New targeted therapies for thyroid cancer

Advances and challenges in thyroid cancer: The interplay of genetic modulators, targeted therapies, and AI-driven approaches

Thyroid cancer continues to exhibit a rising incidence globally, predominantly affecting women. Despite stable mortality rates, the unique characteristics of thyroid carcinoma warrant a distinct approach. Differentiated thyroid cancer, comprising most cases, is effectively managed through standard treatments such as thyroidectomy and radioiodine therapy. However, rarer variants, including anaplastic thyroid carcinoma, necessitate specialized interventions, often employing targeted therapies. Although these drugs focus on symptom management, they are not curative. This review delves into the fundamental modulators of thyroid cancers, encompassing genetic, epigenetic, and non-coding RNA factors while exploring their intricate interplay and influence. Epigenetic modifications directly affect the expression of causal genes, while long non-coding RNAs impact the function and expression of micro-RNAs, culminating in tumorigenesis. Additionally, this article provides a concise overview of the advantages and disadvantages associated with pharmacological and non-pharmacological therapeutic interventions in thyroid cancer. Furthermore, with technological advancements, integrating modern software and computing into healthcare and medical practices has become increasingly prevalent. Artificial intelligence and machine learning techniques hold the potential to predict treatment outcomes, analyze data, and develop personalized therapeutic approaches catering to patient specificity. In thyroid cancer, cutting-edge machine learning and deep learning technologies analyze factors such as ultrasonography results for tumor textures and biopsy samples from fine needle aspirations, paving the way for a more accurate and effective therapeutic landscape in the near future.

Influence of two anti-tumor drugs, pazopanib, and axitinib, on the development and thyroid-axis of zebrafish (Danio rerio) embryos/larvae

Introduction

In recent years, the potential toxicities of different pharmaceuticals toward the thyroid system have received increasing attention. In this study, we aim to evaluate the toxic effects of pazopanib and axitinib, two anti-tumor drugs with widespread clinical use, on thyroid function in the zebrafish model.

Methods

We measured levels of thyroid-related hormones using the commercial Enzyme-Linked Immunosorbent Assay (ELISA) kit. Whole-mount in situ hybridization (WISH) analysis was employed to detect target gene expression changes. Morphology of the thyroid were evaluated by using transgenic Tg (tg: EGFP) fish line under a confocal microscope. The relative mRNA expression of key genes was verified through quantitative real-time polymerase chain reaction (RT‒qPCR). The size and number of the follicles was quantified whereby Hematoxylin-Eosin (H & E) staining under a light microscope.

Results

The results revealed that fertilized zebrafish embryos were incubated in pazopanib or axitinib for 96 hours, development and survival were significantly affected, which was accompanied by significant disturbances in thyroid endocrine system (e.g., increased thyroid-stimulating hormone (TSH) content and decreased triiodothyronine (T3) and thyroxine (T4) content, as well as transcription changes of genes associated with the hypothalamus-pituitary-thyroid (HPT) axis. Moreover, based on whole-mount in situ hybridization staining of tg and histopathological examination of zebrafish embryos treated with pazopanib and axitinib, we observed a significantly abnormal development of thyroid follicles in the Tg (tg: EGFP) zebrafish transgenic line.

Conclusion

Collectively, these findings indicate that pazopanib and axitinib may have toxic effects on thyroid development and function, at least partially, by influencing the regulation of the HPT axis. Thus, we believe that the potential thyroid toxicities of pazopanib and axitinib in their clinical applications should receive greater attention.

Dabrafenib plus trametinib treatment in patients with anaplastic thyroid carcinoma: an Argentinian experience

PURPOSE

To present our real-life experience with dabrafenib and trametinib (D-T) treatment in patients with BRAF V600E-mutated ATC in Argentina.

PATIENTS Y METHODS

We included five patients from four different hospitals. The median age was 70 years, and 60% were male. The performance status at diagnosis was grade 0 in 60% and grade 2 in 40% of patients. Four patients could undergo total thyroidectomy; in one of them, surgical treatment was amenable due to the indication of D-T as neoadjuvant therapy. From the total cohort, the best response to treatment was complete response in 40%, partial response in 20%, and stable disease in 20%. The median duration of response was 20 weeks, ranging from 16 to 92 weeks. All patients experienced at least one adverse event (AE). Grade ≥3 AEs were observed in two (40%) patients. They were upper gastrointestinal bleeding and subclavian vein thrombosis. The median follow-up was 20 weeks (range: 16 to 92).

CONCLUSION

This report contributes to illustrate the feasibility and effectiveness of D-T treatment in five patients with loco-regionally advanced and metastatic BRAF V600E-mutated ATC in a real-life setting. A multidisciplinary approach and rapid molecular-tailored testing are essential to begin this therapeutic option.

Antineoplastic Activity of Pazopanib in Anaplastic Thyroid Cancer in Primary Culture

Anaplastic thyroid cancer (ATC) is a rare and rapidly fatal human cancer. Its usual treatment includes the combination of surgery, external hyperfractionated radiation therapy, and chemotherapy. These treatments permit achieving about 6-10 months of median survival. For this reason, it is challenging to predict the ATC patient clinical therapy responsiveness. Pazopanib is a multitarget tyrosine kinase inhibitor of VEGF receptors, PDGF, and c-Kit. Until now, the effect of pazopanib in primary human ATC cells (pATC) has not been reported in the literature. The aim of our study was to evaluate in vitro the antineoplastic effect of pazopanib in pATC. Surgical thyroidal tissues were collected from five patients with ATC, from thyroid biopsy at the moment of first surgical operation. An inhibition of proliferation, migration, and invasion, and an increase in apoptosis were demonstrated upon treating pATC cells with pazopanib (p < 0.05). Moreover, pazopanib was able to significantly decrease the VEGF expression in pATC cells (p < 0.05). To conclude, in this study, we demonstrate the antineoplastic activity of the antiangiogenic inhibitor, pazopanib, in human pATC in vitro.

