Anaplastic thyroid carcinoma: a therapeutic challenge

Long-Term Survival of a Patient With Anaplastic Thyroid Carcinoma Treated With Hypofractionated Radiotherapy: A Case Report

Anaplastic thyroid carcinoma, a rare type of primary thyroid cancer, is one of the most aggressive neoplasms with a poor prognosis. Many cases are in the advanced stage at the time of the initial visit, and curative treatment is impossible. Because of the highly radioresistant nature of anaplastic thyroid carcinoma, this condition cannot be properly controlled with conventional radiotherapy. Herein, we report the case of a patient with anaplastic thyroid carcinoma who underwent hypofractionated radiotherapy, attained a complete response, and is still alive more than 10 years after treatment with no evidence of disease. To overcome the high radioresistance of anaplastic thyroid carcinoma, we administered 50 Gy in 10 fractions three times a week. Furthermore, we administered paclitaxel and carboplatin sequentially before and after radiotherapy. Consequently, the patient completed treatment and reached a complete response. He is still alive more than 10 years after treatment with no evidence of disease or severe adverse events. Hypofractionated radiation therapy may provide good control of locally advanced anaplastic thyroid carcinoma.

Genetic alterations in thyroid cancer mediating both resistance to BRAF inhibition and anaplastic transformation

A subset of thyroid cancers present at advanced stage or with dedifferentiated histology and have limited response to standard therapy. Tumors harboring the BRAF V600E mutation may be treated with BRAF inhibitors; however, tumor response is often short lived due to multiple compensatory resistance mechanisms. One mode of resistance is the transition to an alternative cell state, which on rare occasions can correspond to tumor dedifferentiation. DNA sequencing and RNA expression profiling show that thyroid tumors that dedifferentiate after BRAF inhibition are enriched in known genetic alterations that mediate resistance to BRAF blockade, and may also drive tumor dedifferentiation, including mutations in the PI3K/AKT/MTOR (PIK3CA, MTOR), MAP/ERK (MET, NF2, NRAS, RASA1), SWI/SNF chromatin remodeling complex (ARID2, PBRM1), and JAK/STAT pathways (JAK1). Given these findings, recent investigations have evaluated the efficacy of dual-target therapies; however, continued lack of long-term tumor control illustrates the complex and multifactorial nature of these compensatory mechanisms. Transition to an immune-suppressed state is another correlate of BRAF inhibitor resistance and tumor dedifferentiation, suggesting a possible role for concurrent targeted therapy with immunotherapy. Investigations into combined targeted and immunotherapy are ongoing, but early results with checkpoint inhibitors, viral therapies, and CAR T-cells suggest enhanced anti-tumor immune activity with these combinations.

Coexistence of Oncocytic (Hürthle cell) carcinoma with foci of anaplastic carcinoma and a metastasizing papillary carcinoma in one thyroid gland: Rare case report

INTRODUCTION AND IMPORTANCE

Anaplastic thyroid cancer is considered one of the most fatal aggressive malignancies with a survival duration estimated in months. When compared to anaplastic thyroid cancer, a well-differentiated thyroid tumor has a better prognosis and a longer survival duration even if it metastasized. Left untreated, the transformation of well-differentiated thyroid carcinoma to aggressive anaplastic malignancy has been considered one of the most devastating complications.

CASE PRESENTATION

A 60-year-old male presented with a complaint of anterior neck swelling and hoarseness examination revealed a huge left thyroid swelling that was mobile, not tender, not attached to the underlying structures. Ultrasonographic examination of the thyroid gland showed a massively enlarged left thyroid lobe. Fine needle aspiration revealed undifferentiated (anaplastic) thyroid carcinoma. Preoperative CT excluded invasion or metastasis, and patient underwent total thyroidectomy and level 6 lymph node dissection. Histopathology showed anaplastic carcinoma foci within a background of Oncocytic (Hürthle cell) carcinoma and an incidental papillary thyroid carcinoma metastasizing into one lymph node.

CLINICAL DISCUSSION

The predominance of an anaplastic thyroid tumor with a few foci of well-differentiated thyroid malignancy, although rare, is the known commonly observed histopathological finding. However, it is extremely rare to find Oncocytic (Hürthle cell) thyroid carcinoma within the anaplastic component. It's presumed that patients who have coexisting well-differentiated thyroid cancer with the anaplastic component are at an overall survival advantage when compared to those who have pure anaplastic thyroid cancer. Our patients had a predominantly well-differentiated component, with a ratio of 80/20, the lesser being anaplastic, which might explain his 10 months cancer free outcome.

CONCLUSION

It's extremely rare to encounter a predominant Oncocytic (Hürthle cell) carcinoma with foci of anaplastic tumor and a separate papillary carcinoma that metastasized to one lymph node. This rare histopathological finding supports that theory of anaplastic transformation from a pre-existing well differentiated thyroid tumor.

Risk Factors for Anaplastic Thyroid Carcinoma: A Case Series From a Tertiary Referral Center for Thyroid Surgery and Literature Analysis

Anaplastic thyroid carcinoma (ATC) is a very rare and extremely aggressive disease with a very poor prognosis. Several risk factors have been hypothesized, but there is no clear-cut literature data on it. We reviewed the literature concerning risk factors for ATC and analyzed the institutional database from 2005 to 2022. In total, 15 papers were suitable for review, while the retrospective data collection search, conducted on our institutional database, provided 13 results. In our experience, in agreement with literature data, ATC seems to be a neoplasm peculiar to old age (in our database, mean age is 72 years), with a higher prevalence in subjects with a low level of education and a long history of multinodular goiter (MNG). The role of cigarette smoking and blood group, hypothesized on some literature data, was more uncertain, although the small sample size evaluated probably had a great influence on these results. The higher incidence of the disease in individuals with a history of MNG could suggest more aggressive choices in the treatment of a benign disease, in contrast to current practice. However, this may be a highly questionable point considering that ATC accounts for no more than 2% of all thyroid neoplasms in surgical departments, even those dedicated to endocrine neck surgery. Further studies are therefore necessary for a step forward in this direction.

Advances in pharmacotherapy for advanced thyroid cancer of follicular origin (PTC, FTC). New approved drugs and future therapies

INTRODUCTION

The most common altered signaling found in aggressive iodine-refractory Thyroid cancer derived from follicular cells (RAI-TC) are RTK, MAPK, PI3K, WNT, BRAF, RAS, RET, and TP53. Tyrosine Kinase Inhibitors (TKI) are multi-kinase inhibitors able to act against different pathways, that elicit an anti-neoplastic activity.

AREAS COVERED

The aim of this paper is to review recent novel molecular therapies of RAI-TC. Recently, sorafenib and lenvatinib, have been approved for the treatment of aggressive RAI-TC. Other studies are evaluating vandetanib and selumetinib in RAI-TC. Furthermore, preliminary studies have evaluated dabrafenib, and vemurafenib in BRAF mutated RAI-TC patients to re-induce 131-iodine uptake. The interplay between cells of the immune system and cancer cells can be altered by immune checkpoints inhibitors. The expression of PDL1 in RAI-TC was related to tumor recurrence and poor survival. Several clinical trials are investigating a combination of different therapies, such as lenvatinib and pembrolizumab.

EXPERT OPINION

Mechanisms of resistance to TKIs inhibitors can be of intrinsic or acquired origin. An acquired resistance to lenvatinib, or sorafenib can be due to upregulation of FGFR; therefore anti-FGFR agents are evaluated. A new strategy is to combine TKIs with immunotherapy. Several studies are evaluating lenvatinib and pembrolizumab in RAI-TC patients.

