Galectin-3 and oncofetal-fibronectin expression in thyroid neoplasia as assessed by reverse transcription-polymerase chain reaction and immunochemistry in cytologic and pathologic specimens

Shielding and nurturing: Fibronectin as a modulator of cancer drug resistance

Resistance to chemotherapy and targeted therapies constitute a common hallmark of most cancers and represent a dominant factor fostering tumor relapse and metastasis. Fibronectin, an abundant extracellular matrix glycoprotein, has long been proposed to play an important role in the pathobiology of cancer. Recent research has unraveled the role of Fibronectin in the onset of chemoresistance against a variety of antineoplastic drugs including DNA-damaging agents, hormone receptor antagonists, tyrosine kinase inhibitors, microtubule destabilizing agents, etc. The current review summarizes the role played by Fibronectin in mediating drug resistance against diverse anticancer drugs. We have also discussed how the aberrant expression of Fibronectin drives the oncogenic signaling pathways ultimately leading to drug resistance through the inhibition of apoptosis, promotion of cancer cell growth and proliferation.

Overexpression of Extradomain-B Fibronectin is Associated with Invasion of Breast Cancer Cells

Breast tumor heterogeneity is a major impediment to oncotherapy. Cancer cells undergo rapid clonal evolution, thereby acquiring significant growth and invasive advantages. The absence of specific markers of these high-risk populations precludes efficient therapeutic and diagnostic management of the disease. Given the critical function of tumor microenvironment in the oncogenic circuitry, we sought to determine the expression profile of the extracellular matrix oncoprotein, extradomain-B fibronectin (EDB-FN) in invasive breast cancer. Analyses of TCGA/GTEx databases and immunostaining of clinical samples found a significant overexpression of EDB-FN in breast tumors, which correlated with poor overall survival. Significant upregulation of EDB-FN was observed in invasive cell populations generated from relatively less invasive MCF7 and MDA-MB-468 cells by long-term TGF-β treatment and acquired chemoresistance. Treatment of the invasive cell populations with an AKT inhibitor (MK2206-HCl) reduced their invasive potential, with a concomitant decrease in their EDB-FN expression, partly through the phosphoAKT-SRp55 pathway. EDB-FN downregulation, with direct RNAi of EDB-FN or indirectly through RNAi of SRp55, also resulted in reduced motility of the invasive cell populations, validating the correlation between EDB-FN expression and invasion of breast cancer cells. These data establish EDB-FN as a promising molecular marker for non-invasive therapeutic surveillance of aggressive breast cancer.

BRAF mutation analysis by ARMS-PCR refines thyroid nodule management

BACKGROUND

Fine-needle aspiration (FNA) of thyroid nodules leads to nearly 25% indeterminate nodules, while BRAF^V600E mutation helps to predicting papillary thyroid carcinoma (PTC). However, the clinical validity and utility of the BRAF^V600E mutation detected using preoperative FNA samples in a large cohort were rarely reported.

AIM

To explore the clinical significance of the BRAF^V600E mutation on preoperative diagnosis and decision-making in a large FNA cohort in China.

DESIGN

This was a prospective study of BRAF^V600E mutation analysis using an amplification refractory mutation system-polymerase chain reaction (ARMS-PCR) in FNA samples.

PATIENTS

The study involved 2640 samples from 2307 patients undergoing FNA procedures in a Chinese medical centre.

RESULTS

A high mutation rate of 86.7% was found in the PTC population. For indeterminate thyroid nodules, the malignant rate of BRAF^V600E+ and BRAF^V600E- was 87.8% and 39.5% in the Bethesda System for Reporting Thyroid Cytopathology (BSRTC) III, and 88.2% and 31.8% in the BSRTC IV, respectively. A cost-effective diagnostic model combining both BSRTC grading and BRAF^V600E mutation status showed the highest sensitivity of 82.9% and specificity of 85.4%. Central lymph node metastasis (CLNM) was independent of the BRAF mutation status and accounted for 34.2% of the patients with PTC. C_T values of BRAF^V600E of patients with PTMC were significantly lower in young patients and patients with CLNM.

CONCLUSIONS

The combined analysis of cytological results and BRAF^V600E mutation is highly recommended in BRAF^V600E high-prevalence regions, including China. Prophylactic central neck dissection should be performed in selected patients without regard to the BRAF mutation status.

Molecular testing in the diagnosis of differentiated thyroid carcinomas

Different genetic mutations and other molecular alterations in papillary thyroid cancer (PTC) and follicular thyroid cancer (FTC) can be detected in fine-needle aspiration (FNA) of thyroid nodules, and can be used successfully to ameliorate cancer diagnosis and management of patients with thyroid nodules. The greatest experience has been obtained with the diagnostic use of BRAF mutation that is strongly specific for malignancy when detected using well-validated techniques. The strongest diagnostic result can be obtained testing FNA samples for a panel of mutations that typically involve TERT, BRAF, PAX8/PPARγ, RAS, and RET/PTC. Finding any of these mutations in a thyroid nodule provides strong indication for malignancy and helps to refine clinical management for a significant proportion of patients with indeterminate cytology. The use of molecular markers, as TERT, BRAF, PAX8/PPARγ, RAS, and RET/PTC, may be considered for patients with indeterminate FNA cytology (FNAC) to help guide management. In patients with indeterminate TIR3 FNA, the combination of precise molecular marker expression analysis with molecular mutations evaluations could ameliorate significantly the accuracy of cancer diagnosis. However other prospective studies are needed to identify more accurate molecular markers. Finally, the knowledge of these molecular pathways has permitted the development of new targeted therapies for aggressive TC.

