Poorly Differentiated and Anaplastic Thyroid Cancer: Insights into Genomics, Microenvironment and New Drugs

Simple Summary

In the last decades, many researchers produced promising data concerning genetics and tumor microenvironment of poorly differentiated thyroid cancer (PDTC) and anaplastic thyroid cancer (ATC). They are trying to tear the veil covering these orphan cancers, suggesting new therapeutic weapons as single or combined therapies.

Abstract

PDTC and ATC present median overall survival of 6 years and 6 months, respectively. In spite of their rarity, patients with PDTC and ATC represent a significant clinical problem, because of their poor survival and the substantial inefficacy of classical therapies. We reviewed the newest findings about genetic features of PDTC and ATC, from mutations occurring in DNA to alterations in RNA. Therefore, we describe their tumor microenvironments (both immune and not-immune) and the interactions between tumor and neighboring cells. Finally, we recapitulate how this upcoming evidence are changing the treatment of PDTC and ATC.

Next-generation sequencing in thyroid cancers: do targetable alterations lead to a therapeutic advantage?: A multicenter experience

ABSTRACT

Radioiodine-refractory thyroid cancers (IRTCs) are uncommon and have a poor prognosis. Treatment options for radioiodine-refractory and anaplastic tumors (ATCs) are limited. Although the genomic landscape of thyroid cancer has been studied, there is little evidence on whether next-generation sequencing (NGS) findings translate to tumor control.We analyzed all patients with IRTC and ATC who underwent commercially available NGS in 3 cancer centers.Twenty-two patients were identified, 16 patients with IRTCs and 6 patients with ATCs. Eighteen (82%) had targetable findings in NGS, nine patients were treated accordingly. Median progression-free survival for targeted treatment was 50 months [95% confidence interval (CI95%) 9.8-66.6] and2 months (CI95% 0.2-16.5) for IRTC and ATC, respectively. Of 4 patients who achieved durable responses of 7 to 50 months, 2 are ongoing. The estimated median OS of IRTC receiving targeted treatment was not reached (CI95% 89.7-111.4 months) and was 77.8 months (CI95% 52.5-114.6) for patients treated conventionally (P = .3).NGS may detect clinically significant genetic alterations and benefit patients with advanced thyroid cancers.

Radiation to the Primary Tumor in Metastatic Anaplastic Thyroid Cancer

BACKGROUND/AIM

Metastatic anaplastic thyroid cancer is associated with a dismal prognosis. We evaluated outcome and prognostic factors in patients receiving radiation to the primary tumor in metastatic anaplastic thyroid cancer (ATC).

PATIENTS AND METHODS

All consecutive patients with metastatic ATC (n=20) undergoing irradiation between 2009 and 2019 for anaplastic thyroid cancer were investigated.

RESULTS

Median survival time and median progression-free survival were 2 (range=1-22) and 2 (1-20) months. In univariate analyses, surgery, concurrent or sequential chemotherapy and higher radiation dose escalation (>39 Gy) were correlated with longer overall survival (p=0.005, p=0.018 and p=0.038), respectively. Karnofsky performance status >70% showed a trend of longer survival time (p=0.062). Limited metastatic disease, surgery and concurrent/sequential chemotherapy are correlated with longer progression-free survival times (p=0.043, p=0.024 and p=0.039), respectively.

CONCLUSION

Radiation to the primary tumor in metastatic anaplastic thyroid cancer is safe and offers durable local control. Treatment intensification including concurrent or sequential chemotherapy and radiation dose escalation were associated with longer survival rates and should be considered in selected patients with metastatic disease.

Thyroid Hormone Receptor Beta Inhibits PI3K-Akt-mTOR Signaling Axis in Anaplastic Thyroid Cancer via Genomic Mechanisms

Thyroid cancer is the most common endocrine malignancy, and the global incidence has increased rapidly over the past few decades. Anaplastic thyroid cancer (ATC) is highly aggressive, dedifferentiated, and patients have a median survival of fewer than 6 months. Oncogenic alterations in ATC include aberrant phosphoinositide 3 kinase (PI3K) signaling through receptor tyrosine kinase (RTK) amplification, loss of phosphoinositide phosphatase expression and function, and protein kinase B (Akt) amplification. Furthermore, the loss of expression of the tumor suppressor thyroid hormone receptor beta (TRβ) is strongly associated with ATC. TRβ is known to suppress PI3K in follicular thyroid cancer and breast cancer by binding to the PI3K regulatory subunit p85α. However, the role of TRβ in suppressing PI3K signaling in ATC is not completely delineated. Here we report that TRβ indeed suppresses PI3K signaling in ATC cell lines through unreported genomic mechanisms, including a decrease in RTK expression and an increase in phosphoinositide and Akt phosphatase expression. Furthermore, the reintroduction and activation of TRβ in ATC cell lines enables an increase in the efficacy of the competitive PI3K inhibitors LY294002 and buparlisib on cell viability, migration, and suppression of PI3K signaling. These findings not only uncover additional tumor suppressor mechanisms of TRβ but shed light on the implication of TRβ status and activation on inhibitor efficacy in ATC tumors.

