translocations and HER2/3 receptors and their clinical impact. We also aim to discuss the usage of targeted therapy in restoring thyroid tumor sensitivity to RAI, and finally turn to extensively discuss the role of immunotherapy as a potential alternative treatment option for advanced thyroid diseases.

Heterogeneity of Thyroid Cancer

There are 5 main histological types of thyroid cancers (TCs): papillary, follicular (also known as differentiated), poorly differentiated, anaplastic (the most aggressive form), and medullary TC, and only the latter arises from thyroid C cells. These different forms of TCs show significant variability, both among and within tumours. This great variation is particularly notable among the first 4 types, which all originate from thyroid follicular cells. Importantly, this heterogeneity is not limited to histopathological diversity only but is also manifested as variation in several genetic and/or epigenetic alterations, the numbers of interactions between the tumour and surrounding microenvironment, and interpatient differences, for example. All these factors contribute to the great complexity in the development of a tumour from cancer cells. In the present review, we summarise the knowledge accumulated about the heterogeneity of TCs. Further research in this direction should help to gain a better understanding of the underlying mechanisms contributing to the development and diversity of TCs, paving the way toward more effective treatment strategies.

Differential expression profile of CXCR3 splicing variants is associated with thyroid neoplasia. Potential role in papillary thyroid carcinoma oncogenesis?

Papillary thyroid cancer (PTC) is the most prevalent endocrine neoplasia. The increased incidence of PTC in patients with thyroiditis and the frequent immune infiltrate found in PTC suggest that inflammation might be a risk factor for PTC development. The CXCR3-ligand system is involved in thyroid inflammation and CXCR3 has been found upregulated in many tumors, suggesting its pro-tumorigenic role under the inflammatory microenvironment. CXCR3 ligands (CXCL4, CXCL9, CXCL10 and CXCL11) trigger antagonistic responses partly due to the presence of two splice variants, CXCR3A and CXCR3B. Whereas CXCR3A promotes cell proliferation, CXCR3B induces apoptosis. However, the relation between CXCR3 variant expression with chronic inflammation and PTC development remains unknown. Here, we characterized the expression pattern of CXCR3 variants and their ligands in benign tumors and PTC. We found that CXCR3A and CXCL10 mRNA levels were increased in non-metastatic PTC when compared to non-neoplastic tissue. This increment was also observed in a PTC epithelial cell line (TPC-1). Although elevated protein levels of both isoforms were detected in benign and malignant tumors, the CXCR3A expression remained greater than CXCR3B and promoted proliferation in Nthy-ori-3-1 cells. In non-metastatic PTC, inflammation was conditioning for the CXCR3 ligands increased availability. Consistently, CXCL10 was strongly induced by interferon gamma in normal and tumor thyrocytes.

Our results suggest that persistent inflammation upregulates CXCL10 expression favoring tumor development via enhanced CXCR3A-CXCL10 signaling. These findings may help to further understand the contribution of inflammation as a risk factor in PTC development and set the basis for potential therapeutic studies.

Aberrant expression of CD20 in thyroid cancer and its clinicopathologic significance

CD20 is the first-line diagnostic marker of B-cells, which serves as the target of the therapeutic monoclonal antibodies in B-cell lymphomas and leukemias. Recently, aberrant CD20 expression has been described in a small series of papillary thyroid carcinomas (PTCs). We aimed to evaluate CD20 immunoexpression and to perform clinicopathologic correlation in a large set of thyroid tumors, including a cohort of high-grade thyroid cancer. A total of 625 cases of thyroid tumor comprised tissue microarrays of 538 PTCs and 47 follicular adenomas, and whole-slide sections of 40 aggressive thyroid carcinomas (10 radioiodine-refractory PTCs and 8 poorly differentiated, 5 anaplastic, and 17 medullary thyroid carcinomas) were immunostained with anti-CD20 monoclonal antibody. BRAF^V600E mutation was tested by direct sequencing in 478 cancers. Our study found that a small subset of PTCs (<10%, mainly of classic variant) exhibited aberrant membranous expression of CD20. These tumors displayed less aggressive histological features and had a lower prevalence of BRAF^V600E mutation. We also discovered that CD20 expression was maintained in 6%-20% of aggressive thyroid cancers but not observed in follicular adenomas. All CD20-positive tumor cells were negative for CD79a and PAX5. Aberrant expression of CD20 by thyroid cancer cells may present a diagnostic pitfall in cytologic evaluation of thyroid and cervical masses. Residual expression of CD20 in aggressive cancers may offer promise for translational implications, which merits further experimental investigation.