M2‑like tumour‑associated macrophage‑secreted IGF promotes thyroid cancer stemness and metastasis by activating the PI3K/AKT/mTOR pathway

M2‑like tumour‑associated macrophages (TAMs) have been demonstrated to promote the growth of anaplastic thyroid carcinoma (ATC). However, the underlying mechanism of M2‑like TAMs in ATC remains unclear. Thus, in the present study, the role and mechanism of M2‑like TAMs in ATC were investigated. M2‑like TAMs were induced by treatment with PMA, plus IL‑4 and IL‑13, and identified by flow cytometry. Transwell and sphere formation assays were applied to assess the invasion and stemness of ATC cells. The expression levels of insulin‑like growth factor (IGF)‑1 and IGF‑2 were examined by ELISA and reverse transcription‑quantitative PCR. Proteins related to the epithelial‑mesenchymal transition (EMT), stemness and the PI3K/AKT/mTOR pathway were examined via western blotting. Immunohistochemistry (IHC) was used to detect the expression of the M2‑like TAM markers CD68 and CD206 in ATC tissues and thyroid adenoma tissues. It was found that treatment with PMA plus IL‑4 and IL‑13 successfully induced M2‑like TAMs. Following co‑culture with M2‑like TAMs, the invasive ability and stemness of ATC cells were significantly increased. The expression levels of the EMT‑related markers N‑cadherin and Vimentin, the stemness‑related markers Oct4, Sox2 and CD133, and the insulin receptor (IR)‑A/IGF1 receptor (IGF1R) were markedly upregulated, whereas E‑cadherin expression was significantly decreased. In addition, the production of IGF‑1 and IGF‑2 was significantly increased. Of note, exogenous IGF‑1/IGF‑2 promoted the invasion and stemness of C643 cells, whereas blocking IGF‑1 and IGF‑2 inhibited metastasis and stemness by repressing IR‑A/IGF‑1R‑mediated PI3K/AKT/mTOR signalling in the co‑culture system. IHC results showed that the expression of CD68 and CD206 was obviously increased in ATC tissues. To conclude, M2‑like TAMs accelerated the metastasis and increased the stemness of ATC cells, and the underlying mechanism may be related to the section of IGF by M2‑like TAMs, which activates the IR‑A/IGF1R‑mediated PI3K/AKT/mTOR signalling pathway.

Survival Benefit of Intervention Treatment in Advanced Anaplastic Thyroid Cancer

Background

The management of anaplastic thyroid cancer (ATC) is controversial; thus, proper treatment and prognostic factors should be investigated.

Objectives

To compare the survival outcomes of the intervention and palliative treatment in ATC patients.

Methods

A hospital-based retrospective study was conducted at a single tertiary university hospital. The medical record charts were retrieved from November 20, 1987, to December 31, 2016. The final follow-up ended by December 31, 2017. The patients' demographic data, laboratory data, clinical presentation, and treatment modality results were analyzed.

Results

One hundred twenty-one records were analyzed with a one-year overall survival rate of 3.5% (median survival time: 77 days); however, 16 cases had insufficient data to classify staging and treatment modalities. Therefore, 105 ATC patients (37 with stage IVa, 39 with stage IVb, and 29 with stage IVc disease) were included with a one-year overall survival rate of 4.0% (median survival time of 82 days). Intervention treatment allowed longer median survival times (p < 0.05) and a better survival rate (p < 0.05). Among the interventional treatment groups, postoperative chemoradiation yielded the longest median survival time (187 days) and the highest survival rate (20%) (p < 0.05). The intervention modality allowed a better median survival time at all stages, particularly in stage IVa (p < 0.05). Unfavorable prognostic factors were adjusted for in a multiple Cox regression model showing that significant factors included age ≥65 years (hazard ratio HR: 2.57), palliative treatment (HR: 1.85), and leukocytosis ≥10,000 cells/mm³ (HR: 2.76).

Conclusions

Intervention treatment provided a better survival outcome in all stages, particularly in stage IVa, with a significantly better median survival time. Among interventional treatments, postoperative chemoradiation led to the longest survival rate, suggesting that this treatment should be considered in ATC patients with resectable tumors and no poor prognostic factors, such as older age and leukocytosis.

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.

Dietary iodine intake, therapy with radioiodine, and anaplastic thyroid carcinoma

Background Anaplastic thyroid cancer (ATC) is one of the most aggressive tumors. The aim of the study was to determine the correlation between a higher dietary intake of iodine, frequency of ATC and the characteristics of ATC, and to find out how often patients with ATC had a history of radioiodine (RAI) therapy. Patients and methods This retrospective study included 220 patients (152 females, 68 males; mean age 68 years) with ATC who were treated in our country from 1972 to 2017. The salt was iodinated with 10 mg of potassium iodide/ kg before 1999, and with 25 mg of potassium iodide/kg thereafter. The patients were assorted into 15-year periods: 1972-1986, 1987-2001, and 2002-2017. Results The incidence of ATC decreased after a higher iodination of salt (p = 0.04). Patients are nowadays older (p = 0.013) and have less frequent lymph node metastases (p = 0.012). The frequency of distant metastases did not change over time. The median survival of patients in the first, second, and third periods was 3, 4, and 3 months, respectively (p < 0.05). The history of RAI therapy was present in 7.7% of patients. Conclusions The number of patients with a history of RAI therapy did not change statistically over time. The incidence of ATC in Slovenia decreased probably because of higher salt iodination.

MicroRNA 483-3p targets Pard3 to potentiate TGF-β1-induced cell migration, invasion, and epithelial-mesenchymal transition in anaplastic thyroid cancer cells

Anaplastic thyroid cancer (ATC) is associated with poor prognosis and is often untreatable. MicroRNA 483-3p (miR-483) and partitioning-defective 3 (Pard3), a member of the Pard family, have functions and regulatory mechanisms in ATC. The abnormal regulation of miR-483 may play an important role in tumorigenesis, and Par3 is known to regulate cell polarity, cell migration, and cell division. Tumor proliferation promoted by the regulation of miRNA expression can be regulated in thyroid cancer by upregulating transforming growth factor-β1 (TGF-β1), which is thought to interact with Pard3. When compared with adjacent non-tumor tissues, we found that miR-483 was upregulated and Pard3 was downregulated in 80 thyroid tumor samples. Disease-free survival was decreased when expression of miR-483 was upregulated and Pard3 expression was downregulated. Cell growth, migration, and invasion were induced by overexpression of miR-483. However, knockdown of miR-483 resulted in a loss of cell invasion and viability, both in vitro and in vivo. The expression of Pard3 was increased by the inhibition of miR-483, but TGF-β1-induced cell migration and invasion were decreased by miR-483 inhibition. A dual-luciferase reporter assay determined that Pard3 expression was downregulated when targeted with miR-483. The epithelial–mesenchymal transition (EMT), as well as Tiam1-Rac signaling, was induced by TGF-β1, which was decreased by the overexpression of Pard3. Pard3 decreased the inhibition of EMT and Tiam-Rac1 signaling, which resulted from transfection of ATC cells with miR-483. Overall, the results showed that downregulation of Pard3 resulted in increased cell invasion and EMT in ATC, which was promoted by treatment with miR-483. These findings suggest novel therapeutic targets and treatment strategies for this disease.