Role of Regulatory Non-Coding RNAs in Aggressive Thyroid Cancer: Prospective Applications of Neural Network Analysis

Thyroid cancer (TC) is the most common endocrine malignancy. Most TCs have a favorable prognosis, whereas anaplastic thyroid carcinoma (ATC) is a lethal form of cancer. Different genetic and epigenetic alterations have been identified in aggressive forms of TC such as ATC. Non-coding RNAs (ncRNAs) represent functional regulatory molecules that control chromatin reprogramming, including transcriptional and post-transcriptional mechanisms. Intriguingly, they also play an important role as coordinators of complex gene regulatory networks (GRNs) in cancer. GRN analysis can model molecular regulation in different species. Neural networks are robust computing systems for learning and modeling the dynamics or dependencies between genes, and are used for the reconstruction of large data sets. Canonical network motifs are coordinated by ncRNAs through gene production from each transcript as well as through the generation of a single transcript that gives rise to multiple functional products by post-transcriptional modifications. In non-canonical network motifs, ncRNAs interact through binding to proteins and/or protein complexes and regulate their functions. This article overviews the potential role of ncRNAs GRNs in TC. It also suggests prospective applications of deep neural network analysis to predict ncRNA molecular language for early detection and to determine the prognosis of TC. Validation of these analyses may help in the design of more effective and precise targeted therapies against aggressive TC.

LncRNA AFAP-AS1 promotes anaplastic thyroid cancer progression by sponging miR-155-5p through ETS1/ERK pathway

Anaplastic thyroid cancer (ATC) is the most common malignant endocrine tumors which resist to majority treatment. Thus, there is impelling need to figure out the mechanism of progress of ATC. In this study, we explored the function and mechanism of lncRNA actin filamentin-1 antisense RNA (AFAP-AS1) which provided a new biomarker for ATC. Viabilities and apoptosis were tested by CCK-8, colony formation and flow cytometry. The interactions between miR-155-5p and AFAP-AS1 or ETS1 was detected by luciferase reporter assays. ETS proto-oncogene1/mitogen-activated protein kinase1 (ETS1/ERK) pathway was assessed by Western blot. Xenograft models were built to confirm the function of AFAP-AS1 in vivo. Firstly, we showed that relative RNA expression of AFAP-AS1 in ATC cells was higher than in immortalized thyroid cells. Next, AFAP-AS1 was verified as an oncogene in ATC since knock-down of AFAP-AS1 inhibited cell proliferation and accelerated apoptosis. In addition, miR-155-5p was negatively regulated by AFAP-AS1. Moreover, AFAP-AS1 regulated ETS1/ERK pathway by sponging miR-155-5p. Finally, we confirmed knock-down of AFAP-AS1 significantly suppressed tumor proliferation in vivo. Our research proved that AFAP-AS1 could facilitate progression of thyroid cancer sponging miR-155-5p through ETS1/ERK pathway.

