Thyroid peroxidase and galectin-3 immunostaining in differentiated thyroid carcinoma with clinicopathologic correlation

Potential Biomarkers of Metastasizing Paragangliomas and Pheochromocytomas

Paragangliomas and pheochromocytomas (PPGLs) are rare neuroendocrine tumors originating from paraganglionic tissue in many sites of the body. Most PPGLs are characterized by nonaggressive behavior but all of them have the potential to metastasize. PPGLs represent a great diagnostic dilemma as it is difficult to recognize tumors that are likely to be metastasizing; criteria of malignancy can be found both in benign and metastatic forms. This review aims to analyze the current knowledge of the nature of metastasizing PPGLs paying particular attention to head and neck paragangliomas (HNPGLs). Potential predictors of the malignancy risk for PPGLs were summarized and discussed. These data may also help in the development of diagnostic and prognostic strategies, as well as in the identification of novel potential therapeutic targets for patients with PPGLs.

The Expression of Snail, Galectin-3, and IGF1R in the Differential Diagnosis of Benign and Malignant Pheochromocytoma and Paraganglioma

Objective

The aim of this study was to investigate the expression of Snail, galectin-3, and IGF1R in benign and malignant pheochromocytoma and paraganglioma (PPGL) and explore their role in the diagnosis of malignant PPGL.

Methods

We retrospectively collected and analyzed surgical tumor tissue from 226 patients initially diagnosed with PPGL who underwent surgery from Jan. 2009 to Jan. 2016 at West China Hospital, Sichuan University. We observed and quantified the expression of Snail, galectin-3, and IGF1R in paraffin-embedded samples by immunohistochemical staining.

Results

The significant difference in survival time among the three groups (benign PHEO, benign PGL, and potentially malignant PPGL) was compared by Kaplan-Meier survival analysis. The positive staining of Snail, galectin-3, and IGF1R in the benign PHEO group was significantly lower than that in the other three groups (P < 0.001). The Kaplan-Meier survival plots indicated that the survival time of the patients with intense positive staining was significantly lower than that of the patients with weak positive staining.

Conclusion

The intense expression of Snail, galectin-3, and IGF1R may be valuable indicators for the diagnosis of malignant PPGL.

Identification of metastatic papillary thyroid carcinoma in FNA specimens using thyroid peroxidase immunohistochemistry

INTRODUCTION

We evaluated immunohistochemical staining for thyroid peroxidase (TPO), a glycoprotein found in the apical plasma membrane of thyroid follicular cells, as a marker for metastatic PTC in FNA samples and compared results with thyroglobulin (Tg) and thyroid transcription factor 1 (TTF1) staining.

METHODS

Cell block sections prepared from 100 FNA specimens were stained with a rabbit monoclonal antibody to TPO (EP159). The FNAs included 64 metastatic malignancies from non-thyroid primary sites, including 18 lung, and 36 cases of thyroid tumours (29 PTC, six cases of medullary thyroid carcinoma and one thyroid anaplastic carcinoma). Thyroid tumours were stained with TTF1 and Tg in addition to TPO. All cases of metastatic lung carcinoma also had TTF-1 staining results.

RESULTS

TPO staining was negative in all non-thyroid malignancies. Ninety percent (26/29) of PTC were positive. All positive cases showed strong cytoplasmic staining, although 54% (14/26) showed positivity in less than half of the cells. By comparison, Tg staining of TPC cases was present in 62% and TTF-1 in 100%. In addition to showing higher sensitivity, interpretation of staining results with TPO was generally easier with than Tg. All metastatic lung adenocarcinomas were positive for TTF-1 and TPO negative. The six medullary cancers showed positivity in 17%, 0% and 83% with TPO, Tg and TTF-1, respectively.

CONCLUSIONS

TPO (mAb EP159) may be a useful addition to immunohistochemical panels for FNA specimens where metastatic PTC is a consideration, particularly in cases where metastatic lung carcinoma features in the differential diagnosis.