Hypofractionated Radiotherapy Is Superior to Conventional Fractionation in an Orthotopic Model of Anaplastic Thyroid Cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) is an aggressive and highly lethal disease with poor outcomes and resistance to therapy. Despite multimodality treatment, including radiation therapy and chemotherapy, response rates remain <15%, with a median time to progression of less than three months. Recent advances in radiotherapy (RT) delivery and gene-expression profiling may help guide patient selection for personalized therapy. The purpose of this study was to characterize the response to radiation in a panel of ATC cell lines and to test alternative RT fractionation schedules for overcoming radioresistance.

MATERIALS AND METHODS

The cellular response to radiation was characterized based on clonogenic assays. Radiation response was correlated with microarray gene-expression data. Hypofractionated and conventional RT was tested in an orthotopic ATC tumor model, and tumor growth was assayed locally and distantly with in vivo and ex vivo bioluminescence imaging.

RESULTS

A spectrum of radiosensitivities was observed in ATC cell lines. Radioresistant cell lines had higher levels of CXCR4 compared to radiosensitive cell lines. Compared to conventionally fractionated RT, hypofractionated RT resulted in significantly improved tumor growth delay, decreased regional and distant metastases, and improved overall survival.

CONCLUSIONS

The findings demonstrate the heterogeneity of response to radiation in ATC tumors and the superiority of hypofractionated RT in improving local control, metastatic spread, and survival in preclinical models. These data support the design of clinical trials targeting radioresistant pathways in combination with hypofractionated RT.

Integrated Therapeutic Strategies for Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) is a very rare neoplasm with an aggressive course. The prognosis has not changed in the last decades and the median survival does not exceed six months. Only few patients with incidental limited ATC will be cured. Different therapeutic options have been explored but the results are disappointing. At present, new drugs and new timing for proper treatment are under investigation. In this short review we have summarized these recent developments.

Antineoplastic Effect of Lenvatinib and Vandetanib in Primary Anaplastic Thyroid Cancer Cells Obtained From Biopsy or Fine Needle Aspiration

Anaplastic thyroid carcinoma (ATC) is a malignant tumor of the thyroid gland, infrequent but with a very poor prognosis, as it rapidly causes death (mean survival of about 6 months). ATC treatment includes a multimodal protocol consisting of surgery, chemotherapy (doxorubicin and cisplatin), and hyperfractionated accelerated external beam radiotherapy (median patient survival of 10 months). For this reason, the identification of an effective systemic treatment for ATC would be a major advance in the management of this deadly thyroid cancer. The opportunity to test the sensitivity to different drugs of primary cells from ATC (pATC) cultures, obtained from each patients, could improve the effectiveness of the treatment. Then, the administration of inactive therapeutics could be avoided. Our aim is to investigate the antineoplastic effect of two tyrosine kinase inhibitors (TKIs; lenvatinib, vandetanib) in pATC obtained both from biopsy (biop-pATC), and from fine needle aspiration (FNA-pATC). The antiproliferative activity of lenvatinib and vandetanib was evaluated in 6 ATC patients, on biop-pATC, such as on FNA-pATC. A significant reduction of proliferation (obtained by WST-1 assay) vs. control was shown with lenvatinib and vandetanib in FNA-pATC, as well as in biop-pATC. The percentage of apoptosis in FNA-pATC, or biop-pATC, increased with both compounds dose-dependently. pATC cells from FNA, or biopsy, had a similar sensitivity to lenvatinib and vandetanib. In conclusion, primary cells (biop-pATC or FNA-pATC) have a similar sensitivity to TKIs, and lenvatinib and vandetanib are effective in reducing cell growth, increasing apoptosis in ATC. The possibility to test the sensitivity to different TKIs in each patient could open the way to personalized treatments, avoiding the administration of ineffective, and potentially dangerous, drugs.

Imaging of Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma is fatal if unresectable. However, improved survival has been reported after gross total resection and multimodality therapy. In this report, we describe the contrast-enhanced high-resolution CT characteristics of anaplastic thyroid carcinoma in 57 patients. Anaplastic thyroid carcinoma presented as a large neck mass with necrosis in 82% of cases. The tumors demonstrated common extrathyroidal extension (91%). Sixty-two percent of tumors demonstrated calcification. Visceral space invasion involved the esophagus (62%), trachea (57%), and larynx (29%). Carotid artery encasement was present in 42%, and 43% involved the internal jugular vein. Sixty-three percent had lateral compartment lymphadenopathy; 58% of these nodes were necrotic, and 11% were cystic. No metastatic nodes had calcification. Central compartment lymphadenopathy was seen in 56% of cases, and lateral retropharyngeal lymphadenopathy was detected in 12%. Knowledge of these imaging features aids in guiding the approach to the initial tissue diagnosis with either fine-needle aspiration or core biopsy, assessing the feasibility of surgical resection, and determining prognosis.

Role of Krüppel-Like Factor 4 in the Maintenance of Chemoresistance of Anaplastic Thyroid Cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) has a very poor prognosis due to its aggressive nature and resistance to conventional treatment. Radiotherapy and chemotherapy are not fully effective because of the undifferentiated phenotype and enhanced drug resistance of ATC. The objective of this study was to evaluate the involvement of Krüppel-like factor 4 (KLF4), a stemness-associated transcription factor, in the undifferentiated phenotype and drug resistance of ATC.

METHODS

ATC cells were compared to papillary thyroid cancer cells in drug resistance and gene expression. The effects of KLF4 knockdown in ATC cells on in vitro and in vivo drug resistance were measured. The effects of KLF4 overexpression and knockdown on ABC transporter activity were determined.

RESULTS

ATC cells, such as HTH83, 8505C, and SW1736, exhibited higher resistance to the anticancer drug paclitaxel and higher expression of KLF4 than TPC-1 papillary thyroid cancer cells. Knockdown of KLF4 expression in ATC cells increased the expression of the thyroid-specific differentiation genes, such as thyrotropin receptor, thyroid peroxidase, thyroglobulin, and sodium-iodide symporter. Knockdown of KLF4 expression in ATC cells decreased the resistance to doxorubicin and paclitaxel, and reduced ABC transporter expression. Luciferase reporter assay results showed that KLF4 overexpression increased ABCG2 promoter activity, which was abolished by KLF4 knockdown. A tumorigenicity assay showed that the combination of paclitaxel treatment and KLF4 knockdown significantly decreased tumor mass originated from HTH83 cells in mice.

CONCLUSIONS

ATC cells show high expression of KLF4, and KLF4 expression is necessary for maintaining the undifferentiated phenotype and drug resistance in vitro and in vivo. The present study identifies KLF4 as a potential therapeutic target for eliminating ATC cells.

Anaplastic thyroid carcinoma: from clinicopathology to genetics and advanced therapies

Anaplastic thyroid carcinoma (ATC) is a rare malignancy, accounting for 1-2% of all thyroid cancers. Although rare, ATC accounts for the majority of deaths from thyroid carcinoma. ATC often originates in a pre-existing thyroid cancer lesion, as suggested by the simultaneous presence of areas of differentiated or poorly differentiated thyroid carcinoma. ATC is characterized by the accumulation of several oncogenic alterations, and studies have shown that an increased number of oncogenic alterations equates to an increased level of dedifferentiation and aggressiveness. The clinical management of ATC requires a multidisciplinary approach; according to recent American Thyroid Association guidelines, surgery, radiotherapy and/or chemotherapy should be considered. In addition to conventional therapies, novel molecular targeted therapies are the most promising emerging treatment modalities. These drugs are often multiple receptor tyrosine kinase inhibitors, several of which have been tested in clinical trials with encouraging results so far. Accordingly, clinical trials are ongoing to evaluate the safety, efficacy and effectiveness of these new agents. This Review describes the updated clinical and pathological features of ATC and provides insight into the molecular biology of this disease. The most recent literature regarding conventional, newly available and future therapies for ATC is also discussed.

