The spectrum of papillary thyroid carcinoma variants

Identification of GJC1 as a novel diagnostic marker for papillary thyroid carcinoma using weighted gene co-expression network analysis and machine learning algorithm

BACKGROUND

The incidence of thyroid papillary carcinoma (PTC) is increasing annually, causing both physical and psychological pressure on patients. Therefore, early recognition and specific interventions for PTC are crucial. The objective of this study is to explore novel diagnostic marker and precise intervention targets for PTC.

METHODS

Based on a weighted gene co-expression network analysis (WGCNA), relevant datasets from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases were collected. Enrichment analysis was performed on differentially expressed genes (DEGs) using Gene Ontology (GO), Disease Ontology (DO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Set Enrichment Analysis (GSEA). Subsequently, three machine learning algorithms Least Absolute Shrinkage and Selection Operator (LASSO), Support Vector Machine Recursive Feature Elimination (SVM-RFE), and Random Forest (RF) were used to identify the core genes. Finally, receiver operating characteristic (ROC) curves were used to analyze the clinical diagnostic value of the core genes.

RESULTS

We found, in total, 11,194 DEGs derived the TCGA and GEO datasets, that are primarily enriched in extracellular matrix (ECM) and inflammation related pathways, such as an ECM receptor interaction, cell adhesion molecules (CAMs), Tumor necrosis factor (TNF) signaling, and nucleotide-binding oligomerization domain (NOD) like receptor signaling pathways. Further analysis of the core genes, identified by the protein-protein interaction network, using three machine learning algorithms discovered three intersecting genes GJC1, KLHL4, and NOL4. Of which, GJC1 has good clinical diagnostic ability, which was verified using both the GEO (area under the ROC curve (AUC) = .982) and TCGA databases (AUC = .840).

CONCLUSIONS

GJC1 is highly expressed in PTC. Therefore, it is considered as a potential biomarker and is expected to become a new target for PTC gene therapy. However, it still needs to be supported and verified by more clinical data.

The Correlation between Proliferative Immunohistochemical Markers and Papillary Thyroid Carcinoma Aggressiveness

Background and Objectives: Papillary thyroid carcinoma (PTC) is one of the most common malignancies of the endocrine system. In order to improve the ability to predict tumor behavior, several studies have been conducted to search for surrogate prognostic immunohistochemical tumor markers. Objective: To evaluate the correlation between the intensity of different immunohistochemical marker staining in PTC and the risk for extrathyroidal extension and metastases. Materials and Methods: The study comprised patients who underwent hemi- or total thyroidectomy. Thyroid tissues were immunohistochemically stained for different tumor proliferative markers: Minichromosome maintenance proteins 2 (MCM2), Ki-67 labeling index, E-Cadherin, Neuropilin-1 and Metallothionein. The correlation between the intensity of each marker staining and the final diagnosis (benign neoplasm and PTC) and the correlation between the intensity of each staining and tumor extrathyroidal extension and metastases were evaluated. Results: The study included 66 patients. Staining for Metallothionein, E-Cadherin and MCM2 significantly differed between benign neoplasm (n = 22) and thyroid-confined PTC (n = 21) (p = 0.002, 0.004 and 0.005, respectively), between benign neoplasm and PTC with extrathyroidal extension (n = 11) (p = 0.001, 0.006 and 0.01, respectively), and between benign neoplasm and PTC with metastases (n = 12) (p = 0.01, <0.001 and 0.037, respectively). No staining correlated with extrathyroidal extension. The intensity of E-Cadherin staining was significantly lower in PTC with metastases than thyroid confined PTC and PTC with extrathyroidal extension (p = 0.028 and 0.021, respectively). Conclusions: Immunohistochemical staining for Metallothionein, E-Cadherin and MCM2 significantly distinguished between benign thyroid tumor and PTC. E-Cadherin staining significantly and inversely correlated with the presence of metastases.

A comparative analysis of histologic types of thyroid cancer between career firefighters and other occupational groups in Florida

BACKGROUND

Florida Firefighters experience a higher risk of thyroid cancer than non-firefighters. This study examines whether the histologic types and tumor stage of thyroid cancer is different among firefighters compared to other occupational groups.