Rationale Efficacy and Safety Evidence of Lenvatinib and Pembrolizumab Association in Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) are highly aggressive malignant tumors with poor overall prognosis despite multimodal therapy. As ATC are extremely rare, no randomized controlled study has been published for metastatic disease. Thyrosine kinase inhibitors, especially lenvatinib and immune checkpoint inhibitors such as pembrolizumab, are emerging drugs for ATC. Few studies have reported the efficacity of pembrolizumab and lenvatinib association, resulting in its frequent off-label use. In this review, we discuss rationale efficacy and safety evidence for the association of lenvatinib and pembrolizumab in ATC. First, we discuss preclinical rationale for pembrolizumab monotherapy, lenvatinib monotherapy and synergistic action of pembrolizumab and lenvatinib in the metastatic setting. We also discuss clinical evidence for immunotherapy and pembrolizumab in ATC through the analysis of studies evaluating immunotherapy, lenvatinib and pembrolizumab lenvatinib association in ATC. In addition, we discuss the safety of this association and potential predictive biomarkers of efficiency.

Combination Strategies Involving Immune Checkpoint Inhibitors and Tyrosine Kinase or BRAF Inhibitors in Aggressive Thyroid Cancer

Thyroid cancer is the most common (~90%) type of endocrine-system tumor, accounting for 70% of the deaths from endocrine cancers. In the last years, the high-throughput genomics has been able to identify pathways/molecular targets involved in survival and tumor progression. Targeted therapy and immunotherapy individually have many limitations. Regarding the first one, although it greatly reduces the size of the cancer, clinical responses are generally transient and often lead to cancer relapse after initial treatment. For the second one, although it induces longer-lasting responses in cancer patients than targeted therapy, its response rate is lower. The individual limitations of these two different types of therapies can be overcome by combining them. Here, we discuss MAPK pathway inhibitors, i.e., BRAF and MEK inhibitors, combined with checkpoint inhibitors targeting PD-1, PD-L1, and CTLA-4. Several mutations make tumors resistant to treatments. Therefore, more studies are needed to investigate the patient's individual tumor mutation burden in order to overcome the problem of resistance to therapy and to develop new combination therapies.

Lenvatinib: an investigational agent for the treatment of differentiated thyroid cancer

INTRODUCTION

Differentiated thyroid cancer (DTC; >90% of all TCs) derives from follicular cells. Surgery is the main therapeutic strategy, and radioiodine (RAI) is administered after thyroidectomy. When DTC progresses, it does not respond to RAI and thyroid-stimulating hormone (TSH)-suppressive thyroid hormone treatment, and other therapies (i.e. surgery, external beam radiation therapy and chemotherapy) do not lead to a better survival. Thanks to the understanding of the molecular pathways involved in TC progression, important advances have been done. Lenvatinib is a multitargeted tyrosine kinase inhibitor of VEGFR1-3, FGFR1-4, PDGFRα, RET, and KIT signaling networks implicated in tumor angiogenesis, approved in locally recurrent or metastatic, progressive, RAI-refractory DTC. Unmet needs regarding the patient clinical therapy responsiveness in aggressive RAI-refractory DTC still remain.

AREAS COVERED

We provide an overview from the literature of in vitro, in vivo and real-life studies regarding lenvatinib as an investigational agent for the treatment of aggressive TC.

EXPERT OPINION

According to the SELECT trial, the treatment should be initiated with a dosage of 24 mg/day, subsequently decreasing it in relation to the side effects. The decision making process in patients with aggressive RAI-refractory DTC should be personalized and the potential toxicity should be properly managed.

Dramatic clinical response to dabrafenib plus trametinib in anaplastic thyroid carcinoma and the challenges faced during the COVID-19 pandemic

Anaplastic thyroid carcinoma is the rarest tumor of the thyroid gland, representing less than 2% of clinically recognized thyroid cancers. Typically, it has an extremely rapid onset, fatal outcomes in most cases, and a median overall survival of 3 to 10 months despite aggressive multidisciplinary management. The presence of targetable mutations in anaplastic thyroid carcinoma patients is an opportunity for treatment when conventional therapeutics approaches are not effective, a frequent situation in the majority of patients. We present our experience in the management of a patient with unresectable anaplastic thyroid cancer who had a remarkable and rapid response to treatment with dabrafenib and trametinib during the COVID-19 pandemic. After four weeks of dabrafenib 150 mg twice daily plus trametinib 2 mg daily, he showed a dramatic reduction of the cervical mass around 90%. Nearly eight weeks under treatment with dabrafenib plus trametinib, the patient remains with minimal locoregional disease without distant metastases.

Molecular targets of tyrosine kinase inhibitors in thyroid cancer

Thyroid cancer (TC) is the eighth most frequently diagnosed cancer worldwide with a rising incidence in the past 20 years. Surgery is the primary strategy of therapy for patients with medullary TC (MTC) and differentiated TC (DTC). In DTC patients, radioactive iodine (RAI) is administered after thyroidectomy. Neck ultrasound, basal and thyroid-stimulating hormone-stimulated thyroglobulin are generally performed every three to six months for the first year, with subsequent intervals depending on initial risk assessment, for the detection of possible persistent/recurrent disease during the follow up. Distant metastases are present at the diagnosis in ∼5 % of DTC patients; up to 15 % of patients have recurrences during the follow up, with a survival reduction (70 %-50 %) at 10-year. During tumor progression, the iodide uptake capability of DTC cancer cells can be lost, making them refractory to RAI, with a negative impact on the prognosis. Significant advances have been done recently in our understanding of the molecular pathways implicated in the progression of TCs. Several drugs have been developed, which inhibit signaling kinases or oncogenic kinases (BRAF^V600E, RET/PTC), such as those associated with Platelet-Derived Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor. Tyrosine kinase receptors are involved in cancer cell proliferation, angiogenesis, and lymphangiogenesis. Several tyrosine kinase inhibitors (TKIs) are emerging as new treatments for DTC, MTC and anaplastic TC (ATC), and can induce a clinical response and stabilize the disease. Lenvatinib and sorafenib reached the approval for RAI-refractory DTC, whereas cabozantinib and vandetanib for MTC. These TKIs extend median progression-free survival, but do not increase the overall survival. Severe side effects and drug resistance can develop in TC patients treated with TKIs. Additional studies are needed to identify a potential effective targeted therapy for aggressive TCs, according to their molecular characterization.

