Interaction between tumor stage and age on survival outcomes of patients with anaplastic thyroid cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) is an aggressive, rare malignancy associated with rapid growth and metastasis, and a very poor prognosis. We investigated the clinical characteristics, survival outcomes and independent prognostic factors associated with anaplastic thyroid cancer.

AIM

To assess to what extent the interaction between age and tumor stage affects mortality.

METHODS

A total of 622 patients diagnosed with anaplastic thyroid cancer, between 2010 and 2017 were enrolled in our study by retrieving data from the Surveillance, Epidemiology and End Results (SEER) database. We analyzed demographics, clinical characteristics, overall mortality (OM) and cancer specific mortality (CSM) of ATC. Variables with a P value < 0.1 were incorporated into the multivariate cox model to determine the independent prognostic factors. Furthermore, we analyzed the interaction between age and tumor stage on mortality.

RESULTS

In the multivariate analyses, the divorced/separated population had a lower OM [hazard ratio (HR) = 0.63, 95%CI: 0.42-0.94, P < 0.05] and CSM (HR = 0.61, 95%CI: 0.40-0.92, P < 0.05). OM was higher in tumors with direct extension only (HR = 6.26, 95%CI: 1.29-30.42, P < 0.05) and tumors with distant spread (HR = 5.73, 95%CI: 1.34-24.51, P < 0.05). CSM was also higher in tumors with direct extension (HR = 5.05, 95%CI: 1.05-24.19, P < 0.05) and tumors with distant spread (HR = 4.57, 95%CI: 1.08-19.29, P < 0.05). Mortality was not adversely affected by lymph node involvement. OM was lower in patients who received radiation (HR = 0.66, 95%CI: 0.53-0.83, P < 0.01), chemotherapy (HR = 0.63, 95%CI: 0.50-0.79, P < 0.01) or surgery (HR = 0.53, 95%CI: 0.43-0.66, P < 0.01). CSM was also lower in patient who received radiation (HR = 0.64, 95%CI: 0.51-0.81, P < 0.01), chemotherapy (HR = 0.62, 95%CI: 0.50-0.78, P < 0.01) or surgery (HR = 0.51, 95%CI: 0.41-0.63, P < 0.01). There was no significant interaction between age and tumor stage that affected mortality.

CONCLUSION

In this large US SEER database retrospective study, we found the mortality to be higher in advanced stage tumors with direct extension and distant metastasis. However, patients who received aggressive therapy showed a better overall survival. The aim of our study is to emphasize the importance of detecting ATC at an early stage and provide aggressive therapy to these patients. Since advanced stage ATC is associated with a dismal prognosis, we emphasize the need for randomized control trials and development of novel therapies that will be used to treat ATC.

An Era of Advances in Systemic Therapies for Advanced Thyroid Cancer

Thyroid carcinomas comprise distinct pathologic subtypes. However, advancements in characterizing the molecular tumorigenesis of thyroid cancers have changed the treatment paradigm in the past decade. Genetic profiling has become an integral component of personalizing cancer care. Oral kinase inhibitors are currently standard-of-care therapies for progressive, radioactive iodine (RAI)-refractory differentiated thyroid carcinomas (DTCs) and medullary thyroid carcinomas (MTCs). Sorafenib, lenvatinib, and cabozantinib are multikinase inhibitors approved for patients with metastatic RAI-refractory DTC, whereas vandetanib and cabozantinib are approved for patients with MTC. Management of thyroid carcinomas has evolved such that targeted therapies have become therapeutic options for patients with BRAF, RET, NTRK, ALK, and ROS1 alterations and even have reported efficacy in anaplastic thyroid carcinomas. In this article, we review the advances made over the years in the treatment of metastatic thyroid carcinoma and focus on the systemic therapies that have recently transformed the treatment landscape of advanced disease.

Ruxolitinib induces apoptosis and pyroptosis of anaplastic thyroid cancer via the transcriptional inhibition of DRP1-mediated mitochondrial fission

Anaplastic thyroid carcinoma (ATC) has a 100% disease-specific mortality rate. The JAK1/2-STAT3 pathway presents a promising target for treating hematologic and solid tumors. However, it is unknown whether the JAK1/2-STAT3 pathway is activated in ATC, and the anti-cancer effects and the mechanism of action of its inhibitor, ruxolitinib (Ruxo, a clinical JAK1/2 inhibitor), remain elusive. Our data indicated that the JAK1/2-STAT3 signaling pathway is significantly upregulated in ATC tumor tissues than in normal thyroid and papillary thyroid cancer tissues. Apoptosis and GSDME-pyroptosis were observed in ATC cells following the in vitro and in vivo administration of Ruxo. Mechanistically, Ruxo suppresses the phosphorylation of STAT3, resulting in the repression of DRP1 transactivation and causing mitochondrial fission deficiency. This deficiency is essential for activating caspase 9/3-dependent apoptosis and GSDME-mediated pyroptosis within ATC cells. In conclusion, our findings indicate DRP1 is directly regulated and transactivated by STAT3; this exhibits a novel and crucial aspect of JAK1/2-STAT3 on the regulation of mitochondrial dynamics. In ATC, the transcriptional inhibition of DRP1 by Ruxo hampered mitochondrial division and triggered apoptosis and GSDME-pyroptosis through caspase 9/3-dependent mechanisms. These results provide compelling evidence for the potential therapeutic effectiveness of Ruxo in treating ATC.

Knockdown of KAT5/KIF11 induces autophagy and promotes apoptosis in anaplastic thyroid cancer cells

K (lysine) acetyltransferase (KAT) 5, which is a member of the KAT family of enzymes, has been found to act as a regulatory factor in various types of cancer. However, the role of KAT5 in anaplastic thyroid carcinoma (ATC) and its underlying mechanism is still elusive. The expression levels of KAT5 and kinesin family member 11 (KIF11) in ATC cells were assessed utilizing reverse transcription-quantitative PCR and western blot analyses. The cell proliferative ability was assessed via Cell Counting Kit-8 assay and using 5-ethynyl-2'-deoxyuridine staining. Flow cytometry and western blot analyses were applied for the assessment of cell apoptosis. Cell autophagy was investigated by employing western blot analysis and immunofluorescence staining. In addition, the enrichment of histone H3 lysine 27 acetylation (H3K27ac) and RNA polymerase II (RNA pol II) was analyzed by chromatin immunoprecipitation assay. It was shown that KAT5 expression was markedly increased in ATC cells. KAT5 depletion suppressed the cell proliferative capability but promoted the induction of apoptosis and autophagy. In addition, the autophagy inhibitor 3-methyladenine reversed the effects of KAT5 deficiency on the proliferative and apoptotic activities of 8505C cells. With regard to the mechanism, it was found that KAT5 inhibited the expression of KIF11 by repressing the enrichment of H3K27ac and RNA pol II. Upregulation of KIF11 expression reversed the effects of KAT5 silencing on the proliferative activity, apoptosis and autophagy of 8505C cells. In conclusion, the results indicated that KAT5 induced autophagy and promoted apoptosis of ATC cells by targeting KIF11, which may provide a promising target for the treatment of ATC.

BI-847325, a selective dual MEK and Aurora kinases inhibitor, reduces aggressive behavior of anaplastic thyroid carcinoma on an in vitro three-dimensional culture

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is the most aggressive subtype of thyroid cancer. In this study, we used a three-dimensional in vitro system to evaluate the effect of a dual MEK/Aurora kinase inhibitor, BI-847325 anticancer drug, on several cellular and molecular processes involved in cancer progression.

METHODS

Human ATC cell lines, C643 and SW1736, were grown in alginate hydrogel and treated with IC₅₀ values of BI-847325. The effect of BI-847325 on inhibition of kinases function of MEK1/2 and Aurora kinase B (AURKB) was evaluated via Western blot analysis of phospho-ERK1/2 and phospho-Histone H3 levels. Sodium/iodide symporter (NIS) and thyroglobulin (Tg), as two thyroid-specific differentiation markers, were measured by qRT-PCR as well as flow cytometry and immunoradiometric assay. Apoptosis was assessed by Annexin V/PI flow cytometry and BIM, NFκB1, and NFκB2 expressions. Cell cycle distribution and proliferation were determined via P16, AURKA, and AURKB expressions as well as PI and CFSE flow cytometry assays. Multidrug resistance was evaluated by examining the expression of MDR1 and MRP1. Angiogenesis and invasion were investigated by VEGF expression and F-actin labeling with Alexa Fluor 549 Phalloidin.