Interstitial fibrosis in papillary thyroid microcarcinoma and its association with biological behavior

Previous studies have revealed that fibrosis may affect the biological behavior of tumors, however associated research on papillary thyroid microcarcinoma (PTMC) is rare. The aim of the present study was to explore the association between interstitial fibrosis (IF) and the biological behavior of PTMC. In the present study, a total of 511 consecutive cases of PTMC were evaluated for the presence of IF and its association with clinical parameters and pathologic biomarkers. IF was identified in 340 of the 511 consecutive cases and it was significantly associated with the age (P=0.033), tumor diameter (P=0.017) and lymphocytic metastasis (P<0.001) of the patient. There were significantly more female in the fibrosis group than in fibrosis-absent group (P=0.024). In the analysis of clinical biomarkers using immunohistochemistical staining, IF was significantly associated with cytokeratin 19 (P=0.008) and galectin-3 (P=0.022). Analysis of patient outcomes indicated that IF was an independent prognostic factor of recurrence (hazard ratio = 2.181; 95% confidence interval = 1.163-4.090; P=0.015). These findings suggest that the combined effect of a patient's age, sex and tumor size may potentially contribute to fibrotic lesions and IF was a factor contributing to poor prognosis in patients with PTMC.

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.

Role of gene expression profiling in defining indeterminate thyroid nodules in addition to BRAF analysis

Fine-needle aspiration (FNA) is routinely used in the preoperative evaluation of thyroid nodules. However, 15% to 30% of aspirations yield indeterminate cytologic findings. Because the assessment of BRAF mutations seems to improve the diagnostic accuracy, this study evaluated BRAF mutations with Sanger sequencing and real-time methods in 650 consecutive thyroid aspirates. In addition, the expression of a large number of genes involved in basement membrane remodeling, extracellular matrix proteolysis, and cell adhesion was studied in both benign and malignant nodules to identify new diagnostic tools. In this prospective series, despite the use of a very sensitive BRAF mutational testing method, the frequency of a BRAF alteration being identified in indeterminate FNA samples was 3 of 68. Expression analysis revealed several genes that were differentially expressed between benign and malignant nodules (transforming growth factor, cadherin 1, collagen α1, catenin α1, integrin α3, and fibronectin 1 [FN1]), between follicular adenomas and follicular variant of papillary thyroid carcinoma (FN1, laminin γ1, integrin β2, connective tissue growth factor, catenin δ1, and integrin αV), and between BRAF-wild-type and BRAF-mutated papillary thyroid carcinomas (TIMP metallopeptidase inhibitor 1; catenin α1; secreted phosphoprotein 1; FN1; ADAM metallopeptidase with thrombospondin type 1 motif, 1; and selectin L). These data were partially confirmed with real-time polymerase chain reaction analysis and immunohistochemistry. When the cost/benefit ratio of the procedures was taken into account, BRAF mutational testing failed to increase diagnostic accuracy in cytologically indeterminate nodules. However, the additional analysis of the expression of specific molecular markers could have possible utility as a diagnostic tool, although further evidence based on a large series of samples is needed before definitive conclusions can be drawn. Cancer Cytopathol 2016;124:340-9. © 2015 American Cancer Society.

Defining the value of CD56, CK19, Galectin 3 and HBME-1 in diagnosis of follicular cell derived lesions of thyroid with systematic review of literature

BACKGROUND

Nodular follicular lesions of thyroid gland comprise benign and malignant neoplasms, as well as some forms of hyperplasia. "Follicular" refers to origin of cells and in the same time to growth pattern - building follicles. Nodular follicular thyroid lesions have in common many morphological features, therefore attempts were made to define additional criteria for distinction between follicular adenoma, follicular carcinoma and follicular variant of papillary carcinoma. Increasing number of immunohistochemical markers is in the continual process of evaluation.

METHODS

Tissue microarrays incorporating, total 201 cases, out of which 122 malignant and 79 benign follicular lesions, including neoplastic and non-neoplastic, were constructed and immunostained with antibodies to CD56, CK19, Galectin-3, HBME-1. Tissue cores were exclusively being acquired from tumour/lesion on interface with normal thyroid tissue. A systematic review of literature was done for period from the year 2001 to present time.

RESULTS

All analysed markers may make a difference between benign lesions/tumours from differentiated thyroid carcinomas (p = <0.01, for all markers). Expression of all markers is significantly higher in papillary carcinoma than in follicular adenoma (p < 0.01). Statistically significant difference in expression of Galectin-3 and CD56 between follicular carcinoma and follicular adenoma was registered (p = 0.043; p = 0.028, respectively). The only marker which expression showed statistically significant difference between adenoma and carcinoma of Hurthle cells was Galectin 3 (p = 0.041). CK19 and HBME-1 were significantly expressed more in papillary carcinoma as compared to follicular carcinoma.

CONCLUSION

Galectin 3 is most sensitive marker for malignancy, while loss of expression of CD56 is very specific for malignancy. Expected co-expression for combination of markers in diagnosis of follicular lesions decreases sensitivity and increases specificity for malignancy.

Digital gene expression profiling of a series of cytologically indeterminate thyroid nodules

BACKGROUND

Fine-needle aspiration cytology (FNAC) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules. Testing for the expression of specific genes should improve the accuracy of FNAC diagnosis, especially when it is performed in samples with indeterminate cytology.

METHODS

In total, 69 consecutive FNACs that had both cytologic and histologic diagnoses were collected, and expression levels of 34 genes were determined in RNA extracted from FNAC cells by using a custom digital mRNA counting assay. A supervised k-nearest neighbor (K-nn) learning approach was used to build a 2-class prediction model based on a subset of 27 benign and 26 malignant FNAC samples. Then, the K-nn models were used to classify the 16 indeterminate FNAC samples.