Primary cell cultures for the personalized therapy in aggressive thyroid cancer of follicular origin

Thyroid cancer (TC) is the most prevalent endocrine malignancy. More than 90 % of TC is represented by differentiated TC (DTC) arising from the follicular thyroid cells. DTC includes papillary TC (PTC), follicular TC (FTC), and Hürthle cell TC. Anaplastic TC (ATC) accounts for 1% of TC, and it represents 15-40 % of TC death. Current treatment strategies are not completely effective against aggressive DTC or ATC, and mortality is one of the most important challenges. Recently, progresses have been obtained in the understanding of the molecular/genetic basis of TC progression, and new drugs have been introduced [i.e. tyrosine kinase inhibitors (TKIs)], able to block the oncogenic or signaling kinases, associated with cellular growth. Thyroid cell lines, obtained from tumoral cells and chosen for high proliferation in vitro, have been used as preclinical models. Actually, these cells lose the characteristic features of the primary tumor, because they adapt to in vitro growth conditions. For these reasons, the use of these cell lines has important limitations, and more recently human primary cell cultures have been established as monolayer cultures, and investigated for their biological behavior. Moreover, in the past, primary TC cells could be collected only through surgical biopsies, while recently human primary cell cultures can be established also from samples of fine-needle aspiration citology from aggressive dedifferentiated DTC or ATC. Testing in vitro different TKIs in each patient can help to develop new personalized treatments, without using ineffective drugs. In conclusion, personalized medicine and precise oncology, which consider both patients and their disease features, represent the future of the treatment approach, and further progress is needed in this direction.

Nutraceuticals in Thyroidology: A Review of in Vitro, and in Vivo Animal Studies

Nutraceuticals are defined as a food, or parts of a food, that provide medical or health benefits, including the prevention of different pathological conditions, and thyroid diseases, or the treatment of them. Nutraceuticals have a place in complementary medicines, being positioned in an area among food, food supplements, and pharmaceuticals. The market of certain nutraceuticals such as thyroid supplements has been growing in the last years. In addition, iodine is a fundamental micronutrient for thyroid function, but also other dietary components can have a key role in clinical thyroidology. Here, we have summarized the in vitro, and in vivo animal studies present in literature, focusing on the commonest nutraceuticals generally encountered in the clinical practice (such as carnitine, flavonoids, melatonin, omega-3, resveratrol, selenium, vitamins, zinc, and inositol), highlighting conflicting results. These experimental studies are expected to improve clinicians’ knowledge about the main supplements being used, in order to clarify the potential risks or side effects and support patients in their use.

Novel treatments for anaplastic thyroid carcinoma

Anaplastic thyroid cancer (ATC) is one of the deadliest human cancers and it is less than 2% of thyroid carcinomas (TCs). The standard treatment of ATC includes surgical debulking, accelerated hyperfractionated external beam radiation therapy (EBRT), and chemotherapy, in particular with cisplatin or doxorubicin, achieving about 10 months of median survival. Since ATC is a rare and aggressive tumor, it is still challenging to predict the patient clinical therapy responsiveness. Several genetic mutations have been described in ATC, involved in different molecular pathways linked to tumor progression, and novel therapies acting on these molecular pathways have been investigated, to improve the quality of life in these patients. Here we review the new targeted therapy of ATC. We report interesting results obtained with molecules targeting different pathways: angiogenesis (vandetanib, combretastatin, sorafenib, lenvatinib, sunitinib, CLM94, CLM3, etc.); EGFR (gefitinib, docetaxel); BRAF (dabrafenib/trametinib, vemurafenib); PPARγ agonists (rosiglitazone, pioglitazone, efatutazone); PD-1 and PD-L1 (pembrolizumab); TERT. To escape resistance to monotherapies, the evaluation of combination strategies with radiotherapy, chemotherapy, or targeted drugs is ongoing. The results of clinical trials with dabrafenib and trametinib led to the approval from FDA of this combination for patients with BRAF V600E mutated ATC with locally advanced, unresectable, or metastatic ATC. The anti-PD-L1 antibody immunotherapy, alone or combined with a BRAF inhibitor, has been shown also promising in the treatment of ATC. Furthermore, to increase the therapeutic success and not to use ineffective or even harmful treatments, a real tailored therapy should be pursued, and this can be achieved thanks to the new available genomic analysis methods and to the possibility to test in vitro novel treatments directly in primary cells from each ATC patient. Exploring new treatment strategies is mandatory to improve the survival of these patients, guaranteeing a good quality of life.

Abemaciclib (CDK4/6 Inhibitor) Blockade Induces Cytotoxicity in Human Anaplastic Thyroid Carcinoma Cells

BACKGROUND

Thyroid cancer is the most prevalent endocrine malignancies globally. Anaplastic thyroid carcinoma (ATC) accounts for 1-3% of all Thyroid cancer. The evidence showed that ATC is a highly invasive solid tumor with poor prognosis. Despite conventional chemotherapy treatments, a considerable number of patients show developing resistance to therapeutic agents and tumor relapse. The aim of this study was the investigation anti-tumor effect of Abemaciclib (novel targeted cancer therapy drug) on Anaplastic Thyroid carcinoma SW1736 and C643 cell lines.

METHODS

SW1736 and C643 cell lines were treated by desire concentrations of Abemaciclib (0, 1, 2.5, 5, 10, and 20 μM) and cell viability was measured by MTT assay. Also, Anoikis resistance assay was conducted for non-adherent the cells in the exposure of Abemaciclib. The gene expression of apoptotic and anti-apoptotic genes was conducted by quantitative Real-time PCR.

RESULTS

Abemaciclib at the concentration of 10 and 20 μM effectively reduced cell proliferation and growth of the ATC cells compared to the control (p=0.000). Furthermore, we showed that 10 and 20 μM doses of the Abemaciclib inhibited the non-adherent ATC cells which were resistant to Anoikis death significantly (p=0.001). Moreover, we demonstrated this targeted therapy significantly reduced anti-apoptotic gene expression levels (BCL2 and CMYC) (p<0.05) and increased apoptotic gene expressions such as P21 and BAX (p<0.05).