RESULTS

Western blot results showed that BI-847325 inhibits MEK1/2 and AURKB functions by decreasing phospho-ERK1/2 and phospho-Histone H3 levels. BI-847325 induced thyroid differentiation markers and apoptosis in ATC cell lines. Inversely, BI-847325 intervention decreased multidrug resistance, cell cycle progression, proliferation, angiogenesis, and invasion at the molecular and/or cellular levels.

CONCLUSION

The results of the present study suggest that BI-857,325 might be an effective multi-targeted anticancer drug for ATC treatment.

Efficacy and safety of larotrectinib in patients with TRK fusion-positive thyroid carcinoma

OBJECTIVE

Larotrectinib is a highly selective tropomyosin receptor kinase (TRK) inhibitor with demonstrated efficacy across various TRK fusion-positive solid tumours. We assessed the efficacy and safety of larotrectinib in patients with TRK fusion-positive thyroid carcinoma (TC).

METHODS

We pooled data from three phase I/II larotrectinib clinical trials (NCT02576431, NCT02122913, and NCT02637687). The primary endpoint was the investigator-assessed objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included duration of response (DoR), progression-free survival (PFS), overall survival (OS), and safety. Data cut-off: July 2020.

RESULTS

Twenty-nine patients (median age: 60; range: 6-80) with TRK fusion-positive TC were treated. Tumour histology was papillary (PTC) in 20 (69%) patients, follicular (FTC) in 2 (7%), and anaplastic (ATC) in 7 (24%) patients. Among 28 evaluable patients, ORR was 71% (95% CI: 51-87); best responses were complete response in 2 (7%) patients, partial response in 18 (64%), stable disease in 4 (14%), progressive disease in 3 (11%), and undetermined in 1 (4%) due to clinical progression prior to the first post-baseline assessment. ORR was 86% (95% CI: 64-97) for PTC/FTC and 29% (95% CI 4-71) for ATC. Median time to response was 1.87 months (range 1.64-3.68). The 24-month DoR, PFS, and OS rates were 81, 69, and 76%, respectively. Treatment-related adverse events were mainly grades 1-2.

CONCLUSION

In TRK fusion-positive TC, larotrectinib demonstrates rapid and durable disease control and a favourable safety profile in patients with advanced disease requiring systemic therapy.

SIGNIFICANCE STATEMENT

NTRK gene fusions are known oncogenic drivers and have been identified in various histologies of thyroid carcinoma, most commonly in papillary thyroid carcinoma. This is the first publication specifically studying a TRK inhibitor in a cohort of TRK fusion-positive thyroid carcinoma patients. In the current study, the highly selective TRK inhibitor larotrectinib showed durable antitumour efficacy and a favourable safety profile in patients with TRK fusion-positive thyroid carcinoma. Our findings show that patients with advanced non-medullary thyroid carcinoma who may require systemic therapy could be considered for testing for gene fusions by next-generation sequencing.

Anaplastic Thyroid Carcinoma: An Update

Anaplastic thyroid carcinoma (ATC) is a rare and undifferentiated form of thyroid cancer. Its prognosis is poor: the median overall survival (OS) of patients varies from 4 to 10 months after diagnosis. However, a doubling of the OS time may be possible owing to a more systematic use of molecular tests for targeted therapies and integration of fast-track dedicated care pathways for these patients in tertiary centers. The diagnostic confirmation, if needed, requires an urgent biopsy reread by an expert pathologist with additional immunohistochemical and molecular analyses. Therapeutic management, defined in multidisciplinary meetings, respecting the patient's choice, must start within days following diagnosis. For localized disease diagnosed after primary surgical treatment, adjuvant chemo-radiotherapy is recommended. In the event of locally advanced or metastatic disease, the prognosis is very poor. Treatment should then involve chemotherapy or targeted therapy and decompressive cervical radiotherapy. Here we will review current knowledge on ATC and provide perspectives to improve the management of this deadly disease.

Exosome-mediated delivery of SCD-1 siRNA promoted the death of anaplastic thyroid carcinoma cells via regulating ROS level

PURPOSE

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive cancers in the world. Stearoyl-CoA desaturase-1 (SCD-1) is one of major enzymes in the de novo synthesis of fatty acids and is related to cancer aggressiveness and poor patient prognosis. The study aimed to construct exosomes loaded SCD-1 interference, investigate its effects and mechanisms on the cell proliferation and apoptosis of ATC cells.

METHODS

The expressions of SCD-1 in normal thyroid cell line and ATC cell lines were determined by qRT-PCR and western blotting, respectively. Exosomes were prepared and purification then loaded with SCD-1 siRNA by electroporation and observed by transmission electron microscopy. Higher SCD-1 mRNA and protein levels were found in ATC cell lines compared than normal thyroid cell line (P < 0.05), and both Hth-7 and FRO cells could uptake PKH67-labeled exosomes. The effects of exosomes loaded SCD-1 siRNA on ATC cells were measured by CCK8 assay and apoptosis detection kit.

RESULTS

When compared with control group, the cell viability significantly decreased in both two ATC cell lines taken up exosomes loaded SCD-1 siRNA (P < 0.001), and apoptotic and necrotic cells obviously increased (P < 0.05). In order to explore the mechanism of exosomes loaded SCD-1 on ATC, the ROS level was detected by fluorescence reagent. It was found that exosomes loaded SCD-1 siRNA significantly increased intracellular ROS level of ATC cells (P < 0.05).

CONCLUSIONS

Exosomes loaded SCD-1 siRNA inhibited ATC cellular proliferation and promoted cellular apoptosis, and the mechanisms involved maybe the regulation of fatty acids metabolism and ROS level. Our study provides a promising therapeutic strategy for ATC.

Long noncoding RNA landscapes specific to benign and malignant thyroid neoplasms of distinct histological subtypes

The main types of thyroid neoplasms, follicular adenoma (FA), follicular thyroid carcinoma (FTC), classical and follicular variants of papillary carcinoma (clPTC and fvPTC), and anaplastic thyroid carcinoma (ATC), differ in prognosis, progression rate and metastatic behaviour. Specific patterns of lncRNAs involved in the development of clinical and morphological features can be presumed. LncRNA landscapes within distinct benign and malignant histological variants of thyroid neoplasms were not investigated. The aim of the study was to discover long noncoding RNA landscapes common and specific to major benign and malignant histological subtypes of thyroid neoplasms. LncRNA expression in FA, FTC, fvPTC, clPTC and ATC was analysed with comprehensive microarray and RNA-Seq datasets. Putative biological functions were evaluated via enrichment analysis of coexpressed coding genes. In the results, lncRNAs common and specific to FTC, clPTC, fvPTC, and ATC were identified. The discovered lncRNAs are putatively involved in L1CAM interactions, namely, pre-mRNA processing (lncRNAs specific to FTC); PCP/CE and WNT pathways (lncRNAs specific to fvPTC); extracellular matrix organization (lncRNAs specific to clPTC); and the cell cycle (lncRNAs specific to ATC). Known oncogenic and suppressor lncRNAs (RMST, CRNDE, SLC26A4-AS1, NR2F1-AS1, and LINC00511) were aberrantly expressed in thyroid carcinomas. These findings enhance the understanding of lncRNAs in the development of subtype-specific features in thyroid cancer.

Study on the Antitumor Effect and Glycolysis of Andrographolide in Anaplastic Thyroid Carcinoma

OBJECTIVE

To investigate the antitumor effect of andrographolide on the ATC cell lines 8505C and CAL62 and to explore the possible mechanism of the effect.

METHODS

CCK8 and colony formation assays were performed to detect proliferation. Cell migration was tested by scratch assay. Annexin V/PI staining was used to detect cell apoptosis and cell cycle. Glucose and lactic acid kits were carried out to evaluate the glycolysis level after andrographolide treatment. Western blot was used to detect the changes in the apoptosis-related proteins and glycolysis-related enzymes in both 8505C and CAL62 cells.

RESULTS

Treatment with 60 μM andrographolide had significant effects on 8505C and CAL62, including inhibition of proliferation, inhibition of migration, arrest of the cell cycle, promotion of apoptosis, and inhibition of glycolysis.

CONCLUSION

Andrographolide has an antitumor effect and can significantly affect glycolysis in ATC cells.