RESULTS

Malignant and benign thyroid nodules had different gene expression profiles. The K-nn approach was able to correctly classify 10 FNAC samples as benign, whereas only 1 sample was grouped in the malignant class. Two malignant FNAC samples were incorrectly classified as benign, and 3 of 16 samples were unclassified.

CONCLUSIONS

Although the current data will require further confirmation in a larger number of cases, the preliminary results indicate that testing for specific gene expression appears to be useful for distinguishing between benign and malignant lesions. The results from this study indicate that, in indeterminate FNAC samples, testing for cancer-specific gene expression signatures, together with mutational analyses, could improve diagnostic accuracy for patients with thyroid nodules.

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.

Molecular characterization of 54 cases of false-negative fine-needle aspiration among 1347 papillary thyroid carcinomas

BACKGROUND

Fine-needle aspiration (FNA) has been widely accepted as the most crucial step in the preoperative assessment of thyroid nodules, but the false-negative rates are generally reported to be between 3.6% and 10.2%. To lower the overall incidence of this false-negative testing, new reporting systems encourage the molecular testing of thyroid nodules. However, to the authors' knowledge, the role of molecular testing in false-negative FNA has not yet been evaluated.

METHODS

In total, 1347 consecutive papillary thyroid carcinomas (PTCs) with both cytological and histological diagnoses were collected from the same center. A blinded revision of the false-negative cases was performed. An analysis of the BRAF and Ras genes in the false-negative cases was then performed.

RESULTS

The false-negative rate at the time of primary FNA diagnosis was 4.8% (65 of 1347 cases). False-negative cases were 15 follicular variant PTCs, 2 classical variant, and 1 solid variant that lacked peculiar PTC cytomorphological features. Adequate cellular material for molecular analysis was available only in 54 of the 65 false-negative cases. Mutations were found in 6 cases (11%), and Ras alterations were present in 16 cases (29.6%). The addition of molecular analysis decreased the false-negative rate to 0.4% (5 of 1347 cases).

CONCLUSIONS

The results of the current study confirm the feasibility of BRAF and Ras analysis in routine FNA. However, when the false-negative FNA rate is low, the cost-benefit analysis of the detection of BRAF and Ras mutations should be carefully evaluated. Consequently, the authors suggest that preoperative molecular assessment could be helpful for benign nodules, but only in the presence of clinical suspicion of malignancy.

An Extracellular Matrix Molecule, Secreted by the Epithelial-Mesenchymal Transition is Associated With Lymph Node Metastasis of Thyroid Papillary Carcinoma

BACKGROUND

Papillary thyroid carcinoma often has lymph node metastasis, compared with follicular thyroid carcinoma. The study showed that epithelial-mesenchymal transition occurs in carcinoma cells during the first stage of metastasis, where some extracellular matrix molecules are secreted in large quantities. Sialic acid carried by fibronectin as the antigen of the monoclonal antibody (MoAb) JT-95, was detected in 90% of papillary thyroid carcinoma cases, and in a few follicular thyroid carcinomas, in the extracellular matrix of thyroid carcinoma cells.

OBJECTIVES

The current study was conducted to investigate the association between increasing the number of extracellular matrix molecules, fibronectin, and lymph node metastasis. We also co-cultured a thyroid carcinoma cell line and lymphocyte cell line, with and without MoAb JT-95, in order to investigate the mechanism of cell to cell interaction.

PATIENTS AND METHODS

Immunostaining with JT-95 was performed in 45 papillary thyroid carcinoma cases, and 20 follicular type tumors, to investigate the association between the quantity of fibronectin expression and the frequency of lymph node metastasis. The thyroid carcinoma cell line (SW1736), which secreted fibronectin, and the B cell-lymphoma cell line (Daudi), which held integrin on the cell surface, were co-cultured to observe the adhesion of cells to each other. The SW1736 cell line, pretreated with JT-95, was also co-cultured with the Daudi cell line.

RESULTS

There were 39 cases with lymph node metastasis in 59 malignant tumors, and 0 cases in 6 benign follicular type tumors. The staining scores by JT-95 of the 39 tumors with lymph node metastasis were 5+ in eight cases and 6+ in 31 cases. On the other hand, the scores of 20 malignant tumors without lymph node metastasis were < 4+ in all of the cases. In the co-cultured assay, numerous adhesions were observed between the SW1736 and Daudi cells. In contrast, the inhibition of adherences was observed in proportion to the concentrations of JT-95.

CONCLUSIONS

Increased fibronectin expression in thyroid malignancies is correlated with lymph node metastasis.

Expression of CK-19, galectin-3 and HBME-1 in the differentiation of thyroid lesions: systematic review and diagnostic meta-analysis

Background

To distinguish between malignant and benign lesions of the thyroid gland histological demonstration is often required since the fine-needle aspiration biopsy method applied pre-operatively has some limitations. In an attempt to improve diagnostic accuracy, markers using immunocytochemistry and immunohistochemistry techniques have been studied, mainly cytokeratin-19 (CK-19), galectin-3 (Gal-3) and Hector Battifora mesothelial-1 (HBME-1). However, current results remain controversial. The aim of the present article was to establish the diagnostic accuracy of CK-19, Gal-3 and HBME-1 markers, as well as their associations, in the differentiation of malignant and benign thyroid lesions.

Methods

A systematic review of published articles on MEDLINE and The Cochrane Library was performed. After establishing inclusion and exclusion criteria, 66 articles were selected. The technique of meta-analysis of diagnostic accuracy was employed and global values of sensitivity, specificity, area under the summary ROC curve, and diagnostic odds ratio (dOR) were calculated.

