Prognostic value of E-cadherin expression in thyroid follicular carcinoma

Multi-Omics and Management of Follicular Carcinoma of the Thyroid

Follicular thyroid carcinoma (FTC) is the second most common cancer of the thyroid gland, accounting for up to 20% of all primary malignant tumors in iodine-replete areas. The diagnostic work-up, staging, risk stratification, management, and follow-up strategies in patients who have FTC are modeled after those of papillary thyroid carcinoma (PTC), even though FTC is more aggressive. FTC has a greater propensity for haematogenous metastasis than PTC. Furthermore, FTC is a phenotypically and genotypically heterogeneous disease. The diagnosis and identification of markers of an aggressive FTC depend on the expertise and thoroughness of pathologists during histopathological analysis. An untreated or metastatic FTC is likely to de-differentiate and become poorly differentiated or undifferentiated and resistant to standard treatment. While thyroid lobectomy is adequate for the treatment of selected patients who have low-risk FTC, it is not advisable for patients whose tumor is larger than 4 cm in diameter or has extensive extra-thyroidal extension. Lobectomy is also not adequate for tumors that have aggressive mutations. Although the prognosis for over 80% of PTC and FTC is good, nearly 20% of the tumors behave aggressively. The introduction of radiomics, pathomics, genomics, transcriptomics, metabolomics, and liquid biopsy have led to improvements in the understanding of tumorigenesis, progression, treatment response, and prognostication of thyroid cancer. The article reviews the challenges that are encountered during the diagnostic work-up, staging, risk stratification, management, and follow-up of patients who have FTC. How the application of multi-omics can strengthen decision-making during the management of follicular carcinoma is also discussed.

Assessment of Biomarkers for Clinical Diagnosis of Papillary Thyroid Carcinoma with Distant Metastasis

Early diagnosis and treatment of thyroid cancers are critical for better prognosis and better survival rates. The purpose of this study was to identify potential diagnostic markers for papillary thyroid carcinomas with distant metastasis. Fifty-eight papillary thyroid tumor specimens (27 papillary thyroid carcinomas with distant metastasis and 31 without metastasis) were examined, and protein expression of pituitary tumor-transforming gene (PTTG), E-cadherin, p27kip1, vascular endothelial growth factor (VEGF)-C, metalloproteinase (MMP) 2, MMP9, chemokine receptor CXCR4, and basic fibroblast growth factor (bFGF) in these tumors was assessed by immunohistochemistry. The clinicopathological variables with diagnostic significance were determined by multivariate analysis, and their diagnostic values were evaluated by ROC curve analysis. PTTG, VEGF-C, MMP2, MMP9, CXCR4, and bFGF were overexpressed in metastatic papillary thyroid carcinomas, whereas p27kip1 expression was elevated only in carcinomas lacking metastasis. Multiple-factor binary ordinal logistic regression analysis revealed that PTTG, VEGF-C, MMP2, and bFGF were independently related to biological metastatic behavior in thyroid tumors, suggesting their potential use as biomarkers. ROC curve analysis showed that among these four proteins, VEGF-C and bFGF were the best diagnostic biomarkers. A VEGF-C and bFGF cluster was the most useful factor for the differential diagnosis between metastatic and non-metastatic papillary thyroid cancers. Thus, the combined use of VEGF-C and bFGF as biomarkers may improve the diagnostic accuracy of papillary thyroid carcinoma and may be useful in multimodal screening programs for the clinical diagnosis of papillary thyroid carcinoma and early detection of papillary thyroid carcinoma with distant metastasis.

Inflammatory mediators drive metastasis and drug resistance in head and neck squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

The presence of regional metastases in head and neck squamous cell carcinoma (HNSCC) patients is a common and adverse event associated with poor prognosis. Understanding the molecular mechanisms that mediate HNSCC metastasis may enable identification of novel therapeutic targets. E-cadherin plays a key role in epithelial intercellular adhesion; its downregulation is a hallmark of the epithelial-to-mesenchymal transition (EMT) (an essential process during tumor progression); and it is associated with invasion, metastasis, and decreased survival. Inflammatory cytokines have been implicated in the progression of HNSCC. Herein, the mechanisms by which the inflammatory mediator, Interleukin-1β (IL-1β), might contribute to EMT in HNSCC is investigated. The pathways involved in E-cadherin regulation in HNSCC had not previously been defined. It is hypothesized that 1) inflammatory mediators upregulate cyclooxygenase-2/prostaglandin E2 (COX-2/PGE2), which then in turn regulate E-cadherin expression in HNSCC; and 2) PGE2 downregulates E-cadherin via transcriptional repressors of E-cadherin (such as Snail) in HNSCC. The outcome of the proposed research will allow us to define how resistance to epidermal growth factor receptor (EGFR)-selective tyrosine kinase inhibitors is mediated and whether the benefits of combination therapy are due to the capacity of COX-2 inhibitors to increase E-cadherin expression and thus create a more sensitive target for EGFR TK inhibition.