Leveraging the immune system to treat advanced thyroid cancers

Inflammation has long been associated with the thyroid and with thyroid cancers, raising seminal questions about the role of the immune system in the pathogenesis of advanced thyroid cancers. With a growing understanding of dynamic tumour-immune cell interactions and the mechanisms by which tumour cells evade antitumour immunity, the field of cancer immunotherapy has been revolutionised. In this Review, we provide evidence to support the presence of an antitumour immune response in advanced thyroid cancers linked to cytotoxic T cells and NK cells. This antitumour response, however, is likely blunted by the presence of immunosuppressive pathways within the microenvironment, facilitated by tumour-associated macrophages or increased expression of negative regulators of cytotoxic T-cell function. Current and future efforts to incorporate immune-based therapies into existing tumour cell or endothelial-derived therapies-eg, with kinase inhibitors targeting tumour-associated macrophages or antibodies blocking negative regulators on T cells-could provide improved and durable responses for patients with disease that is otherwise refractory to treatment.

High IL-17 expression is associated with an unfavorable prognosis in thyroid cancer

Previous studies have indicated that cancer may be promoted and/or exacerbated by inflammation and infection. The cytokines produced by activated innate immune cells that stimulate tumor growth and progression are considered as important components in this process. The interleukin (IL)-23/T helper (Th)17 axis, which exerts marked pro-inflammatory effects, has emerged as an important mediator in inflammation-associated cancer. Increasing clinical evidence indicates that Th17 may promote or inhibit tumor progression, however, the function of Th17 in the pathogenesis of benign and malignant thyroid neoplasms remains unclear. The present study investigated the association between the IL-23/Th17 axis and neoplastic and non-neoplastic thyroid lesions using immunohistochemistry. A total of 131 thyroid biopsy specimens were analyzed, which revealed high IL-17 and IL-23 expression in differentiated thyroid cancer and medullary thyroid cancer tissues when compared with benign lesions, including follicular thyroid adenoma and goiter tissues. Furthermore, high IL-17 expression was associated with recurrence and mortality. These results indicate that the IL-23/Th17 axis exhibits a pivotal function in the development of thyroid neoplasms.

Evaluation of proinflammatory cytokine and neopterin levels in women with papillary thyroid carcinoma

INTRODUCTION

Papillary thyroid cancer is a disease that has been associated with chronic inflammation. The purpose of this study is to measure the production of the proinflammatory cytokines IL-1β, IL-6 and IL-8 and neopterin, which is a novel biomarker for cellular immune response in papillary thyroid cancer.

MATERIALS AND METHODS

The serum IL-1β, IL-6, IL-8 and neopterin values of 31 papillary thyroid cancer patients undergoing bilateral total thyroidectomy were measured before and 20 days after surgery. The values were compared with those of 39 healthy controls.

RESULTS

Serum IL-1β levels were similar across groups. IL-6 (p&lt;0.001), IL-8 (p = 0.015) and neopterin levels (p = 0.002) were higher in presurgical samples and returned to normal following surgery.

CONCLUSIONS

The proinflammatory cytokines IL-6 and IL-8, but not IL-1β, were produced in greater amounts in papillary thyroid cancer. Serum neopterin seems to be a valid biological marker supporting the presence of papillary thyroid cancer.

Tumor-Infiltrating T Cells and the PD-1 Checkpoint Pathway in Advanced Differentiated and Anaplastic Thyroid Cancer

CONTEXT

Five to 10% of patients with differentiated thyroid cancers (DTC) develop invasive and/or distant metastatic disease that is marginally improved with standard therapies. Prognosis is poor for patients with anaplastic thyroid cancer, with a median survival of 3-5 months. We suggest that a paradigm shift is necessary in the treatment of advanced cases.

OBJECTIVE

We hypothesized that a T-cell response is generated in advanced thyroid cancer and may be a viable therapeutic target.

DESIGN

Primary DTCs were analyzed by quantitative RT-PCR (n = 92) for expression of CD3, CD8, forkhead box (Fox)-P3, programmed death (PD)-1, PD-1 ligand-1, and PD-1 ligand-2 and biopsied for cellular analysis by flow cytometry (n = 11). Advanced pT4 cases (n = 22) and metastases (n = 5) were analyzed by immunohistochemistry.