METHODS

Eligible cases were firefighters (n = 120) identified in a linkage of Florida Cancer Data System (FCDS) registry records (1981-2014) and Florida State Fire Marshal's Office employment and certification records, and non-firefighters classified into: blue-collar (n = 655), service (n = 834), white-collar (n = 4,893), and other (n = 1,789). Differences in thyroid histologic type (papillary, follicular, and rare/other less common forms of thyroid cancer), tumor stage, and age at diagnosis were evaluated using multinomial logistic regression models comparing blue-collar, service, white-collar, and other occupational groups with firefighters. Univariate odds ratios as well as odds ratios adjusted for age, gender, race, tumor stage, and year of diagnosis (aOR) and 95% confidence intervals (95%CI) were reported.

RESULTS

Service (aOR = 4.12; 95%CI: 1.25-13.65), white-collar (aOR = 3.51; 95%CI: 1.08-11.36), and blue-collar (aOR = 4.59; 95%CI: 1.40-15.07) workers had significantly higher odds of being diagnosed with rare histologic types of thyroid cancer vs papillary type compared to firefighters. Service (aOR = 0.42; 95%CI: 0.27-0.66), white-collar (aOR = 0.39; 95%CI: 0.26-0.59), blue-collar (aOR = 0.36; 95%CI: 0.23-0.56), and other (aOR = 0.34; 95%CI: 0.22-0.53) occupational groups have a significantly lower odds of being diagnosed with rare vs papillary type at a younger age (30-49 years) vs 50-69 years compared to firefighters. However, stage at diagnosis was not significantly different among occupational groups.

CONCLUSION

Firefighters diagnosed with thyroid cancer experience a higher odds of papillary compared to rare histologic types of thyroid cancer relative to other workers; there is no evidence of an increased odds of late-stage diagnosis in firefighters relative to other worker groups. Firefighters may benefit from routine screening and active surveillance of suspected thyroid tumors especially given the excellent treatment outcomes available for those diagnosed with early-stage papillary thyroid tumors.

First case of huge classic papillary thyroid cancer rupturing spontaneously leading to ischemic necrosis, perforation and inflammation of overlying skin: Case report and review of the literature

Introduction

Papillary thyroid cancer (PTC) is the commonest form of well-differentiated endocrine carcinoma. It is categorized into indolent and aggressive, where the indolent subtypes (classic, follicular) rarely demonstrate aggressive behavior. We present a classic PTC presenting with a rapidly growing huge anterior neck mass that subsequently spontaneously ruptured subcutaneously resulting in ischemia, necrosis, and perforation of overlying skin leading to inflammation.

Presentation of case

A 37-year-old female with no comorbidities presented to our emergency department with a neck swelling of 2 years duration that rapidly enlarged one week prior to presentation. Though the mass initially appeared of inflammatory nature, the tumor was a PTC, and she underwent total thyroidectomy with selective right side neck dissection and debridement of necrotic skin. The gross specimen revealed a fragmented non-intact right thyroid lobe mass causing pressure ischemia, necrosis and perforation of the skin. Histopathology showed a 9 × 9 × 5 cm classic PTC staged as pT3b N1b. Postoperative course was uneventful, she was discharged by the eighth postoperative day, and then she received a high dose of radioactive iodine ablation (RAI).

Discussion

Classic PTC is usually of a smaller size and a relatively benign course compared to other PTC subtypes and thyroid cancers. It is indolent with favorable prognosis. Although it is associated with increased risk of lymph node metastases at the time of diagnosis, it is slow growing with high survival rates approaching 95%.

Conclusion

Despite that classic PTC progresses slowly, it should still be suspected in neck swellings presenting with rapid and aggressive behavior. Prompt and systematic assessment is required with surgical intervention and radioactive iodine ablation therapy.

•

Classic PTC is of indolent nature, slow progression and favorable prognostic outcomes when treated.

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We present a huge mass, rapid progression, spontaneous rupture causing ischemia, necrosis and perforation of overlying skin.

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Systematic investigations are required using US, FNA and CT followed by surgical intervention is the mainstay of treatment.

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High risk patients must undergo RAI soon after surgery with semiannual then annual follow-up to assess any recurrence.

A population-based study of the three major variants of papillary thyroid carcinoma

Objective

To explore the clinicopathological features and relative prognostic risks of the three major variants of papillary thyroid carcinoma (PTC).

Methods

We retrospectively analyzed the clinicopathological characteristics and prognoses of patients with the three major PTC variants, conventional papillary thyroid carcinoma (CPTC), follicular-variant papillary carcinoma (FVPTC), and tall-cell papillary thyroid carcinoma (TCPTC), based on data from the Surveillance, Epidemiology, and End Results database from 2005 to 2009.