Poorly Differentiated and Anaplastic Thyroid Cancer

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) and anaplastic (undifferentiated) thyroid carcinoma (ATC) comprise a small subset of thyroid tumors that are associated with a poor prognosis and account for a significant portion of the morbidity and mortality related to thyroid cancer. Since management strategies vary between these two entities, it is important for clinicians to be able to differentiate PDTC from ATC.

METHODS

We reviewed the literature on PDTC and ATC and compared clinical and histopathologic features important in defining the disease process.

RESULTS

Both PDTC and ATC display aggressive behavior with increased locoregional and distant disease. In most cases, patients are older and have large, locally advanced tumors. PDTC may represent an intermediate entity in the progression of well-differentiated thyroid carcinoma to ATC. The use of surgical management may be curative or palliative and differs between PDTC and ATC. The roles of radiotherapy and chemotherapy have not been well described.

CONCLUSIONS

PDTC and ATC are rare diseases that carry a poor prognosis. Recognition of their different clinicopathologic features is important to the optimal management of these tumors.

Genomic complexity and targeted genes in anaplastic thyroid cancer cell lines

Anaplastic thyroid cancer (ATC) is a highly malignant disease with a very short median survival time. Few studies have addressed the underlying somatic mutations, and the genomic landscape of ATC thus remains largely unknown. In the present study, we have ascertained copy number aberrations, gene fusions, gene expression patterns, and mutations in early-passage cells from ten newly established ATC cell lines using single nucleotide polymorphism (SNP) array analysis, RNA sequencing and whole exome sequencing. The ATC cell line genomes were highly complex and displayed signs of replicative stress and genomic instability, including massive aneuploidy and frequent breakpoints in the centromeric regions and in fragile sites. Loss of heterozygosity involving whole chromosomes was common, but there were no signs of previous near-haploidisation events or chromothripsis. A total of 21 fusion genes were detected, including six predicted in-frame fusions; none were recurrent. Global gene expression analysis showed 661 genes to be differentially expressed between ATC and papillary thyroid cancer cell lines, with pathway enrichment analyses showing downregulation of TP53 signalling as well as cell adhesion molecules in ATC. Besides previously known driver events, such as mutations in BRAF, NRAS, TP53 and the TERT promoter, we identified PTPRD and NEGR1 as putative novel target genes in ATC, based on deletions in six and four cell lines, respectively; the latter gene also carried a somatic mutation in one cell line. Taken together, our data provide novel insights into the tumourigenesis of ATC and may be used to identify new therapeutic targets.

Combination of SL327 and Sunitinib Malate leads to an additive anti-cancer effect in doxorubicin resistant thyroid carcinoma cells

BACKGROUND

Receptor tyrosine kinases (RTKs) play crucial roles in numerous cancer cell processes including cell survival, proliferation, and migration. MEK1/2 MAPK kinases are very important for cancer survival and development. Anaplastic thyroid carcinoma (ATC) is a deadly type of thyroid cancer and there are no very effective systemic treatment strategies for ATC so far. Also, ATC can easily become resistant to therapy of traditional therapeutic drugs for ATC, such as doxorubicin. Drug combination treatment could be a promising therapeutic strategy for ATC, especially for drug resistant ATC.

METHODS

We explored the combination effect between a MEK1/2 inhibitor SL327 and a multi-targeted RTK inhibitor Sunitinib Malate in doxorubicin resistant ATC cells using cell viability assay, cell migration assay, nuclei morphology and caspase-3 activity analysis, as well as in vivo tumor growth assay.

RESULTS

There is a significant additive effect between SL327 and Sunitinib Malate in reducing viability, increasing apoptosis, and suppressing migration of doxorubicin-resistant ATC cells. Importantly, combination of SL327 and Sunitinib Malate induced significant additive suppression of in vivo doxorubicin-resistant ATC tumor growth.

CONCLUSIONS

Our results suggest that the combination of MEK1/2 inhibitor and RTK inhibitor is promising for treatment of ATC especially doxorubicin-resistant ATC. The combination might not only enhance the anti-cancer efficacy, but also reduce the side effects and overcome drug resistance developed in ATC treatment. All these might provide useful information for clinical therapeutics of ATC.

Targeting Autophagy Sensitizes BRAF-Mutant Thyroid Cancer to Vemurafenib

CONTEXT

The RAF inhibitor vemurafenib has provided a major advance for the treatment of patients with BRAF-mutant metastatic melanoma. However, BRAF-mutant thyroid cancer is relatively resistant to vemurafenib, and the reason for this disparity remains unclear. Anticancer therapy-induced autophagy can trigger adaptive drug resistance in a variety of cancer types and treatments. To date, role of autophagy during BRAF inhibition in thyroid cancer remains unknown.

OBJECTIVE

In this study, we investigate if autophagy is activated in vemurafenib-treated BRAF-mutant thyroid cancer cells, and whether autophagy inhibition improves or impairs the treatment efficacy of vemurafenib.

DESIGN

Autophagy level was determined by western blot assay and transmission electron microscopy. The combined effects of autophagy inhibitor and vemurafenib were assessed in terms of cell viability in vitro and tumor growth rate in vivo. Whether the endoplasmic reticulum (ER) stress was in response to vemurafenib-induced autophagy was also analyzed.

RESULTS

Vemurafenib induced a high level of autophagy in BRAF-mutant thyroid cancer cells. Inhibition of autophagy by either a pharmacological inhibitor or interfering RNA knockdown of essential autophagy genes augmented vemurafenib-induced cell death. Vemurafenib-induced autophagy was independent of MAPK signaling pathway and was mediated through the ER stress response. Finally, administration of vemurafenib with the autophagy inhibitor hydroxychloroquine promoted more pronounced tumor suppression in vivo.

CONCLUSIONS

Our data demonstrate that vemurafenib induces ER stress response-mediated autophagy in thyroid cancer and autophagy inhibition may be a beneficial strategy to sensitize BRAF-mutant thyroid cancer to vemurafenib.

Radiotherapy in anaplastic thyroid carcinoma: An Australian experience

INTRODUCTION

Anaplastic thyroid cancer is a rare and fatal malignancy, associated with significant local tumour and often treatment related morbidity. We report our experience in treating this cancer over a 20-year period.

METHODS

A retrospective review of prospectively collected data from a single Australian Institution (Alfred Health Radiation Oncology) was carried out on patients referred with anaplastic thyroid carcinoma between 1992 and 2013.

RESULTS

Thirty patients (17 females and 13 males) were identified with a median age at presentation of 72 years. At presentation, six (20%), 14 (47%) and 10 (33%) patients had stage IVA, IVB and IVC disease respectively. Thirteen patients underwent radical surgical resection with five having microscopic residual (R1) and eight having macroscopic residual (R2) disease. Twenty-eight patients were offered radiotherapy with 27 proceeding with treatment. Of those who received radiotherapy, three, six and 18 were treated with adjuvant, definitive and palliative intent respectively. Six patients had concomitant chemotherapy of which three received trimodality therapy. Only one patient experienced a grade 3 toxicity (oesophagitis). Median survival was 5.3 months and at last follow-up or time of death, 19 of 27 (70.4%) maintained loco-regional control. All patients who had R1 surgical resections and radiotherapy had loco-regional control. Seven of nine (77.8%) and 12 of 18 (66.7%) achieved loco-regional control after receiving definitive or palliative radiotherapy, respectively.

