Recent Updates on the Management of Medullary Thyroid Carcinoma

Correlation of pN Stage and Hypoechogenicity with Tumour Encapsulation and Vascular Invasion in Thyroid Cancer (TC): A Comprehensive Analysis and Clinical Outcomes

In this retrospective study, the relationship between the pN stage of TC and the ultrasound hypoechogenicity of tumour encapsulation and vascular invasion was investigated. The data of a total of 678 TC patients were analysed. The goal of this study was to assess the significance of the pTNM score and preoperative ultrasound features in predicting cancer prognosis and guiding therapeutic decisions in patients with TC. The main research methods included a retrospective analysis of patient data, mainly the pTNM score and presence of tumour encapsulation and vascular invasion obtained from histopathological results and preoperative ultrasound imaging. Patients with well-differentiated TCs (papillary and follicular) were extracted from TC patients to better unify the results because of similar clinical strategies for these TCs. Significant associations were observed between advanced pN stage and the presence of encapsulation and vessel invasion. The majority of pN1a patients exhibited encapsulation (77.71%; p < 0.0001) and vascular invasion (75.30%; p < 0.0001), as did the majority of pN1b patients (100%; p < 0.0001 and 100%; p < 0.0001, respectively). Less than half of the patients with hypoeghogenic patterns presented with encapsulation (43.30%; p < 0.0001) and vascular invasion (43.52%; p < 0.0001), while the vast majority of patients without hypoechogenicity did not present with encapsulation (90.97%; p < 0.0001) or vascular invasion (90.97%; p < 0.0001). Hypoechogenicity was found to be indicative of aggressive tumour behaviour. The results of this study underscore the importance of accurate N staging in TC and suggests the potential use of ultrasound features in predicting tumour behaviour. Further research is needed to confirm these findings and explore additional prognostic markers to streamline TC management strategies and improve patient outcomes.

Evaluation of PD-L1 antigen expression using immunohistochemistry technique in medullary thyroid carcinoma samples

BACKGROUND

Markers related to the mechanism of tumoral cell escape from the immune system have received more attention. The PD-L1 molecule encoded by the "CD274" gene binds to T lymphocytes and can inhibit these cells. Therefore, increasing the expression of this marker on inflammatory or tumor cells can indicate tumor progression invasiveness and long-term consequences. The present study aimed to determine the expression of the PD-L1 marker in thyroid medullary tumors and to evaluate its role in predicting long-term outcomes after cancer.

METHODS

This retrospective longitudinal study was performed on pathology samples of patients with medullary thyroid carcinoma referred to the Cancer Institute of Imam Khomeini Hospital from 2015 to 2020. Slides related to medullary thyroid tumors were examined. A tissue microarray was used to evaluate the immunohistochemistry of PD-L1. Patients were followed up to assess the occurrence of recurrence. Out of 207 patients evaluated in the present study, histopathological information of 144 patients was available.

RESULTS

The expression rate of PD-L1 in our community was 14.6% in lymphocyte cells, 35.4% in tumor cells, and 12.5% in both cells. The presence of metastasis at the time of diagnosis was reported in 35 cases (72.9%), and the occurrence of tumor recurrence was reported in 38 cases (79.2%). There was no relationship between the expression of this marker and the sex and age of patients. In addition, PD-L1 expression was unrelated to the two main characteristics of this cancer, namely tumor size and its focality. The presentation of tumor PD (L1) (but not lymphocytic) was a prognostic marker for synchronous metastasis at cancer diagnosis but could not predict tumor recurrence.

CONCLUSION

PD-L1 tumor marker expression is predictable in 14.6% of lymphocyte cells, 35.4% of tumor cells, and 12.5% in the selected Iranian population with medullary thyroid cancer. The expression of this marker is not related to the morphological characteristics of the tumor, such as tumor size or focality.

Total thyroidectomy vs thyroid lobectomy for localized medullary thyroid cancer in adults: A propensity-matched survival analysis

BACKGROUND

This study aimed to clarify whether the extent of thyroidectomy (total thyroidectomy vs thyroid lobectomy) influences survival in adults with localized medullary thyroid cancer.

METHODS

Patients with localized medullary thyroid cancer were identified using the Surveillance, Epidemiology, and End Results database (2000-2018). An independent cohort of patients with localized medullary thyroid cancer were retrospectively reviewed from three medical centers in China from 2010 to 2020. The patients were grouped by the extent of surgery (total thyroidectomy vs thyroid lobectomy). Primary end points were overall survival and disease-specific survival.

RESULTS

From 1,686 patients with medullary thyroid cancer identified in SEER, 1,122 patients met inclusion for matching, with a median follow-up of 99 months. After propensity score matching, 122 patients underwent a total thyroidectomy and 122 patients underwent a thyroid lobectomy. The 10-year overall survival was 85.2% (77.9%-90.7%) and 83.1% (75.5%-90.7%) in total thyroidectomy group and in thyroid lobectomy group, respectively. The 10-year disease-specific survival was 100% and 96.8% (93.1%-100%) in total thyroidectomy group and in thyroid lobectomy group, respectively. There was no statistically significant difference in overall survival or disease-specific survival in patients with localized medullary thyroid cancer undergoing total thyroidectomy or thyroid lobectomy (hazard ratio = 0.83, 95% confidence interval 0.44-1.57, P = .57 and hazard ratio = 0.49, 95% confidence interval 0.10-2.41, P = .39, respectively). Forty-seven patients with localized medullary thyroid cancer were identified in an independent Chinese cohort (n = 29 in total thyroidectomy group vs n = 18 in thyroid lobectomy group). After a median follow-up of 47 months, there was no mortality observed in either group.