Results

A total of 29,555 patients were enrolled. In terms of their demographic and clinicopathological characteristics, TCPTC had the highest prevalence of older patients, men, patients with locally advanced stage (T stage and N stage), and mortality, while FVPTC had the lowest prevalence in relation to these factors. The three variants differed significantly in terms of 5-year overall survival and 5-year disease-specific survival. Cox regression analysis identified male sex, age ≥45 years, and higher American Joint Committee on Cancer and TNM stage as independent factors predicting a poor prognosis in relation to both overall and disease-specific survival.

Conclusions

CPTC, FVPTC, and TCPTC have different clinicopathological characteristics and prognoses, indicating the need for different treatment strategies for these three variants of PTC.

Site-Specific Metastasis and Survival in Papillary Thyroid Cancer: The Importance of Brain and Multi-Organ Disease

Introduction-heterogeneity in clinical outcomes and survival was observed in patients with papillary thyroid cancer (PTC) and distant metastases. Here, we investigated the effect of distant metastases sites on survival in PTC patients. Methods-patients with a diagnosis of PTC and known metastases were identified using the Surveillance, Epidemiology, and End Results database (1975-2016). Univariate and multivariate Cox regression analyses were performed to analyze the effect of distant metastases sites on thyroid cancer-specific survival (TCSS) and overall survival (OS). Results-from 89,694 PTC patients, 1819 (2%) developed distant metastasis at the initial diagnosis, of whom 26.3% presented with the multiple-organ disease. The most common metastatic sites were lung (53.4%), followed by bone (28.1%), liver (8.3%), and brain (4.7%). In metastatic patients, thyroid cancer-specific death accounted for 73.2%. Kaplan-Meier curves showed decreased OS in patients with metastases to the brain (median OS = 5 months) and liver (median OS = 6 months) compared to lung (median OS = 10 months) and bone (median OS = 23 months). Moreover, multiple organ metastasis had a higher mortality rate (67.4%) compared to single organ metastasis (51.2%, p < 0.001). Using multivariate analysis, risk factors that significantly influence TCSS and OS were male gender (HR = 1.86, 95% CI = 1.17-2.94, p < 0.001, and HR = 1.90, 95% CI = 1.40-2.57, p = 0.009), higher tumor grade (HR = 7.31, 95% CI = 2.13-25.0, p < 0.001 and HR = 4.76, 95% CI = 3.93-5.76, p < 0.001), multiple organ involvement (HR = 6.52, 95% CI = 1.50-28.39, p = 0.026 and HR = 5.08, 95% CI = 1.21-21.30, p = 0.013), and brain metastasis (HR = 1.82, 95% CI = 1.15-2.89, p < 0.001 and HR = 4.21, 95% CI = 2.20-8.07, p = 0.010). Conclusion-the pattern of distant metastatic organ involvement was associated with variability in OS in PTC. Multi-organ metastasis and brain involvement are associated with lower survival rates in PTC. Knowledge of the patterns of distant metastasis is crucial to personalize the treatment and follow-up strategies.

Genetic Profiles of Aggressive Variants of Papillary Thyroid Carcinomas

Aggressive variants of papillary thyroid carcinoma (PTC) have been described with increasing frequency and are associated with unfavorable clinical outcomes. However, limited data exist on the comprehensive genetic profile of these variants. We performed targeted next-generation sequencing in 36 patients with aggressive variants of PTC and compared it to PTC from The Cancer Genome Atlas (TCGA) project and poorly differentiated thyroid cancers (PDTCs)/anaplastic thyroid cancers (ATCs) from the Memorial Sloan Kettering Cancer Center (MSKCC). BRAF mutation was the most prevalent (89%) in aggressive variants of PTC compared to that in other thyroid cancers. RAS mutation was identified in one patient (3%), which was less frequent than in others. TERT promoter mutation (17%) ranged between that of PTCs (9%) and PDTCs (40%). Tumor suppressor genes, ZFHX3, TP53, and CHEK2, were mutated in 14%, 3%, and 6% of aggressive variants of PTC, respectively. The mutation rate of TP53 (3%) was significantly higher than that of PTCs (0.7%) and lower than that of ATCs (73%). Mutations in three functional groups, histone methyl transferases, SWI/SNF chromatin remodeling complex, and the PI3K/AKT/mTOR pathway, were present in 11%, 14%, and 11% of samples, respectively. In conclusion, aggressive variants of PTC had higher BRAF and lower NRAS mutation prevalence than other thyroid cancers. The prevalence of mutations in the TERT promoter, TP53, and genes encoding three functional groups ranged between that of PTCs and PDTCs/ATCs.