SETTING

The study was conducted at the University of Colorado Hospital.

PATIENTS

Thyroid cancer patients undergoing thyroidectomy or completion surgery for advanced disease between 2002 and 2013 participated in the study.

INTERVENTION

There were no interventions.

MAIN OUTCOME MEASURE

Immune markers were analyzed for association with disease severity.

RESULTS

Immune markers were commonly expressed at the RNA level. PD-L1 was higher (P = .0443) in patients with nodal metastases. FoxP3(+) (P < .0001), PD-1(+)CD8(+) (P = .0058), and PD-1(+)CD4(+) (P = .0104) T cells were enriched in DTC biopsies. CD8(+) and FoxP3(+) T cells were detected by immunohistochemistry in all pT4 tumors and a subset of metastases. PD-1(+) lymphocytes were found in 50% of DTCs. PD-L1 was expressed by tumor and associated leukocytes in 13 of 22 cases, and expression was more diffuse in anaplastic thyroid cancer (P = .0373). BRAF(V600E) mutation was associated with higher frequencies of tumor-associated lymphocytes (P = .0095) but not PD-L1 expression.

CONCLUSIONS

PD-1 checkpoint blockades may have therapeutic efficacy in patients with aggressive forms of thyroid cancer.

The immune network in thyroid cancer

The immune system plays critical roles in tumor prevention, but also in its initiation and progression. Tumors are subjected to immunosurveillance, but cancer cells generate an immunosuppressive microenvironment that favors their escape from immune-mediated elimination. During chronic inflammation, immune cells can contribute to the formation and progression of tumors by producing mitogenic, prosurvival, proangiogenic and lymphangiogenic factors. Thyroid cancer is the most frequent type of endocrine neoplasia and is the most rapidly increasing cancer in the US. In this review, we discuss recent findings on how different immune cells and mediators can contribute to thyroid cancer development and progression.

Until Death Do Us Part: Necrosis and Oxidation Promote the Tumor Microenvironment

Tumor proliferation is concomitant with autophagy, limited apoptosis, and resultant necrosis. Necrosis is associated with the release of damage-associated molecular pattern molecules (DAMPs), which act as 'danger signals', recruiting inflammatory cells, inducing immune responses, and promoting wound healing. Most of the current treatment strategies for cancer (chemotherapy, radiation therapy, hormonal therapy) promote DAMP release following therapy-induced tumor death by necroptosis and necrosis. Myeloid cells (monocytes, dendritic cells (DCs), and granulocytes), as well as mesenchymal stromal cells (MSCs) belong to the early immigrants in response to unscheduled cell death, initiating and modulating the subsequent inflammatory response. Responding to DAMPs, MSCs, and DCs promote an immunosuppressive milieu, while eosinophils induce oxidative conditions limiting the biologic activity of DAMPs over time and distance. Regulatory T cells are strongly affected by pattern recognition receptor signaling in the tumor microenvironment and limit immune reactivity coordinately with myeloid-derived suppressor cells. Means to 'aerobically' oxidize DAMPs provide a novel strategy for limiting tumor progression. The present article summarizes our current understanding of the impact of necrosis on the tumor microenvironment and the influence of oxidative conditions found within this setting.

May the neutrophil/lymphocyte ratio be a predictor in the differentiation of different thyroid disorders?

BACKGROUND

The neutrophil/lymphocyte ratio (NLR) is a simple index of systemic inflammatory response, and has been shown to be a prognostic indicator in some types of cancer. Inflammation has been implicated in the initiation and progression of thyroid cancer. The aim of this study was to examine the relationship of NLR with papillary thyroid cancer (PTC) and different benign thyroid pathologies like multinodular goiter (MNG) and lymphocytic thyroiditis (LT).

MATERIALS AND METHODS

We retrospectively evaluated the neutrophil, lymphocyte counts and NLR calculated from these parameters of 232 patients with histologically confirmed as multinodular goiter (group MNG) (n=70), lymphocytic thyroiditis (group LT) (n=97), LT with PTC (group LT- PTC) (n=25) and PTC (group PTC) (n=40). The optimal cut-off value for NLR was determined.

RESULTS

NLR level was significantly higher in groups LT-PTC and PTC as compared to groups MNG and LT (p<0.05). NLR of LT subgroups according to TSH levels were not different (p>0.05). When we grouped the patients as benign and malignant according to PTC presence, the optimum NLR cut-off point obtained from ROC analysis was 1.91 (sensitivity 89.0% and specificity 54.5%).