CONCLUSIONS

Our study suggests that radiotherapy with or without surgery or chemotherapy is well-tolerated and results in durable loco-regional control in a high proportion of patients with anaplastic thyroid carcinoma.

Description and Comparison of the Sonographic Characteristics of Poorly Differentiated Thyroid Carcinoma and Anaplastic Thyroid Carcinoma

OBJECTIVES

Although poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma account for a substantial portion of the morbidity and mortality associated with thyroid cancer, a chance of a cure exists with aggressive treatment, especially in patients with poorly differentiated thyroid carcinoma. The goal of this study was to evaluate the sonographic characteristics of poorly differentiated thyroid carcinoma and to compare the sonographic findings of poorly differentiated and anaplastic thyroid carcinomas.

METHODS

The study included 29 patients with 30 poorly differentiated thyroid carcinomas and 26 patients with 26 anaplastic thyroid carcinomas. Two radiologists retrospectively reviewed sonographic findings. Clinical and sonographic findings were compared between poorly differentiated and anaplastic thyroid carcinomas by univariate and multivariate analyses.

RESULTS

In the group of patients with poorly differentiated thyroid carcinoma, the mean age was 53.7 years (range, 14-73 years), and the mean tumor size was 3.6 cm (range, 0.6-10.0 cm). The common sonographic findings of poorly differentiated thyroid carcinoma were heterogeneous echogenicity (93.3%), solitary nodules (80.0%), a circumscribed margin (63.3%), an oval-to-round shape (63.3%), and hypoechogenicity (60.0%). A circumscribed margin (P = .003) and an oval-to-round shape (P = .015) were significantly more frequent in poorly differentiated thyroid carcinoma than in anaplastic thyroid carcinoma. In the multivariate analysis, only the circumscribed margin on sonography was an independent predicting factor for poorly differentiated thyroid carcinoma (odds ratio, 4.642).

CONCLUSIONS

Both poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma commonly present as a relatively large malignant mass on sonography; however, poorly differentiated thyroid carcinoma showed a significantly higher incidence of a circumscribed margin and an oval-to-round shape than anaplastic thyroid carcinoma. Knowledge of sonographic characteristics will be useful for differentiation of poorly differentiated and anaplastic thyroid carcinomas.

The "next-generation" knowledge of papillary thyroid carcinoma

The application of Next-Generation Sequencing for studying the genetics of papillary thyroid carcinomas (PTC) has recently revealed new somatic mutations and gene fusions as potential new tumor-initiating events in patients without any known driver lesion. Gene and miRNA expression analyses defined clinically relevant subclasses correlated to tumor progression. In addition, it has been shown that tumor driver mutations in BRAF, and RET rearrangements - altogether termed "BRAF-like" carcinomas - have a very similar expression pattern and constitute a distinct category. Conversely, "RAS-like" carcinomas have a different genomic, epigenomic, and proteomic profile. These findings justify the need to reconsider PTC classification schemes.

Core needle biopsy could reduce diagnostic surgery in patients with anaplastic thyroid cancer or thyroid lymphoma

OBJECTIVE

To evaluate the diagnostic performance of fine needle aspiration (FNA) and core needle biopsy (CNB) in patients with anaplastic thyroid cancer (ATC) or thyroid lymphoma (TL).

METHODS

Between January 2000 and March 2012, 104 patients were diagnosed with ATC or TL by means of ultrasound (US)-guided FNA, CNB, or surgery. This study ultimately included 99 patients with ATC (n = 59) or TL (n = 40). We evaluated the sensitivity and positive predictive value of FNA and CNB for the diagnosis of ATC and TL, and compared the rates of diagnostic surgery between FNA and CNB.

RESULTS

FNA was used in 83 patients, and CNB was used in 32 patients initially (n = 16), after FNA results (n = 8), or simultaneously with FNA (n = 8). CNB achieved sensitivity of 87.5 % (28/32) and positive predictive value of 100.0 % (28/28) for the diagnosis of ATC and TL. The respective values for FNA were 50.6 % (40/79) and 90.9 % (40/44). The rate of diagnostic surgery was significantly lower after CNB (4/32, 12.5 %) than after FNA (28/79, 35.4 %) (p = 0.020).

CONCLUSIONS

CNB was able to reduce unnecessary diagnostic surgery in patients with ATC or TL by virtue of its superior diagnostic sensitivity and positive predictive value compared to FNA.

KEY POINTS

• Diagnostic sensitivity and PPV for CNB were 87.5 % and 100.0 %, respectively. • The respective values for FNA were 50.6 % and 91.0 % for ATC and TL. • Diagnostic surgery rates were reduced after CNB compared to FNA (p = 0.020).

Anaplastic Thyroid Cancer: Experience of the Philippine General Hospital

BACKGROUND

Anaplastic thyroid cancer (ATC) is a rare type of thyroid malignancy and one of the most aggressive solid tumors, responsible for between 14% and 50% of the total annual mortality associated with thyroid cancer.

METHODS

A retrospective study was made of all ATC cases diagnosed by biopsy in the Philippine General Hospital between 2008 and 2013.

RESULTS

A total of 15 patients were identified, with a median age at diagnosis of 63 years. All tumors were at least 6 cm in size upon diagnosis. All patients had a previous history of thyroid pathology, presenting with an average duration of 11 years. Eleven patients presented with cervical lymphadenopathies, whereas seven exhibited signs of distant metastases, for which the lungs appeared to be the most common site. More than 70% of the patients presented with a rapidly growing neck mass, leading to airway obstruction. Only three patients were treated using curative surgery; the majority received palliative and supportive forms of treatment. In addition, only three patients were offered radiotherapy. Chemotherapy was not offered to any patient. Only two patients were confirmed to still be alive during the study period. The median survival time for the other patients was 3 months; in the majority of cases the patient died within the first year following diagnosis.

CONCLUSION

Our experience with ATC demonstrated concordance with other institutions with respect to current clinical profile, presentation, and prognosis. An absence of distant metastases and lymph node involvement was associated with improved survival outcomes, whereas age at diagnosis and tumor size did not affect survival. Curative surgery offers the most effective means of prolonging survival. Radiotherapy and chemotherapy in combination with surgery represents a promising treatment strategy.

PATZ1 acts as a tumor suppressor in thyroid cancer via targeting p53-dependent genes involved in EMT and cell migration

PATZ1, a POZ-Zinc finger protein, is emerging as an important regulator of development and cancer, but its cancer-related function as oncogene or tumor-suppressor is still debated. Here, we investigated its possible role in thyroid carcinogenesis. We demonstrated PATZ1 is down-regulated in thyroid carcinomas compared to normal thyroid tissues, with an inverse correlation to the degree of cell differentiation. In fact, PATZ1 expression was significantly further down-regulated in poorly differentiated and anaplastic thyroid cancers compared to the papillary histotype, and it resulted increasingly delocalized from the nucleus to the cytoplasm proceeding from differentiated to undifferentiated thyroid carcinomas. Restoration of PATZ1 expression in three thyroid cancer-derived cell lines, all characterized by fully dedifferentiated cells, significantly inhibited their malignant behaviors, including in vitro proliferation, anchorage-independent growth, migration and invasion, as well as in vivo tumor growth. Consistent with recent studies showing a role for PATZ1 in the p53 pathway, we showed that ectopic expression of PATZ1 in thyroid cancer cells activates p53-dependent pathways opposing epithelial-mesenchymal transition and cell migration to prevent invasiveness. These results provide insights into a potential tumor-suppressor role of PATZ1 in thyroid cancer progression, and thus may have potential clinical relevance for the prognosis and therapy of thyroid cancer.