New Treatment Strategy Targeting Galectin-1 against Thyroid Cancer

Although the overall survival rate of papillary or follicular thyroid cancers is good, anaplastic carcinomas and radio iodine refractory cancers remain a significant therapeutic challenge. Galectin-1 (Gal-1) is overexpressed in tumor cells and tumor-associated endothelial cells, and is broadly implicated in angiogenesis, cancer cell motility and invasion, and immune system escape. Our team has previously demonstrated a higher serum level of Gal-1 in patients with differentiated thyroid cancers versus healthy patients, and explored, by a knockdown strategy, the effect of Gal-1 silencing on cell proliferation and invasion in vitro, and on tumor and metastasis development in vivo. OTX008 is a calixarene derivative designed to bind the Gal-1 amphipathic β-sheet conformation and has previously demonstrated anti-proliferative and anti-invasive properties in several cancer cell lines including colon, breast, head and neck, and prostate cancer lines. In the current work, the impacts of OTX008 were evaluated in six thyroid cancer cell lines, and significant inhibitions of proliferation, migration, and invasion were observed in all lines expressing high Gal-1 levels. In addition, the signaling pathways affected by this drug were examined using RPPA (reverse phase protein array) and phosphoprotein expression assays, and opposite regulation of eNos, PYK2, and HSP27 by OTX008 was detected by comparing the two anaplastic lines 8505c and CAL 62. Finally, the sensitive 8505c line was xenografted in nude mice, and 3 weeks of OTX008 treatment (5 mg/kg/day) demonstrated a significant reduction in tumor and lung metastasize sizes without side effects. Overall, OXT008 showed significant anti-cancer effects both in vitro and in vivo in thyroid cancer lines expressing Gal-1, supporting further investigation of the molecular mechanisms of the drug and future clinical trials in patients with anaplastic thyroid cancer.

Efficacy of adavosertib therapy against anaplastic thyroid cancer

Wee1 is a kinase that regulates the G2/M progression by the inhibition of CDK1, which is critical for ensuring DNA damage repair before initiation of mitotic entry. Targeting Wee1 may be a potential strategy in the treatment of anaplastic thyroid cancer, a rare but lethal disease. The therapeutic effects of adavosertib, a Wee1 inhibitor for anaplastic thyroid cancer was evaluated in this study. Adavosertib inhibited cell growth in three anaplastic thyroid cancer cell lines in a dose-dependent manner. Cell cycle analysis revealed cells were accumulated in the G2/M phase. Adavosertib induced caspase-3 activity and led to apoptosis. Adavosertib monotherapy showed significant retardation of the growth of two anaplastic thyroid cancer tumor models. The combination of adavosertib with dabrafenib and trametinib revealed strong synergism in vitro and demonstrated robust suppression of tumor growth in vivo in anaplastic thyroid cancer xenograft models with BRAFV600E mutation. The combination of adavosertib with either sorafenib or lenvatinib also demonstrated synergism in vitro and had strong inhibition of tumor growth in vivo in an anaplastic thyroid cancer xenograft model. No appreciable toxicity appeared in mice treated with either a single agent or combination treatment. Our findings suggest adavosertib holds the promise for the treatment of patients with anaplastic thyroid cancer.

Novel Recurrent Altered Genes in Chinese Patients With Anaplastic Thyroid Cancer

BACKGROUND

Anaplastic thyroid cancer (ATC) is a rare but lethal malignancy, and few systematic investigations on genomic profiles of ATC have been performed in Chinese patients.

METHODS

Fifty-four ATC patients in West China Hospital between 2010 to 2020 were retrospectively analyzed, while 29 patients with available samples were sequenced by whole-exome sequencing (WES). The associations between genomic alterations and clinical characteristics were statistically evaluated.

RESULTS

The median overall survival was 3.0 months in the entire cohort, which was impacted by multiple clinical features, including age, tumor size, and different treatment strategies. In the WES cohort, totally 797 nonsilent mutations were detected; the most frequently altered genes were TP53 (48%), BRAF (24%), PIK3CA (24%), and TERT promoter (21%). Although these mutations have been well-reported in previous studies, ethnic specificity was exhibited in terms of mutation frequency. Moreover, several novel significantly mutated genes were identified including RBM15 (17%), NOTCH2NL (14%), CTNNA3 (10%), and KATNAL2 (10%). WES-based copy number alteration analysis also revealed a high frequent gain of NOTCH2NL (41%), which induced its increased expression. Gene mutations and copy number alterations were enriched in phosphatidylinositol 3-kinase/AKT/mechanistic target of rapamycin (mTOR), NOTCH, and WNT pathways.

CONCLUSIONS

This study reveals shared and ethnicity-specific genomic profiles of ATC in Chinese patients and suggests NOTCH2NL may act as a novel candidate driver gene for ATC tumorigenesis.