CONCLUSION

Our data suggested that Abemaciclib can be utilized as a novel therapeutic agent in ATC cancer. Further in vivo and in vitro investigations are needed to evaluate molecular and clinical mechanisms of Abemaciclib.

The significance of gene mutations across eight major cancer types

Mutations occur spontaneously, which can be induced by either chemicals (e.g. benzene) or biological factors (e.g. virus). Not all mutations cause noticeable changes in cellular functions. However, mutation in key cellular genes leads to developmental disorders. It is one of the main ways in which proto-oncogenes can be changed into their oncogenic state. The progressive accumulation of multiple mutations throughout life leads to cancer. In the past few decades, extensive research on cancer biology has discovered many genes and pathways having role in cancer development. In this review, we tried to summarize the current knowledge of mutational effect on different cancer types and its consequences in brief for future reference and guidance of researchers in cancer biology.

Genotoxicity Evaluation of the Soybean Isoflavone Genistein in Human Papillary Thyroid Cancer Cells. Study of Its Potential Use in Thyroid Cancer Therapy

Genistein is one of the several known isoflavonic phytoestrogens found in a number of plants, with soybeans and soy products being the primary food source. The aim of the study is to evaluate if genistein is able to exert antineoplastic action in primary human papillary thyroid cancer (PTC) cells. Thyroid tissues were treated with genistein (1-10-50-100 µM). Cell viability, proliferation, DNA primary damage and chromosomal damage were evaluated. An antiproliferative effect was induced by the highest doses of genistein, and such an effect was synergistically enhanced by the cotreatment with the antineoplastic drug sorafenib. Comet assay did not show any genotoxic effect in terms of primary DNA damage at all the times (4 and 24 h) and tested doses. A reduction of hydrogen peroxide-induced DNA primary damage in primary thyrocytes from PTC cells pretreated with genistein was observed. Data suggest that genistein exerts antineoplastic action, does not induce genotoxic effects while reduces oxidative-induced DNA damage in primary thyrocytes from PTC cells, supporting its possible use in therapeutic intervention.

Resistance to Src inhibition alters the BRAF-mutant tumor secretome to promote an invasive phenotype and therapeutic escape through a FAK>p130Cas>c-Jun signaling axis

Few therapy options exist for patients with advanced papillary and anaplastic thyroid cancer. We and others have previously identified c-Src as a key mediator of thyroid cancer pro-tumorigenic processes and a promising therapeutic target for thyroid cancer. To increase the efficacy of targeting Src in the clinic, we sought to define mechanisms of resistance to the Src inhibitor, dasatinib, to identify key pathways to target in combination. Using a panel of thyroid cancer cell lines expressing clinically relevant mutations in BRAF or RAS, which were previously developed to be resistant to dasatinib, we identified a switch to a more invasive phenotype in the BRAF-mutant cells as a potential therapy escape mechanism. This phenotype switch is driven by FAK kinase activity, and signaling through the p130Cas>c-Jun signaling axis. We have further shown this more invasive phenotype is accompanied by alterations in the secretome through the increased expression of pro-inflammatory cytokines, including IL-1β, and the pro-invasive metalloprotease, MMP-9. Furthermore, IL-1β signals via a feedforward autocrine loop to promote invasion through a FAK>p130Cas>c-Jun>MMP-9 signaling axis. We further demonstrate that upfront combined inhibition of FAK and Src synergistically inhibits growth and invasion, and induces apoptosis in a panel of BRAF- and RAS-mutant thyroid cancer cell lines. Together our data demonstrate that acquired resistance to single-agent Src inhibition promotes a more invasive phenotype through an IL-1β>FAK>p130Cas>c-Jun >MMP signaling axis, and that combined inhibition of FAK and Src has the potential to block this inhibitor-induced phenotype switch.

Molecular testing in the diagnosis of differentiated thyroid carcinomas

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

ERBB1- and ERBB2-Positive Medullary Thyroid Carcinoma: A Case Report

Medullary thyroid carcinomas (MTCs) are rare thyroid tumors occurring in both sporadic and hereditary forms, whose pathogenesis is related to RET proto-oncogene alterations. MTCs originate from parafollicular cells, which produce calcitonin that represents the biochemical activity of MTC. Total thyroidectomy is the main treatment for MTC and often cures patients with confined diseases. In the presence of metastasis, the therapeutic approach depends on the rate of disease progression. We report a case of a 54-year-old female with a single, incidentally discovered, thyroid nodule of 1 cm, classified as suspicious MTC after a stimulation test with intravenous (iv) calcium. After surgery, we examined the nodule using immunohistochemistry, immunofluorescence, and electron microscopy. In addition to calcitonin, we found that it expressed intracellular positivity for the tyrosine kinase RTK receptors ERBB1 and ERBB2. Consistently with MTC features, the ultrastructural examination of the tumor displayed heterogeneous spindle-shaped cells containing two groups of secretory granules. Because of the significant correlation found between high ERBB1/ERBB2 levels in MTCs and extrathyroidal growth, the detection of ERBB1 and ERBB2 expression suggests that the two oncoproteins may be involved in the tumor proliferative responses and/or in the differentiation of parafollicular C-cells. The biological, prognostic, and therapeutic significance of these patterns would merit further investigations.

The role of external beam radiation therapy in well-differentiated thyroid cancer

INTRODUCTION

This review article explores the use of external beam radiotherapy (EBRT) in well differentiated thyroid cancer. Areas covered: The published literature on EBRT for advanced pT4 disease and macroscopic unresectable disease to improve locoregional control is reviewed. EBRT techniques, volumes and doses are discussed in detail. The potential acute and late toxicities of EBRT are discussed in the context of the published literature. The use of EBRT for patients with metastatic disease is also described. Expert commentary: There is good retrospective evidence for EBRT in the setting of unresectable gross residual well-differentiated thyroid cancer as this can result in long-term local control. However, the benefit of EBRT in patients with locally advanced disease that is completely resected is less clear. The use of EBRT for these patients requires careful consideration of age, pathologic factors, comorbidities and patient preference, preferably by a multi-disciplinary team.