The Role of Tracheostomy in Anaplastic Thyroid Carcinoma

Even though management of thyroid cancer is generally standardized and has an overall excellent long-term outcome, anaplastic thyroid cancer (ATC) continues to be a major diagnostic and therapeutic challenge. ATC is an uncommon thyroid malignancy with a poor prognosis. American Thyroid Association guidelines acknowledge the complexity of airway management in these patients. We studied the literature with the aim of providing guidance in airway management in ATC. Tracheotomy can facilitate completion of palliative treatment in those patients with ATC and stridor. Given the short life expectancy of these patients, a balanced decision must be made regarding the role and timing of tracheotomy.

Management of the compromised airway and role of tracheotomy in anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is an uncommon thyroid malignancy with a poor prognosis. American Thyroid Association (ATA) guidelines acknowledge the complexity of airway management in these patients. We studied our local experience with the aim of providing guidance in airway management in ATC.

METHODS

Patients with histologically confirmed ATC from January 2004 to December 2011 were identified from our institutional database. The data were retrospectively analyzed using hospital case notes.

RESULTS

Twenty-six patients were identified with ATC, 25 of who died from the disease. Five of 26 patients (19%) had stridor at presentation. A further 6 of 26 patients (23%) developed stridor during or soon after radiotherapy. Nine patients (36%) died of airway obstruction.

CONCLUSION

Tracheotomy can facilitate completion of palliative treatment in those patients with ATC and stridor. Given the short life expectancy of these patients, a balanced decision must be made regarding the role and timing of tracheotomy.

miRNA expression in anaplastic thyroid carcinomas

Anaplastic thyroid carcinoma (ATC) is the most lethal form of thyroid neoplasia and represents an end stage of thyroid tumor progression. No effective treatment exists so far. In this study, we analyzed the miRNA expression profiles of 11 ATC by microarrays and their relationship with the mRNA expression profiles of the same 11 ATC samples. ATC show distinct miRNA expression profiles compared to other less aggressive thyroid tumor types. ATC show 18 commonly deregulated miRNA compared to normal thyroid tissue (17 downregulated and 1 upregulated miRNA). First, the analysis of a combined approach of the mRNA gene expression and of the bioinformatically predicted mRNA targets of the deregulated miRNA suggested a role for these regulations in the epithelial to mesenchymal transition (EMT) process in ATC. Second, the direct interaction between one of the upregulated mRNA target, the LOX gene which is an EMT key player, and a downregulated miRNA, the miR-29a, was experimentally validated by a luciferase assay in HEK cell. Third, we confirmed that the ATC tissue is composed of about 50% of tumor associated macrophages (TAM) and suggested, by taking into account our data and published data, their most likely direct or paracrine intercommunication between them and the thyroid tumor cells, amplifying the tumor aggressiveness. Finally, we demonstrated by in situ hybridization a specific thyrocyte localization of 3 of the deregulated miRNA: let-7g, miR-29a and miR-30e and we pointed out the importance of identifying the cell type localization before drawing any conclusion on the physiopathological role of a given gene.

Identification of thyroid carcinoma related genes with mRMR and shortest path approaches

Thyroid cancer is a malignant neoplasm originated from thyroid cells. It can be classified into papillary carcinomas (PTCs) and anaplastic carcinomas (ATCs). Although ATCs are in an very aggressive status and cause more death than PTCs, their difference is poorly understood at molecular level. In this study, we focus on the transcriptome difference among PTCs, ATCs and normal tissue from a published dataset including 45 normal tissues, 49 PTCs and 11 ATCs, by applying a machine learning method, maximum relevance minimum redundancy, and identified 9 genes (BCL2, MRPS31, ID4, RASAL2, DLG2, MY01B, ZBTB5, PRKCQ and PPP6C) and 1 miscRNA (miscellaneous RNA, LOC646736) as important candidates involved in the progression of thyroid cancer. We further identified the protein-protein interaction (PPI) sub network from the shortest paths among the 9 genes in a PPI network constructed based on STRING database. Our results may provide insights to the molecular mechanism of the progression of thyroid cancer.

CLM3, a multitarget tyrosine kinase inhibitor with antiangiogenic properties, is active against primary anaplastic thyroid cancer in vitro and in vivo

CONTEXT AND OBJECTIVE

We have studied the antitumor activity of a pyrazolo[3,4-d]pyrimidine compound (CLM3) proposed for a multiple signal transduction inhibition [including the RET tyrosine kinase, epidermal growth factor receptor, and vascular endothelial growth factor (VEGF) receptor and with antiangiogenic activity] in primary anaplastic thyroid cancer (ATC) cells, in the human cell line 8305C (undifferentiated thyroid cancer), and in an ATC-cell line (AF).

DESIGN AND MAIN OUTCOME MEASURES

CLM3 was tested in primary ATC cells at the concentrations of 5, 10, 30, and 50 μM; in 8305C cells, in AF cells, at 1, 5, 10, 30, 50, or 100 μM; and in AF cells in CD nu/nu mice.

RESULTS

CLM3 significantly inhibited the proliferation of 8305C and AF cells, also inducing apoptosis. A significant reduction of proliferation with CLM3 in ATC cells (P < .01, ANOVA) was shown. CLM3 increased the percentage of apoptotic ATC cells dose dependently (P < .001, ANOVA) and inhibited migration (P < .01) and invasion (P < .001). The AF cell line was injected sc in CD nu/nu mice, and tumor masses became detectable 15 days later. CLM3 (50 mg/kg per die) significantly inhibited tumor growth (starting 16 d after the beginning of treatment). CLM3 significantly decreased the VEGF-A expression and microvessel density in AF tumor tissues. Furthermore, CLM3 inhibited epidermal growth factor receptor, AKT, and ERK1/2 phosphorylation and down-regulated cyclin D1 in 8305C and AF cells.

CONCLUSIONS

The antitumor and antiangiogenic activity of a pyrazolo[3,4-d]pyrimidine compound (CLM3) is very promising in anaplastic thyroid cancer, opening the way to a future clinical evaluation.

Additive effect by combination of Akt inhibitor, MK-2206, and PDGFR inhibitor, tyrphostin AG 1296, in suppressing anaplastic thyroid carcinoma cell viability and motility

The phosphatidylinositol-3-kinase/Akt pathway and receptor tyrosine kinases regulate many tumorigenesis related cellular processes including cell metabolism, cell survival, cell motility, and angiogenesis. Anaplastic thyroid carcinoma (ATC) is a rare type of thyroid cancer with no effective systemic therapy. It has been shown that Akt activation is associated with tumor progression in ATC. Here we observed the additive effect between an Akt inhibitor (MK-2206) and a novel platelet-derived growth factor receptor inhibitor (tyrphostin AG 1296) in ATC therapy. We found an additive effect between MK-2206 and tyrphostin AG 1296 in suppressing ATC cell viability. The combination of MK-2206 and tyrphostin AG 1296 induces additive apoptosis, additive suppression of the Akt signaling pathway, as well as additive inhibition of cell migration and invasion of ATC cells. Furthermore, the combination of MK-2206 and tyrphostin AG 1296 induced additive suppression of ATC tumor growth in vivo. In summary, our studies suggest that the combination of Akt and receptor tyrosine kinase inhibitors may be an efficient therapeutic strategy for ATC treatment, which might shed new light on ATC therapy.