Thyroid Carcinoma: Phenotypic Features, Underlying Biology and Potential Relevance for Targeting Therapy

Thyroid carcinoma consists a group of phenotypically heterogeneous cancers. Recent advances in biological technologies have been advancing the delineation of genetic, epigenetic, and non-genetic factors that contribute to the heterogeneities of these cancers. In this review article, we discuss new findings that are greatly improving the understanding of thyroid cancer biology and facilitating the identification of novel targets for therapeutic intervention. We review the phenotypic features of different subtypes of thyroid cancers and their underlying biology. We discuss recent discoveries in thyroid cancer heterogeneities and the critical mechanisms contributing to the heterogeneity with emphases on genetic and epigenetic factors, cancer stemness traits, and tumor microenvironments. We also discuss the potential relevance of the intratumor heterogeneity in understanding therapeutic resistance and how new findings in tumor biology can facilitate designing novel targeting therapies for thyroid cancer.

Pitfalls in Thyroid Cytopathology

Fine-needle aspiration (FNA) is among the first diagnostic tools used in the evaluation of thyroid nodules. It has the ability to triage patients with benign and malignant lesions, thus defining the optimum clinical and/or surgical management. The Bethesda System for Reporting Thyroid Cytopathology has found worldwide acceptance. Thyroid FNA offers high positive predictive value (97%-99%), with sensitivities and specificities of 65% to 99% and 72% to 100%, respectively. Nonetheless, many potential diagnostic pitfalls exist that can lead to false-positive and/or false-negative results. This article discusses several of the potential pitfalls in the cytologic evaluation of thyroid lesions.

Variants of Papillary Thyroid Carcinoma: An Algorithmic Cytomorphology-Based Approach to Cytology Specimens

BACKGROUND

Thyroid cancer accounts for 1% of cancer cases in developed countries, in which papillary thyroid carcinoma (PTC) is the most common type. There are multiple variants of PTC described to date, some of them with aggressive behavior and poor clinical outcome. These variants are well described and accepted in recent guidelines of many international societies, and the prognostic and management implications are well laid out. Due to their established clinical importance and to guide appropriate surgical management, it is now imperative in clinical practice, including cytopathology, to differentiate aggressive variants from nonaggressive ones. This review aims to describe the variants of PTC and to provide a practical algorithmic approach to facilitate the cytological diagnosis of these variants.

SUMMARY

Subtyping PTC variants on fine needle aspiration cytology (FNAC) is challenging even for the most experienced cytopathologist. To facilitate a correct subtyping on FNAC, we propose a stepwise approach that is mainly designed for conventional smear methodology. This approach requires first to stratify the lesions into oncocytic and nononcocytic features before analyzing further details in cell morphology and pattern. Key Messages: (1) Subtyping in PTC is possible on cytopathology. (2) The main aim of the cytopathologist is to differentiate aggressive from nonaggressive variants. (3) The subtyping of PTC can help in the surgical management of the patients.

IGSF1: A novel oncogene regulates the thyroid cancer progression

Thyroid cancer has been continuously increasing and extraordinarily prevalent worldwide. The genetic diagnosis has been widely used in fine needle aspiration. IGSF1, an immunoglobulin superfamily member 1, has been shown to be associated with the regulation of thyroid hormone. But the function of IGSF1 in thyroid cancer has not been explored yet. In this article, we will illuminate the correlation between IGSF1 expression and thyroid cancer. We analysed the level of IGSF1 expression in 55 pairs of tissue samples by real-time polymerase chain reaction (PCR) and The Cancer Genome Atlas (TCGA) data portal. After that, we transfected small interfering RNA to silence IGSF1 in thyroid cancer cell lines (KTC-1 and BCPAP) and confirmed the function of IGSF1 by performed colony formation, migration, invasion, cell counting kit-8, and apoptosis assays. IGSF1 was upregulated in thyroid cancer tissues compared with the adjacent normal tissues (t = 5.783, df = 54; P < .0001) and TCGA (T: N = 65.91 ± 3.998, n = 501: 2.824 ± 0.273, n = 58; P < .0001). In thyroid cell lines, experiments showed that downregulated IGSF1 inhibited proliferation, metastasis, and promoted cell apoptosis. Meanwhile, inhibited IGSF1 expression could downregulate N-cadherin, vimentin, and EZH2, which is associated with metastasis. Thyroid cancer cells IGSF1 expression levels are a correlation with its ability to growth, metastasis, and apoptosis.