Ym155 Induces Oxidative Stress-Mediated DNA Damage and Cell Cycle Arrest, and Causes Programmed Cell Death in Anaplastic Thyroid Cancer Cells

Anaplastic thyroid cancer (ATC) is one of the most lethal malignancies with a median survival time of about 4 months. Currently, there is no effective treatment, and the development of new therapies is an important and urgent issue for ATC patients. YM155 is a small molecule that was identified as the top candidate in a high-throughput screen of small molecule inhibitors performed against a panel of ATC cell lines by the National Cancer Institute. However, there were no follow-up studies investigating YM155 in ATC. Here, we determined the effects of YM155 on ATC and human primary benign thyroid cell (PBTC) survival with alamarBlue assay. Our data show that YM155 inhibited proliferation of ATC cell lines while sparing normal thyroid cells, suggesting a high therapeutic window. YM155-induced DNA damage was detected by measuring phosphorylation of γ-H2AX as a marker for DNA double-strand breaks. The formamidopyrimidine-DNA glycosylase (FPG)-modified alkaline comet assay in conjunction with reactive oxygen species (ROS) assay and glutathione (GSH)/glutathione (GSSG) assay suggests that YM155-mediated oxidative stress contributes to DNA damage. In addition, we provide evidence that YM155 causes cell cycle arrest in S phase and in the G2/M transition and causes apoptosis, as seen with flow cytometry. In this study, we show for the first time the multiple effects of YM155 in ATC cells, furthering a potential therapeutic approach for ATC.

Perspectives on the Treatment of Advanced Thyroid Cancer: Approved Therapies, Resistance Mechanisms, and Future Directions

For differentiated thyroid cancer (DTC), systemic therapy with radioactive iodine (RAI) is utilized for radiosensitive disease, while for radioiodine refractory (RAIR) disease, current standard of care is treatment with multikinase tyrosine kinase inhibitors (TKI). For BRAF-mutant DTC or anaplastic thyroid cancer (ATC), treatment with inhibitors targeting BRAF and MEK are important advances. RET-inhibitors for RET-mutated medullary thyroid cancer (MTC) recently have been FDA-approved for metastatic disease. Nevertheless, treatment of thyroid cancer resistant to current systemic therapies remains an important area of need. Resistance mechanisms are being elucidated, and novel therapies including combinations of BRAF and MEK inhibitors with RAI or other targeted therapies or TKIs combined with checkpoint inhibition are current areas of exploration.

Tunicamycin as a Novel Redifferentiation Agent in Radioiodine Therapy for Anaplastic Thyroid Cancer

The silencing of thyroid-related genes presents difficulties in radioiodine therapy for anaplastic thyroid cancers (ATCs). Tunicamycin (TM), an N-linked glycosylation inhibitor, is an anticancer drug. Herein, we investigated TM-induced restoration of responsiveness to radioiodine therapy in radioiodine refractory ATCs. ¹²⁵I uptake increased in TM-treated ATC cell lines, including BHT101 and CAL62, which was inhibited by KClO₄, a sodium-iodide symporter (NIS) inhibitor. TM upregulated the mRNA expression of iodide-handling genes and the protein expression of NIS. TM blocked pERK1/2 phosphorylation in both cell lines, but AKT (protein kinase B) phosphorylation was only observed in CAL62 cells. The downregulation of glucose transporter 1 protein was confirmed in TM-treated cells, with a significant reduction in ¹⁸F-fluorodeoxyglucose (FDG) uptake. A significant reduction in colony-forming ability and marked tumor growth inhibition were observed in the combination group. TM was revealed to possess a novel function as a redifferentiation inducer in ATC as it induces the restoration of iodide-handling gene expression and radioiodine avidity, thereby facilitating effective radioiodine therapy.

Therapeutic inhibition of polo-like kinases in anaplastic thyroid cancer

Polo‐like kinases (PLKs) are potent regulators of cell proliferation and cell survival. Polo‐like kinases are potential targets in the treatment of anaplastic thyroid cancer (ATC), a rare but deadly disease. The therapeutic effects of volasertib, a PLK inhibitor, was evaluated for the treatment of ATC either alone or in combination with sorafenib. Volasertib decreased cell viability in three ATC cell lines (8505C, 8305C, and KAT18) in a dose‐dependent manner. Volasertib caused ATC cells to accumulate in G₂/M phase, activated caspase‐3 activity, and induced apoptosis. Combination therapy using volasertib and sorafenib in ATC cells showed mostly synergistic effects. In vivo studies revealed that combination therapy of volasertib and sorafenib was effective in the treatment of 8505C xenografts. Single‐agent volasertib treatment was sufficient to retard 8305C tumor growth. No substantial morbidity was observed in animals that received either single‐agent or combination treatment. These preclinical findings suggest that volasertib could be an effective drug in treating ATC.