Results

For the immunohistochemistry technique, the positivity of CK-19 for the diagnosis of malignant thyroid lesions demonstrated global sensitivity of 81% and specificity of 73%; for Gal-3, sensitivity of 82% and specificity of 81%; and for HBME-1, sensitivity of 77% and specificity of 83%. The association of the three markers determined sensitivity of 85%, specificity of 97%, and diagnostic odds ratio of 95.1. Similar results were also found for the immunocytochemistry assay.

Conclusion

This meta-analysis demonstrated that the three immunomarkers studied are accurate in pre- and postoperative diagnosis of benign and malignant thyroid lesions. Nevertheless, the search for other molecular markers must continue in order to enhance this diagnostic accuracy since the results found still show a persistency of false-negative and false-positive tests.

Virtual slides

Http://www.diagnosticpathology.diagnomx.eu/vs/3436263067345159

Thyroid nodules; interpretation and importance of fine-needle aspiration (FNA) for the clinician - practical considerations

Thyroid nodules are very common lesions. Despite that the great majority is benign, in a significant percentage of them there is an underlying malignancy. Malignant thyroid nodules should be managed surgically, while the more common benign thyroid nodules may be managed conservatively. A systemic and careful diagnostic evaluation is needed to recognize nodules (overtly malignant or with malignant potential), and to avoid unnecessary surgery in a large percentage of patients with benign disease. Fine-needle aspiration (FNA) has a central role in the diagnostic investigation of the patient with thyroid nodules. FNA is a safe, useful, and cost-effective procedure. To increase accuracy, FNA can be performed under ultrasonographic guidance (if needed). Its results may be particularly helpful in determining the indication for surgery. In contrast, the role of FNA in selecting the extent of surgery is limited today. This is due to the fact that during the last decade there is a clear trend toward radical surgical management of thyroid nodular disease (both benign and malignant) by total/near-total thyroidectomy.

Oncofetal fibronectin mRNA is highly abundant in the blood of patients with papillary thyroid carcinoma and correlates with high-serum thyroid-stimulating hormone levels

BACKGROUND

Papillary thyroid carcinoma (PTC) cells express oncofetal fibronectin (onfFN) mRNA, which may be useful to detect circulating tumor cells. The objective of this study was to determine the fraction of PTC patients having onfFN mRNA in their peripheral blood and to determine if onfFN mRNA levels are correlated with the status of the disease or with thyroid-stimulating hormone (TSH) serum concentrations.

METHODS

This study included 95 PTC patients, who were previously treated by thyroidectomy and radioactive iodine administration. Patients were examined by cervical sonography, whole-body (131)I scintigraphy, thyroglobulin measurement, and onfFN mRNA quantification both when they were being treated with L-thyroxine (L-T4) and after L-T4 withdrawal. The mean value for onfFN mRNA in blood from 25 healthy subjects was used as control for the onfFN mRNA assay.

RESULTS

After L-T4 withdrawal, serum TSH levels rose and onfFN mRNA was found in the peripheral blood of 33 of 64 (52%) disease-free patients, 15 of 23 (65%) patients with local residual disease, and 6 of 8 (75%) patients with known local or distant metastases. Continuous administration of L-T4 repressed serum TSH. In this state none of 17 (0%) disease-free patients and 1 of 4 (25%) patients with local residual disease had an elevated onfFN mRNA level, and 2 of 4 (50%) patients with metastasis had positive tests for serum onfFN mRNA.

CONCLUSIONS

onfFN transcripts are highly abundant in the peripheral blood of patients with PTC. L-T4 withdrawal, which produced elevated serum TSH concentrations in these athyroidic patients, markedly increased the fraction with positive tests for serum onfFN mRNA at all stages of the disease. Analyzing onfFN mRNA in the absence of a TSH stimulus allows a much better discrimination of different states of PTC disease and, based on current concepts of the significance of circulating mRNA, may be a useful tool to detect circulating thyroid cancer cells.

CXC chemokine receptor 4 immunodetection in the follicular variant of papillary thyroid carcinoma: comparison to galectin-3 and hector battifora mesothelial cell-1

BACKGROUND

The cytological discrimination between benign and malignant follicular-patterned lesions of the thyroid can represent a diagnostic challenge, even for experienced pathologists. We evaluated the diagnostic use of protein expression of CXC chemokine receptor 4 (CXCR4) and galectin-3 (gal-3) that were found to be upregulated in papillary thyroid carcinoma compared to normal thyroid and of mesothelial cell surface protein recognized by monoclonal antibody Hector Battifora Mesothelial cell (HBME)-1 in thyroid tumors.

METHODS

Expression of CXCR4, HBME-1, and gal-3 was examined immunohistochemically in total of 100 aspirates of thyroid lesions, categorized as benign (n = 22), indeterminate lesion (n = 43), suspicious of papillary thyroid carcinoma (n = 10), or malignant (n = 25) by preoperative cytology.

RESULTS

Expression of each individual marker was significantly associated with malignancy (p < 0.0001), although the sensitivity of detection ranged from 56% for gal-3 to 94% for HBME-1. When focusing on the indeterminate lesions, only CXCR4 and HBME-1 expression was associated with malignancy; moreover, these two markers either used individually or in combination showed good values of diagnostic accuracy (88.4% and 90.7%, respectively). Further, the combination of CXCR4 plus HBME-1 or the simultaneous use of all the three markers provided absolute value of sensitivity and negative predictive value in the same group of lesions.