STUDY DESIGN

Basic science, molecular biology, animal model, immunohistochemistry.

METHODS

We evaluated the effect of IL-1β on the molecular events of EMT in surgical specimens and HNSCC cell lines. We examined the correlation with tumor histologic features, and a severely compromised immunodeficient (SCID) xenograft model was used to assess the effects in vivo.

RESULTS

COX-2-dependent pathways contribute to the modulation of E-cadherin expression in HNSCC. An inverse relationship between COX-2 and E-cadherin was demonstrated in situ by double immunohistochemical staining of human HNSCC tissue sections. Treatment of HNSCC cells with IL-1β caused the downregulation of E-cadherin expression and upregulation of COX-2 expression. This effect was blocked in the presence of COX-2 small hairpin RNA (shRNA). IL-1β -treated HNSCC cell lines demonstrated a significant decrease in E-cadherin messenger RNA (mRNA) and an increase in the mRNA expression of the transcriptional repressor Snail. IL-1β exposure led to enhanced Snail binding at the chromatin level. ShRNA-mediated knockdown of Snail interrupted the capacity of IL-1β to downregulate E-cadherin. Snail overexpression in normal oral keratinocytes and HNSCC cells is sufficient to drive EMT and confers resistance to erlotinib. In a SCID xenograft model, HNSCC Snail overexpressing cells demonstrated significantly increased primary and metastatic tumor burdens.

CONCLUSIONS

The inflammatory mediator IL-1β modulates Snail and thereby regulates COX-2-dependent E-cadherin expression in HNSCC. This is the first report indicating the role of Snail in the inflammation-induced promotion of EMT in HNSCC. This newly defined pathway for transcriptional regulation of E-cadherin in HNSCC has important implications for targeted chemoprevention and therapy.

LEVEL OF EVIDENCE

N/A.

Metastatic Follicular Thyroid Carcinoma Secreting Thyroid Hormone and Radioiodine Avid without Stimulation: A Case Report and Literature Review

Introduction. This is an extremely rare case of a patient with metastatic follicular thyroid cancer who continued to produce thyroid hormone and was iodine scan positive without stimulation after thyroidectomy and radioiodine (I-131) therapy. Patient Findings. A 76-year-old Caucasian male was diagnosed with metastatic follicular thyroid carcinoma on lung nodule biopsy. Total thyroidectomy was performed and he was ablated with 160 mCi of I-131 after recombinant human thyrotropin (rhTSH) stimulation. Whole body scan (WBS) after treatment showed uptake in bilateral lungs, right sacrum, and pelvis. The thyroglobulin decreased from 2,063 to 965 four months after treatment but rapidly increased to 2,506 eleven months after I-131. Thyroid stimulating hormone (TSH) remained suppressed and free T4 remained elevated after I-131 therapy without thyroid hormone supplementation. He was treated with an additional 209 mCi with WBS findings positive in lung and pelvis. Despite I-131, new metastatic lesions were noted in the left thyroid bed and large destructive lesion to the first cervical vertebrae four months after the second I-131 dose. Conclusions. This case is exceptional because of its rarity and also due to the dissociation between tumor differentiation and aggressiveness. The metastatic lesions continued to secrete thyroid hormone and remained radioiodine avid with rapid progression after I-131 therapy.