Limited efficacy of lenvatinib in heavily pretreated anaplastic thyroid cancer: a French overview

Anaplastic thyroid cancer (ATC) is a rare lethal disease. Lenvatinib is an off-label therapeutic option for ATC in most countries, except in Japan. The aim of this multicenter retrospective survey was to analyze the efficacy and the toxicity profile of off-label lenvatinib treatment in all adults advanced ATC patients, in France. Of the 23 patients analysed (14 males; mean age 64 years), 15 were pure ATC and 8 were mixed tumors (i.e. with a differentiated or poorly differentiated component). Prior treatments included neck external beam irradiation in 74%, at least one line of chemotherapy in 22 cases, two lines of chemotherapy in 11 patients, other TKI in 4 cases. A central RECIST assessment was performed. Since lenvatinib initiation, median PFS was 2.7 months (95% CI; 1.9-3.5) and median OS was 3.1 months (95% CI; 0.6-5.5). OS was significantly longer in case of mixed tumors compared with pure ATC (6.3 vs 2.7 months, P = 0.026). Best tumor response was partial response in two cases and stable disease in seven. Clinical improvement was achieved in seven patients. Lethal adverse events occurred in three patients, consisting in haemoptysis in two cases and pneumothorax in one case. Among long-surviving ATC patients (>6 months), four underwent biopsy of distant metastasis, revealing poorly differentiated histology; three of them had initial mixed ATC histology. Efficacy of lenvatinib appears limited, although pure vs mixed ATC disclose differences in disease aggressiveness and treatment response. Long-surviving ATC patients might benefit from biopsy of persistent disease, searching for histological transition or molecular target.

Radiotherapy Plus Chemotherapy Leads to Prolonged Survival in Patients With Anaplastic Thyroid Cancer Compared With Radiotherapy Alone Regardless of Surgical Resection and Distant Metastasis: A Retrospective Population Study

BACKGROUND

Whether anaplastic thyroid cancer (ATC) patients benefit more from radiotherapy plus chemotherapy (RCT) than from radiotherapy alone (RT) was controversial. We aimed to investigate the effectiveness of RCT versus RT on ATC overall and within subgroups by surgical resection and distant metastasis in a large real-world cohort.

METHODS

Patients with ATC diagnosed between 2004 and 2015 were identified from the Surveillance, Epidemiology, and End Results Program database. Inverse probability weighting (IPW) was performed to balance variables between the two groups. Multivariate Cox proportional hazard model and Fine-Gray compete-risk model were carried out to investigate prognostic factors relating to overall survival (OS) and cancer-specific survival (CSS). Subgroup analysis was carried out, and a forest plot was graphed.

RESULTS

Of the 491 ATC patients, 321 (65.4%) were in the RCT group and 170 (34.6%) were in the RT group. The median OS was 4 months [interquartile range (IQR) 2-7] and 2 months (IQR 1-4) for patients in the RCT and RT groups, respectively. As indicated by the inverse probability weighting multivariate regression, RCT was associated with significantly improved OS (adjusted HR = 0.69, 95% CI = 0.56-0.85, p < 0.001) and CSS (adjusted subdistribution HR = 0.77, 95% CI = 0.61-0.96, p = 0.018). The prominent effect of RCT versus RT alone remains significant within each subgroup stratified by surgical resection and distant metastasis. Older age, single marital status, surgical resection, distant metastasis, and tumor extension were significant prognostic factors of survival.

CONCLUSIONS

RCT contributes to prolonged OS and CSS compared with RT alone in ATC patients, regardless of surgical resection and distant metastasis. RCT should be preferentially applied to ATC patients.

[Cardiac metastasis from primary anaplastic thyroid carcinoma]

Cardiac neoplasms are rare entities in the clinical practice. Cardiac metastatic involvement is 20 to 40 times more frequent than the primary form, representing 95% of all cardiac tumors; however, they are frequently underdiagnosed because of their clinical and oncologic features. In this report, we present two cases of cardiac metastasis from primary anaplastic thyroid carcinoma: a 69-years-old woman with right ventricular metastasis and a 61-years-old man with right atrial metastasis. Both patients died during their hospitalization and one of them underwent an autopsy.