Combination of Lenvatinib and Pembrolizumab Is an Effective Treatment Option for Anaplastic and Poorly Differentiated Thyroid Carcinoma

Background: Anaplastic thyroid carcinoma (ATC) and metastatic poorly differentiated thyroid carcinomas (PDTCs) are rare aggressive malignancies with poor overall survival (OS) despite extensive multimodal therapy. These tumors are highly proliferative, with frequently increased tumor mutational burden (TMB) compared with differentiated thyroid carcinomas, and elevated programmed death ligand 1 (PD-L1) levels. These tumor properties implicate responsiveness to antiangiogenic and antiproliferative multikinase inhibitors such as lenvatinib, and immune checkpoint inhibitors such as pembrolizumab. Patients and Methods: In a retrospective study, we analyzed six patients with metastatic ATC and two patients with PDTC, who received a combination therapy of lenvatinib and pembrolizumab. Lenvatinib was started at 14-24 mg daily and combined with pembrolizumab at a fixed dose of 200 mg every three weeks. Maximum treatment duration with this combination was 40 months, and 3 of 6 ATC patients are still on therapy. Patient tumors were characterized by whole-exome sequencing and PD-L1 expression levels (tumor proportion score [TPS] 1-90%). Results: Best overall response (BOR) within ATCs was 66% complete remissions (4/6 CR), 16% stable disease (1/6 SD), and 16% progressive disease (1/6 PD). BOR within PDTCs was partial remission (PR 2/2). The median progression-free survival was 17.75 months for all patients, and 16.5 months for ATCs, with treatment durations ranging from 1 to 40 months (1, 4, 11, 15, 19, 25, 27, and 40 months). Grade III/IV toxicities developed in 4 of 8 patients, requiring dose reduction/discontinuation of lenvatinib. The median OS was 18.5 months, with three ATC patients being still alive without relapse (40, 27, and 19 months) despite metastatic disease at the time of treatment initiation (UICC and stage IVC). All patients with long-term (>2 years) or complete responses (CRs) had either increased TMB or a PD-L1 TPS >50%. Conclusions: Our results implicate that the combination of lenvatinib and pembrolizumab might be safe and effective in patients with ATC/PDTC and can result in complete and long-term remissions. The combination treatment is now being systematically examined in a phase II clinical trial (Anaplastic Thyroid Carcinoma Lenvatinib Pembrolizumab [ATLEP]) in ATC/PDTC patients.

Presentation and outcomes of patients with undifferentiated thyroid carcinoma: a national perspective

Background

Undifferentiated thyroid cancer (UTC) accounts for only 1-2% of all thyroid cancers. UTC is one of the most aggressive solid tumors with high metastatic rates and mortality. The objectives of this study are to examine the characteristics of patients with UTC and their overall survival.

Methods

Retrospective analysis utilizing the National Cancer Database, 2004-2014 is performed. The study population included adults (≥18 years) patients with UTC or differentiated thyroid carcinoma (DTC), which served as a reference group.

Results

A total of 1,870 UTC and 209,707 DTC patients were identified. The median follow-up time of UTC patients was 3.9 months (interquartile range: 1.6-9.0 months). When compared to DTC patients, patients with UTC were more likely to be ≥45-year-old [OR: 48.62, 95% CI: (35.75, 66.14), P<0.001], male [OR: 2.02, 95% CI: (1.84, 2.22), P<0.001], and/or black [OR: 1.27, 95% CI: (1.08, 1.49), P=0.004]. UTC patients were more likely to have Medicaid/Medicare or no insurance and treated in low-volume hospitals (P<0.001). Overall survival in patients with UTC was lower in patients older than 65 years [OR: 1.63, 95% CI: (1.12, 2.38), P=0.011], with multiple comorbidities [OR: 1.65, 95% CI: (1.02, 2.67), P=0.040] and/or presented with metastatic disease [OR: 1.93, 95% CI: (1.71, 2.17), P<0.001]. Compared to thyroidectomy alone, patients without metastasis who received adjuvant radiotherapy and/or chemotherapy had a better overall survival (P<0.001 each). In patients with metastatic disease, any intervention or combination of interventions other than thyroidectomy alone improved survival (P<0.05).

Conclusions

Older age, male, and/or black are associated with a higher prevalence of UTC compared to DTC. Although overall survival is poor in UTC, utilization of multi-modal treatment may improve survival.

Personalized radioiodine therapy for thyroid cancer patients with known disease

Radioactive iodine (RAI) ¹³¹I is a targeted therapy for patients with RAI-avid follicular cell-derived thyroid cancer. However, the responsiveness to ¹³¹I therapy varies among thyroid cancer patients mainly owing to differential RAI uptake and RAI radiosensitivity among patients’ lesions. A personalized approach to maximize ¹³¹I therapeutic efficacy is proposed based on recent scientific advances and future opportunities.

Small bowel perforation and death caused by anaplastic thyroid carcinoma metastasis in a patient with concomitant colonic and bilateral breast carcinoma

Undifferentiated or anaplastic thyroid carcinoma (ATC) is rare and one of the most aggressive human malignancies. The tumor is usually voluminous and fast-growing and mostly affects older women. The most common sites of distant metastases are the lungs, brain, and bones. Herein, we describe the case of a 66-year-old woman with a history of bilateral breast carcinoma and ATC, who presented with an acute abdomen and subsequently died. At autopsy, an isolated metastasis of ATC in the small intestine leading to bowel perforation was found. Moreover, there was adenocarcinoma in the descending colon. The review of extra-abdominal malignancies metastasizing to bowel and coincidence of breast and thyroid carcinoma is included.

IGF2BP1 is the first positive marker for anaplastic thyroid carcinoma diagnosis

Anaplastic thyroid carcinomas (ATC) are rare, but represent the most lethal malignancy of the thyroid. Selective molecular markers and drivers distinguishing ATC from other thyroid carcinomas of follicular origin remain largely unknown, limiting advances in diagnosis and treatment. In a retrospective study, we analyzed gene expression in 36 ATC, 18 poorly differentiated, 132 papillary, and 55 follicular thyroid carcinoma, as well as 124 paired and unpaired normal thyroid tissues in three independent cohorts by RNA-sequencing and immunohistochemistry. RNA-sequencing data in the test cohort suggested selective ATC protein biomarkers. Evaluation of these revealed that ATCs are characterized by the de novo expression of various testis antigens, including melanoma-associated antigen A3 (MAGEA3), but most importantly the oncofetal IGF2 mRNA binding protein 1 (IGF2BP1). Shallow whole genome sequencing essentially excluded that IGF2BP1 upregulation results from gene copy number alterations. Immunohistochemical analyses in all three tumor cohorts confirmed the selective de novo expression of IGF2BP1 protein in ATC. In sum, 75% (27/36) of all tested ATC and 0.5% (1/204) of poorly and well-differentiated thyroid carcinoma tissue samples were positive for IGF2BP1 protein. This indicates that IGF2BP1 protein expression identifies ATC with a diagnostic odds ratio of 612 (95% CI: 74.6-5021). In addition, we found that MAGEA3 is exclusively, although less consistently upregulated in ATC, presenting with an odds ratio of 411 (95% CI: 23.8-7098.7). Importantly, we provide confirmatory evidence that IGF2BP1 and MAGEA3 expression distinguishes ATC from poorly differentiated thyroid carcinoma. IGF2BP1 furthermore identified ATC foci within low-grade follicular thyroid carcinoma. In conclusion, IGF2BP1 represents the most promising single-gene marker available for ATC, followed by MAGEA3, improving on current techniques. Robust markers are essential to help distinguish this high-grade malignancy from other thyroid carcinomas, to guide surgical decision making, therapy and post-resection/therapy monitoring strategies.

A study of 17 cases for the identification of prognostic factors for anaplastic thyroid carcinoma

Anaplastic thyroid cancer (ATC) has a poor prognosis. ATC accounts for only 1-2% of all thyroid carcinomas, yet it is one of the most lethal neoplasms in humans. Notably, there are no established treatment protocols for ATC. The present study investigated the prognostic and predictive factors of ATC. A retrospective analysis was conducted on 17 patients with histologically confirmed ATC. The median overall survival of all patients was 3.8 months. In patients under the age of 70 years, the statistically significant prognostic factors indicating longer survival were the absence of distant metastasis and treatment by radical resection. Furthermore, in contrast to previous findings, tumor size and white blood cell count were not associated with ATC prognosis in the present cohort. Importantly, tracheostomy did not contribute to improvement of prognosis and should perhaps not be considered, when unnecessary, to preserve the patient's quality of life. Prognostic factors for ATC are critical to clinicians to enable them to determine which patients will benefit from aggressive treatment strategies, as opposed to supportive care.