Deregulation of microRNA expression in thyroid neoplasias

MicroRNAs (miRNAs) have emerged as a class of powerful gene expression regulators. Acting at the post-transcriptional level, miRNAs modulate the expression of at least one-third of the mRNAs that are encoded by the human genome. The expression of a single gene can be regulated by several miRNAs, and every miRNA has more than one target gene. Thus, the miRNA regulatory circuit, which affects essential cellular functions, is of enormous complexity. Moreover, a fundamental role for miRNAs has been determined in the onset and progression of human cancers. Here, we summarize the main alterations in miRNA expression that have been identified in thyroid neoplasias and examine the mechanisms through which miRNA deregulation might promote thyroid cell transformation. We also discuss how the emerging knowledge on miRNA deregulation could be harnessed for the diagnosis and treatment of thyroid neoplasias.

Surgical management of thyroid cancer

Thyroid cancer is the most common endocrine neoplasm; however, it only accounts for less than 1% of all human malignances. Thyroid cancers are divided into well differentiated and non-well differentiated cancers, according to their histology and behavior. The surgical management options of well-differentiated thyroid cancer include total or near-total thyroidectomy, subtotal thyroidectomy and lobectomy plus isthmusectomy. The extent of surgery for thyroid cancer continues to be an area of controversy. Complications associated with thyroid surgery are directly proportional to the extent of thyroidectomy and inversely proportional to the experience of the operating surgeon. They occur less frequently with good surgical technique and better understanding of surgical anatomy, and include wound healing and infections (seroma, hematoma and wound infection), nerve injury, hypoparathyroidism, hypothyroidism, postoperative hemorrhage and respiratory obstruction.

Anaplastic thyroid cancer: ultrasonographic findings and the role of ultrasonography-guided fine needle aspiration biopsy

PURPOSE

To investigate the ultrasonographic (US) features of anaplastic thyroid cancer (ATC) and the diagnostic performance of US-guided fine needle aspiration biopsy (FNAB) therein.

MATERIALS AND METHODS

Eighteen cases of ATC diagnosed between January 2001 and May 2011 were included. FNAB was performed in all cases. Initial FNAB results were divided into three groups: 1) the cytological ATC group, cytological diagnosis of ATC; 2) the underestimated group, cytological diagnoses of malignancy other than ATC; and 3) the false negative group, cytological diagnoses of atypical, benign and non-diagnostic lesions. We retrospectively reviewed US findings and compared treatment modalities between each group.

RESULTS

Among the 18 patients, there were nine in the initially cytological ATC group, four in the underestimated group and five in the false negative group. The most common US features of ATC were a solid (64.7%) and irregular shaped (88.2%) mass with lymph node involvement (76.4%). However, except for lymph node involvement (p=0.003), US findings for each group were not statistically different. The initial cytological diagnostic accuracy of ATC was 50% (9/18). Surgery was performed less in the ATC group (11%) and the false negative group (20%) than the underestimated group (75%).

CONCLUSION

The US features of ATC were not especially different from other types of aggressive thyroid cancer. A correct diagnosis of ATC by initial US-FNAB was made in 50% of the patients, which is significant in that therapeutic surgery can be undertaken in lower numbers if correctly diagnosed.

Clinical significance of microscopic anaplastic focus in papillary thyroid carcinoma

BACKGROUND

On occasion, a microscopic anaplastic focus (MAF) is discovered in papillary thyroid carcinoma (PTC). The relevance of MAF has not been well studied with regard to its clinical implications. MAF is defined as the microscopic presence of focally dedifferentiated follicular cells within the PTC.

METHODS

A total of 3,606 patients who underwent primary thyroid surgery between 1995 and 2007 were selected from the database of Seoul National University Hospital. Patients were divided into 3 groups based on histology: PTC without MAF (3,574 patients), PTC with MAF (13 patients), and anaplastic thyroid carcinoma (19 patients).

RESULTS

Mean ± standard deviation age was 48 ± 12 years (range, 17-83) in the PTC without MAF group, 57 ± 14 years (range, 29-76) in the PTC with MAF group, and 64 ± 14 years (range, 24-86) in the ATC group (P < .001). Mean tumor sizes were 1.2 ± 0.9 cm (range, 0.5-13), 2.1 ± 1.2 cm (range, 0.7-5), and 3.7 ± 1.4 cm (range, 0.4-6), respectively (P < .001). The median follow-up was 32 months. The cause-specific survival at 5 years was 98% in the PTC without MAF group, 64% in the PTC with MAF group, and 11% in the ATC group (P < .001). Multivariate analysis showed that MAF was a prognostic factor for the outcome of PTC patients (hazard ratio, 12.9; 95% confidence interval, 3.1-54.1; P < .001).

CONCLUSION

MAF negatively influenced the prognosis of patients with PTC. Further research and the design of more aggressive treatment strategies for MAF might be helpful for patients with PTC.

Sites of metastases of anaplastic thyroid carcinoma: autopsy findings in 45 cases from a single institution

BACKGROUND

Despite surgical treatment, chemotherapy, and/or radiotherapy, the vast majority of patients with anaplastic thyroid carcinoma (ATC) have a dismal prognosis. Better knowledge of the frequency of metastases to different sites might help us to perform the appropriate diagnostic tests before treatment and during the course of the disease. The aim of this study was to determine the frequency of metastases from ATC in different sites as found at autopsy.

METHODS

Altogether, 205 patients were treated for ATC at our institute during the years 1972-2008. Autopsy was performed in 45 cases (30 females, 15 males; median age 66 years). The relative frequencies of metastases in different sites were analyzed using descriptive statistics.

RESULTS

Altogether, 41 cases (91%) had metastases at autopsy. The most common sites of metastases were the lungs (78%), intrathoracic lymph nodes (58%), neck lymph nodes (51%), pleura (29%), adrenal glands (24%), liver (20%), brain (18%), heart (18%), and retroperitoneal lymph nodes (18%). Less common sites of distant metastases were the pericardium (13%), bones (13%), kidneys (13%), mesentery or peritoneum (13%), skin (9%), pancreas (4%), stomach (4%), diaphragm (4%), pituitary gland (2%), ovary (2%), jejunum (2%), axillary lymph nodes (2%), and gingival mucosa (2%). Both distant and regional metastases were present in 23 cases, while only distant metastases were present in 18 cases. An extensive local infiltration of the primary tumor was found in 76% of the cases. The total number of the involved organs and lymph node basins were 123 and 58, respectively. The mean number of metastatic sites was 4.02±2.75. Lung metastases were present in 34 of 38 (89%) of our patients who had distant metastases found at autopsy. Of these 34 patients, 27 were known to have lung metastases when they were alive.

CONCLUSION

Two or more metastatic sites were found at autopsy in 84% of cases. The most common metastatic sites are lungs, followed by the intrathoracic and neck lymph nodes.

Phenotypic characterization of metastatic anaplastic thyroid cancer stem cells

Emerging evidence suggests cancer stem cells (CSCs) may initiate new tumors in anaplastic thyroid carcinoma (ATC), one of the most aggressive solid tumors in humans. However, the involvement of CSCs in human tumorigenesis has not been previously studied in authenticated ATC cell lines. Here we demonstrate a functional role of CSCs in four new validated human ATC cell lines (THJ-11T, THJ-16T, THJ-21T and THJ-29T). We identified and enriched CSCs using a spheroid-forming assay. About 3 to 9% of cells from four ATC cell lines formed thyrospheres. The thyrospheres expressed the stem cell markers NANOG and Oct4 and possessed the ability to self-renew. Injection of these thyrospheres into the thyroids of NOD/SCID Il2rg-/- mice resulted in the formation of metastatic tumors that recapitulated the clinical features of human ATC. To our knowledge, this is the first in vivo characterization of thyroid CSCs using validated human ATC cell lines. The availability of disease-specific thyrospheres and our orthotopic tumor models will enable the elucidation of disease mechanisms and the environmental niche of CSCs. They may also be useful for preclinical therapeutic screening and for monitoring the effects of biological therapies on ATC.