CONCLUSIONS

An immunohistochemical panel, including CXCR4, could be useful in the differential diagnosis between benign and malignant well-differentiated follicular-patterned thyroid lesions.

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.

Molecular markers in thyroid cancer diagnostics

Although fine-needle aspiration biopsy (FNA) remains the mainstay of the preoperative workup of thyroid nodules, it does not provide a diagnosis in up to 20% of nodules. This group of indeterminate lesions, including lesions with cellular atypia, suspicious cytology, and demonstrating a follicular pattern, provides one of the greatest challenges to researchers in thyroid cancer today. Over the last 2 decades, considerable work has been done to find molecular markers to resolve this diagnostic dilemma. This article explores some of the markers including galectin-3, HBME-1, BRAF, RET/PTC, PAX8-PPARgamma, hTERT, telomerase, miRNA, and microarray and multigene assays. Although no one marker has proven to be a panacea, several combinations of markers have shown great promise as an adjunct to FNA.

Perspectives for improved and more accurate classification of thyroid epithelial tumors

CONTEXT

Histologic examination of thyroid nodules is the current standard to distinguish benign from malignant thyroid epithelial tumors and to classify histologic subtypes. This review analyzes the problems in histological differential diagnosis as well as contradictions between histology and molecular data and describes possibilities to combine histology with molecular data in an effort to more accurately classify thyroid epithelial tumors.

EVIDENCE ACQUISITION

Published literature, addressing the current recommendations for thyroid tumor classification, as well as literature on the application of histology and molecular studies on the etiology of thyroid tumors is analyzed.

EVIDENCE SYNTHESIS

The current histologic criteria to classify thyroid tumors, especially follicular-patterned tumors, are hampered by considerable interobserver variability. The detection of somatic mutations via genotyping and the definition of potentially informative gene expression signatures by microarray analyses, which can distinguish cancer subtypes as well as low- and high-risk cohorts, have recently demonstrated significant diagnostic potential. Moreover, in a routine diagnostic setting, micro-RNA profiling appears most promising due to their relative stability and the high accuracy of their expression profiles.

CONCLUSIONS

It is very likely that molecular definitions of thyroid tumors mentioned in the current World Health Organization classification will be further developed, leading to future progress in defining thyroid tumor types by an integrated histologic and molecular approach. These integrated classifications need to be evaluated for their specific impact on thyroid tumor diagnosis and prognosis.

Thyroid fine-needle aspiration samples inadequate for reverse transcriptase-polymerase chain reaction analysis

BACKGROUND

Analysis of different tumor markers by reverse transcriptase-polymerase chain reaction (RT-PCR) in fine-needle aspiration samples of thyroid nodules has been studied with the objective of improving the accuracy of the preoperative diagnosis of thyroid lesions. The aim of the current study was to investigate thyroid fine-needle aspiration samples inadequate for RT-PCR analysis and to determine whether there is a correlation between their proportion and the method of sampling used or the greatest dimension of the nodules.

METHODS

A total of 350 fine-needle aspiration samples from patients with thyroid nodules were analyzed. After the aspirate was smeared for conventional cytology, the leftover material in the needle was used for RT-PCR analysis in 1 group of 175 patients. In another group of 175 patients, a separate puncture was performed to obtain material for RT-PCR analysis only. Samples were considered adequate for RT-PCR analysis if the expression of both glyceraldehyde-3-phosphate dehydrogenase and thyroglobulin was found by RT-PCR.

RESULTS

In total, 61 (17.4%) samples inadequate for RT-PCR were detected. All 12 samples that were inadequate for cytologic diagnosis were also found to be inadequate for RT-PCR analysis. The proportion of inadequate samples for RT-PCR was found to be significantly higher in samples taken from leftover material in the needle (21.7%) then in samples from a separate puncture (13.1%) (P = .049). No statistically significant correlation between the adequacy of samples for RT-PCR and the largest dimension of the nodule was found.

CONCLUSIONS

The proportion of samples inadequate for RT-PCR was found to be higher in samples taken from leftover material in the needle than in samples obtained from a separate puncture.

Fine-needle aspiration molecular analysis for the diagnosis of papillary thyroid carcinoma through BRAF V600E mutation and RET/PTC rearrangement

OBJECTIVE

To evaluate BRAF(V600E) mutation on consecutive fine-needle aspiration biopsy (FNAB) specimens in order to assess FNAB's usefulness in preoperative papillary thyroid carcinoma (PTC) diagnosis with the contemporaneous analysis of RET/PTC1 and RET/PTC3 rearrangements obtained from ex vivo thyroid nodules.

DESIGN

Thyroid FNABs from 156 subjects with nodules and 49 corresponding surgical samples were examined for the presence of BRAF mutation by real-time allele-specific polymerase chain reaction, confirmed with the use of a laser pressure catapulting system. Samples were also examined for RET/PTC rearrangements. The results were compared with the cytological diagnosis and histopathology.

MAIN OUTCOMES

13/156 cytological examinations were diagnostic for PTC and 19/156 showed suspicious/indeterminate FNAB (12.2%). FNAB-BRAF(V600E) mutation was detected in 11/16 (69%) cases with histological confirmation of PTC. In our series, RET/PTC rearrangement was detected in only one case of PTC, whereas it was not present in any case of adenoma, goiter, or Hashimoto's thyroiditis. No PTC case was found positive at the same time for BRAF mutation and RET/PTC rearrangements.

CONCLUSION

BRAF(V600E) mutation detected on FNAB specimens, more than RET/PTC rearrangements, is highly specific for PTC and its routine research might well be an adjunctive and integrative diagnostic tool for the preoperative diagnostic iter.