Bilateral pneumothorax in a patient with anaplastic thyroid carcinoma and lung metastasis during lenvatinib therapy: a case report

The prognosis of anaplastic thyroid carcinoma (ATC) is very poor. In most patients, ATC presents with cervical lymph node metastasis, and more than 40% of patients have distant metastasis at the time of diagnosis. Lenvatinib, a multi-targeted tyrosine kinase inhibitor, is a novel drug that has antitumor effects on radioactive iodine-refractory papillary cancer and anaplastic cancer. The development of bilateral pneumothorax during targeted therapy is very rare in patients with thyroid cancer. We recently encountered a case of bilateral pneumothorax in a patient with ATC and lung metastasis during lenvatinib therapy. The patient underwent video-assisted thoracoscopic surgery (VATS) in both the lungs because the pneumothorax continued to aggravate even after the insertion of chest tubes. Clinicians need to be aware that the development of pneumothorax is a possibility during lenvatinib therapy for ATC and lung metastasis. The case is reported herein, along with a review of relevant literature.

Updates on the Management of Thyroid Cancer

The diagnostic modalities, stratification tools, and treatment options for patients with thyroid cancer have rapidly evolved since the development of the American Thyroid Association (ATA) guidelines in 2015. This review compiles newer concepts in diagnosis, stratification tools and treatment options for patients with differentiated thyroid cancer (DTC), medullary thyroid carcinoma (MTC) and anaplastic thyroid cancer (ATC). Newer developments apply precision medicine in thyroid cancer patients to avoid over-treatment in low risk disease and under-treatment in high risk disease. Among novel patient-tailored therapies are selective RET inhibitors that have shown efficacy in the treatment of MTC with limited systemic toxicity compared with non-specific tyrosine kinase inhibitors. The combination of BRAF and MEK inhibitors have revolutionized management of BRAF V600E mutant ATC. Several immunotherapeutic agents are being actively investigated in the treatment of all forms of thyroid cancer. In this review, we describe the recent advances in the diagnosis and management of DTC, MTC, and ATC, with an emphasis on novel treatment modalities.

Sesquiterpene Lactones from Calea pinnatifida: Absolute Configuration and Structural Requirements for Antitumor Activity

This work describes the chromatographic fractionation of the aerial parts of Calea pinnatifida and the structural characterization and determination of the absolute configuration of the isolated compounds as well as their antitumor potential. The HPLC fractionation of the CH₂Cl₂ phase of the MeOH extract from the leaves of C. pinnatifida led to the isolation of two related sesquiterpene lactones (STLs): calein C (1) and calealactone B (2). Additionally, during the purification process, a derivative of calein C (3) was formed as a product of the Michael addition of MeOH. The structures of Compounds 1–3 were established based on spectroscopic and spectrometric data, while the absolute stereochemistry was established by vibrational circular dichroism. In order to evaluate the effect of the conjugated double bonds on the cytotoxic activity of STLs, Compounds 1–3 were tested against anaplastic (KTC-2) and papillary (TPC-1) thyroid carcinoma cells. Calein C was the most active of the STLs, and displayed activity against both KTC-2 and TPC-1. On the other hand, the calein C derivative (3) was the least cytotoxic of all the compounds tested. These results are promising and suggest the importance of studying sesquiterpene lactones isolated from C. pinnatifida in terms of antitumor activity, especially considering the effects of α,β-unsaturated carbonyl systems.

The role of immune checkpoint inhibitors in anaplastic thyroid cancer (Case Series)

Anaplastic thyroid carcinoma (ATC) is a rare type of thyroid neoplasm. However, it is one of the most aggressive forms of malignancy accounting for approximately 50% of mortality associated with all thyroid cancers. Here we report two cases of ATC treated with immune checkpoint inhibitors. Next generation sequencing identified BRAFV600E mutation in one of the patients who also derived benefit from BRAF targeted therapy. We here discuss these cases highlighting the importance of expert pathological review, utilizing molecular testing to identify the underlying genetic targets for personalized therapy, and the potential role of PD-1 inhibitors for the treatment of ATC.

Effect of mesoporous silica nanoparticles co‑loading with 17‑AAG and Torin2 on anaplastic thyroid carcinoma by targeting VEGFR2

Anaplastic thyroid carcinoma (ATC) is a highly aggressive tumor with a poor prognosis and a low median survival rate because of insufficient effective therapeutic modalities. Recently, mesoporous silica nanoparticles (MSNs) as a green non-toxic and safe nanomaterial have shown advantages to be a drug carrier and to modify the targeting group to the targeted therapy. To aim of the study was to explore the effects of MSNs co-loading with 17-allylamino-17-demethoxy-geldanamycin (17-AAG; HSP90 inhibitor) and 9-(6-aminopyridin-3-yl)-1-(3-(trifluoromethyl)phenyl)benzo[h][1,6]naphthyridin-2(1H)-one (Torin2; mTOR inhibitor) by targeting vascular endothelial growth factor receptor 2 (VEGFR2) on the viability of human anaplastic thyroid carcinoma FRO cells. The cytotoxicity of 17-AAG and Torin2 were analyzed by MTT assay. The possible synergistic antitumor effects between 17-AAG and Torin2 were evaluated by CompuSyn software. Flow cytometry was performed to assess the VEGFR2 targeting of (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab and uptake by FRO cells. An ATC xenograft mouse model was established to assess the antitumor effect of (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab in vivo. The results revealed that the combination of 17-AAG and Torin2 inhibited the growth of FRO cells more effectively compared with single use of these agents. Additionally, the synergistic antitumor effect appeared when concentration ratio of the two drugs was 1:1 along with total drug concentration greater than 0.52 µM. Furthermore, in an ATC animal model, it was revealed that the (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab therapy modality could most effectively prolong the median survival time [39.5 days vs. 33.0 days (non-targeted) or 27.5 days (control)]. Compared to (17-AAG+Torin2)@MSNs, the (17-AAG+Torin2)@MSNs-anti-VEGFR2 ab could not only inhibit ATC cell growth but also prolong the median survival time of tumor-bearing mice in vivo and vitro more effectively, which may provide a new promising therapy for ATC.

Current Insights into Combination Therapies with MAPK Inhibitors and Immune Checkpoint Blockade

The recent development of high-throughput genomics has revolutionized personalized medicine by identifying key pathways and molecular targets controlling tumor progression and survival. Mitogen-activated protein kinase (MAPK) pathways are examples of such targets, and inhibitors against these pathways have shown promising clinical responses in patients with melanoma, non-small-cell lung cancer, colorectal cancer, pancreatic cancer, and thyroid cancer. Although MAPK pathway-targeted therapies have resulted in significant clinical responses in a large proportion of cancer patients, the rate of tumor recurrence is high due to the development of resistance. Conversely, immunotherapies have shown limited clinical responses, but have led to durable tumor regression in patients, and complete responses. Recent evidence indicates that MAPK-targeted therapies may synergize with immune cells, thus providing rationale for the development of combination therapies. Here, we review the current status of ongoing clinical trials investigating MAPK pathway inhibitors, such as BRAF and MAPK/ERK kinase (MEK) inhibitors, in combination with checkpoint inhibitors targeting programmed death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), and cytotoxic T cell associated antigen-4 (CTLA-4). A better understanding of an individual drug's mechanism of action, patterns of acquired resistance, and the influence on immune cells will be critical for the development of novel combination therapies.

Combinatorial Therapies in Thyroid Cancer: An Overview of Preclinical and Clinical Progresses

Accounting for about 2% of cancers diagnosed worldwide, thyroid cancer has caused about 41,000 deaths in 2018. Despite significant progresses made in recent decades in the treatment of thyroid cancer, many resistances to current monotherapies are observed. In our complete review, we report all treatments that were tested in combination against thyroid cancer. Many preclinical studies investigating the effects of inhibitors of the MAPK and PI3K pathways highlighted the importance of mutations in such signaling pathways and their impacts on the subsequent efficacy of targeted therapies, thus reinforcing the need of more personalized therapeutic strategies. Our review also points out the multiple possibilities of combinatory strategies, particularly using therapies targeting proliferation, survival, angiogenesis, and in combination with conventional treatments such as chemotherapies. In any case, resistances to anticancer therapies always develop through the activation of alternative signaling pathways. Combinatory treatments aim to blockade such mechanisms, which are gradually decrypted, thus offering new perspectives for the future. The preclinical and clinical aspects of our review allow us to have a global opinion of the different therapeutic options currently evaluated in combination and to be aware about new perspectives of treatment of thyroid cancer.