Pitfalls in the staging of cancer of thyroid

Thyroid cancer includes several neoplasms originating from the thyroid gland-from indolent and curable histologies of differentiated thyroid carcinoma to aggressive anaplastic thyroid carcinoma. Differentiation of thyroid nodules is problematic on CT and MR imaging unless there is evidence of extrathyroidal extension. Evaluation of regional lymph nodes is often performed clinically or with ultrasound. The retropharyngeal and mediastinal lymph nodes are better evaluated by CT and MR imaging. Nuclear scintigraphy is useful for staging and treatment of distant metastasis in differentiated thyroid carcinoma. PET may have a role in aggressive cancers. Accurate staging affects surgical management and subsequent therapy.

Phase II trial of sorafenib in patients with advanced anaplastic carcinoma of the thyroid

BACKGROUND

Anaplastic thyroid cancer (ATC) is a rare but highly aggressive malignancy with a median survival of 3-5 months. The BRAF oncogene is mutated to its active form in up to 24% of ATC cases. Sorafenib is a tyrosine kinase inhibitor that acts on the RAF-1 serine/threonine kinase. In preclinical mouse models, sorafenib inhibits the growth of ATC xenografts and improves survival. No study of sorafenib in ATC has been conducted. We conducted a multi-institutional phase II trial of sorafenib in patients with ATC who had failed up to two previous therapies.

METHODS

The primary endpoint of the trial was the Response Evaluation Criteria In Solid Tumors (RECIST)-defined imaging response rate. Twenty patients with ATC were treated with sorafenib 400 mg twice daily.

RESULTS

Two of the 20 patients had a partial response (10%) and an additional 5 of 20 (25%) had stable disease. The duration of response in the two responders was 10 and 27 months, respectively. For the patients with stable disease, the median duration was 4 months (range 3-11 months). The overall median progression-free survival was 1.9 months with a median and a 1-year survival of 3.9 months and 20%, respectively. Toxicity was manageable and as previously described for sorafenib, including hypertension and skin rash.

CONCLUSION

Sorafenib has activity in ATC, but at a low frequency and similar to our previous experience with fosbretabulin. One patient with a response had previously progressed on fosbretabulin. Toxicities were both predictable and manageable.

The impairment of the High Mobility Group A (HMGA) protein function contributes to the anticancer activity of trabectedin

Trabectedin (Ecteinascidin-743 or ET-743) is a novel antitumour agent of marine origin with potent antitumour activity both in vitro and in vivo. It interacts with the minor groove of DNA, interfering with transcriptional activity and DNA repair pathways. Here, we report a novel mechanism by which trabectedin exerts its cytotoxic effects on carcinoma cells. It is based on its ability to impair the function of the High-Mobility Group A (HMGA) proteins. These proteins have a key role in cell transformation, and their overexpression is a common feature of human malignant neoplasias, representing a poor prognostic index often correlated to anti-cancer drug resistance. They bind the minor groove of DNA, alter chromatin structure and, thus, regulate the transcription of several genes by enhancing or suppressing the activity of transcription factors. We first report that trabectedin has a higher cytotoxic effect on thyroid and colon carcinoma cells expressing abundant levels of HMGAs in comparison with cells not expressing them. Then, we have shown that trabectedin treatment displaces HMGA proteins from the HMGA-responsive promoters, including ATM promoter, impairing their transcriptional activity. Finally, we report a synergism between Ionising Radiations and trabectedin treatment restricted to the HMGA-overexpressing cancer cells. This result might have important clinical implications since it would suggest the use of trabectedin for the treatment of neoplasias expressing abundant HMGA levels that are frequently associated to chemoresistance and poor prognosis.

mRNA expression in papillary and anaplastic thyroid carcinoma: molecular anatomy of a killing switch

Anaplastic thyroid carcinoma (ATC) is the most lethal form of thyroid neoplasia and represents the end stage of thyroid tumor progression. No effective treatment exists so far. ATC frequently derive from papillary thyroid carcinomas (PTC), which have a good prognosis. In this study, we analyzed the mRNA expression profiles of 59 thyroid tumors (11 ATC and 48 PTC) by microarrays. ATC and PTC showed largely overlapping mRNA expression profiles with most genes regulated in all ATC being also regulated in several PTC. 43% of the probes regulated in all the PTC are similarly regulated in all ATC. Many genes modulations observed in PTC are amplified in ATC. This illustrates the fact that ATC mostly derived from PTC. A molecular signature of aggressiveness composed of 9 genes clearly separates the two tumors. Moreover, this study demonstrates gene regulations corresponding to the ATC or PTC phenotypes like inflammatory reaction, epithelial to mesenchymal transition (EMT) and invasion, high proliferation rate, dedifferentiation, calcification and fibrosis processes, high glucose metabolism and glycolysis, lactate generation and chemoresistance. The main qualitative differences between the two tumor types bear on the much stronger EMT, dedifferentiation and glycolytic phenotypes showed by the ATC.

Update on thyroid cancer treatment

Surgery and radioiodine therapy are usually effective for most patients with differentiated thyroid cancer. However, poorly differentiated and anaplastic thyroid carcinomas represent a challenge to physicians on the basis of the current cancer treatment modalities. These cancer subtypes are often lethal and refractory to radioiodine therapy as well as most of the common chemotherapy drugs. Several kinase inhibitors are promising targeted therapies for these malignancies; however, clinical trials involving these drugs have provided controversial results and their clinical use is still under debate. Advanced medullary thyroid carcinomas may also be refractory to conventional therapies and novel kinase inhibitors may also be useful to control tumor progression in certain patients. Novel evidence is emerging that thyroid cancer is a stem cell disease, thereby implying that the driving force of thyroid cancers is a subset of undifferentiated cells (thyroid cancer stem cells) with unlimited growth potential and resistance to conventional therapeutic regimens. Thyroid cancer stem cells have been proposed as responsible for tumor invasiveness, metastasis, relapse and differentiation. Therefore, drugs that selectively target these cells could serve as a cornerstone in the treatment of poorly differentiated thyroid cancer.

Pathogenic mechanisms of deregulated microRNA expression in thyroid carcinomas of follicular origin

Thyroid cancer is one of the most common malignancies of the endocrine system with increasing incidence. The vast majority of thyroid carcinomas derive from thyroid hormone producing follicular cells. Carcinomas of follicular origin are classified as follicular (FTCs), papillary (PTCs), partially differentiated (PDTCs) or anaplastic (ATCs) thyroid carcinomas. While FTCs and PTCs can be managed effectively, ATCs are considered one of the most lethal human cancers. Despite the identification of various genetic alterations, pathogenic mechanisms promoting the progression of thyroid carcinomas are still largely elusive. Over the recent years, aberrant microRNA expression was revealed in all as yet analyzed human cancers, including thyroid carcinomas. In view of the rapidly evolving perception that deregulated microRNA expression serves a pivotal role in tumor progression, microRNAs provide powerful tools for the diagnosis of thyroid carcinomas as well as the identification of potential therapeutic targets. Here, we summarize recent findings on microRNA signatures in thyroid carcinomas of follicular origin and discuss how deregulated microRNA expression could promote cancer progression.