Galectin-3 Performance in Histologic a Cytologic Assessment of Thyroid Nodules: A Systematic Review and Meta-Analysis

The literature on Galectin-3 (Gal-3) was systematically reviewed to achieve more robust information on its histologic reliability in identifying thyroid cancers and on the concordance between Gal-3 test in histologic and cytologic samples. A computer search of the PubMed and Scopus databases was conducted by combinations of the terms thyroid and Gal-3. Initially, 545 articles were found and, after their critical review, 52 original papers were finally included. They reported 8172 nodules with histologic evaluation of Gal-3, of which 358 with also preoperative FNAC Gal-3 assessment. At histology, Gal-3 sensitivity was 87% (95% confidence intervals [CI] from 86% to 88%), and specificity 87% (95% CI from 86% to 88%); in both cases, we found heterogeneity (I₂ 85% and 93%, respectively) and significant publication bias (p < 0.001). The pooled rate of positive Gal-3 at fine needle aspiration (FNAC) among cancers with histologically proven Gal-3 positivity was 94% (95% CI from 89% to 97%), with neither heterogeneity (I₂ 14.5%) nor bias (p = 0.086). These data show high reliability of Gal-3 for thyroid cancer at histology, while its sensitivity on FNAC samples is lower. The limits of cytologic preparations and interpretation of Gal-3 results have to be solved.

Low Elasticity of Thyroid Nodules on Ultrasound Elastography Is Correlated with Malignancy, Degree of Fibrosis, and High Expression of Galectin-3 and Fibronectin-1

BACKGROUND

Thyroid ultrasound (US) elastography provides an estimation of tissue stiffness and is helpful to differentiate malignant from benign lesions. Tissue proprieties and molecules causing stiffness are not established. The aim of the study was to correlate US elastography findings with tissue properties in thyroid nodules.

METHODS

A total of 115 thyroid nodules from 112 patients who underwent surgery for the presence of Thy 3 (indeterminate) cytology (n = 67), Thy 4-5 (suspicious-indicative of carcinoma) cytology (n = 47), or large goiter in the presence of Thy 2 cytology (n = 1) and suspicious US features were examined by US elastography. Tissues obtained after surgery were characterized for cell number, microvessel density, fibrosis, and expression of galectin-3 (Gal-3) and fibronectin-1 (FN-1).

RESULTS

Low elasticity on qualitative US elastography (LoEl) was found in 66 nodules (one benign and 65 carcinomas); high elasticity (HiEl) was found in 49 nodules (46 benign and three carcinomas; p < 0.0001). Quantitative analysis, performed in 24 nodules and expressed as elastic ratio between the strain of the nodule and that of the surrounding thyroid parenchyma, showed a mean of 1.90 (interquartile range [IQR] 1.18-2.77) in 14 nodules with LoEl, and a mean of 1.01 (IQR 0.91-1.10) in 10 nodules with HiEl (p = 0.002). Stiffness did not correlate with cell number and was inversely correlated with microvessel density. Fibrosis was higher in nodules with LoEl than in those with HiEl (p = 0.009) and in carcinomas than in benign nodules (p = 0.02). Fibrosis was higher in nodules with high expression of Gal-3 (p < 0.001) and FN-1 (p = 0.004). Fibrosis and expression of Gal-3 and FN-1 were higher in the classic compared with the follicular variant of papillary thyroid carcinoma and lower in follicular adenomas.

CONCLUSIONS

Low elasticity at US elastography is highly correlated with malignancy. Nodule stiffness is correlated with fibrosis and expression of Gal-3 and FN-1. These features are more evident in the classic than in the follicular variant of papillary thyroid carcinoma.

Expression of Cytokeratin-19 and Thyroperoxidase in Relation to Morphological Features in Non-Neoplastic and Neoplastic Lesions of Thyroid

INTRODUCTION

Thyroperoxidase (TPO) is a protein involved in thyroid hormone synthesis. TPO gene suppression and mutation were involved in thyroid tumours. CK-19 plays important role in the structural integrity of epithelial cells. Reduced TPO expression with increased CK-19 immunoreactivity has been implicated as a marker for differentiating non neoplastic and neoplastic thyroid lesions.

AIM

To study the histopathological features of thyroid lesions and to evaluate the diagnostic role of thyroperoxidase and CK-19 in non-neoplastic and neoplastic thyroid lesions.

MATERIALS AND METHODS

Prospective observational study of 65 thyroid specimens was studied for detailed histopathological examination and Expression of Immunohistochemical Markers Cytokeratin-19 (CK-19) and Thyroperoxidase.