SOX13/TRIM11/YAP axis promotes the proliferation, migration and chemoresistance of anaplastic thyroid cancer

Anaplastic thyroid cancer (ATC) is one of the most aggressive and virulent solid tumors. The ubiquitin proteasome system presents in all eukaryotic cells and is essential for cellular homeostasis. While its underlying role in ATC remains largely unclear. TRIM11 is an E3 ubiquitin ligase and has been reported to act as an oncogene in several human cancers. The present study aims to reveal the oncogenic function of TRIM11 in ATC. Western blot was used to measure the protein expression of TRIM11 and YAP, while the YAP target genes were measured by real-time PCR. CCK8 assay was used to detect cell viability; wound-healing assay and transwell assay were used to measure the migration ability of ATC. The xeno-graft tumor model was used for in vivo study. Immuno-precipitation assay was used to detect the interaction domain between YAP and TRIM11. And the ubiquitin-based Immuno-precipitation assays were used to detect the specific ubiquitination manner happened on YAP. TRIM11 depletion significantly decreases cell proliferation and migration capabilities of ATC cells, and elevates cell sensitivity to chemotherapy, which effect could be further rescued by YAP overexpression. TRIM11 depletion decreases YAP protein level and YAP/TEAD target genes, such as CTGF, ANKRD1 and CYR61 in ATC. Indicating that TRIM11 is a regulator of Hippo signaling pathway. Immuno-precipitation assay shows that the RING domain of TRIM11 is essential for the interaction with WW domain of YAP. Further mechanistic analysis suggests that TRIM11 promotes the mono-ubiquitination of YAP, thus prolongs its protein half. Furthermore, TRIM11 promoter analysis revealed that SOX13 activates TRIM11 transcription by binding to the promoter of TRIM11. In summary, our study describes the oncogenic function of TRIM11 in ATC, which acts as a post-translational modulating factor of Hippo pathway. Targeting TRIM11 may be a potential therapeutic method for ATC treatment.

Resveratrol and its Nanoparticle suppress Doxorubicin/Docetaxel-resistant anaplastic Thyroid Cancer Cells in vitro and in vivo

Background: Docetaxel and doxorubicin combination has been widely used in anaplastic thyroid cancer/ATC treatment but often results in serious adverse effects and drug resistance. Resveratrol effectively inhibits ATC cell proliferation in vitro without affecting the corresponding normal cells, while its in vivo anti-ATC effects especially on the ones with docetaxel/doxorubicin-resistance have not been reported due to its low bioavailability. Nanoparticles with sustained-release and cancer-targeting features may overcome this therapeutic bottleneck. Methods: The resveratrol nanoparticles with sustained-release and IL-13Rα2-targeting capacities (Pep-1-PEG3.5k-PCL4k@Res) were prepared to improve the in vivo resveratrol bioavailability. Human THJ-16T ATC cell line was employed to establish nude mice subcutaneous transplantation model. The tumor-bearing mice were divided into four groups as Group-1, without treatment, Group-2, treated by 30 mg/kg free resveratrol, Group-3, treated by 30 mg/kg Pep-1-PEG3.5k-PCL4k@Res and Group-4, treated by 5 mg/kg docetaxel/5 mg/kg doxorubicin combination. TUNEL staining was used to detect the apoptotic cells in the tumor tissues. Docetaxel/doxorubicin resistant xenografts named as THJ-16T/R were isolated and subjected to 2D and 3D culture. The docetaxel/doxorubicin and resveratrol sensitivities of the original THJ-16T and THJ-16T/R cells were analyzed by multiple methods. Results: Docetaxel/doxorubicin and Pep-1-PEG3.5k-PCL4k@Res but not free resveratrol significantly delayed tumor growth (P < 0.01) and caused extensive apoptosis. The mice in docetaxel/doxorubicin-treated group suffered from weight loss (> 10%) and 2/3 of them died within 3 times of treatment and the chemotherapy was stop to avoid further animal loss. One week after drug withdrawal, the subcutaneous tumors regrew and the tumor volume increased 55.28% within 14 days. The cells isolated from the regrowing tumors (THJ-16T/R) were successfully cultured under 2D and 3D condition and underwent drug treatments. Compared with THJ-16T, the death rate of docetaxel/doxorubicin-treated THJ-16T/R population was lower (39.3% vs 18.0%), which remained almost unchanged in resveratrol-treated group (45.3% vs 49.3%). Conclusion: Resveratrol sustained-release targeting nanoparticles effectively inhibit in vivo ATC growth. Docetaxel/doxorubicin suppresses ATC xenografts but causes obvious side effects and secondary drug resistance that can be overcome by resveratrol.