Clinical importance and therapeutic implication of E-cadherin gene methylation in human ovarian cancer

E-cadherin (E-cad) is widely expressed in epithelial cells and acts as a pivotal tumor suppressor. The promoter methylation of E-cad has been reported to closely relate to its downregulation in many kinds of cancers. E-cad expression and methylation status were detected by immunohistochemistry (IHC) and methylation-specific polymerase chain reaction (MS-PCR) in 50 ovarian cancer tissues. 5-Aza-2'-deoxycytidine (5-Aza-dC) was used to demethylate E-cad in SKOV3 and ES2 ovarian cancer cell lines, of which the effect was verified by Western blot and MS-PCR. Then MTT and transwell experiments were conducted to detect the capacity of cell proliferation and migration for these cells. Downregulation of E-cad expression was observed in 60 % of ovarian cancer tissues (30/50) by IHC, whereas MS-PCR result indicated that E-cad was methylated in 64 % of (32/50) ovarian cancer specimens. And E-cad expression was significantly correlated with E-cad methylation (P = 0.004). 5-Aza-dC was used to process SKOV3 and ES2 ovarian cancer cell lines. By MTT experiment, we found that the proliferation of 5-Aza-dC-treated SKOV3 and ES2 was significantly suppressed by 28.0 % (P < 0.05) and 32.3 % (P < 0.05). By transwell experiment, the motility of SKOV3 and ES2 was found to be significantly suppressed by 38.2 and 27.4 % (P < 0.05), respectively, after treated with 5-Aza-dC. E-cad methylation is one of the main reasons for the expression reduction in ovarian cancer. 5-Aza-dC treatment could significantly restore the expression of E-cad and suppress growth and invasion of SKOV3 and ES2 cells. These results suggest E-cad methylation may be a promising target for ovarian cancer therapy.

Prognostic biomarkers in thyroid cancer

Thyroid carcinomas represent a challenging problem from the prognostic standpoint. Despite an overall good prognosis of the most frequent endocrine malignancy, 10-15 % of papillary thyroid carcinomas (PTCs) turn refractory to radioactive iodine therapy. The increased incidence of thyroid cancer has led to the search for solid prognostic biomarkers that predict the behaviour of these tumours. Clinical and histopathological prognostic factors remain the only safe elements to be used for diagnosis and prognosis of patients with thyroid tumours. Despite the huge amount of genetic information of thyroid tumours, very few new markers revealed diagnostic or prognostic value per se. BRAF mutation can have some value if associated to other clinico-pathological parameters, or in the particular setting of iodine refractory tumours. Others can prove interesting in the future as predictive biomarkers of therapeutic response, but more studies are needed to confirm these potential biomarkers.

Diagnostic impact of promoter methylation and E-cadherin gene and protein expression levels in laryngeal carcinoma

Aim of the study

Inactivation of the tumor suppressor E-cadherin (CDH1) and its decreased expression is an important occurrence during carcinogenesis. Nevertheless, the relationship of CDH1 expression and the promoter methylation with laryngeal cancer cell aggressiveness is still unclear. The purpose of this study was to elucidate the gene and protein E-cadherin expression and the DNA methylation levels and to describe the correlations with morphological features in squamous cell laryngeal cancer.

Material and methods

The authors studied E-cadherin and the DNA methylation level in 86 cases to gain a further understanding of the clinicopathologic significance of analyzed parameters. The pathological evaluation included pTNM classification and the tumor front grading (TFG) criteria. Quantitative analysis of the amplified product in real time (qRT-PCR) for estimation of CDH1 mRNA was used. The methylation status was investigated by using methyl-specific polymerase chain reaction (MSP). The level of CDH1 protein expression by Western blot was determined.

Results

Downregulation of E-cadherin was found to be related to promoter methylation (p < 0.001). In tumors with the highest invasiveness according to TFG criteria the lowest E-cadherin gene and protein level in the study group was observed (p = 0.046 and p = 0.0002, respectively). In SCLC with muscle and cartilage invasion and disperse infiltration the lowest CDH1 gene and protein expression was noted (p = 0.0003 and p = 0.003 for deep invasion, p = 0.033 and p = 0.003 for multifocal infiltration, respectively).

Conclusions

The current findings suggest an association of E-cadherin tumor expression with progression of laryngeal cancer. CDH1 gene level may be an auxiliary molecular marker for advanced cases of laryngeal carcinoma; however, further studies are necessary.