RESULTS

TPO IHC marker was expressed by non-neoplastic and benign lesions of thyroid but not in malignancy. CK-19 was expressed 100% in papillary carcinoma of thyroid and its variants, focal and weak staining noted in goitre and hyperplastic areas.

CONCLUSION

Most of the non-neoplastic and neoplastic lesions were diagnosed based on histopathological features. When the histopathological diagnosis are equivocal, immunohistochemical markers aids in diagnosing malignancy. Diffuse and strong TPO expression indicates non-neoplastic thyroid lesions whereas diffused and strong CK-19 expression indicates thyroid malignancy.

Can galectin-3 be a useful marker for conventional papillary thyroid microcarcinoma?

BACKGROUND

Galectin-3 staining of fine-needle aspiration (FNA) samples is very useful for diagnosis of thyroid malignancy. As reported in several studies, galectin-3 is associated with prognostic factor in papillary thyroid carcinoma, but its expression and prognostic role has not been evaluated in papillary microcarcinoma (PTMC). This study was performed to investigate the prevalence of galectin-3 in preoperative ultrasonography (US)-guided FNA cytology and to evaluate the association between galectin-3 expression and prognostic factors of PTMC.

METHODS

Between January 2011 and December 2012, 440 conventional PTMCs which had undergone US-guided FNA with galectin-3 analysis and underwent subsequent surgery were enrolled. Preoperative US features and clinicopathologic results including extrathyroidal extension and lymph node metastasis were compared between galectin-3 positive and galectin-3 negative PTMC.

RESULTS

Of the 440 PTMCs, 201 (45.7%) PTMCs had galectin-3 positivity in preoperative FNA samples. There was no significant difference in US features between galectin-3 positive and negative PTMC. Galectin-3 expression had no significant association with prognostic factors such as extrathyroidal extension (44.8% vs. 44.8%, P = 0.999) and lymph node metastasis (25.9% vs. 26.8%, P = 0.914) in conventional PTMC.

CONCLUSION

Preoperative galectin-3 analysis using FNA cytology may be not advisable in patients with conventional PTMC.

The value of thyroperoxidase as a prognostic factor for differentiated thyroid cancer -- a long-term follow-up study

Background

Thyroperoxidase (TPO) is a membrane-bound protein essential for the production of thyroid hormones; because of this, TPO expression may be impaired in selected thyroid diseases. The goal of this study is to analyze TPO immune expression in differentiated thyroid cancer, and to determine whether TPO has any prognostic value.

Methods

A total of 139 patients who required surgery due to a thyroid nodule with signs or symptoms suspicious for malignancy during their physical, ultrasound and/or cytology examination were consecutively selected for the study. A study of TPO immunohistochemical expression was carried out on these patients using the MoAb47 monoclonal antibody. In addition, cell proliferation marker Ki67 and tumor suppressor p53 were also measured for comparison.

Results

A total of 139 cases, 43 benign tumors, 42 papillary carcinomas, 38 follicular carcinomas, 8 undifferentiated carcinomas, and 8 sporadic medullary carcinomas were analyzed. The relationship between TPO expression and disease was statistically significant (p <0.001), and decreased with tumor dedifferentiation extent. Increased TPO expression in benign lesions as compared to decreased expression in papillary carcinomas and undifferentiated tumors is outstanding. Differences in TPO expression were observed in minimally invasive follicular carcinoma (MIFC) compared to widely invasive follicular carcinoma (WIFC). TPO expression decreases in undifferentiated malignancies in contrast with p53 and Ki67 expression, which increases in that setting. TPO, p53 and Ki67 expression was significantly related to TNM stage (p <0.001). Survival rate was 72 % after a 20-year follow-up, and 100 % for subjects with higher TPO expression.

Conclusions

TPO may be useful in confirming or ruling out benign diseases from differentiated thyroid carcinoma, with the exception of low-risk carcinoma such as MIFC. It could be used as a prognostic factor for differentiated thyroid cancer and patient follow-up, together with other markers.

Application of Immunohistochemistry in Thyroid Pathology

Context

Accurate classification of follicular-patterned thyroid lesions is not always an easy task on routine surgical hematoxylin-eosin–stained or cytologic fine-needle aspiration specimens. The diagnostic challenges are partially due to differential diagnostic criteria that are often subtle and subjective. In the past decades, tremendous advances have been made in molecular gene profiling of tumors and diagnostic immunohistochemistry, aiding in diagnostic accuracy and proper patient management.