Anaplastic thyroid carcinoma: changing trends of treatment strategies and associated overall survival

PURPOSE

The prognosis of anaplastic thyroid cancer (ATC) is poor. Despite various attempts to modify common treatment modalities, including surgery, external beam radiation (EBRT) and chemotherapy (CTX), no standardized treatment is yet established. This study aimed to analyze the changing trends of treatment concepts and associated overall survival (OS) over the last two decades.

METHODS

A retrospective analysis was conducted on 42 patients with histologically confirmed ATC. The outcome measures included the evaluation of clinical characteristics and treatments performed with regard to OS.

RESULTS

Median OS for all tumor stages was 6 (range 1 week-79) months, 6.5 months for stage IVA/B and 4 months for stage IVC carcinoma patients. Twenty-one patients with stage IVA/B carcinomas underwent curative treatment, including thyroidectomy with lymphadenectomy (TTX plus LAD, n = 11) or multimodal treatment with TTX plus LAD and EBRT plus/minus CTX (n = 10). The median OS of patients with stage IVA/B carcinomas was significantly prolonged after multimodal treatment than after surgery alone (25 vs. 3 months, p = 0.04). Fifteen of 18 patients with stage IVC carcinomas received palliative, 3 patients multimodal treatment. The median OS of stage IVC patients after trimodal therapy was not significantly longer than after debulking procedures (6 vs. 7 months, p = 0.25). In the time period 1999-2009, only 4 (21%) patients received multimodal treatment compared to 9 (39%) in the period from 2009 to 2019, but this did not result in a significantly prolonged survival in the latter period (8.5 vs. 15 months, p = 0.61).

CONCLUSION

Concurrent radio- and/or chemotherapy in combination with surgery seems to result in improved survival in stage IVA/B ATC, whereas this is not the case in patients with stage IVC tumors. Novel treatment regimens are urgently needed to improve the dismal prognosis of ATC.

Antimalarial drug artesunate is effective against chemoresistant anaplastic thyroid carcinoma via targeting mitochondrial metabolism

Anaplastic thyroid carcinoma (ATC) is the most aggressive type of thyroid malignancies and resistant to chemotherapy. Novel therapeutic strategy is required for better management of ATC. In this work, we show that artesunate, an antimalarial drug, is active against chemoresistant ATC cells. Artesunate dose-dependently inhibits growth and induces apoptosis in chemo-sensitive (8505C and KAT-4) and -resistant (8505C-r and KAT-4-r) ATC cells, and acts synergistically with doxorubicin. Using multiple xenograft mouse models, artesunate is active against chemo-sensitive and -resistant ATC cells in vivo at doses that do not cause toxicity in mice. Our mechanism analysis reveals that artesunate acts on ATC cells through suppressing mitochondrial functions without affecting glycolysis, leading to oxidative stress and damage, regardless of whether they are sensitive or resistant to chemotherapy. Interestingly, KAT-4-r cells demonstrate decreased glycolysis, increased mitochondrial membrane potential and mitochondrial respiration compared to KAT-4 cells whereas such phenomenon is not observed between 8505C and 8505C-r cells. This suggests that some but not all ATC cells gain enhanced mitochondrial biogenesis after prolonged exposure to chemotherapy drug, which may explain the different sensitivities of 8505C-r and KAT-4-r to artesunate. Our work demonstrates that artesunate is a potential addition to the treatment armamentarium for ATC, particularly those with chemoresistance. Our findings also highlight the therapeutic value of targeting mitochondria in chemoresistant ATC.

Adjuvant external beam radiotherapy for surgically resected, nonmetastatic anaplastic thyroid cancer

BACKGROUND

EBRT in resected, nonmetastatic anaplastic thyroid cancer (ATC) remains undefined. We evaluated patterns/outcomes with EBRT and chemotherapy in this setting.

METHODS

This retrospective analysis included patients identified from the National Cancer Database with nonmetastatic ATC from 2004 to 2014 who underwent non-palliative resection.

RESULTS

Our analysis included 496 patients, including 375 who underwent adjuvant EBRT (among whom 198 received concurrent chemotherapy). The median age was 68 years. On MVA, EBRT was associated with sex (OR 0.5, 95% CI 0.3-0.8, P = .002) and income (OR 2.2, 95% CI 1.4-3.3, P < .001). EBRT was associated with longer OS on UVA (12.3 vs 9.1 months, P = .004) and MVA (HR 0.7 [CI 0.6-0.9], P = .004). Concurrent chemoradiation was associated with longer OS on UVA (14.0 vs 9.1 months, P = .003) and MVA (HR 0.6 [CI 0.5-0.8], P < .001).

CONCLUSION

Adjuvant EBRT is associated with longer OS in resected, nonmetastatic ATC, with additional improved survival with concurrent chemotherapy.

Anaplastic Thyroid Carcinoma Histologically Mimicking a Plasmacytoma

Anaplastic (undifferentiated) thyroid carcinoma (ATC) is a rare malignancy which may arise from transformation of a pre-existing differentiated carcinoma. We report the unique case where a lesion of thyroid origin presented with the histological features of mature plasma cells. Immunohistochemistry confirmed the lesion to be an anaplastic thyroid carcinoma arising from papillary thyroid carcinoma. A tumor mimicking a malignancy of a different cellular origin can lead clinicians to incorrect treatment approaches. Careful correlation with clinical details and knowledge of these unique presentations is important for reaching the correct diagnosis.

A Novel Multimodal Therapy for Anaplastic Thyroid Carcinoma: 125 I Seed Implantation Plus Apatinib After Surgery

Anaplastic thyroid cancer is known to be the most lethal malignancy among endocrine tumors for its extremely limited survival rate after diagnosis. As a result of this poor survival prognosis, multimodal therapy is currently under investigation to address this global concern. In this reported case, the ¹²⁵I seed implantation and vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor apatinib were co-applied to treat a 49-year-old woman with anaplastic thyroid cancer. After the patient began apatinib administration and underwent ¹²⁵I seed implantation twice, the tumor size shrank successfully. After a follow-up of 13 months since the initial diagnosis of anaplastic thyroid cancer, the patient survived with a stable disease pathology. In conclusion, this study supports ¹²⁵I seed implantation and apatinib as effective therapeutic alternatives for inoperable anaplastic thyroid cancer patients.

Dramatic Response to First Line Single Agent Pembrolizumab in Anaplastic Thyroid Carcinoma

Anaplastic thyroid carcinoma (ATC) is a deadly disease with very limited therapeutic options. There is an urgent need for new and efficacious drugs. Unfortunately accrual in clinical trials is problematic because of the rarity of the disease and often poor performance status at diagnosis. Recently some data have emerged suggesting a role for immunotherapy in the treatment of ATC. We describe the case of a 75-year-old patient with poor performance status and compromised airway and oesophagus at diagnosis, showing a rapid and dramatic response to first line single agent pembrolizumab. Disease progression in the brain occurred 16 months after initial diagnosis. At that time there was ongoing extracranial disease control.

BRMS1 downregulation is a poor prognostic biomarker in anaplastic thyroid carcinoma patients

Background

Anaplastic thyroid carcinoma (ATC) is the most aggressive cancer in humans with no optimal treatment strategy available. The molecular mechanisms of ATC remain unclear. The aim of this study was to investigate the prognostic value and role of BRMS1 in the progression of ATC.

Methods

BRMS1 expression was examined in thyroid cell lines using Western blot analysis. Immunohistochemistry was also performed to assess BRMS1 expression in ATC and papillary thyroid cancer (PTC) tissue. Cell proliferation assays, colony formation analysis, cell migration assays, cell apoptosis analysis, and animal studies were used to examine the effects of BRMS1 expression on ATC progression.

Results

The expression of BRMS1 was significantly lower in ATC than in PTC and was associated with poor prognosis in ATC patients. Downregulation of BRMS1 expression promoted the proliferation and migration of 8505C cells and decreased their expression of CX43. Over-expressed BRMS1 promoted the apoptosis and impaired the proliferation and migration of CAL-62 cells via upregulated CX43. In vivo, BRMS1 significantly promoted apoptosis and impaired cell proliferation.