Association between E-cadherin (CDH1) polymorphisms and papillary thyroid carcinoma risk in Han Chinese population

The aim of this study is to investigate the associations between E-cadherin gene (CDH1) polymorphisms and papillary thyroid carcinoma (PTC) risk predisposition. We undertook a case-control study to analyze three CDH1 polymorphisms (+54T>C, -160C>A, and -347G→GA) in an Han Chinese population, by extraction of genomic DNA from the peripheral blood of 98 patients with PTC and 176 control participants, and performed CDH1 genotyping using DNA sequencing. The obtained results indicated that overall, no statistically significant association was observed in +54T>C. Nevertheless, -347G→GA genotype was at increased risk of PTC (P = 0.001; odds ratio (OR) = 2.12, CI 95%:1.24-3.34). Furthermore, -347GA/GA genotype thyroid cancers were more significantly common in patients with tumor size of ≥20 mm than G or G/GA genotypes PTC and in cases of advanced T stage. However, -160C>A genotype demonstrated a protective effect in PTCs (P = 0.006; OR = 0.59, CI 95%: 0.42-0.87). These findings led us to conclude that polymorphism in -347G→GA was observed to be associated with susceptibility of PTC. However, -160C>A polymorphism indicated to play a protective role in susceptibility to PTC. Nevertheless, further investigation with a larger sample size is needed to support our results.

Colorectal adenocarcinoma: a pediatric case review with a focus on mismatch repair gene mutations and E-cadherin expression

Colorectal adenocarcinoma (CRAC) is exceedingly rare in the pediatric population (fewer than 2 cases per 1 million children). There are 2 major categories of pediatric colorectal adenocarcinoma syndromes: polyposis-related and hereditary nonpolyposis colorectal cancer, also known as Lynch syndrome. Germ line mutations in DNA mismatch repair (MMR) genes (eg, MLH1, MSH2, PMS2, MSH6) have been established as the molecular genetic basis of Lynch syndrome. Another prognostic factor in adult CRAC is the reduced expression of epithelial cadherin (E-cadherin), which has been associated with poor outcome in some adult CRAC cases; however, its role in predicting prognoses in pediatric cases remains unclear. Seven pediatric patients with primary CRAC were reviewed. Available molecular genetic test results were evaluated, and immunohistochemical labeling for MMR proteins and E-cadherin were performed on 5 patients. Four of the 5 patients in our study with available paraffin blocks showed loss of MMR protein expression, consistent with Lynch syndrome. In cases stained for E-cadherin, 3 were strongly positive and 2 were weakly positive; however, with the small sample size and the relatively short follow-up period, an accurate correlation between E-cadherin and prognosis cannot be reached with any degree of certainty. Our findings highlight the importance of genetic testing for MMR gene mutations in children with colorectal cancer and suggest further investigation into the prognostic role of E-cadherin in pediatric CRAC.

SKI-606, an Src inhibitor, reduces tumor growth, invasion, and distant metastasis in a mouse model of thyroid cancer

PURPOSE

Src is overexpressed or hyperactivated in a variety of human cancers, including thyroid carcinoma. Src is a central mediator in multiple signaling pathways that are important in oncogenesis and cancer progression. In this study, we evaluated the effects of an Src inhibitor, SKI-606 (bosutinib), in a spontaneous metastatic thyroid cancer model with constitutively activated Src (Thrb(PV/PV)Pten(+/-) mice).

EXPERIMENTAL DESIGN

Thrb(PV/PV)Pten(+/-) mice were treated with SKI-606 or vehicle controls, beginning at 6 weeks of age until the mice succumbed to thyroid cancer. We assessed the effects of SKI-606 on thyroid cancer progression and analyzed the impact of SKI-606 on aberrant Src-mediated signaling.

RESULTS

SKI-606 effectively inhibited aberrant activation of Src and its downstream targets to markedly inhibit the growth of thyroid tumor, thereby prolonging the survival of treated mice. While Src inhibition did not induce cell apoptosis, it decreased cell proliferation by affecting the expression of key regulators of cell-cycle progression. Importantly, SKI-606 dramatically prevented dedifferentiation, vascular invasion, and lung metastasis of thyroid cancer cells. These responses were meditated by downregulation of mitogen-activated protein kinase pathways and inhibition of the epithelial-mesenchymal transition.

CONCLUSIONS

Our findings suggest that Src is critical in the progression of thyroid cancer, making oral SKI-606 a promising treatment strategy for refractory thyroid cancer.