Objective

To evaluate the diagnostic utility of the most commonly studied immunomarkers in the field of thyroid pathology by review of the literature, using the database of indexed articles in PubMed (US National Library of Medicine) from 1976–2013.

Data Sources

Literature review, authors' research data, and personal practice experience.

Conclusions

The appropriate use of immunohistochemistry by applying a panel of immunomarkers and using a standardized technical and interpretational method may complement the morphologic assessment and aid in the accurate classification of difficult thyroid lesions.

Hypoxia induces cardiac fibroblast proliferation and phenotypic switch: a role for caveolae and caveolin-1/PTEN mediated pathway

BACKGROUND

Cardiac fibrosis following myocardial infarction (MI) results in heart failure. Caveolin-1, the main structural protein of caveolae, regulates signal transduction pathways controlling cell proliferation and apoptosis. Meanwhile, low phosphatase and tensin homolog (PTEN) activity enhances the PI3K/Akt signal pathway to induce cell proliferation. But whether caveolin-1 and PTEN activation regulates cardiac fibroblast proliferation and contributes to cardiac fibrosis from ischemic injury is incompletely understood. This study investigates whether hypoxia inducing cardiac fibroblast proliferation and phenotypic switch is caveolin-dependent.

METHODS

We used in vitro and in vivo models of ischemic injury, immunohistochemical staining, and cell proliferation assays to address this hypothesis.

RESULTS

We found that MI induced collagen deposition and cardiac dysfunction. After MI, mice displayed reduced caveolin-1 and PTEN expression and increased α-smooth muscle actin (α-SMA) expression in the infarct zone. Qualitative and quantitative analyses indicated that caveolin-1 expression was lowest at 7 days after MI, accompanied by increased collagen deposition and attenuated cardiac function. We cultured cardiac fibroblasts of mice were in hypoxia or normoxia conditions for 12, 24 and 48 hours. At all the time points, caveolin-1 and PTEN expression were gradually reduced, whereas, α-SMA was gradually increased. We also observed that cell viability was increased at 12 and 24 h after hypoxia then lightly decreased at 48 h. Additionally, disruption of caveolae with methyl-β-cyclodextrin (MβCD) enhanced p-Akt and α-SMA expression and fibroblast proliferation and phenotypic switch.

CONCLUSIONS

These findings suggest a key role for caveolae, perhaps through the caveolin-1/PTEN signaling pathway, in cardiac fibroblast proliferation and phenotypic switch under hypoxia.

Caveolin-1 Expression in Papillary Thyroid Carcinoma

Objective

We aimed to investigate the role of caveolin-1 in papillary thyroid carcinoma pathogenesis.

Study Design

Case series with chart review.

Setting

Institute for the Application of Nuclear Energy.

Subjects and Methods

We evaluated the expression of caveolin-1 in papillary thyroid carcinoma (PTC) by Western blot (WB) and compared the findings with immunohistochemical (IHC) expression of both epithelial and stromal caveolin-1 on the corresponding histological specimens. The results were related to clinicopathological features and BRAF mutation status.

Results

Caveolin-1 expression was found in malignant thyroid epithelium and more abundantly in tumor stroma but varied in both compartments within and between PTC subtypes. Caveolin-1 expression in the epithelium was more intense in classical PTC than in the other histological types. On the contrary, stromal caveolin-1 expression was stronger in the follicular, solid, and trabecular PTC variants than in classical PTC. Trends for down-regulation of caveolin-1 expression in epithelium and up-regulation in stroma from the classical via follicular to the solid variant were observed. The relation of WB and IHC results with clinicopathological parameters showed lower caveolin-1 tissue content in BRAF mutated tumors ( P < .05), a positive correlation of epithelial caveolin-1 expression with lymph node metastasis ( P < .05), and a negative association of stromal caveolin-1 expression with the degree of neoplastic infiltration and BRAF status.

Conclusion

Altered expression of caveolin-1 in the thyroid epithelial and stromal compartments may be involved in the pathogenesis of PTC. The potential clinical significance of caveolin-1 expression, as well as its relation to BRAF mutation status, deserves further investigation.