Novel treatment options for anaplastic thyroid cancer

Several genetic alterations have been identified in different molecular pathways ofanaplastic thyroid cancer (ATC) and associated with tumor aggressiveness and progression (BRAF, p53,RAS, EGFR, VEGFR-1, VEGFR-2, etc). New drugs targeting these molecular pathways have beenrecently evaluated in ATC. Areas covered: We review the new targeted therapies of ATC. Interesting results have been reported with molecules targeting different pathways, as: a-BRAF (dabrafenib/trametinib, vemurafenib); b-angiogenesis (sorafenib, combretastatin, vandetanib, sunitinib, lenvatinib, CLM3, etc); c-EGFR (gefitinib); d- PPARγ agonists (rosiglitazone, pioglitazone, efatutazone). In patients with ATC treated with lenvatinib, a median overall survival of 10.6 (3.8-19.8) months was reported. In order to bypass the resistance to the single drug, the capability of targeted drugs to synergize with radiation, or chemotherapy, or other targeted drugs is explored. Expert commentary: New, affordable and individual genomic analysis combined with the opportunity to test these new treatments in primary cell cultures from every ATC patient in vitro, may permit the personalization of therapy. Increasing the therapeutic effectiveness and avoiding the use of ineffective drugs. The identification of new treatments is necessary, to extend life duration guaranteing a good quality of life. To bypass the resistance to asingle drug, the capability of targeted drugs to synergize with radiation, or chemotherapy, or othertargeted drugs is explored. Moreover, new affordable individual genomic analysis and the opportunity totest these novel treatments in primary cell cultures from every ATC patient in vitro, might permit topersonalize the therapy, increasing the therapeutic effectiveness and avoiding the use of ineffectivedrugs.

Lentivirus-mediated silencing of MPHOSPH8 inhibits MTC proliferation and enhances apoptosis

Thyroid carcinoma (TC) is the most common malignancy of the endocrine organs, and its incidence rate has steadily increased over the last decade. For medullary thyroid cancer (MTC), a type of TC, a high mortality rate has been reported. In previous studies, M-phase phosphoprotein 8 (MPHOSPH8) displayed an elevated expression in various human carcinoma cells. Thus, MPHOSPH8 may be a sensitive biomarker that could be used for the diagnosis and follow-up of MTC. In the present study, plasmids of RNA interference targeting the MPHOSPH8 gene were constructed. Once these lentiviruses targeting MPHOSPH8 were transfected into the MTC cell line TT, cell viability and proliferation were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry was used to assess the cell cycle distribution and apoptosis. The expression levels of MPHOSPH8 were detected by reverse transcription quantitative-polymerase chain reaction and western blot analyses. Depletion of MPHOSPH8 significantly inhibited cell proliferation. Furthermore, knockdown of MPHOSPH8 in TT cells led to G0/G1 phase cell cycle arrest and apoptosis. The results of the present study suggest that MPHOSPH8 promotes cell proliferation and may be a potential target for anticancer therapy of MTC.

Transient partial response of poorly-differentiated thyroid carcinoma to sunitinib treatment: A case report

Thyroid cancer is the most common endocrine malignancy, with an increasing prevalence worldwide. Poorly-differentiated thyroid cancer (PDTC) is relatively rare and its prognosis is poor. To date, no ideal treatment strategy is available for patients with advanced recurrent PDTC, particularly for patients in crisis. However, partial success in treating thyroid cancer has been achieved with targeted therapy, and advances made in understanding the molecular biology of the tumor. The current study describes the case of a patient diagnosed with PDTC following presentation with hoarseness, orthopnea, and a large right neck mass. A transient partial response to sunitinib malate treatment was achieved for >3 months. In addition, the current study reviewed the relevant literature and discussed the therapeutic value of sunitinib as a more favorable treatment strategy for patients with advanced recurrent PDTC compared with the currently available treatments. Successful treatment with sunitinib, as well as molecular analysis of the tumor, occurred in the present case. Sunitinib was determined to have potential in treating thyroid tumors, however, larger prospective studies are required to validate the findings of the current case study prior to the application of this agent in clinical practice.

Sorafenib in the treatment of thyroid cancer

Sorafenib has been evaluated in several Phase II and III studies in patients with locally advanced/metastatic radioactive iodine-refractory differentiated thyroid carcinomas (DTCs), reporting partial responses, stabilization of the disease and improvement of progression-free survival. Best responses were observed in lung metastases and minimal responses in bone lesions. On the basis of these studies, sorafenib was approved for the treatment of metastatic DTC in November 2013. Few studies suggested that reduction of thyroglobulin levels, or of average standardized uptake value at the fluorodeoxyglucose-PET, could be helpful for the identification of responding patients; but further studies are needed to confirm these results. Tumor genetic marker levels did not have any prognostic or predictive role in DTC patients.The most common adverse events observed included skin toxicity and gastrointestinal and constitutional symptoms. Encouraging results have also been observed in patients with medullary thyroid cancer. Many studies are ongoing to evaluate the long-term efficacy and tolerability of sorafenib in DTC patients.

PTEN loss is associated with follicular variant of Middle Eastern papillary thyroid carcinoma

Background:

PTEN gene at chromosomes 10q23.3 is a tumour suppressor gene that is inactivated in many types of human cancers. The known mechanisms of PTEN inactivation are rendered to mutation, epigenetic silencing by aberrant methylation or gene deletion. Although PTEN role has been documented in many cancers, PTEN alteration in papillary thyroid carcinoma (PTC) has not been fully elucidated. The aim of this study is to comprehensively investigate PTEN alterations in a large cohort of Middle Eastern papillary thyroid cancer by immunohistochemistry and fluorescent in situ hybridisation (FISH).

Methods:

PTEN protein expression was analysed by immunohistochemistry in a tissue microarray (TMA) format in a large cohort of more than 1000 patients with papillary thyroid cancer. Copy number changes in PTEN were analysed by FISH and data were correlated with clinicopathological parameters along with survival analysis.