CONCLUSIONS

Since NLR was significantly elevated in group LT-PTC and group PTC, NLR value may give an opinion as a potential marker in differentiation of benign and malign thyroid disorders. For this purpose a cut-off value of 1.91 for NLR may be accepted.

Thyroid Cancer Metabolism: A Review

Metabolic dysregulation within the tumor microenvironment (TME) is critical to the process of tumorigenesis in various cancer types. Thyrocyte metabolism in papillary and anaplastic thyroid cancer, however, remains poorly characterized, and studies analyzing the role of multicompartment metabolism in thyrocyte oncogenesis are sparse. We present a review of the current knowledge on cellular metabolism in non-cancerous and cancerous thyroid tissues, focusing on the monocarboxylate transporters MCT1 and MCT4, and on a transporter of the outer mitochondrial membrane TOMM20. Understanding the metabolic phenotype of tumor cells and associated stromal cells in thyroid cancer can have profound implications on the use of biomarker staining in detecting subclinical cancer, imaging as it relates to expression of various transport proteins, and therapeutic interventions that manipulate this dysregulated tumor metabolism to halt tumorigenesis and eradicate the cancer. Future studies are required to confirm the prognostic significance of these biomarkers and their correlation with existing staging schemas such as the AGES, AMES, ATA and MACIS scoring systems.

Tumor-Associated Mast Cells in Thyroid Cancer

There is compelling evidence that the tumor microenvironment plays a major role in mediating aggressive features of cancer cells, including invasive capacity and resistance to conventional and novel therapies. Among the different cell populations that infiltrate cancer stroma, mast cells (MCs) can influence several aspects of tumor biology, including tumor development and progression, angiogenesis, lymphangiogenesis, and tissue remodelling. Thyroid cancer (TC), the most frequent neoplasia of the endocrine system, is characterized by a MC infiltrate, whose density correlates with extrathyroidal extension and invasiveness. Recent evidence suggests the occurrence of epithelial-to-mesenchymal transition (EMT) and stemness in human TC. The precise role of immune cells and their mediators responsible for these features in TC remains unknown. Here, we review the relevance of MC-derived mediators (e.g., the chemokines CXCL1/GRO-α, CXCL10/IP-10, and CXCL8/IL-8) in the context of TC. CXCL1/GRO-α and CXCL10/IP-10 appear to be involved in the stimulation of cell proliferation, while CXCL8/IL-8 participates in the acquisition of TC malignant traits through its ability to induce/enhance the EMT and stem-like features of TC cells. The inhibition of chemokine signaling may offer novel therapeutic approaches for the treatment of refractory forms of TC.

CD1a-positive dendritic cell density predicts disease-free survival in papillary thyroid carcinoma

OBJECTIVES

Dendritic cells are common in inflammatory processes and in papillary thyroid carcinoma (PTC). Previous studies of the predictive value of S100-positive dendritic cell density for PTC outcome yielded inconsistent results. This study investigated the association of dendritic cell density and PTC recurrence based on CD1a expression.

METHODS

Representative slides from 56 consecutive specimens of PTC were immunostained with anti-CD1a antibodies, and dendritic cell density was analyzed by disease-free survival.

RESULTS

Dendritic cells were abundant in the tumoral tissue and sparse in the normal peritumoral tissue. Peritumoral dendritic cell density >1.1 cells/HPF was inversely associated with the risk of recurrence. Similar results were obtained with tumoral dendritic cell density (>12 cells/HPF), although the statistical significance was marginal.

CONCLUSIONS

High CD1a-positive dendritic cell density is associated with improved disease-free survival in PTC. The specificity of anti-CD1a immunostain for activated dendritic cells may explain the better outcome prediction in this study than in studies using S100 protein.