Loss of estrogen receptor Beta expression in follicular thyroid carcinoma predicts poor outcome

BACKGROUND

Well-differentiated follicular thyroid carcinomas (FTCs) usually act indolently, while aggressively acting tumors are difficult to detect early enough. Estrogen receptors (ERs) have prognostic significance in many cancers. Thyroid diseases, including neoplasms, are associated with the female sex. The prognostic significance of ERs in FTCs has not been reported previously.

METHODS

We studied the role of ERα and ERβ in 83 cases of follicular thyroid adenoma (FTA) and 43 FTC cases, including seven cases of poorly differentiated FTC, obtained from the Department of Surgery, Helsinki University Central Hospital between 1990 and 2009. Patient follow-up was conducted until March 2011. Expression of ERα, ERβ, and MIB-1/Ki-67 was investigated by immunohistochemistry and correlated with clinicopathological characteristics, including survival.

RESULTS

Two major observations were apparent. First, ERβ expression was significantly higher in FTA than in FTC, and it was a stronger differential diagnostic marker than MIB-1/Ki-67. Second, low ERβ expression correlated with poor survival in FTC. All cancer-specific deaths due to FTC were among low ERβ-score patients.

CONCLUSION

ERβ is a differential marker for malignancy and could thus be used as a preoperative tool. FTC patients with a low ERβ score need more thorough follow-up and may benefit from more aggressive treatment.

Absence of galectin-3 immunostaining in fine-needle aspiration cytology specimens from papillary thyroid carcinoma is associated with favorable pathological indices

BACKGROUND

Galectin-3 (G3) immunostaining of fine-needle aspiration (FNA) samples from thyroid nodules is very useful for the diagnosis of malignancy. The objective of the present study was to determine whether the absence of G3 immunostaining in preoperative FNA samples is associated with favorable clinicopathological parameters, including lymph node (LN) metastasis, in papillary thyroid carcinoma (PTC).

METHODS

The records of 868 patients with PTC who had prethyroidectomy ultrasonography-guided FNA with G3 immunostaining between January 2006 and December 2009 were retrospectively reviewed. G3 immunostaining was considered positive if the percentage of tumor cells showing definite cytoplasmic immunostaining exceeded 5%. Patients who had negative G3 immunostaining of FNA samples were assigned to the G3-negative (G3N) group; whereas those who had positive G3 immunostaining were assigned to the G3-positive (G3P) group.

RESULTS

There were 92 patients who were assigned to the G3N group (10.6%) because of the negative staining for G3 in the preoperative FNA samples from their thyroid nodules. The proportion of PTC subtypes in the G3N and G3P groups was similar (p=0.376). There was less frequent thyroid capsular invasion (46.7% vs. 66.5%, p<0.001), extrathyroidal extension (28.3% vs. 48.5%, p<0.001), and LN metastasis (22.2% vs. 48.7%, p<0.001) in the G3N group than the G3P group. In multivariate regression analysis, G3N expression predicted a lower risk of LN metastasis (odds ratio=0.37, 95% confidence interval 0.18-0.78) after adjustment for other clinicopathological parameters. Over a median follow-up of 33 months, no association was observed between G3N and disease-free survival.

CONCLUSION

The absence of G3 expression in FNA samples from PTC is associated with pathological parameters considered less aggressive than is the case for PTCs with G3 expression, including being a negative predictor of negative LN involvement. Long-term follow-up studies, however, are needed to verify whether G3N patients have lower recurrence and mortality rates.

Aberrant expression of TfR1/CD71 in thyroid carcinomas identifies a novel potential diagnostic marker and therapeutic target

BACKGROUND

Type I receptor for transferrin (TfR1/CD71) is overexpressed in several malignant tumors, but no studies are available on thyroid carcinomas. Our previous comparative analyses of the relative distribution of transferrin in benign versus papillary thyroid carcinoma (PTC) tissues highlighted a marked malignancy-associated abundance of the molecule. The aim of the present study was to evaluate whether TfR1/CD71 is also differentially expressed in benign versus malignant thyroid tissues.

METHODS

Tissue samples, including benign lesions and follicular-derived carcinomas, from 241 patients and a total of 35 benign and malignant fresh specimens were assayed for TfR1/CD71 expression by reverse transcriptase-polymerase chain reaction, Western blot, and immunohistochemistry.