Results:

PTEN inactivation reflected by complete absence of staining was seen in 24.5% of PTC samples, whereas PTEN deletion was seen only in 4.8% of the tested samples by FISH. No association was seen between PTEN loss of protein expression and PTEN gene deletion. However, interestingly, PTEN loss of expression was significantly associated with the follicular variant subset of papillary thyroid cancer.

Conclusion:

Our study confirmed that PTEN might have a role in pathogenesis in a subset of PTC. PTEN loss of protein expression is a more common event in follicular variant of papillary thyroid cancer. Lack of association between PTEN loss of protein expression and PTEN gene deletion might indicate that gene deletion may not be the sole cause for PTEN loss of expression and these results might raise the possibility of other mechanism such as promoter methylation-mediated gene silencing to be responsible for PTEN inactivation.

Tyrosine kinase inhibitors for the therapy of anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is often incurable so new therapeutic approaches are needed. Tyrosine kinases inhibitors (such as imanitib, sunitinib or sorafenib) are under evaluation for the treatment of ATC. Other vascular disrupting agents, such as combretastatin A4 phosphate, and antiangiogenic agents, such as aplidin, PTK787/ZK222584 and human VEGF monoclonal antibodies (bevacizumab, cetuximab), have been evaluated. Small-molecule adenosine triphosphate competitive inhibitors directed intracellularly at EGFRs tyrosine kinase, such as erlotinib or gefitinib, are also studied. Furthermore, new molecules have been shown to be active against ATC, such as CLM94 and CLM3. However, more research is needed to finally identify therapies able to control and to cure this disease.

Sorafenib for the treatment of thyroid cancer: an updated review

INTRODUCTION

Sorafenib (Nexavar) is an oral multi-kinase inhibitor targeting B-type Raf kinase (BRAF) (both wild type and BRAF(V600E)), VEGFR1, VEGFR2, VEGFR3, PDGFRβ and RET (also RET/PTC) influencing both differentiated thyroid cancer (DTC) cell proliferation and angiogenesis.

AREAS COVERED

Encouraging results achieved in numerous Phase II trials were confirmed in a Phase III study conducted in radioiodine-refractory DTC. Sorafenib compared to placebo significantly prolongs progression-free survival, 10.8 versus 5.8 months, respectively. However, its administration resulted mainly in disease stabilization. No complete remission was obtained in any study. Beneficial effects were also demonstrated for medullary and anaplastic thyroid cancer; however further studies fulfilling evidence based medicine criteria are necessary. Its toxicity profile is convergent with other VEGFR inhibitors. The most common treatment-related side-effects involve skin toxicity (predominantly hand-foot skin reaction, different rashes and alopecia), gastrointestinal disturbances (diarrhea, abdominal pain), constitutional adverse reactions (anorexia, weight loss, fatigue) and hypertension. Although most adverse reactions are manageable, > 50% of patients required dose reduction.

EXPERT OPINION

Sorafenib constitutes the first line treatment option in advanced, radioiodine-refractory DTC. However, there are still no data on its efficacy in patients progressed after another tyrosine kinase inhibitor. Other applications of the drug, such as use as adjuvant therapy to 131-I treatment, requires further studies.

Molecular profiling of thyroid cancer subtypes using large-scale text mining

Background

Thyroid cancer is the most common endocrine tumor with a steady increase in incidence. It is classified into multiple histopathological subtypes with potentially distinct molecular mechanisms. Identifying the most relevant genes and biological pathways reported in the thyroid cancer literature is vital for understanding of the disease and developing targeted therapeutics.

Results

We developed a large-scale text mining system to generate a molecular profiling of thyroid cancer subtypes. The system first uses a subtype classification method for the thyroid cancer literature, which employs a scoring scheme to assign different subtypes to articles. We evaluated the classification method on a gold standard derived from the PubMed Supplementary Concept annotations, achieving a micro-average F1-score of 85.9% for primary subtypes. We then used the subtype classification results to extract genes and pathways associated with different thyroid cancer subtypes and successfully unveiled important genes and pathways, including some instances that are missing from current manually annotated databases or most recent review articles.

Conclusions

Identification of key genes and pathways plays a central role in understanding the molecular biology of thyroid cancer. An integration of subtype context can allow prioritized screening for diagnostic biomarkers and novel molecular targeted therapeutics. Source code used for this study is made freely available online at https://github.com/chengkun-wu/GenesThyCan.

Molecular diagnostics of fine needle aspiration for the presurgical screening of thyroid nodules

"The incidence of thyroid cancer, the most common endocrine malignancy, is rising. The two most common types of thyroid cancer are papillary and follicular" thyroid carcinomas. "Fine-needle aspiration (FNA) of thyroid nodules" can permit to detect many genetic mutations and other molecular alterations, including RAS and BRAF point mutations, PAX8/peroxisome proliferator-activated receptor (PPAR)γ and "RET/PTC rearrangements, occurring in thyroid papillary and follicular carcinomas" (more than 70% of cases), which can be used successfully to improve the diagnosis "and the management of patients with thyroid nodules". The most extensive experience has been accumulated with "the diagnostic use of BRAF mutation", which is highly specific for malignancy. "Testing FNA samples for a panel of mutations" that typically includes RAS, BRAF, PAX8/PPARγ and RET/PTC could permit to achieve the biggest diagnostic impact. "The accuracy of cancer diagnosis in thyroid nodules could be improved significantly using these and other emerging molecular markers".

Proteomics, and metabolomics: magnetic resonance spectroscopy for the presurgical screening of thyroid nodules

We review the progress and state-of-the-art applications of studies in Magnetic Resonance Spectroscopy (MRS) and Imaging as an aid for diagnosis of thyroid lesions of different nature, especially focusing our attention to those lesions that are cytologically undetermined. It appears that the high-resolution of High-Resolution Magic-Angle-Spinning (HRMAS) MRS improves the overall accuracy of the analysis of thyroid lesions to a point that a significant improvement in the diagnosis of cytologically undetermined lesions can be expected. This analysis, in the meantime, allows a more precise comprehension of the alterations in the metabolic pathways induced by the development of the different tumors. Although these results are promising, at the moment, a clinical application of the method to the common workup of thyroid nodules cannot be used, due to both the limitation in the availability of this technology and the wide range of techniques, that are not uniformly used. The coming future will certainly see a wider application of these methods to the clinical practice in patients affected with thyroid nodules and various other neoplastic diseases.