Conclusion

Taken together, these findings demonstrate that decreased expression of BRMS1 is a poor prognostic biomarker in ATC patients. BRMS1 significantly promoted apoptosis and impaired cell proliferation via CX43 and P53. Loss of BRMS1 expression is therefore, one of the key pathomechanisms in ATC.

Anaplastic Thyroid Cancer: Clinical Picture of the Last Two Decades at a Single Oncology Referral Centre and Novel Therapeutic Options

Anaplastic thyroid cancer (ATC) is a rare tumour but also one of the most lethal malignancies. Therapeutic modalities have usually been limited, but clinical trials with new drugs are now being implemented. The aims of this study were to analyse the clinical presentation, therapeutic modalities and independent prognostic factors for survival. We also reviewed the most recent literature on novel ATC therapies. We performed a retrospective analysis of 79 patients diagnosed between 2000 and 2018. Variables with impact on survival were identified using the Cox proportional-hazard regression model. At presentation, 6.3% had thyroid-confined disease, 30.4% evidenced extrathyroidal extension and 60.8% were already metastatic. Surgery was feasible in 41.8% and radiotherapy was applied to 35.4%, with those receiving >45 Gy having longer estimated survival (p = 0.020). Chemotherapy, either conventional or with tyrosine kinase inhibitors, was performed in 17.7% and 7.6%, respectively. Multimodality therapy with surgery, radiotherapy and chemotherapy/tyrosine kinase inhibitors (TKI) had the greatest impact on disease specific survival (DSS), providing a risk reduction of death of 96.9% (hazard ratio (HR) = 0.031, 0.005–0.210, p < 0.001). We concluded that most of these patients join reference centres at advanced stages of disease and multimodality treatment may offer the best chances for prolonging survival.

Targeting CD47 in Anaplastic Thyroid Carcinoma Enhances Tumor Phagocytosis by Macrophages and Is a Promising Therapeutic Strategy

Background: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive human cancers, with a median survival of only three to six months. Standard treatment options and even targeted therapies have so far failed to improve long-term overall survival. Thus, novel treatment modalities for ATC, such as immunotherapy, are urgently needed. CD47 is a "don't eat me" signal, which prevents cancer cells from phagocytosis by binding to signal regulatory protein alpha on macrophages. So far, the role of macrophages and the CD47-signal regulatory protein alpha signaling axis in ATC is not well understood. Methods: This study analyzed 19 primary human ATCs for macrophage markers, CD47 expression, and immune checkpoints by immunohistochemistry. ATC cell lines and a fresh ATC sample were assessed by flow cytometry for CD47 expression and macrophage infiltration, respectively. CD47 was blocked in phagocytosis assays of co-cultured macrophages and ATC cell lines. Anti-CD47 antibody treatment was administered to ATC cell line xenotransplanted immunocompromised mice, as well as to tamoxifen-induced ATC double-transgenic mice. Results: Human ATC samples were heavily infiltrated by CD68- and CD163-expressing tumor-associated macrophages (TAMs), and expressed CD47 and calreticulin, the dominant pro-phagocytic molecule. In addition, ATC tissues expressed the immune checkpoint molecules programmed cell death 1 and programmed death ligand 1. Blocking CD47 promoted the phagocytosis of ATC cell lines by macrophages in vitro. Anti-CD47 antibody treatment of ATC xenotransplanted mice increased the frequency of TAMs, enhanced the expression of macrophage activation markers, augmented tumor cell phagocytosis, and suppressed tumor growth. In double-transgenic ATC mice, CD47 was expressed on tumor cells, and blocking CD47 increased TAM frequencies. Conclusions: Targeting CD47 or CD47 in combination with programmed cell death 1 may potentially improve the outcomes of ATC patients and may represent a valuable addition to the current standard of care.

Anticancer Effects of Baicalein in FRO Thyroid Cancer Cells Through the Up-regulation of ERK/p38 MAPK and Akt Pathway

BACKGROUND/AIM

The aim of the study was to evaluate the anticancer effects of baicalein in FRO anaplastic thyroid cancer (ATC) cells.

MATERIALS AND METHODS

FRO cells were treated with baicalein and viability was measured by the MTT assay. Cell apoptosis was observed by staining with Hoechst dye. The expression of apoptotic proteins (Bax, Bcl-2, PARP, cytochrome c, and caspase-3) and the inflammatory protein Cox-2 and the phosphorylation of MAPKs and Akt were determined by western blot.

RESULTS

Treatment with baicalein inhibited cell proliferation in a time-dependent manner and increased DNA fragmentation and apoptosis in FRO cells. Baicalein at 50 and 100 μM inhibited the expression of Bax, PARP, cytochrome c, cleaved caspase-3, and Cox-2, and increased the expression of Bcl-2. Baicalein increased the phosphorylation of ERK, p38 MAPK, and Akt and decreased JNK phosphorylation.

CONCLUSION

Baicalein caused anticancer effects in FRO ATC cells through induction of apoptosis and regulation of the MAPK and Akt pathway.

Targeting Super-Enhancer-Driven Oncogenic Transcription by CDK7 Inhibition in Anaplastic Thyroid Carcinoma

Background: Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancies, with no effective treatment currently available. The molecular mechanisms of ATC carcinogenesis remain poorly understood. The objective of this study was to investigate the mechanisms and functions of super-enhancer (SE)-driven oncogenic transcriptional addiction in the progression of ATC and identify new drug targets for ATC treatments. Methods: High-throughput chemical screening was performed to identify new drugs inhibiting ATC cell growth. Cell viability assay, colony formation analysis, cell-cycle analysis, and animal study were used to examine the effects of drug treatments on ATC progression. Chromatin immunoprecipitation sequencing was conducted to establish a SE landscape of ATC. Integrative analysis of RNA sequencing, chromatin immunoprecipitation sequencing, and CRISPR/Cas9-mediated gene editing was used to identify THZ1 target genes. Drug combination analysis was performed to assess drug synergy. Patient samples were analyzed to evaluate candidate biomarkers of prognosis in ATC. Results: THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), was identified as a potent anti-ATC compound by high-throughput chemical screening. ATC cells, but not papillary thyroid carcinoma cells, are exceptionally sensitive to CDK7 inhibition. An integrative analysis of both gene expression profiles and SE features revealed that the SE-mediated oncogenic transcriptional amplification mediates the vulnerability of ATC cells to THZ1 treatment. Combining this integrative analysis with functional assays led to the discovery of a number of novel cancer genes of ATC, including PPP1R15A, SMG9, and KLF2. Inhibition of PPP1R15A with Guanabenz or Sephin1 greatly suppresses ATC growth. Significantly, the expression level of PPP1R15A is correlated with CDK7 expression in ATC tissue samples. Elevated expression of PPP1R15A and CDK7 are both associated with poor clinical prognosis in ATC patients. Importantly, CDK7 or PPP1R15A inhibition sensitizes ATC cells to conventional chemotherapy. Conclusions: Taken together, these findings demonstrate transcriptional addiction in ATC pathobiology and identify CDK7 and PPP1R15A as potential biomarkers and therapeutic targets for ATC.

Blockade of the programmed death ligand 1 (PD-L1) as potential therapy for anaplastic thyroid cancer

PURPOSE

Anaplastic thyroid carcinoma (ATC) is a rare, highly aggressive form of thyroid cancer (TC) characterized by an aggressive behavior and poor prognosis, resulting in patients' death within a year. Standard treatments, such as chemo and radiotherapy, as well as tyrosine kinase inhibitors, are ineffective for ATC treatment. Cancer immunotherapy is one of the most promising research area in oncology. The PD-1/PD-L1 axis is of particular interest, in light of promising data showing a restoration of host immunity against tumors, with the prospect of long-lasting remissions.

METHODS

In this study, we evaluated PD-L1 expression in a large series of TCs (20 cases) showing a progressive dedifferentiation of the thyroid tumor from well differentiated TC to ATC, employing two different antibodies [R&D Systems and VENTANA PD-L1 (SP263) Rabbit Monoclonal Primary Antibody]. We also tested the anti PD-L1 mAb in an in vivo animal model.

RESULTS

We found that approximately 70-90% of ATC cases were positive for PD-L1 whereas normal thyroid and differentiated TC were negative. Moreover, all analyzed cases presented immunopositive staining in the endothelium of vessels within or in close proximity to the tumor, while normal thyroid vessels were negative. PD-L1 mAb was also effective in inhibiting ATC growth in an in vivo model.