RESULTS

We found that transcription of TfR1/CD71 gene is constitutive in thyroid epithelia, but the mRNA is differently translated in benign and malignant tissues. Western blot revealed higher levels of TfR1/CD71 protein in malignant versus benign tissues. Immunohistochemically, most carcinomas exhibited overexpression of the receptor, predominantly in the cytoplasm of neoplastic cells. The highest expression level was detected in primary and metastatic papillary carcinomas and anaplastic carcinomas, with positive results ranging from 86% to 100% of the cases. In contrast, most benign tissues were negative, with only a minority of cases showing focal and weak immunoreactivity.

CONCLUSIONS

Our findings suggest that altered expression of TfR1/CD71 may be used as a marker helpful in distinguishing PTC from papillary hyperplasia and follicular variant PTC from benign follicular-patterned lesions. Additionally, the present observations support the rationale for the use of radiolabeled transferrin/transferrin analogs and/or anti-TfR1/CD71 antibodies for diagnostic and/or radiotherapeutic purposes in TfR1/CD71-expressing thyroid tumors.

Diagnostic utility of galectin-3 in thyroid cancer

Galectin-3 (Gal-3), which has received significant recent attention for its utility as a diagnostic marker for thyroid cancer, represents the most well-studied molecular candidate for thyroid cancer diagnosis. Gal-3 is a protein that binds to beta-galactosidase residues on cell surface glycoproteins and has also been identified in the cytoplasmic and nuclear compartment. This marker has been implicated in regulation of normal cellular proliferation and apoptosis, as well as malignant transformation and the metastasis of cancer cells. We here present a mechanistic review of Gal-3 and its role in cancer development and progression. Gal-3 expression studies in thyroid tissue and cytologic tumor specimens and their methodological considerations are also discussed in this article. Despite great variance in their methodology, the majority of immunohistochemical studies found that Gal-3 was differentially expressed in thyroid carcinoma compared with benign and normal thyroid specimens, suggesting that Gal-3 is a good diagnostic marker for thyroid cancer. Recent studies have also demonstrated improved methodological reliability. On the other hand, Gal-3 genomic expression studies have shown inconsistent results for diagnostic utility and are not recommended. Overall, the development of Gal-3 as a diagnostic marker for thyroid cancer represents a promising avenue for future study, and its clinical application could significantly reduce the number of diagnostic thyroid operations performed for cases of indeterminant fine needle aspiration biopsy cytology, and thus positively impact the current management of thyroid nodular disease.

Increasing the number of thyroid lesions classes in microarray analysis improves the relevance of diagnostic markers

Background

Genetic markers for thyroid cancers identified by microarray analysis have offered limited predictive accuracy so far because of the few classes of thyroid lesions usually taken into account. To improve diagnostic relevance, we have simultaneously analyzed microarray data from six public datasets covering a total of 347 thyroid tissue samples representing 12 histological classes of follicular lesions and normal thyroid tissue. Our own dataset, containing about half the thyroid tissue samples, included all categories of thyroid lesions.

Methodology/Principal Findings

Classifier predictions were strongly affected by similarities between classes and by the number of classes in the training sets. In each dataset, sample prediction was improved by separating the samples into three groups according to class similarities. The cross-validation of differential genes revealed four clusters with functional enrichments. The analysis of six of these genes (APOD, APOE, CLGN, CRABP1, SDHA and TIMP1) in 49 new samples showed consistent gene and protein profiles with the class similarities observed. Focusing on four subclasses of follicular tumor, we explored the diagnostic potential of 12 selected markers (CASP10, CDH16, CLGN, CRABP1, HMGB2, ALPL2, ADAMTS2, CABIN1, ALDH1A3, USP13, NR2F2, KRTHB5) by real-time quantitative RT-PCR on 32 other new samples. The gene expression profiles of follicular tumors were examined with reference to the mutational status of the Pax8-PPARγ, TSHR, GNAS and NRAS genes.

Conclusion/Significance

We show that diagnostic tools defined on the basis of microarray data are more relevant when a large number of samples and tissue classes are used. Taking into account the relationships between the thyroid tumor pathologies, together with the main biological functions and pathways involved, improved the diagnostic accuracy of the samples. Our approach was particularly relevant for the classification of microfollicular adenomas.