Cytologic features of aggressive variants of follicular-derived thyroid carcinoma

Certain carcinomas of the thyroid gland behave aggressively resulting in increased patient morbidity and poor patient prognosis. The diagnosis of these aggressive thyroid cancer subtypes is sometimes challenging and subject to increased interobserver variability. This review deals with the cytological features of such tumors including aggressive variants of papillary thyroid carcinoma, poorly differentiated thyroid carcinoma, and anaplastic thyroid carcinoma. These malignancies fall into 2 groups based on their cytomorphology: those that exhibit distinct microscopic features (eg, nuclear findings typical of classical papillary thyroid carcinoma or marked anaplasia) and those that present with more subtle cytologic features (eg, nuclear pseudostratification, "soap bubble" nuclei, supranuclear or subnuclear cytoplasmic vacuoles, rosette-like structures, hobnail cells). We review the literature regarding these aggressive thyroid cancers and highlight important phenotypic characteristics that can be useful for their diagnosis based on fine needle aspiration.

Independent predictors and lymph node metastasis characteristics of multifocal papillary thyroid cancer

The multifocal papillary thyroid cancer (PTC), with more aggressive and poorer prognosis, is not rare in papillary histotype. Few studies evaluated risk factors and lymph node metastasis in multifocal PTC. The aim of this present study focusing on risk factors and lymph node metastasis characteristics in multifocal PTC was excepted to assist clinical decisions regarding surgery.It was a retrospective study. The 1249 consecutive patients with PTC were reviewed. Of these, 570 patients who met the criteria were selected: 285 with solitary papillary thyroid cancer and 285 with multifocal PTC. The risk factors and lymph node metastasis in multifocal PTC were investigated by univariate and multivariate analysis.Multifocal PTC showed a higher positive rate of capsular invasion, extrathyroidal extension, tumor size >10 mm, pathological T classification, N+ stage, local recurrence, and radioactive iodine ablation (RAI). Capsular invasion (hazard ratio [HR], 1.589; 95% confidence interval [CI],1.352-1.984), advanced pathological T classification (HR, 3.582; 95% CI, 2.184-5.870), and pathological N+ stage (HR, 1.872; 95% CI, 1.278-2.742) were related to increased risk of multifocality and there was a significant increased HR for central neck compartment involvement in male sex (HR, 2.694; 95% CI, 1.740-4.169), advanced pathological T classification (HR, 2.403; 95% CI, 1.479-3.907) and multifocality (HR, 1.988; 95% CI, 1.361-2.906).There is a significant association between capsular invasion, advanced pathological T classification, N+ stage, and multifocal PTC. Total thyroidectomy plus prophylactic bilateral central lymph node dissection should be recommended during surgery due to a stronger predilection for level VI lymph node metastasis in multifocal PTC.

Molecular pathology of thyroid tumours of follicular cells: a review of genetic alterations and their clinicopathological relevance

Thyroid cancer is the most common endocrine malignancy. Knowledge of the molecular pathology of thyroid tumours originating from follicular cells has greatly advanced in the past several years. Common molecular alterations, such as BRAF p.V600E, RAS point mutations, and fusion oncogenes (RET-PTC being the prototypical example), have been, respectively, associated with conventional papillary carcinoma, follicular-patterned tumours (follicular adenoma, follicular carcinoma, and the follicular variant of papillary carcinoma/non-invasive follicular thyroid neoplasm with papillary-like nuclear features), and with papillary carcinomas from young patients and arising after exposure to ionising radiation, respectively. The remarkable correlation between genotype and phenotype shows how specific, mutually exclusive molecular changes can promote tumour development and initiate a multistep tumorigenic process that is characterised by aberrant activation of mitogen-activated protein kinase and phosphoinositide 3-kinase-PTEN-AKT signalling. Molecular alterations are becoming useful biomarkers for diagnosis and risk stratification, and as potential treatment targets for aggressive forms of thyroid carcinoma. What follows is a review of the principal genetic alterations of thyroid tumours originating from follicular cells and of their clinicopathological relevance.

Special role of JUN in papillary thyroid carcinoma based on bioinformatics analysis

Background

Papillary thyroid carcinoma (PTC) is the most common malignancy in thyroid tissue, and the number of patients with PTC has been increasing in recent years. Discovering the mechanism of PTC genesis and progression and finding new potential diagnostic biomarkers/therapeutic target genes of PTC are of great significance.