Thyro-gastric autoimmunity in patients with differentiated thyroid cancer: a prospective study

Thyro-gastric autoimmunity has not been previously evaluated in patients with differentiated thyroid cancer (DTC), although its long-term complications may be relevant for the management of DTC patients. We assessed the prevalence of gastric autoimmunity and autoimmune gastritis (AG) in patients with Hashimoto's thyroiditis (HT) and concomitant DTC. Prevalence of parietal cell antibody (PCA) positivity, iron deficiency anemia (IDA), and pernicious anemia (PA) were prospectively assessed in 150 DTC patients referred for radioiodine ablation after total thyroidectomy. Patients were classified as HT (n = 31) and non-HT (n = 119) based on a combination of serological, ultrasonographic, and histological findings. Patients with PCA positivity were subsequently addressed to endoscopy for confirmation of atrophy body gastritis, required for the diagnosis of AG. For all the variables under study, a comparison between groups was made using Fisher's exact test and appropriate parametric and non-parametric tests. PCA positivity was significantly more prevalent in HT than in non-HT patients (12.9 vs 1.6 %, p = 0.017). After Hp eradication, a reversal of PCA positivity was observed in 3/4 patients in the HT group. IDA and PA did not differ significantly between groups. In the HT group, only one patient had endoscopical confirmation of mild gastric corporal atrophy. Gastric autoimmunity shows higher prevalence in patients with DTC and concomitant HT than in patients with DTC alone; however, in most cases, PCA positivity was associated with Hp infection. Furthermore, although previous reports found up to one-third of patients with HT to have associated AG, in our cohort AG was extremely rare.

The neutrophil to lymphocyte ratio can discriminate anaplastic thyroid cancer against poorly or well differentiated cancer

PURPOSE

We evaluated the capability of the neutrophil to lymphocyte ratio (NLR) as a diagnostic tool to discriminate between poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC) from well differentiated thyroid cancer (WDTC).

METHODS

The NLR of 3,870 patients with benign and malignant thyroid tumors were analyzed. There were 436 benign, 3,364 papillary, 15 medullary, 34 follicular or hurthle type, 14 PDTC, and 7 ATC type neoplasms. Patients were divided into two groups: a high NLR group and a low NLR group.

RESULTS

The NLR of all 3,870 patients was a normal distribution, and the median value was 1.57. Advanced stage cancer, such as T3 or T4 was high (30.4% vs. 26.5%, P = 0.027), and cancer-specific deaths were also high (1.2% vs. 0.4%, P = 0.018) in the high NLR group. The proportion of PDTC (0.6% vs. 0.1%) and ATC (0.3% vs. 0.1%) was higher in the high NLR group. The NLR can discriminate between PTC, PDTC, and ATC (P = 0.035, P = 0.002, and P = 0.025, respectively), and the cutoff value was 3.8 between PDTC versus ATC. None of the NLR of PDTC exceeded the cutoff value of 3.8.

CONCLUSION

NLR can play a relevant role as a discriminating tool and may be considered as a new diagnostic criterion in discriminating as well as in selecting therapeutic approaches to these aggressive forms of thyroid cancer.

Tumor-Associated Inflammatory Cells in Thyroid Carcinomas

The complex interactions between immune cells and tumor cells in cancer play a major role in tumor development and subsequent patient outcomes. Different types of tumor-associated inflammatory cells (TAICs), such as dendritic cells, macrophages, lymphocytes, and mast cells, have been recognized for many years in several tumors; however, the role of TAICs in cancer is still not completely understood. This review article focuses on the major types of TAICs, including their general role in cancer and, more specifically, their role and distribution in thyrocyte-derived carcinomas.

The role of the inflammatory microenvironment in thyroid carcinogenesis

Immune responses against thyroid carcinomas have long been demonstrated and associations between inflammatory microenvironment and thyroid carcinomas repeatedly reported. This scenario has prompted scientists throughout the world to unveil how the inflammatory microenvironment is established in thyroid tumors and what is its influence on the outcome of patients with thyroid carcinoma. Many studies have reported the role of evasion from the immune system in tumor progression and reinforced the weakness of the innate immune response toward thyroid cancer spread in advanced stages. Translational studies have provided evidence that an increased density of tumor-associated macrophages in poorly differentiated thyroid carcinoma (DTC) is associated with an aggressive phenotype at diagnosis and decreased cancer-related survival, whereas well-DTC microenvironment enriched with macrophages is correlated with improved disease-free survival. It is possible that these different results are related to different microenvironments. Several studies have provided evidence that patients whose tumors are not infiltrated by lymphocytes present a high recurrence rate, suggesting that the presence of lymphocytes in the tumor microenvironment may favor the prognosis of patients with thyroid carcinoma. However, the effect of lymphocytes and other immune cells on patient outcome seems to result from complex interactions between the tumor and immune system, and the molecular pattern of cytokines and chemokines helps to explain the involvement of the immune system in thyroid tumor progression. The inflammatory microenvironment may help to characterize aggressive tumors and to identify patients who would benefit from a more invasive approach, probably sparing the vast majority of patients with an indolent disease from unnecessary procedures.