Dynamic changes in E-cadherin gene promoter methylation during metastatic progression in papillary thyroid cancer

Thyroid cancer cells undergo epithelial to mesenchymal transition (EMT) in the invasive front of tumor. To determine whether the mesenchymal feature of invasive cancer cells is maintained in metastatic sites, we examined E-cadherin methylation and E-cadherin expression in 66 papillary thyroid cancer (PTC) samples and in 34 corresponding lymph node metastases (LNM). Relationships between E-cadherin and cell motility were evaluated using thyroid cancer cell lines. Hypermethylation of the E-cadherin gene promoter was detected in 39.3% of the PTCs, and loss of E-cadherin expression correlated with lymphocytic infiltration, extrathyroidal invasion and the presence of metastases. Comparing primary PTCs to the corresponding LNM, E-cadherin methylation status was identical in 60% of the cases. The switch in E-cadherin promoter status from unmethylated in PTCs to hypermethylated in LNM was detected in 5%; and from hypermethylatated in PTCs to unmethylated in LNM in 35%. Loss of epigenetic silencing in LNM was associated with a gain of E-cadherin expression. Hypermethylation of the E-cadherin gene promoter was detected in thyroid cancer cell lines with mesenchymal-like morphology. Loss of E-cadherin expression in these cells correlated with high migratory ability. Inhibition of RAS/ERK or PI3K/AKT signaling decreased the migratory ability of these cells but did not induce E-cadherin expression. In the cells with epithelial-like morphology, treatments with phorbol-ester or tumor necrosis factor (TNF)-α resulted in translocation of membranous E-cadherin to the cytoplasm and induction of migration. E-cadherin promoter methylation status and E-cadherin expression were not affected by TNF. Demethylating agents induced apoptosis in the mesenchymal-like cells but had no effect on E-cadherin expression or on migratory ability. Together, dynamic changes in E-cadherin methylation occur during metastatic progression in thyroid cancer. Epigenetic mechanisms and TNF-inducible signaling independently contribute to the regulation of E-cadherin expression and localization. These mechanisms may play a role in the induction of EMT in primary tumors and in the conversion from the mesenchymal to the epithelial phenotype in metastases.

Proinflammatory mediators upregulate snail in head and neck squamous cell carcinoma

PURPOSE

Inflammatory cytokines have been implicated in the progression of head and neck squamous cell carcinoma (HNSCC). Herein we investigate the mechanisms by which interleukin-1beta (IL-1beta) might contribute to Epithelial-Mesenchymal Transition (EMT) in HNSCC.

EXPERIMENTAL DESIGN

We evaluated the effect of IL-1beta on the molecular events of EMT in surgical specimens and HNSCC cell lines. We examined the correlation with tumor histologic features, and a SCID xenograft model was used to assess the effects of Snail overexpression.

RESULTS

Cyclooxygenase-2 (COX-2)-dependent pathways contribute to the modulation of E-cadherin expression in HNSCC. An inverse relationship between COX-2 and E-cadherin was shown in situ by double immunohistochemical staining of human HNSCC tissue sections. Treatment of HNSCC cells with IL-1beta caused the downregulation of E-cadherin expression and upregulation of COX-2 expression. This effect was blocked in the presence of COX-2 small hairpin RNA. IL-1beta-treated HNSCC cell lines showed a significant decrease in E-cadherin mRNA and an increase in the mRNA expression of the transcriptional repressor Snail. IL-1beta exposure led to enhanced Snail binding at the chromatin level. Small hairpin RNA-mediated knockdown of Snail interrupted the capacity of IL-1beta to downregulate E-cadherin. In a SCID xenograft model, HNSCC Snail-overexpressing cells showed significantly increased primary and metastatic tumor burdens.

CONCLUSIONS

IL-1beta modulates Snail and thereby regulates COX-2-dependent E-cadherin expression in HNSCC. This is the first report indicating the role of Snail in the inflammation-induced promotion of EMT in HNSCC. This newly defined pathway for transcriptional regulation of E-cadherin in HNSCC has important implications for targeted chemoprevention and therapy.

Clinicopathological correlations of Bcl-xL and Bax expression in differentiated thyroid carcinoma

OBJECTIVE

The Bcl-2 family proteins are essential mediators in the apoptotic process. Our aim was to investigate whether anti-apoptotic Bcl-xL and pro-apoptotic Bax were over-expressed in a large series of differentiated thyroid carcinomas (DTC) and to study their association with tumour presentation at diagnosis and prognosis.