Cytological and histological diagnoses of recurrent thyroid carcinoma with monoclonal antibody JT-95, which can detect modified fibronectin

Although fine needle aspiration (FNA) cytology has increasingly gained importance as a tool in thyroid diagnosis over the recent years, up to 20% of thyroid carcinomas, in particular follicular tumors and follicular variant tumors, are inconclusive by FNA. The monoclonal antibody (MoAb) JT-95 detects the modified fibronectin, expressed in most thyroid carcinomas. Consequently, it has been applied to FNA and tissue section specimens obtained from thyroid tumors during surgery. For FNA specimens of 57 thyroid tumors followed-up for more than 10 years postoperatively and stained with both the Papanicolaou and the immunoperoxidase technique using MoAb JT-95, we retrospectively compared the sensitivity, specificity, and diagnostic accuracy of the two procedures. Histological specimens stained with HE and investigated by JT-95 were also re-evaluated. The pathological results of aspirated specimens, after a change in diagnosis following recurrence, revealed that 43 of 47 malignant lesions were positive, while nine of 10 benign tumors remained unreactive using MoAb JT-95. Sensitivity was 91.4%, specificity 90.0%, and diagnostic accuracy 91.2% by JT-95 cytology. By contrast, sensitivity ascertained by the Papanicolaou technique was 78.1%, specificity 100%, and accuracy 82.4%. Of the six examples that recurred during the 10-12-year follow-up period, tissue sections of all six and aspirated materials of five of the six were stained by JT-95.

Galectin-3 is highly expressed in nonencapsulated papillary thyroid carcinoma but weakly expressed in encapsulated type; comparison with Hector Battifora mesothelial cell 1 immunoreactivity

The histologic diagnosis of the follicular variant of papillary thyroid carcinoma (FVPTC) may be troublesome, especially in its encapsulated form. We evaluated the expression of galectin-3 (gal-3) and Hector Battifora mesothelial cell (HBME-1) in 200 formalin-fixed thyroid tissues with diagnosis of classical variant of papillary thyroid carcinoma or FVPTC, encapsulated or with infiltrative growth, with or without lymph node metastasis. All cases of classical variant of papillary thyroid carcinoma were consistently positive for gal-3; similar results have been obtained by using HBME-1. Interestingly, the invasive type of FVPTC, with or without metastasis, was strongly positive for gal-3 (78.2% and 96%, respectively), whereas only 46.8% of encapsulated FVPTCs without metastasis showed immunostaining for this marker. In the latter group, the HBME-1 expression achieved a significantly higher percentage of positivity (87%). Surprisingly, gal-3 immunodetection showed negative results in 4 encapsulated FVPTCs, despite the strong immunoreactivity in corresponding metastasis. Our data suggest that gal-3 immunodetection alone is not able to support the diagnosis of encapsulated FVPTCs.

Perspectives and limitations of microarray-based gene expression profiling of thyroid tumors

Microarray technology has become a powerful tool to analyze the gene expression of tens of thousands of genes simultaneously. Microarray-based gene expression profiles are available for malignant thyroid tumors (i.e., follicular thyroid carcinoma, and papillary thyroid carcinoma), and for benign thyroid tumors (such as autonomously functioning thyroid nodules and cold thyroid nodules). In general, the two main foci of microarray investigations are improved understanding of the pathophysiology/molecular etiology of thyroid neoplasia and the detection of genetic markers that could improve the differential diagnosis of thyroid tumors. Their results revealed new features, not known from one-gene studies. Simultaneously, the increasing number of microarray analyses of different thyroid pathologies raises the demand to efficiently compare the data. However, the use of different microarray platforms complicates cross-analysis. In addition, there are other important differences between these studies: 1) some studies use intraindividual comparisons, whereas other studies perform interindividual comparisons; 2) the reference tissue is defined as strictly nonnodular healthy tissue or also contains benign lesions such as goiter, follicular adenoma, and hyperplastic nodules in some studies; and 3) the widely used Affymetrix GeneChip platform comprises several GeneChip generations that are only partially compatible. Moreover, the different studies are characterized by strong differences in data analysis methods, which vary from simple empiric filters to sophisticated statistic algorithms. Therefore, this review summarizes and compares the different published reports in the context of their study design. It also illustrates perspectives and solutions for data set integration and meta-analysis, as well as the possibilities to combine array analysis with other genetic approaches.

Molecular classification and biomarker discovery in papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, with an incidence of approximately 22,000 cases in 2004 in the USA. Incidence is increasing, with a global estimate of half a million new cases this year. PTC is found in a variety of morphologic variants, usually grows slowly and is clinically indolent, although rare, aggressive forms with local invasion or distant metastases can occur. In recent years, thyroid cancer has been at the forefront of molecular pathology as a result of the consequences of the Chernobyl disaster and the recognition of the role of Ret/PTC rearrangements in PTC. Nonetheless, the molecular pathogenesis of this disease remains poorly characterized. In the clinical setting, benign thyroid nodules are far more frequent, and distinguishing between them and malignant nodules is a common diagnostic problem. It is estimated that 5-10% of people will develop a clinically significant thyroid nodule during their lifetime. Although the introduction of fine-needle aspiration has made PTC identification more reliable, clinicians often have to make decisions regarding patient care on the basis of equivocal information. Thus, the existing diagnostic tools available to distinguish benign from malignant neoplasms are not always reliable. This article will critically evaluate recently described putative biomarkers and their potential future role for diagnostic purposes in fine-needle aspiration cytology samples. It will highlight the evolution of our understanding of the molecular biology of PTC, from a narrow focus on specific molecular lesions such as Ret/PTC rearrangements to a pan-genomic approach.