Molecular pathways associated with aggressiveness of papillary thyroid cancer

The most common thyroid malignancy is papillary thyroid cancer (PTC). Mortality rates from PTC mainly depend on its aggressiveness. Geno- and phenotyping of aggressive PTC has advanced our understanding of treatment failures and of potential future therapies. Unraveling molecular signaling pathways of PTC including its aggressive forms will hopefully pave the road to reduce mortality but also morbidity from this cancer. The mitogen-activated protein kinase and the phosphatidylinositol 3-kinase signaling pathway as well as the family of RAS oncogenes and BRAF as a member of the RAF protein family and the aberrant expression of microRNAs miR-221, miR-222, and miR-146b all play major roles in tumor initiation and progression of aggressive PTC. Small molecule tyrosine kinase inhibitors targeting BRAF-mediated events, vascular endothelial growth factor receptors, RET/PTC rearrangements, and other molecular targets, show promising results to improve treatment of radioiodine resistant, recurrent, and aggressive PTC.

Personalization of targeted therapy in advanced thyroid cancer

Although generally the prognosis of differentiated thyroid carcinoma (DTC) is good, approximately 5% of people are likely to develop metastases which fail to respond to radioactive iodine, and other traditional therapies, exhibiting a more aggressive behavior. Nowadays, therapy is chosen and implemented on a watch-and-wait basis for most DTC patients. Which regimen is likely to work best is decided on the basis of an individual's clinical information, but only data referring to outcomes of groups of patients are employed. To predict the best course of therapy, an individual patient's biologic data is rarely employed in a systematic way. Anyway, the use of not expensive individual genomic analysis could lead us to a new era of patient-specific and personalized care. Recently, key targets that are now being evaluated in the clinical setting have been evidenced in the pathogenesis of these diseases. Some of the known genetic alterations playing a crucial role in the development of thyroid cancer include B-Raf gene mutations, rearranged during transfection/ papillary thyroid carcinoma gene rearrangements, and vascular endothelial growth factor receptor-2 angiogenesis pathways. The development of targeted novel compounds able to induce clinical responses and stabilization of disease has overcome the lack of effective therapies for DTC, which are resistant to radioiodine and thyroid stimulating hormone-suppressive therapy. Interestingly, the best responses have been demonstrated in patients treated with anti-angiogenic inhibitors such as vandetanib and XL184 in medullary thyroid cancer, and sorafenib in papillary and follicular DTC.

Thyroid dysfunctions induced by tyrosine kinase inhibitors

INTRODUCTION

Recently, tyrosine kinase inhibitors (TKIs) have emerged as a new class of anticancer therapy. Although generally considered less toxic than cytotoxic chemotherapy, TKIs do cause significant side effects including fatigue and hypertension. In addition, thyroid dysfunction is a well-known adverse effect of TKI.

AREAS COVERED

This review provides a comprehensive assessment of TKI-induced thyroid dysfunctions by sunitinib, sorafenib, pazopanib, imatinib, dasatinib, nilotinib, vandetanib, axitinib, motesanib and tivozanib. Furthermore, the potential mechanisms that result in this toxicity, the clinical impact of thyroid dysfunction in these patients and the controversies regarding treatment with thyroid hormone (TH) therapy are evaluated.

EXPERT OPINION

Detection of TKI-induced thyroid dysfunction requires routine monitoring of thyroid function and may necessitate treatment. Potential benefits in developing thyroid dysfunction and potential harm in treating it necessitate controlled studies. Finally, if treatment is pursued, appropriate dosing and timing of TH replacement will require prospective clinical evaluation.

Clinical response to sunitinib as a multitargeted tyrosine-kinase inhibitor (TKI) in solid cancers: a review of clinical trials

Angiogenesis is an integral process in carcinogenesis, and molecular inhibitors of angiogenic factors are currently being tested as treatments for cancer. Sunitinib is an oral multitargeted tyrosine-kinase inhibitor that blocks activation through the stem cell-factor receptor (Kit) and platelet-derived growth-factor receptor. Sunitinib has shown potent antitumor activity against several solid tumors, including renal cell carcinoma, gastrointestinal stromal tumors, and neuroendocrine tumors in several Phase II/III trials. Recently, sunitinib has been used to treat other solid cancers, such as lung cancer, pancreatic cancer, chondrosarcoma, esophageal cancer, bladder cancer, glioma, and aggressive fibromatosis, and also showed potential efficacy in progression-free survival and overall survival. In this review, we examine the efficacy of sunitinib as a molecular-targeted therapy in patients with different types of solid cancers.

High prevalence of mTOR complex activity can be targeted using Torin2 in papillary thyroid carcinoma

The mammalian target of rapamycin (mTOR) signaling cascade is a key regulatory pathway controlling initiation of messenger RNA in mammalian cells. Although dysregulation of mTOR signaling has been reported earlier in cancers, there is paucity of data about mTOR expression in papillary thyroid carcinoma (PTC). Therefore, in this study, we investigated the presence of mTORC2 and mTORC1 complexes in a large cohort of >500 PTC samples. Our clinical data showed the presence of active mTORC1 and mTORC2 in 81 and 39% of PTC samples, respectively. Interestingly, coexpression of mTORC1 and mTORC2 activity was seen in a 32.5% (164/504) of the PTC studied and this association was statistically significant (P = 0.0244). mTOR signaling complex was also found to be associated with activated AKT and 4E-BP1. In vitro, using Torin2, a second-generation mTOR inhibitor or gene silencing of mTOR expression prevented mTORC1 and mTORC2 activity leading to inactivation of P70S6, 4E-BP1, AKT and Bad. Inhibition of mTOR activity led to downregulation of cyclin D1, a gene regulated by messenger RNA translation via phosphorylation of 4E-BP1. Torin2 treatment also inhibited cell viability and induced caspase-dependent apoptosis via activation of mitochondrial apoptotic pathway in PTC cells. Finally, Torin2 treatment induces anticancer effect on PTC xenograft tumor growth in nude mice via inhibition of mTORC1 and mTORC2 and its associated pathways. Our results suggest that coexpression of mTORC1 and mTORC2 is seen frequently in the clinical PTC samples and dual targeting of mTORC1 and mTORC2 activity may be an attractive therapeutic target for treatment of PTC.