Urinary neopterin levels in patients with thyroid cancer

Increased urinary neopterin concentrations have been described in many cancers. We aimed to evaluate the urinary neopterin levels in thyroid cancer. Sixty-nine patients with thyroid cancer, 76 patients with benign thyroid pathology and 33 healthy subjects were evaluated. First morning urine samples were collected from the patients and normal subjects for neopterin and creatinine measurement and stored at -80 °C until analysed. Neopterin levels were 149.3 (15.2-1,602.2) μmol/mol creatinine in the malignant group, 32 (5.2-275.6) μmol/mol creatinine in the benign group and 9.2 (2.7-78.7) μmol/mol creatinine in normal subjects (p ≤ 0.001). Urinary neopterin levels were significantly higher in patients with thyroid cancer than patients with benign thyroid pathologies and normal subjects. Also the patients with benign thyroid pathologies had a higher urinary neopterin level than the normal subjects. Malignant group was divided to two groups; patients with/without chronic thyroiditis (confirmed histologically). There were 22 (31.9 %) patients with and 47 (68.1 %) patients without chronic thyroiditis. Urinary levels of neopterin didn't differ in both groups (168.6 (21.3-716.8) μmol/mol creatinine and 135.3 (15.2-1,602.2) μmol/mol creatinine respectively; p = 0.381). Urinary neopterin levels are high in thyroid cancer patients independently from the presence of chronic thyroiditis.

FoxP3 expression in papillary thyroid carcinoma: a possible resistance biomarker to iodine 131 treatment

BACKGROUND

The forkhead transcription factor FoxP3 plays an important role in regulatory T cell (Treg) functions. Tregs are critical in maintaining immunologic tolerance. It has been shown that vaccination against FoxP3-expressing cells is associated with enhancement of tumor immunity. Tregs appear to be increased in blood and in the tumor microenvironment of patients with different cancer types. Tumor cells themselves can express FoxP3. The present study investigates the possible role of FoxP3 expression in a series of human papillary thyroid cancers with a mean follow-up time of 15 years.

METHODS

One hundred five cases of papillary thyroid carcinoma (PTC) were investigated, and FoxP3 expression was evaluated in both tumor cells and tumor-associated infiltrates. For all patients, clinical/pathologic features were considered and the results analyzed by statistical tests.

RESULTS

Of the 105 PTC cases, 45 (43%) scored FoxP3-positive and 60 (57%) were negative. FoxP3 staining was localized predominantly in the cytoplasm of tumor cells. In some cases, both nuclear and cytoplasmic staining was seen in infiltrating cells. FoxP3 expression in tumor cells was correlated with the presence of extrathyroid invasion (p=0.04) and distant metastasis (p=0.04), but not with overall survival. Interestingly, FoxP3 expression in neoplastic cells was significantly associated with a resistance phenotype to radioiodine treatment (p=0.041).

CONCLUSIONS

The data show an association of FoxP3 expression with features of PTC that seem to have a specific impact on radioiodine sensitivity.

Immune response in thyroid cancer: widening the boundaries

The association between thyroid cancer and thyroid inflammation has been repeatedly reported and highly debated in the literature. In fact, both molecular and epidemiological data suggest that these diseases are closely related and this association reinforces that the immune system is important for thyroid cancer progression. Innate immunity is the first line of defensive response. Unlike innate immune responses, adaptive responses are highly specific to the particular antigen that induced them. Both branches of the immune system may interact in antitumor immune response. Major effector cells of the immune system that directly target thyroid cancer cells include dendritic cells, macrophages, polymorphonuclear leukocytes, mast cells, and lymphocytes. A mixture of immune cells may infiltrate thyroid cancer microenvironment and the balance of protumor and antitumor activity of these cells may be associated with prognosis. Herein, we describe some evidences that immune response may be important for thyroid cancer progression and may help us identify more aggressive tumors, sparing the vast majority of patients from costly unnecessary invasive procedures. The future trend in thyroid cancer is an individualized therapy.