Evolution of anaplastic thyroid cancer management: perspectives in the era of precision oncology

Anaplastic thyroid cancer is a rare aggressive malignancy resulting in poor outcomes, including significant morbidity and mortality. Historically, the overall survival of patients with anaplastic thyroid cancer has been less than 12 months. Multidisciplinary approaches combining surgery, radiation, and chemotherapy have been implemented to control this ominous disease. The evolution in science and technology has promoted deeper knowledge in the genetic pathways and mechanisms driving advance thyroid cancer. Furthermore, understanding molecular pathways resulted in the application of antineoplastic agents used in other tumors to thyroid cancer and the development of new highly selective drugs. A major landmark in anaplastic thyroid cancer management history was recently reached with the approval of BRAF and MEK inhibitor combination, specifically dabrafenib and trametinib for BRAF-mutated anaplastic thyroid cancer; this treatment has improved survival and outcomes in this population. Similarly, newer kinase inhibitors and immunotherapy are further shifting advanced thyroid cancer management to consider as first-line therapy inhibiting actionable oncogenic alterations. Therefore, newer treatment paradigms are incorporating molecular testing to provide personalized cancer care in anaplastic thyroid cancer. In this review, the principal aim is to provide an overview of the available international data on tyrosine kinase inhibitors and immunotherapy in the management of anaplastic thyroid cancer.

Age Influences the Prognosis of Anaplastic Thyroid Cancer Patients

BACKGROUND

The staging system for patients with anaplastic thyroid cancer (ATC) was updated in the 8^th edition of the American Joint Committee on Cancer Staging Manual. A cut-off age of 55 years was stipulated as a prognostic factor for differentiated thyroid cancer; however, age was not considered for ATC patients. To this end, this study investigated the relationship between age at diagnosis and prognosis of ATC patients.

METHODS

The clinical information on ATC patients was acquired from the Surveillance, Epidemiology, and End Results Program public database. Youden's index and X-tile analyses were used to calculate the high-point age at diagnosis associated with prognosis. Cox proportional hazards models, Kaplan-Meier curves, and 1000-person-year were then used for verifying the accuracy of the high-point age.

RESULTS

After inclusion/exclusion criteria was applied, 586 patients were included in this study. The high-point age was determined to be 70 years by both the Youden's index and X-tile plot methods. The hazard ratio was 1.662 (95% confidence interval [CI]: 1.321-2.092), indicating that there was an increased risk of poor prognosis for patients > 70 years of age. The cancer-specific mortality rates per 1000-person-years for patients ≤ and > 70 years-old were 949.980 (95% CI: 827.323-1090.822) and 1546.667 (95% CI: 1333.114-1794.428), respectively. P-values were < 0.001 for the results shown above.

CONCLUSION

Our study found that age influenced the prognosis of ATC patients. Furthermore, we determined that the high-point age at diagnosis was 70 years and that > 70 years of age was associated with a poor prognosis. These results provide a useful addition to the staging manual and can improve the diagnosis, treatment strategies and prognosis of ATC patients.

Novel Therapeutics in Radioactive Iodine-Resistant Thyroid Cancer

Iodine-resistant cancers account for the vast majority of thyroid related mortality and, until recently, there were limited therapeutic options. However, over the last decade our understanding of the molecular foundation of thyroid function and carcinogenesis has driven the development of many novel therapeutics. These include FDA approved tyrosine kinase inhibitors and small molecular inhibitors of VEGFR, BRAF, MEK, NTRK and RET, which collectively have significantly changed the prognostic outlook for this patient population. Some therapeutics can re-sensitize de-differentiated cancers to iodine, allowing for radioactive iodine treatment and improved disease control. Remarkably, there is now an FDA approved treatment for BRAF-mutated patients with anaplastic thyroid cancer, previously considered invariably and rapidly fatal. The treatment landscape for iodine-resistant thyroid cancer is changing rapidly with many new targets, therapeutics, clinical trials, and approved treatments. We provide an up-to-date review of novel therapeutic options in the treatment of iodine-resistant thyroid cancer.

BSA-Stabilized Mesoporous Organosilica Nanoparticles Reversed Chemotherapy Resistance of Anaplastic Thyroid Cancer by Increasing Drug Uptake and Reducing Cellular Efflux