Methods

In this work, the datasets GSE3467 and GSE3678 were downloaded from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified with the limma package in R. GO function and KEGG pathway enrichment were conducted with DAVID tool. The interaction network of the DEGs and other genes was performed with Cytoscape plugin BisoGenet, while clustering analysis was performed with Cytoscape plugin ClusterOne.

Results

A total of 1800 overlapped DEGs were detected in two datasets. Enrichment analysis of the DEGs found that the top three enriched GO terms in three ontologies and four significantly enriched KEGG pathways were mainly concerned with intercellular junction and extracellular matrix components. Interaction network analysis found that transcription factor hepatocyte nuclear factor 4, alpha (HNF4A) and DEG JUN had higher connection degrees. Clustering analysis indicated that two function modules, in which JUN was playing a central role, were highly relevant to PTC genesis and progression.

Conclusions

JUN may be used as a specific diagnostic biomarker/therapeutic molecular target of PTC. However, further experiments are still needed to confirm our results.

Multifocal Papillary Thyroid Cancer Increases the Risk of Central Lymph Node Metastasis

BACKGROUND

Papillary thyroid cancer (PTC) is the most common thyroid malignancy, with a strong predilection for lymph node metastasis, most commonly to the central neck compartment (level VI). Few studies have evaluated lymph node metastasis in multifocal PTC, and the role of level VI dissection in the management of PTC remains controversial. This retrospective analysis evaluated the rate of level VI lymph node positivity in multifocal PTC, as compared with unifocal disease, in order to inform surgical decision making better.

METHODS

Patients with PTC who underwent total or hemi-thyroidectomy plus level VI lymph node dissection at the authors' institution between January 2008 and June 2014 were included (N=227). The number and laterality of PTC foci, lymphovascular invasion (LVI), extrathyroidal extension (ETE), and positive/total number of level VI lymph nodes were recorded. Fisher's exact test was used to determine univariate associations, and multivariate analysis was done by logistical regression.

RESULTS

There was an association between the number of PTC foci and level VI node positivity (p<0.001), with an odds ratio (OR) of 2.355 in patients with three or more tumor foci (p=0.026). The OR for central neck metastasis was 1.088 with each additional focus of PTC (p=0.018). The risk of level VI node positivity in the presence of one or two foci was only 19%, with no appreciable difference between one and two foci. This risk increased in the presence of between three and nine foci (38%), and 10 or more foci (88%). Level VI node positivity was associated with ETE (p<0.001), LVI (p<0.001), and size of the largest focus (p<0.001). There was no association between level VI lymph node positivity and male sex (p=0.089), bilaterality (p=0.276), or age (p=0.076).

CONCLUSIONS

There is a significant association between multifocal PTC and level VI lymph node positivity, increasing proportionally with the number of foci. These findings recognize multifocality as a sign of tumor aggressiveness, as evidenced by a higher propensity for lymph node metastasis.

Tall cell variant of papillary thyroid carcinoma: a population-based study in Iceland

BACKGROUND

The tall cell variant (TCV) of papillary thyroid carcinoma (PTC) is an aggressive variant of PTC that is believed to have worse outcomes than classical PTC. The objective of this study was to investigate the incidence, survival, and disease recurrence of patients with TCV and compare them with other PTC in a whole population.

METHODS

Information on all thyroid carcinomas diagnosed in Iceland from 1990 to 2009 was obtained from the Icelandic Cancer Registry. PTC diagnosed postmortem was excluded. The date of diagnosis, sex, and age at diagnosis were registered. All histopathology material was re-evaluated, and papillary thyroid tumors classified as either TCV or other types of PTC. Tumors were classified as TCV if >50% of cells were tall (height > twice the width). TNM stage was determined for all the cases. Endpoints were thyroid cancer-specific death and thyroid cancer recurrence.

RESULTS

Out of 376 patients diagnosed with PTC in the study period, 49 (13%) were classified as TCV. Patients with TCV were older (66 years vs. 49 years, p<0.001), more often had pT4 tumors (71% vs. 15%, p<0.001), had higher rates of nodal metastasis (51% vs. 22%, p<0.001), and more often distant metastasis (14% vs. 2%, p<0.001). The age-adjusted incidence of TCV for men was 0.5/100,000 [confidence interval (CI) 0.3-0.7] and for women 0.7/100,000 [CI 0.4-1.0] between 1990 and 2009. The five-year disease-specific survival for TCV was 83% [CI 68-91] compared to 98% [CI 96-99] for other PTC respectively (p<0.001). In multivariate analysis, TCV histology was an independent risk factor for recurrence (hazard ratio (HR) 3.18 [CI 1.48-6.84]) but not for disease specific survival (HR 1.86 [CI 0.77-4.73]).