BRAF mutation positive papillary thyroid carcinoma is less advanced when Hashimoto's thyroiditis lymphocytic infiltration is present

BACKGROUND

Concomitant papillary thyroid cancer (PTC) and Hashimoto's thyroiditis (HT) is a frequent occurrence. Whether these two conditions are linked and whether PTC with concurrent HT has distinct clinicopathological characteristics are still debated issues. Lymphocytic infiltration is abundant in HT and might be relevant in the pathogenesis and progression of PTC. BRAF(V600E) mutation is associated with a more advanced PTC at diagnosis; however, its role in the clinicopathological characteristics of PTC with concurrent HT is unknown.

DESIGN AND PATIENTS

We enrolled 146 patients with histological diagnosis of PTC. Microscopic assessment of histology samples was performed to identify the presence of lymphocytic infiltration. Detection of BRAF(V600E) was performed on cytology samples by both direct sequencing and pyrosequencing, and results were correlated with clinical parameters.

RESULTS

Concurrent HT lymphocytic infiltration was associated with the female gender, smaller tumour size, a less frequent extracapsular extension and a lower grade of TNM staging. BRAF(V600E) was more frequent in PTC with concomitant lymphocytic infiltration. In PTC harbouring BRAF(V600E) , concurrent lymphocytic infiltration was still associated with the female gender, a less frequent extracapsular extension and a lower TNM staging.

CONCLUSIONS

These results suggest that lymphocytic infiltration of HT is a protective factor against PTC progression, and it is independent of BRAF mutational status.

Implications of thyroglobulin antibody positivity in patients with differentiated thyroid cancer: a clinical position statement

BACKGROUND

Even though the presence of antithyroglobulin antibodies (TgAbs) represents a significant problem in the follow-up of patients with differentiated thyroid cancer (DTC), the current guidelines on the management of DTC that have been published in recent years contain no text concerning the methods to be used for detecting such antibody-related interference in thyroglobulin (Tg) measurement or how to manage TgAb-positive patients in whom Tg cannot be used reliably as a tumor marker.

AIM

An international group of experts from the European Thyroid Association Cancer Research Network who are involved in the care of DTC patients met twice to form a consensus opinion on how to proceed with treatment and follow-up in TgAb-positive DTC patients based on the available evidence in the literature. Here we will report on the consensus opinions that were reached regarding technical and clinical issues.

RESULTS

This clinical opinion article provides an overview of the available evidence and the resulting consensus recommendations. The current literature does not provide sufficient data for giving evidence-based answers to many questions arising in the care of TgAb-positive DTC patients. Where insufficient evidence was available, a thorough discussion by a group of physician-scientists, all of whom have a distinguished track record in thyroid cancer care, was held to arrive at a consensus expert opinion. The questions and answers discussed were then summarized into an algorithm for the management of TgAb-positive patients.

CONCLUSION

We were able to define 26 consensus expert recommendations and a resulting algorithm for the care of TgAb-positive DTC patients.

Fine-needle aspiration of primary Langerhans cell histiocytosis of the thyroid gland, a potential mimic of papillary thyroid carcinoma

BACKGROUND

The clinical presentation of Langerhans cell histiocytosis (LCH) as a primary solitary nodule in the thyroid gland is rare. As a result, there are few reports of its cytologic features in thyroid aspirates where it can pose a diagnostic pitfall. CASE AND CONCLUSION: To foster familiarity with its cytomorphology, we report the fine-needle aspiration biopsy (FNAB) findings of 3 specimens from 2 patients with LCH presenting as a solitary thyroid nodule. All aspirates contained numerous dispersed cells with prominent nuclear grooves, and the background showed a mixed pattern of chronic inflammation including scattered eosinophils. The aspirate from patient 1 raised a differential diagnosis that included chronic lymphocytic thyroiditis and a thyroglossal duct cyst, while the aspirate from patient 2 was interpreted as 'suspicious for papillary thyroid carcinoma'. The diagnosis of LCH was confirmed in both patients after lobectomy and immunohistochemical studies that revealed positive reactivity for CD1a and S-100. LCH of the thyroid gland is rare and can pose significant diagnostic challenges, but increased familiarity with its characteristic cytomorphology can help in avoiding diagnostic pitfalls.

Patterns of FOXE1 expression in papillary thyroid carcinoma by immunohistochemistry

BACKGROUND

FOXE1, a thyroid-specific transcription factor also known as TTF-2, was recently identified as a major genetic risk factor for papillary thyroid carcinoma (PTC). Its role in thyroid carcinogenesis, however, remains unknown. The purpose of the present study was to assess the relationship between the FOXE1 immunohistochemical features and the clinical and genetic characteristics of PTC.