Anaplastic thyroid cancer (ATC) is a highly aggressive and the most lethal type of thyroid cancer. The standard-of-care for unresectable ATC is radiotherapy and chemotherapy, usually based on doxorubicin (Dox). However, most patients develop resistance shortly after treatment. To overcome the drug resistance, we synthesized the mesoporous organosilica nanoparticles (MONPs) loaded with Dox and stabilized the nanocomposites by bovine serum albumin (BSA). The surface area and pore volume of MONPs were 612.653 m²/g and 0.589 cm³/g. The loading capacity of Dox-MONPs reached 47.02%. Compared to Dox-MONPs and free Dox, BSA-Dox-MONPs had more durable tumor-killing power on both drug-sensitive cell line HTh74 and drug-resistant cell line HTh74R. The cellular uptake of BSA-Dox-MONPs was 28.14 and 65.53% higher than that of Dox-MONP in HTh74 and HTh74R. Furthermore, the BSA coating decreased the efflux rate of nanocomposites in HTh74 (from 38.95 to 33.05%) and HTh74R (from 43.03 to 32.07%). In summary, BSA-Dox-MONPs reversed the chemotherapy resistance of ATC cells via increased drug uptake and inhibited drug efflux, offering a promising platform for the treatment of chemo-resistant ATC.

Lenvatinib Promotes the Antitumor Effect of Doxorubicin in Anaplastic Thyroid Cancer

Purpose

Anaplastic thyroid cancer (ATC) is a kind of rare thyroid cancer with very poor prognosis. Doxorubicin has been approved in ATC treatment as a single agent, but monotherapy still shows no improvement of the total survival in advanced ATC. Lenvatinib was investigated with encouraging results in treating patients with radioiodine-refractory differentiated thyroid cancer (DTC). However, antitumor efficacy of combination therapy with lenvatinib and doxorubicin remains largely unclear.

Materials and Methods

The antitumor efficacy of combination therapy with lenvatinib and doxorubicin on ATC cell proliferation was assessed by the MTT assay and colony formation. Flow cytometry was employed to assess ATC cells’ apoptosis and cell cycle arrest in response to combination therapy. Transwell assay was used to test the migration and invasion in response to combination therapy. Xenograft models were used to test its in vivo antitumor activity.

Results

Lenvatinib monotherapy was less effective than doxorubicin in treating ATC cell lines and xenograft model. The combination therapy of lenvatinib and doxorubicin significantly inhibited ATC cell proliferation and tumor growth in nude mice, and induced cell apoptosis and cell cycle arrest as compared to lenvatinib or doxorubicin monotherapy.

Conclusion

Lenvatinib promotes the antitumor effect of doxorubicin in ATC cell and xenograft model. The lenvatinib/doxorubicin combination may be a potential candidate therapeutic approach for anaplastic thyroid cancer.

Dsg2-mediated c-Met activation in anaplastic thyroid cancer motility and invasion

Anaplastic thyroid cancer (ATC) is a rapidly growing, highly metastatic cancer with limited therapeutic alternatives, thus targeted therapies need to be developed. This study aimed to examine desmoglein 2 (Dsg2) expression in ATC and its biological role and potential as a therapeutic target in ATC. Consequently, Dsg2 was downregulated or aberrantly expressed in ATC tissues. ATC patients with low Dsg2 expression levels also presented with distant metastasis. Dsg2 depletion significantly increased cell migration and invasion, with a relatively limited effect on ATC cell proliferation in vitro and increased distant metastasis in vivo. Dsg2 knockdown induced cell motility through the hepatocyte growth factor receptor (HGFR, c-Met)/Src/Rac1 signaling axis, with no alterations in the expression of EMT-related molecules. Further, specific targeting of c-Met significantly inhibited the motility of shDsg2-depleted ATC cells. Decreased membrane Dsg2 expression increased the metastatic potential of ATC cells. These results indicate that Dsg2 plays an important role in ATC cell migration and invasiveness. Therapies targeting c-Met might be effective among ATC patients with low membrane Dsg2 expression levels, indicating that the analysis of Dsg2 expression potentially provides novel insights into treatment strategies for ATC.

Anaplastic Thyroid Cancer Arising from Dyshormonogenetic Goiter: c.3070T>C and Novel c.7070T>C Mutation in the Thyroglobulin Gene

Concomitant thyroid cancer in patients with congenital thyroid dyshormonogenesis (TD) is extremely rare and few cases of differentiated thyroid cancer in patients with TD have been reported thus far. In this study, we describe anaplastic thyroid cancer in a 46-year-old woman with TD who had two germline thyroglobulin (TG) gene mutation, c.3790T>C (p, Cys1264Arg) in exon 17 and a novel c.7070T>C (p.Leu2357Pro) in exon 41 of the TG gene. Two affected younger sisters were also found to have the same TG mutation but not anaplastic thyroid cancer. Any thyroid nodular lesions that develop in patients with TD should be investigated carefully.