CONCLUSIONS

TCV comprises 13% of all diagnosed PTC in Iceland with an incidence of 0.5/100,000 for men and 0.7/100,000 for women. Patients diagnosed with TCV have worse five-year disease-specific survival than patients with other PTC. TCV histology is an independent risk factor for disease recurrence but not for disease-specific survival.

Significance of IMP3, Nucleophosmin, and Ki-67 Expression in Papillary Thyroid Carcinoma

The purpose of our study was to investigate the diagnostic value of expression of IMP3, nucleophosmin, and correlation of these markers with Ki-67 proliferation index in papillary thyroid carcinoma and benign neoplasms of thyroid gland. The aim was also to investigate whether there is a difference between papillary and micropapillary carcinomas with regard to clinicopathologic parameters beside IMP3, nucleophosmin, and Ki-67 proliferation index. It was concluded that IMP3 and nucleophosmin cannot be a routine diagnostic marker for discrimination of papillary carcinomas and benign lesions. IMP3 positive staining was quite scarce in IMP3 positive papillary carcinomas although specifity of IMP3 is 100%. A statistically significant correlation was not detected between nucleophosmin, IMP-3, and Ki-67 proliferation index. A statistically significant correlation was found between tumor size, lymphovascular embolism, and Ki-67 proliferation index. There was also significant correlation between tumor size and lymphovascular embolism.

Papillary thyroid carcinoma with predominant spindle cell component: report of two rare cases and discussion on the differential diagnosis with other spindled thyroid neoplasm

Spindle cell transformation or metaplasia has been so far demonstrated in the context of both benign and malignant conditions. Spindle cell lesions of the thyroid gland of either primary or secondary origin to metastatic disease represent rare entities. We describe two patients with papillary thyroid carcinoma (PTC) showing spindle cell metaplasia, submitted to thyroidectomy due to euthyroid bilateral nodular thyroid disease. Cytological examination of fine-needle aspiration biopsy performed in the dominant nodules was consistent with follicular neoplasm in one case and with a hyperplastic/adenomatous nodule in the other patient. Histological examination disclosed unencapsulated follicular variant of PTC with spindle cell metaplasia in either cases. Both patients are doing well without clinical or laboratory evidence of PTC recurrence at 3- and 1-year follow-up, respectively. We present the clinical, pathological, and immunohistochemical aspects of these unusual cases and thoroughly discuss the differential diagnosis with other spindle cell lesions of the thyroid gland.

Higher incidence of tall cell variant of papillary thyroid carcinoma in Graves' Disease

BACKGROUND

Patients with Graves' disease (GD) and thyroid nodules have an elevated risk of developing thyroid carcinomas, which is primarily accounted for by well-differentiated tumors. Among these tumors, certain histological variants, such as the diffuse sclerosing and tall cell carcinoma, are characterized by a more aggressive behavior. The aim of this study was to evaluate the incidence, the clinical behavior in relation to histological variants, and the outcome of papillary thyroid carcinoma (PTC) in a cohort of patients with GD who had undergone thyroidectomy.

METHODS

A total of 2188 patients who underwent total thyroidectomy participated in this retrospective, nonrandomized, population-based study at a General Hospital. Of these patients, 181 had GD. The parameters examined included the clinical characteristics of the tumor and the final pathological examination of the thyroid carcinoma.

RESULTS

PTC was diagnosed in 570 patients. Among the 61 with PTC GD-positive, 59.0% presented with the pure papillary variant, 19.7% with the follicular variant, 6.6% with the sclerosing variant, and 18.0% with the tall cell variant (TCV) of PTC. Among 509 PTC GD-negative, 80.6% had pure papillary variant, 9.0% follicular variant, 3.7% sclerosing variant, and 6.1% TCV. Patients with tumor size >5 and ≤10 mm demonstrated that lymph node metastasis (p=0.001) and TCV in histological examination (p=0.003) were statistically significantly associated with GD-positive PTC.

CONCLUSIONS

The incidence of PTC in GD-positive patients is higher than that in GD-negative patients. Aggressive variants of PTC, such as the TCV, were more frequent in nodular micro-PTC. These findings suggest that prompt and meticulous evaluation of nodules in any patient with GD associated with nodular alterations must be considered.