CONCLUSIONS

These data suggest that immunotherapy may be a promising treatment specific for ATC suggesting the need to start with clinical TRIALs.

MET overexpression and activation favors invasiveness in a model of anaplastic thyroid cancer

In thyroid cancers, MET receptor overexpression has been associated with higher risk of metastatic progression. In this study, it was shown that the anaplastic thyroid cancer (ATC)-derived TTA1 cell line overexpressed MET. By using FISH and relative quantification by qPCR, it was demonstrated that this overexpression resulted from a MET amplification with more than 20 copies. As expected, MET overexpression led to its constitutive activation and upregulated signaling towards the MAPK, PI3K/AKT, STAT3 and NF-κB pathways. Since the usual feature of MET-amplified cell lines is the "MET addiction" for their cell proliferation, the effect of the highly selective ATP competitive MET inhibitor PHA665752 was analyzed. While PHA665752 strongly inhibited the MAPK pathway, it did not reduce cell proliferation in TTA1 cells (IC₅₀ = 4100 nM). This resistance to PHA665752 of the TTA1 cell line was demonstrated to be related to EGFR-MET functional cross-talk and PI3K/AKT and NF-κB signaling. Nevertheless, PHA665752 suppressed the anchorage-independent growth capacity of the TTA1 cell line and reduced cell migration and invasion in a transwell assay. The role of activated MET in these neoplastic properties of the TTA1 cells was also proved with si-MET-RNA targeting. Thus, this work highlights the TTA1 cell line as the first model of MET amplification in an ATC cell line, which leads to MET constitutive activation and underlies its neoplastic properties. Besides being a useful model for MET inhibitors screening, the TTA1 cell line also supports the argument for searching for MET amplification in ATC, as it could have therapeutic implications.

Therapeutic options for advanced thyroid cancer

Thyroid cancer can be largely classified as well-differentiated, poorly differentiated, medullary and anaplastic. Differentiated thyroid cancer (DTC) includes follicular and papillary subtypes, with the incidence of papillary thyroid cancer (PTC) on the rise. The mainstay of treatment for DTC includes a combination of surgery, radioactive iodine (RAI) and levothyroxine suppression. DTC portends a favorable prognosis, even in the presence of distant metastases, with a 50% rate of 5-year survival largely due to tumor cell's sensitivity to RAI therapy influencing disease outcome. In radioactive iodine refractory differentiated thyroid cancer (RAI-refractory DTC) there is a lower survival rate prompting the use of other therapeutic options available. RAI refractoriness is more common in older patients (age >40), large metastases and lesions that are fluorodeoxyglucose (FDG) avid on position emission tomography (PET). Over the past decade, Identification of genetic mutations in the signaling pathway involved in thyroid tumorigenesis has led to the approval of tyrosine kinase inhibitors (TKIs); Sorafenib and Lenvatinib in RAI-refractory DTC. Similarly, metastatic medullary thyroid cancer (MTC) implies an unfavorable 10-year survival rate of only 20% as the principal treatment options focuses on loco regional control via surgical and/or non-surgical options. The approval of TKIs such as Cabozantinib and Vandetanib has introduced an encouraging, novel, systemic therapeutic option for metastatic MTC. Lastly, anaplastic thyroid cancer (ATC) carries the worst prognosis with high recurrence rates. Treatment includes surgery, chemotherapy and external beam radiation. The FDA recently approved Dabrafenib plus trametinib for BRAF V600E mutated ATC. Considering the modality of chemotherapy and the expanding field of targeted therapies, the role of the oncologist and interaction with endocrinologist in the management of thyroid cancer needs further clarification aiming at collaborative management plans more than ever. This review summarizes the key phase III trials that led to the approval of TKIs in the treatment of DTC and metastatic MTC. Additionally, the review aims to clarify the patient selection criteria for initiation of TKIs and examine the implications, considerations and adverse effects prior to utilizing targeted therapy. Clinical trials are ongoing with promising results and may contribute to the addition of several targeted molecules and immune check point inhibitors to the therapeutic armamentarium for RAI-refractory DTC, medullary and anaplastic thyroid cancer.

Circulating BRAF V600E Cell-Free DNA as a Biomarker in the Management of Anaplastic Thyroid Carcinoma

Purpose

Anaplastic thyroid cancer (ATC) is a deadly form of thyroid cancer. BRAF V600E is the only actionable mutation for which there is a Food and Drug Administration-approved drug combination. Rapid detection of BRAF V600E and initiation of therapy is critical. We explored the ability of droplet digital polymerase chain reaction (ddPCR) to identify this mutation in circulating cell-free DNA (cfDNA) in plasma.

Materials and Methods

The ddPCR assay was evaluated for its sensitivity, specificity for detection of BRAF V600E cfDNA, and concordance with tumor tissue. The assay also was used to evaluate its potential role as a biomarker of response.

Results

Forty-four patients with ATC who were tested for the BRAF mutation by tumor tissue DNA sequencing or immunohistochemistry were included. Sixteen BRAF V600E-positive patients had treatment samples to evaluate cfDNA levels as a biomarker of response in correlation with restaging scans. Concordance of ddPCR with tumor tissue was 93%, with a sensitivity of 85% and specificity of 100%. Area under the curve by Wilcoxon rank sum test was 0.9 (95% CI, 0.80 to 0.99; P < .001). As a biomarker of response to treatment, 94% of ddPCR samples were concordant with tumor shrinkage in restaging scans, and 47% were concordant with tumor growth (Fisher's exact test P = .0061). In addition, cfDNA levels by ddPCR were predictive of treatment response in 71% of samples.

Conclusion

cfDNA detection by ddPCR is highly sensitive, specific, and concordant with mutation status on ATC tumors. ddPCR also can be used for monitoring cfDNA levels in conjunction with imaging scans in patients with ATC.

Mitosis perturbation by MASTL depletion impairs the viability of thyroid tumor cells

Even if thyroid tumors are generally curable, a fraction will develop resistance to therapy and progress towards undifferentiated forms, whose treatment remains a demanding challenge. To identify potential novel targets for treatment of thyroid cancer, in a previous study using siRNA-mediated functional screening, we identified several genes that are essential for the growth of thyroid tumor, but not normal cells. Among the top-ranking hits, we found microtubule associated serine/threonine kinase-like (MASTL), which is known to play an essential role in mitosis regulation, and is also involved in the DNA damage response. Herein, we examine the effects of MASTL depletion on growth and viability of thyroid tumor cells. MASTL depletion impaired cell proliferation and increased the percentage of cells presenting nuclear anomalies, which are indicative of mitotic catastrophe. Furthermore, MASTL depletion was associated with enhanced DNA damage. All these effects eventually led to cell death, characterized by the presence of apoptotic markers. Moreover, MASTL depletion sensitized thyroid tumor cells to cisplatin. Our results demonstrate that MASTL represents vulnerability for thyroid tumor cells, which could be explored as a therapeutic target for thyroid cancer.

Combinations of BRAF inhibitor and anti-PD-1/PD-L1 antibody improve survival and tumour immunity in an immunocompetent model of orthotopic murine anaplastic thyroid cancer

Background

Patients with anaplastic thyroid cancer (ATC) have an extremely poor prognosis despite aggressive multimodal therapy. ATC has a high prevalence of BRAF^V600E mutations and is associated with an immunosuppressive microenvironment; we previously demonstrated that the combination of BRAF inhibitor and checkpoint inhibitor immunotherapy synergistically reduce tumour volume in an immunocompetent mouse model of orthotopic ATC.

Methods

We again utilised our mouse model of ATC to assess the combination of BRAF^V600E inhibitor PLX4720 and anti-PD-L1 or anti-PD-1 antibody on survival, and performed immune cell profiling of lymphoid and myeloid-lineage cells during maximal treatment response and tumour regrowth.

Results

Combination therapy dramatically improved mouse survival. Maximal tumour reduction was associated with increases in the number and cytotoxicity of CD8⁺ T cells and NK cells, as well as increases in mostly M1-polarised tumour-associated macrophages (TAM) and decreases in myeloid-derived suppressor-like cells. Regrowth of tumour occurred after 2–3 weeks of ongoing combination therapy, and was most significantly associated with decreased TAMs and a dramatic increase in M2-polarisation.

Conclusions

Combination of PLX4720 and anti-PD-L1/PD-1 antibody dramatically reduced tumour volume, prolonged survival and improved the anti-tumour immune profile in murine ATC. Tumour growth inevitably recurred and demonstrated re-emergence of an immunosuppressive tumour microenvironment.