Galectin-3 expression in papillary thyroid carcinoma: relation to histomorphologic growth pattern, lymph node metastasis, extrathyroid invasion, and tumor size

BACKGROUND

Galectin-3 has been recently recognized as a promising presurgical marker of thyroid malignancy.

METHODS

Galectin-3 expression was examined immunohistochemically in 202 specimens of papillary thyroid carcinoma (PTC) in relation to histomorphologic subtypes and clinicopathologic data. RESULTS.: The sensitivity of galectin-3 immunostaining versus conventional histology was 98% (100 of 102) for classical PTC, 85.2% (46 of 54) for follicular variant, and 50% (23 of 46) for follicular/solid variant of PTC. All cases (n = 36) involving lymph node metastases and 42 of 45 cases with extrathyroid invasion expressed galectin-3. However, among the galectin-3-positive cases (n = 169), 133 were without lymph node metastases, and 127 were without extrathyroid invasion. Galectin-3 expression was not related to the size of intrathyroid PTC.

CONCLUSIONS

Galectin-3 immunohistochemical expression itself is not an indicator of local metastatic spread or extrathyroid invasion of PTC, thus being irrelevant clinically from this aspect. Galectin-3 is an excellent marker for classical PTC but must be used with caution in diagnosing unconventional variants of PTC because of the possibility of false-negative results.

Usefulness of HBME-1, cytokeratin 19 and galectin-3 immunostaining in the diagnosis of thyroid malignancy

AIMS

To investigate the usefulness of immunohistochemical expression and immunolocalization of a panel of thyroid malignancy markers including HBME-1, cytokeratin (CK) 19 and galectin-3.

METHODS AND RESULTS

We evaluated 170 thyroid lesions including 148 neoplastic lesions [84 papillary carcinomas (PC), 38 follicular carcinomas (FC), 18 follicular adenomas, one hyalinizing trabecular tumour, five medullary carcinomas, two anaplastic carcinomas] and 22 non-neoplastic lesions (12 adenomatous nodules and 10 Hashimoto's thyroiditis). HBME-1, galectin-3 and CK 19 were expressed in 94%, 72.6%, 72.6% of PCs and in 63%, 21%, 21% of FCs. The three markers were mostly negative in all normal tissues. Although the most helpful marker in terms of sensitivity and specificity for the follicular variant of PC and for FC diagnosis was HBME-1, when we consider the differentiation between cases of follicular variant of papillary carcinoma (FVPC) and FC or adenoma, in terms of percentage of positive cells, galectin-3 and CK 19 were more relevant.

CONCLUSIONS

HBME-1 is the most sensitive marker for thyroid malignancy but the three markers may be useful in specific cases. This panel of markers is useful to differentiate the follicular patterned lesions, with special reference to the FVPC.

Oncofoetal fibronectin--a tumour-specific marker in detecting minimal residual disease in differentiated thyroid carcinoma

Supposedly, thyrocyte-specific transcripts such as thyroglobulin (Tg) and thyroid-stimulating hormone receptor (TSH-R) were proposed to be useful for the diagnosis of circulating tumour cells in patients suffering from differentiated thyroid carcinoma (DTC). However, several research groups reported blood-borne Tg transcripts in healthy individuals. This study determines in particular the origin of Tg mRNA in nucleated blood cells and analyses whether other tumour-associated sequences are absent in leukocytes, but widely expressed in DTC. Therefore, expression analyses for Tg, TSH-R, cytokeratin 19 (CK 19), human telomerase reverse transcriptase (hTERT) and oncofoetal fibronectin (onfFN) were carried out using cDNAs derived from (1) leukocyte fractions, (2) 18 follicular thyroid carcinomas (FTCs) and 48 papillary thyroid carcinomas (PTCs), and (3) leukocytes of two thyrocyte-depleted individuals treated for C-cell carcinoma of the thyroid. Expression of onfFN was additionally analysed by semiquantitative RT–PCR and by quantitative fluorescence-based real-time PCR. Tg and TSH-R expression was demonstrated not only in both athyroid individuals, but in all leukocyte subgroups tested, while hTERT was absent in resting CD4⁺ cells and only weakly expressed in the CD8⁺ group. CK 19 was notable in each leukocyte population except for resting CD14⁺, as well as for activated and resting CD19⁺ cells. All blood cell fractions proved negative for onfFN mRNA, whereas its presence in thyroid carcinoma was 78/98% (FTC/PTC). Threshold cycle values were calculated at: porphobilinogen deaminase (PBGD) =25.95±0.73 (FTC)/24.55±5.43 (PTC) (P=0.2878); onfFN=25.48±3.15 (FTC)/21.44±3.44 (PTC) (^*P=0.0001). Finally, onfFN transcripts were detected in blood samples of six out of nine patients with known DTC metastases, demonstrating a reliable assay functionality. We propose that real-time RT–PCR of onfFN mRNA is superior to other markers in monitoring minimal residual disease in DTC with regard to both assay sensitivity and specificity.

Galectin-3 expression in papillary microcarcinoma of the thyroid

AIMS

Galectin-3 is a beta-galactoside binding protein, recently recognized as a promising molecular marker of thyroid malignancy. As reported in several studies, galectin-3 is highly expressed in papillary thyroid carcinoma, but its expression has not been investigated in papillary microcarcinoma, which is a variant of papillary thyroid carcinoma.