DESIGN AND PATIENTS

We examined the immunohistochemical expression of Bcl-xL and Bax in benign nodular thyroid disease (BNTD) and DTC and their association with clinicopathological parameters. Thyroid tissue samples were collected from an unselected series of patients undergoing surgical resection for DTC (n = 74) or BNTD (n = 15).

RESULTS

Among DTC cases, expression of Bcl-xL was found to be high in 43.2% and low or absent in 56.8%. Expression of Bax was high in 75.7% and low or absent in 24.3%. Non-neoplastic thyroid tissue was largely unstained for both proteins. Among BNTD cases, expression of Bcl-xL was high in 13.3% and low or absent in 86.6%. Expression of Bax was high in 14.3% and low or absent in 86.6%. A significant association was found between Bcl-xL expression and the presence of high-risk histological subtype (P < 0.05), and regional lymph node (P < 0.01) and distant metastases (P < 0.01). The association between high Bcl-xL expression levels and a longer time of persistent disease after radioiodine ablation was also significant (P < 0.01). Bcl-xL expression was confirmed as an independent prognostic factor for persistent disease in DTC (relative risk, 2.5; 95% confidence interval, 1.1-5.9; P < 0.05).

CONCLUSIONS

Immunohistochemical expression of Bcl-xL might be a valuable tool in the prediction of tumour aggressiveness in DTC.

Loss of epithelium cadherin expression is associated with reduced overall survival and disease-free survival in early-stage squamous cell cervical carcinoma

Epithelium cadherin (E-cad) is important for cell-to-cell adhesion of epithelial cells. Impairment of E-cad may have a role in the development and spreading of different malignancies and associated with poor differentiation, increased invasiveness, and poor prognostic factors in nongynecological carcinomas. However, prognostic significance of E-cad expression has not been investigated properly in cervical squamous cell carcinoma (SCC). The objective of this study was to investigate the association between reduced E-cad expression and clinicopathologic variables of cervical carcinoma. Specimens from 53 consecutive patients with stage IB-IIA SCC were evaluated immunohistochemically for E-cad expression, and the results were compared to grade, lymphvascular space invasion (LVSI), deep stromal involvement (DSI), parametrial involvement, lymph node metastasis, recurrences, and survival. Patients were divided into two groups arbitrarily: E-cad expression less than 10% (group 1) and E-cad expression more than 10% (group 2). There was no significant relationship between E-cad expression and DSI, LVSI, lymphatic metastasis. However, there was significant relationship between reduced E-cad expression and parametrial involvement (P= 0.024). Kaplan-Meier survival analysis revealed that reduced E-cad expression is significantly associated with reduced overall survival (OS) and disease-free survival (DFS). Furthermore, Cox regression analysis revealed that reduced E-cad expression is significantly associated with OS (P= 0.004, RR = 6.08, 95% CI: 1.75-21.1) and recurrences (P= 0.027, RR = 1.75, 95% CI: 1.06-2.88). We conclude that loss of E-cad expression is significantly associated with reduced OS and DFS in patients with SCC. Therefore, it might be used as an indicator of aggressive clinical behavior and tailoring aggressive adjuvant therapy in early-stage SCC. Further studies with larger number of patients are needed to evaluate the clinical significance of reduced E-cad expression in SCC.

Derangement of the E-cadherin/catenin complex is involved in transformation of differentiated to anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid cancer arises, or transforms, from pre-existing differentiated thyroid cancer. E-cadherin functions as a cell-cell adhesion molecule that complexes with catenin proteins for function. The objective of this study was to evaluate the change in E-cadherin/beta-catenin expression in the transformation of differentiated to anaplastic thyroid carcinoma.

METHODS

A tissue microarray was constructed from 12 anaplastic thyroid tumors and their adjacent associated differentiated foci. Immunohistochemistry was used to evaluate tumor expression of E-cadherin and beta-catenin.

RESULTS

There was decreased expression of E-cadherin and beta-catenin by the anaplastic tumors when compared with the differentiated thyroid tumors from which they evolved. The expression of E-cadherin and beta-catenin was 92% and 67%, respectively, by the differentiated thyroid carcinoma, and 17% and 50%, respectively, by the anaplastic tumors.

CONCLUSIONS

This report shows that derangement of the E-cadherin/catenin complex is associated with the transformation of differentiated into anaplastic thyroid carcinoma.