Anaplastic Thyroid Carcinoma with Gastric Metastasis

Introduction. Carcinomas of the thyroid gland represent 3% of all malignancies, with 1.3 to 9.8% corresponding to anaplastic thyroid carcinomas (ATC). Metastases are present in 50% of patients when ATC is diagnosed. Gastrointestinal metastases are a rare finding in patients with thyroid carcinoma. Case report. A 68-year old gentleman with a history of papillary thyroid carcinoma (PTC) underwent surgery and radiopharmaceutical therapy. Restaging studies nine months later suggested wall thickening localizing to the distal stomach. Endoscopy results showed a large, infiltrative, subepithelial, and ulcerated gastric mass and biopsies revealed anaplastic thyroid carcinoma Conclusion. Incidental thickening or other findings in the stomach in a patient with ATC without gastrointestinal symptoms should be further investigated with endoscopy and biopsies to rule out gastric metastases from anaplastic thyroid carcinoma.

Salvage pembrolizumab added to kinase inhibitor therapy for the treatment of anaplastic thyroid carcinoma

BACKGROUND

Anaplastic thyroid carcinoma (ATC) is a rare but deadly form of thyroid cancer. Kinase inhibitors kinase inhibitors have shown clinical efficacy in the management of ATC, however, eventually these tumors acquire resistance to KI and patients succumb to their disease. Salvage therapy in this setting is limited. As ATC tumors diffusely express the programmed cell death protein ligand (PD-L1), anti- programmed cell death protein (PD-1) drugs such as pembrolizumab offer therapeutic potential. We sought to explore the efficacy of adding pembrolizumab to kinase inhibitors at progression in ATC.

METHODS

We retrospectively reviewed the charts of ATC patients initiated on pembrolizumab in combination with KI at the time of progression on kinase inhibitors at MD Anderson Cancer Center between August 2016 and August 2017. Efficacy was evaluated with best overall response (BOR) using RECISTv1.1 criteria. Progression free survival (PFS) from the start of pembrolizumab and overall survival (OS) from the start of kinase inhibitors, as well as from the time of addition of pembrolizumab were calculated.

RESULTS

Twelve patients were treated with combination kinase inhibitors plus pembrolizumab at the time of progression on their KI therapy. Median age at initiation of pembrolizumab was 60 years (range 47-84 years). BOR was as follows: 5/12 (42%) had partial response, 4/12 (33%) had stable disease and 3/12 (25%) had progressive disease. Median OS from the start of kinase inhibitor was 10.43 months (95% CI = 6.02, 14.83, range 5.4-40 months). Median OS and PFS from the addition of pembrolizumab were 6.93 months (95% CI = 1.7, 12.15, range 3-15.9 months) and 2.96 months (95% CI = 2.2, 3.7, range 0.57-13.14 months), respectively. Fatigue, anemia and hypertension were the most common AEs encountered on these combinations. Therapy had to be discontinued in 2 patients due to drug induced rash and altered mental status likely from progression of disease.

CONCLUSION

In a subset of ATC patients, pembrolizumab may be an effective salvage therapy added to kinase inhibitors at the time of progression on these drugs. However, better treatment strategies aimed at incorporating immunotherapy in patients with ATC should be explored. Frontline combination of KI with immunotherapy should be studied in prospective clinical trials.

Anti-hTERT siRNA-Loaded Nanoparticles Block the Growth of Anaplastic Thyroid Cancer Xenograft

The high frequency of hTERT-promoting mutations and the increased expression of hTERT mRNA in anaplastic thyroid cancer (ATC) make TERT a suitable molecular target for the treatment of this lethal neoplasm. In this study, we encapsulated an anti-hTERT oligonucleotide in biocompatible nanoparticles and analyzed the effects of this novel pharmaceutical preparation in preclinical models of ATC. Biocompatible nanoparticles were obtained in an acidified aqueous solution containing chitosan, anti-hTERT oligoRNAs, and poloxamer 188 as a stabilizer. The effects of these anti-hTERT nanoparticles (Na-siTERT) were tested in vitro on ATC cell lines (CAL-62 and 8505C) and in vivo on xenograft tumors obtained by flank injection of CAL-62 cells into SCID mice. The Na-siTERT reduced the viability and migration of CAL-62 and 8505C cells after 48-hour incubation. Intravenous administration (every 48 hours for 13 days) of this encapsulated drug in mice hosting a xenograft thyroid cancer determined a great reduction in the growth of the neoplasm (about 50% vs. untreated animals or mice receiving empty nanoparticles), and decreased levels of Ki67 associated with lower hTERT expression. Moreover, the treatment resulted in minimal invasion of nearby tissues and reduced the vascularity of the xenograft tumor. No signs of toxicity appeared following this treatment. Telomere length was not modified by the Na-siTERT, indicating that the inhibitory effects of neoplasm growth were independent from the enzymatic telomerase function. These findings demonstrate the potential suitability of this anti-TERT nanoparticle formulation as a novel tool for ATC treatment. Mol Cancer Ther; 17(6); 1187-95. ©2018 AACR.

Inhibiting 6-phosphogluconate dehydrogenase reverses doxorubicin resistance in anaplastic thyroid cancer via inhibiting NADPH-dependent metabolic reprogramming

Anaplastic thyroid carcinoma (ATC) is the most aggressive type of thyroid malignancies and resistant to chemotherapy. Little is known on the underlying mechanisms of ATC resistance to chemotherapy. In our work, we identified that 6-phosphogluconate dehydrogenase (6PGD) is critically involved in the development of ATC resistance to doxorubicin. We found that 6PGD mRNA, protein and enzyme activity levels are significantly upregulated in ATC cells during the prolonged exposure to doxorubicin in a time-dependent manner. 6PGD inhibition by genetic and pharmacological approaches significantly inhibits growth and survival of ATC cells that are highly resistant to doxorubicin. Consistently, 6PGD inhibition also sensitizes ATC cells to doxorubicin treatment. Of note, we observed the decreased level of NADPH, NADH and enzymatic activity of sirtuin-1 in response to 6PGD inhibition in doxorubicin-resistant ATC cells. Lactate level was also reduced by 6PGD inhibition. All these indicate that 6PGD inhibition disrupts metabolic reprogramming in doxorubicin-resistant ATC cells. Our work demonstrates 6PGD activation-mediated resistance in response to doxorubicin and provides an alternative therapeutic strategy to overcome resistance to chemotherapy for ATC treatment. Our findings also highlight the importance of metabolic reprogramming in ATC chemoresistance.

Long glucocorticoid-induced leucine zipper regulates human thyroid cancer cell proliferation

Long glucocorticoid-induced leucine zipper (L-GILZ) has recently been implicated in cancer cell proliferation. Here, we investigated its role in human thyroid cancer cells. L-GILZ protein was highly expressed in well-differentiated cancer cells from thyroid cancer patients and differentiated thyroid cancer cell lines, but poorly expressed in anaplastic tumors. A fusion protein containing L-GILZ, when overexpressed in an L-GILZ-deficient 8505C cell line derived from undifferentiated human thyroid cancer tissue, inhibited cellular proliferation in vitro. In addition, when this protein was injected into nude mice, in which cells from line 8505C had been transplanted, xenograft growth was reduced. Since the mitogen-activated protein kinase (MAPK) pathway is frequently hyperactivated in thyroid cancer cells as a result of the BRAF^V600E or Ras mutation, we sought to further investigate the role of L-GILZ in the MAPK pathway. To this end, we analyzed L-GILZ expression and function in cells treated with MAPK inhibitors. We used 8505C cells, which have the BRAF^V600E mutation, or the CAL-62 cell line, which harbors a Ras mutation. The cells were treated with the BRAF-specific drug vemurafenib (PLX4032) or the MEK1/2 inhibitor, U0126, respectively. Treatment with these agents inhibited MAPK activation, reduced cell proliferation, and upregulated L-GILZ expression. L-GILZ silencing reversed the antiproliferative activity of the MAPK inhibitors, consistent with an antiproliferative role. Treatment with MAPK inhibitors led to the phosphorylation of the cAMP/response element-binding protein (CREB), and active CREB bound to the L-GILZ promoter, contributing to its transcription. We suggest that the CREB signaling pathway, frequently deregulated in thyroid tumors, is involved in L-GILZ upregulation and that L-GILZ regulates thyroid cancer cell proliferation, which may have potential in cancer treatment.