METHODS AND RESULTS

Using a monoclonal antibody to galectin-3 and the avidin-biotin-peroxidase complex (ABC) immunohistochemical technique, we analysed galectin-3 expression in 63 cases of papillary microcarcinoma. The results showed immunohistochemical reactivity for galectin-3 in 51 (80.9%) cases. Intensity of staining varied from strong or moderate to weak. Galectin-3 localization was mostly cytoplasmic, but also membranous or nuclear in some cells. Immunohistochemical expression of galectin-3 was not found in 12 (19.1%) cases. Most galectin-3 negative microcarcinomas (10/12) were of the non-classical type, i.e. without papillary architecture. Neither the frequency nor the intensity of a positive reaction was related to tumour size.

CONCLUSIONS

Galectin-3 gene is expressed at the protein level in most papillary microcarcinomas, although with slightly lower frequency than that reported for clinically evident papillary thyroid carcinoma. The presence of galectin-3 in clinically silent microcarcinomas may indicate that galectin-3 is not related to growth or aggressiveness of papillary thyroid microcarcinomas but rather plays some other role in thyroid tumour biology.

Galectin-3 is not useful in thyroid FNA

INTRODUCTION

Previous studies have suggested that galectin-3 immunohistochemistry may be useful in the fine needle aspiration (FNA) diagnosis of thyroid carcinoma as it has been reported to selectively stain carcinomas and not adenomas or goitres.

METHODS

Fifty-one patients were included in a prospective study of galectin-3 in thyroid FNA; 88.2% were female and 11.8% male, mean age 53 years, range 25-87 years. Cell blocks were prepared and stained for galectin-3 if any cells were present in needle washings from the respective FNAs.

RESULTS

Twelve of 51 (23.5%) of cell blocks contained epithelial cells. One benign and one inadequate FNA were negative for galectin-3 staining. One of five non-diagnostic FNA cases, a papillary carcinoma on final histology showed positive staining. Four follicular neoplasm/suspicious of carcinoma cases showed negative staining. One malignant FNA case, a papillary carcinoma showed positive staining with galectin-3 but three further carcinomas, two papillary and one follicular were galectin-3 negative.

CONCLUSION

Galectin-3 immunohistochemistry does not appear to be a useful adjunct to diagnosis in thyroid FNA as it does not reliably distinguish malignant and benign lesions. Many thyroid aspirates are of low cellularity and are not suitable for cell block immunohistochemistry.

Electrical impedance scanning of thyroid nodules before thyroid surgery: a prospective study

BACKGROUND

Electrical impedance scanning (EIS) is a novel imaging technique based on differential electrical conductivity and capacitance of malignant and normal human tissues. The aim of this study was to evaluate the accuracy of EIS in the detection of thyroid malignancies.

METHODS

Patients with thyroid nodules scheduled for thyroid surgery were eligible for the study. Enrolled patients underwent EIS with a T-Scan 2000ED. Nodule location, size, and type (cystic vs. solid) measured by ultrasound, cytology results, thyroid conductivity, and capacitance calculated by EIS were recorded. EIS results were interpreted as positive or negative for malignancy and compared with final histopathology results. Study end points included EIS accuracy, sensitivity, specificity, negative and positive predictive values, and false-positive and false-negative rates.

RESULTS

Sixty-four patients were enrolled onto the study, and all underwent either lobectomy-isthmusectomy (20%) or total thyroidectomy (80%). The mean tumor diameter was 2.64 +/- 14.8 mm. Thyroid cancers were identified by histology in 30 patients (46.9%). There were 11 false-positive and four false-negative cases. The overall diagnostic accuracy of EIS was 76.6% (49 of 64 correct diagnoses). The sensitivity and specificity of EIS were 86.7% (26 of 30 true positive) and 67.6% (23 of 34 true negative), respectively. The corresponding positive and negative predictive values were 70.3% and 85.2%.

CONCLUSIONS

EIS is a potentially useful imaging modality for differentiating thyroid neoplasms. If these results are confirmed in large-scale trials, EIS may be an important part of the evaluation of thyroid nodules.

Human galectin-3 immunoexpression in thyroid follicular adenomas with cell atypia

Human galectin-3 (hgal-3) is a beta-galactoside binding protein involved in a number of physiological and pathological processes. Increasing hgal-3 immunoexpression has been reported in several human tumors, including thyroid carcinomas, but not in benign thyroid lesions. We analyzed the immunolocalization of hgal-3 in cell compartments of benign and malignant thyroid lesions. Hgal-3 immunoperoxidase reaction was carried out on 133 thyroid tissue samples obtained from 113 patients; 20 of these were normal (NT), 85 were benign thyroid lesions [20 colloid nodules (CN), 21 nodular hyperplasias (NH), 7 focal lymphocytic thyroiditis (FLT), 15 Hashimoto's thyroiditis (HT), 22 follicular adenomas (FA)], 25 differentiated carcinomas [15 papillary carcinomas (PC), 6 follicular carcinomas (FC) and 4 Hürthle cell carcinomas (HC)] and 3 anaplastic carcinomas (AC). Among the malignant thyroid lesions, hgal-3 was detected in 12/15 (80%) PC, 3/4 (75%) HC and in 4/6 (66.6%) FC, but in none of the 3 AC. Conversely, hgal-3 immunoexpression was absent in NT and in all benign thyroid lesions, but 1/15 HT and 10/22 (45.4%) FA. In the latter, hgal-3 was mostly expressed in microfollicular areas and in five of the six atypical FA. Hgal-3 cytoplasmic-perinuclear immunolocalization was observed in the majority of thyroid carcinomas and in more than half of the FA, theoretically suggesting an involvement of this protein in thyroid tumorigenesis throughout an antiapoptotic activity. Moreover, hgal-3 expression in FA might anticipate the likelihood of evolution of these benign lesions towards malignancy.