METHODS

Immunohistochemical staining of FOXE1 was performed in 48 PTC cases. Two single nucleotide polymorphisms immediately inside (rs1867277) or in the vicinity (rs965513) of the FOXE1 gene were genotyped by direct sequencing. Histopathological, clinical, and genetic data were included in statistical analyses.

RESULTS

FOXE1 exhibited cytoplasmic overexpression in tumor tissue compared to the normal counterpart (p<0.001). Both cancer and normal thyroid cells demonstrated the highest FOXE1 scores in the areas closest to the tumor border (<300 μm) compared with more distant areas (p<0.001). No differences in FOXE1 staining distributions were found between microcarcinomas and PTC of larger size, between different histopathological variants of PTC, and encapsulated and nonencapsulated tumors. Multivariate regression analysis revealed that nuclear FOXE1 expression in neoplastic cells in the vicinity of the tumor border independently associated with the genotype at rs1867277 (the dominant model of inheritance, p=0.037) and tumor multifocality (p=0.032), and with marginal significance with capsular invasion (p=0.051).

CONCLUSIONS

FOXE1 overexpression and translocation to the cytoplasm are phenotypic hallmarks of tumor cells suggesting that FOXE1 is involved in the pathogenesis of PTC. Nuclear FOXE1 expression in tumor cells in the vicinity of the PTC border is associated with the presence of a risk allele of rs1867277 (c.-238G>A) in the 5' untranslated region of the FOXE1 gene, as well as with pathological characteristics of PTC, suggesting possible FOXE1 involvement in the facilitation of tumor development beginning at an early stage.

Revisiting immune-based therapies for aggressive follicular cell-derived thyroid cancers

BACKGROUND

With our growing understanding of the immune system and mechanisms employed by tumors to evade destruction, the field of cancer immunotherapy has been revitalized. Concurrent inflammation has long been associated with follicular cell-derived thyroid cancer (FDTC). In the last decade, much research has focused on characterizing the tumor-associated immune response in patients with FDTC.

SUMMARY

Mast cells, natural killer cells, macrophages, dendritic cells, B cells, and T cells have been identified within FDTC-associated immune infiltrate. Collectively, these findings suggest that the immune response to FDTC is compromised and may even promote tumor progression. A more thorough characterization of the tumor-associated immune response in FDTC may lead to the development of immune-based adjuvant therapies for patients with aggressive disease.

CONCLUSIONS

Immune-based therapies could provide essential alternatives to patients that cannot be treated surgically, those with recurrent or persistent lymph node metastases, and those with anaplastic thyroid cancer.

Histologic assessment of tumor-associated CD45(+) cell numbers is an independent predictor of prognosis in small cell lung cancer

BACKGROUND

Small cell lung carcinoma (SCLC) continues to have a poor prognosis, with a 2-year survival of < 20%. Studies have suggested that SCLC may affect the immune system to allow it to evade immunologic responses. We hypothesized that any such effect would be characterized by a decrease in the lymphoid cells associated with the tumor in biopsy specimens and that this might relate to patient outcome.

METHODS

Sixty-four SCLC biopsy specimens were immunohistochemically stained with anti-CD45 antibody to identify immune cells associated with the tumor. A mean CD45 count per high-power field for each case was obtained, and the results were correlated with age, sex, stage, performance status (PS), treatment with chemotherapy/radiotherapy, and overall survival.

RESULTS

The median CD45 count for all cases was taken as 40 (CD45(40)). Kaplan-Meier plots demonstrated better survival for patients with a CD45(40) > 40 ( P < .009). No relationship between CD45 40 and age, sex, stage, or treatment by chemotherapy or radiotherapy was identified. Although PS was a significant predictor of survival ( P = .014), it did not correlate with CD45 40. In patients with better Eastern Cooperative Oncology Group PS (≤ 2), the CD45(40) demonstrated a highly significant survival advantage for those with CD45(40) > 40 ( P < .0001).

CONCLUSIONS

The data indicate that (1) simple immunohistochemical assessment of immune cell infiltrates in routinely processed and stained biopsy specimens of primary tumors can provide prognostic information in SCLC and (2) tumor-associated CD45(+) cells in SCLC biopsy specimens may be a good clinical marker to identify patients with poor prognosis despite good PS.