Interleukin-10-1082 gene polymorphism is associated with papillary thyroid cancer

The etiopathogenesis of thyroid cancer has not been clearly elucidated although the role of chronical inflammation and the imbalance between pro- and anti-inflammatory cytokines may play a role in the etiology. The aim of the present study was to investigate whether cytokine gene polymorphisms are associated with papillary thyroid cancer (PTC), and to evaluate the relationship between genotypes and clinical/laboratory manifestation of PTC. Tumor necrosis factorα (TNFα) G-308A (rs 1800629), interleukin-6 (IL-6) G-174C (rs 1800795) and IL-10 A-1082G (rs 1800896) single nucleotide polymorphisms in DNA from peripheral blood leukocytes of 190 patients with thyroid cancer and 216 healthy controls were investigated by real-time PCR combined with melting curve analysis. There was no notable risk for PTC afflicted by TNFα-308 and IL-6-174 alone. However, IL-10-1082 G allele frequency were higher among PTC patients than healthy controls (p=0.009). The patients with IL-10-1082 GG geotype have twofold increased risk of developing thyroid cancer according to AA genotype (OR 2.07, 95% CI 1.21-3.55). In addition, the concomitant presence of IL-10-1082 G allele (GG+AG genotypes) together with IL-6 -174 GG genotype has a nearly twofold increased risk for thyroid cancer (OR 1.75 with 95% CI 1.00-3.05, p=0.049). We suggest that IL-10-1082 G allele is associated with an increased risk of PTC. The polymorphism of IL-10 gene can improve our knowledge about the pathogenesis of PTC, and could provide to estimate people at the increased risk for PTC.

Thyroid gland papillary carcinomas with "micropapillary pattern," a recently recognized poor prognostic finding: clinicopathologic and survival analysis of 7 cases

Micropapillary carcinoma is a histologic pattern, rather than an independent entity, that has an aggressive clinical behavior regardless of location. Histologically, it is characterized by papillary cell groups in clear spaces. The micropapillary pattern in the thyroid gland has not been studied until recently but under other names such as hobnail features or oncocytic and, therefore, is poorly understood, and reported cases are few. We report the clinicopathologic features of 7 cases obtained from a cohort of 496 papillary thyroid carcinomas, which corresponds to a prevalence of 1.4%. The proportion of the micropapillary component accounted for between 5% and 20% of the tumors, was slightly more prevalent in men, correlated with the presence of lymphovascular permeation, and, in the survival analysis, showed lower survival (even at a short follow-up, 8.5 years) than conventional carcinoma without this component (P = .001); this is consistent with poor overall survival in the short term (2-5 years) reported for carcinomas with micropapillary pattern of other locations. We believe that owing to this difference in survival (>95% of patients with conventional papillary carcinoma are alive at 8.5 years versus 42% of those having at least 5% of micropapillary pattern), the micropapillary pattern should be correctly identified and stated in the pathology report when comprising at least 5% of the tumor.

K-Ras gene mutation status as a prognostic and predictive factor in patients with colorectal cancer undergoing irinotecan- or oxaliplatin-based chemotherapy

BACKGROUND

CRC caused more than 600,000 estimated deaths in 2008. Dysregulated signaling through the RAS/RAF/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway due to mutations in K-Ras and B-Raf are common events in CRC.

METHODS

Incidence of mutations in codons 12 and 13 of K-Ras and exons 11 and 15 of B-Raf were analyzed in amplified PCR products from primary tumors of 273 patients with CRC, and their prognostic and predictive significance was assessed. The prognostic role of clinical and pathological factors was also examined.

RESULTS

K-Ras mutations were present in 89 patients (32.6%), of whom 76 (85.4%) had mutations in codon 12 and 10 (11.2%) had mutations in codon 13. B-Raf gene mutations were present in 17 patients (6.9%), of whom 6 (35.3%) had mutations in exon 15. Multivariate analysis revealed a predictive significance for K-Ras mutations with respect to time to progression in patients treated with irinotecan and oxaliplatin as first-line chemotherapy. There was no predictive significance for B-Raf gene mutation status in these patients. The following risk factors were found to affect overall survival (OS) rates: primary tumor location, lymph node involvement grade, carcinoembryonic antigen (CEA) level before treatment, and performance status according to WHO criteria.

CONCLUSIONS

Based on the results of this study, K-Ras mutation status may be a suitable indicator of patient eligibility and a prognostic indicator for responsiveness to anti-EGFR therapy alone, or in combination with chemotherapy. Also, K-Ras mutation status may predict time to progression in patients treated with irinotecan and oxaliplatin.