The truncated isoform of somatostatin receptor5 (sst5TMD4) is associated with poorly differentiated thyroid cancer

Somatostatin receptors (ssts) are expressed in thyroid cancer cells, but their biological significance is not well understood. The aim of this study was to assess ssts in well differentiated (WDTC) and poorly differentiated thyroid cancer (PDTC) by means of imaging and molecular tools and its relationship with the efficacy of somatostatin analog treatment. Thirty-nine cases of thyroid carcinoma were evaluated (20 PDTC and 19 WDTC). Depreotide scintigraphy and mRNA levels of sst-subtypes, including the truncated variant sst5TMD4, were carried out. Depreotide scans were positive in the recurrent tumor in the neck in 6 of 11 (54%) PDTC, and in those with lung metastases in 5/11 cases (45.4%); sst5TMD4 was present in 18/20 (90%) of PDTC, being the most densely expressed sst-subtype, with a 20-fold increase in relation to sst2. In WDTC, sst2 was the most represented, while sst5TMD4 was not found; sst2 was significantly increased in PDTC in comparison to WDTC. Five depreotide positive PDTC received octreotide for 3–6 months in a pilot study with no changes in the size of the lesions in 3 of them, and a significant increase in the pulmonary and cervical lesions in the other 2. All PDTC patients treated with octreotide showed high expression of sst5TMD4. ROC curve analysis demonstrated that only sst5TMD4 discriminates between PDTC and WDTC. We conclude that sst5TMD4 is overexpressed in PDTC and may be involved in the lack of response to somatostatin analogue treatment.

Sorafenib in metastatic radioactive iodine-refractory differentiated thyroid cancer: A pilot study

The incidence and mortality of thyroid cancer are on the increase worldwide and the treatment options for progressive, radioactive iodine (RAI)-refractory metastatic differentiated thyroid cancer (DTC) patients are currently limited. Sorafenib is a multikinase inhibitor that targets several molecular signals, which are believed to be involved in the pathogenesis of DTC. In this study, we reported our experience with the off-label use of sorafenib in Chinese cancer patients. A total of 8 patients (7 with papillary and 1 with follicular thyroid cancer) were recruited in this study. The partial response (PR) rate was 50.0% and 5 of the 8 patients (62.5%) achieved a durable response. The median progression-free survival (PFS) and overall survival (OS) were 40.1 and 55.0 weeks, respectively. Lung metastases were more sensitive to sorafenib compared to lymph nodes. The tumor marker response was not in accordance with the radiological response, although patients with tumor marker complete response (CR) exhibited a longer PFS and OS compared to those without a CR. Common adverse events (AEs) included palmar-plantar erythrodysesthesia, hypertension, diarrhea, weight loss and alopecia. Grade 4 AEs comprised hypocalcemia (1 patient) and elevated amylase levels (1 patient). A dose reduction was required in 62.5% of the patients. In conclusion, sorafenib exhibited a clinically relevant antitumor activity in patients with progressive metastatic RAI-refractory DTC, although the majority of the patients required a dose reduction due to intolerable toxicity.

Biomarkers for anti-angiogenic therapy in cancer

Angiogenesis, the development of new vessels from existing vasculature, plays a central role in tumor growth, survival, and progression. On the molecular level it is controlled by a number of pro- and anti-angiogenic cytokines, among which the vascular endothelial growth factors (VEGFs), together with their related VEGF-receptors, have an exceptional position. Therefore, the blockade of VEGF signaling in order to inhibit angiogenesis was deemed an attractive approach for cancer therapy and drugs interfering with the VEGF-ligands, the VEGF receptors, and the intracellular VEGF-mediated signal transduction were developed. Although promising in pre-clinical trials, VEGF-inhibition proved to be problematic in the clinical context. One major drawback was the generally high variability in patient response to anti-angiogenic drugs and the rapid development of therapy resistance, so that, in total, only moderate effects on progression-free and overall survival were observed. Biomarkers predicting the response to VEGF-inhibition might attenuate this problem and help to further individualize drug and dosage determination. Although up to now no definitive biomarker has been identified for this purpose, several candidates are currently under investigation. This review aims to give an overview of the recent developments in this field, focusing on the most prevalent tumor species.

The Use of Sorafenib in the Thyroid Cancer

There are not effective therapies for metastatic unresectable, non-RAI-avid thyroid carcinomas. Fortunately, thyroid carcinomas represent a promising paradigm for targeted therapy due to the presence of activing mutations of genes coding the kinase tyrosines which are involved in all functions of cancer cells (such as: growth or invasion). In this paper an efficacy and toxicity of sorafenib, one of the multi-kinase inhibitors in thyroid carcinomas treatment is presented.

The effect of sorafenib treatment on the diabetic status of patients with renal cell or hepatocellular carcinoma

AIM

To evaluate the effect of sorafenib on the glucose tolerance and diabetic status of patients with metastatic renal cell carcinoma (RCC) or advanced hepatocellular carcinoma (HCC).

MATERIALS & METHODS

Eighty patients with metastatic RCC or advanced HCC received 400 mg sorafenib twice daily for an average of approximately 8 and 5 months, respectively; 22 had diabetes mellitus and three had prediabetes.

RESULTS

One of 55 nondiabetic patients, and one of three patients with impaired fasting glucose or impaired glucose tolerance developed diabetes mellitus, one of 12 patients on oral antihyperglycemic agents switched to insulin and no patient treated with insulin needed to increase their dose.

CONCLUSION

Sorafenib has the potential to be a feasible and safe treatment option for patients with advanced HCC or metastatic RCC and comorbid diabetes mellitus or prediabetes.