CONCLUSION

This study suggests that the extent of thyroidectomy does not influence survival for patients with early-stage localized medullary thyroid cancer and that thyroid lobectomy might be adequate in this patient population.

Naphthoquinones and derivatives as potential anticancer agents: An updated review

One of the leading global causes of death is cancer; even though several treatment methods have improved survival rates, the incidence and fatality rates remain high. Naphthoquinones are a type of quinone that is found in nature and has vital biological roles. These chemicals have anticancer (antineoplastic), analgesic, anti-inflammatory, antimalarial, antifungal, antiviral, antitrypanosomal, antischistosomal, leishmanicidal, and anti-ulcerative effects. Direct addition of a substituent group to the 1,4-naphthoquinone ring can alter the naphthoquinone's oxidation/reduction and acid/base characteristics, and the activity can be altered. Because of their pharmacological properties, such as anticancer activity and probable therapeutic application, naphthoquinones have greatly interested the scientific community. Some chemicals having a quinone ring in malignant cells have been found to have antiproliferative effects. Naphthoquinones' deadly impact is connected with the inhibition of electron transporters, the uncoupling of oxidative phosphorylation, the creation of ROS, and the formation of protein adducts, notably with -SH enzyme groups. This review article aims to discuss naphthoquinones and their derivatives, which act against cancer and their future perspectives. This review covers several studies highlighting the potent anticancer properties of naphthoquinones. Further, various proposed mechanisms of anticancer actions of naphthoquinones have been summarized in this review.

Multiple endocrine neoplasia 2: an overview

This review article discusses the diagnosis and treatment of patients with multiple endocrine neoplasia type 2 (MEN2). The most common tumors associated with MEN2 are those of the parathyroid, thyroid, and adrenal glands. Additional manifestations include characteristic clinical phenotypes or features as described in the article. This review provides an overview of clinical manifestations, screening, diagnosis, treatment, and surveillance of patients with MEN2.

Effects of marital status on survival of medullary thyroid cancer stratified by age

Purpose

Marital status has emerged as an important influence on several cancer outcomes, but its role in medullary thyroid cancer (MTC) remains unclear. This study was to explore the effects of marital status on the prognosis of MTC patients and to determine whether its effects vary by age.

Patients and methods

We retrospectively extracted 1344 eligible patients diagnosed with MTC between 2004 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. Based on the marital status, we divided those patients into married and unmarried groups. We compared the difference in overall survival (OS) and cancer‐specific survival (CSS) between married and unmarried via the Kaplan–Meier analysis. Univariate and multivariate Cox proportional models were performed to identify the prognostic factors of OS and CSS.

Results

There were 1344 MTC eligible patients in a total of which 883 (65.7%) were married and 461 (34.3%) were unmarried. The comparison observed between married and unmarried patients was as follows: male (45.2% vs. 28.0%), age (≥52 years) (55.9% vs. 44.6%), White (86.7% vs. 78.7%), and undergo surgery (97.7% vs. 93.3%). Multivariate analysis revealed unmarried status as a risk factor independently associated with worse OS (HR: 2.15, 95% CI: 1.59–2.92) rate and CSS (HR: 1.70, 95% CI: 1.17–2.47) rate. In a further analysis stratified by age, there was no significant difference in OS and CSS between married and unmarried patients younger than 52 years. For the remaining group with 52 years old and higher, unmarried patients showed significantly higher risk of OS and CSS than married patients at all stages of the pathology except M1 stage.

Conclusion

Married patients with MTC have a better prognosis than unmarried ones. Age can affect the association between marital status and the survival of MTC, and married elders may benefit more than youngers.

Decision Making When Cancer Becomes Chronic: Needs Assessment for a Web-Based Medullary Thyroid Carcinoma Patient Decision Aid

BACKGROUND

In cancers with a chronic phase, patients and family caregivers face difficult decisions such as whether to start a novel therapy, whether to enroll in a clinical trial, and when to stop treatment. These decisions are complex, require an understanding of uncertainty, and necessitate the consideration of patients' informed preferences. For some cancers, such as medullary thyroid carcinoma, these decisions may also involve significant out-of-pocket costs and effects on family members. Providers have expressed a need for web-based interventions that can be delivered between consultations to provide education and prepare patients and families to discuss these decisions. To ensure that these tools are effective, usable, and understandable, studies are needed to identify patients', families', and providers' decision-making needs and optimal design strategies for a web-based patient decision aid.

OBJECTIVE

Following the international guidelines for the development of a web-based patient decision aid, the objectives of this study are to engage potential users to guide development; review the existing literature and available tools; assess users' decision-making experiences, needs, and design recommendations; and identify shared decision-making approaches to address each need.

METHODS

This study used the decisional needs assessment approach, which included creating a stakeholder advisory panel, mapping decision pathways, conducting an environmental scan of existing materials, and administering a decisional needs assessment questionnaire. Thematic analyses identified current decision-making pathways, unmet decision-making needs, and decision support strategies for meeting each need.

RESULTS

The stakeholders reported wide heterogeneity in decision timing and pathways. Relevant existing materials included 2 systematic reviews, 9 additional papers, and multiple educational websites, but none of these met the criteria for a patient decision aid. Patients and family members (n=54) emphasized the need for plain language (46/54, 85%), shared decision making (45/54, 83%), and help with family discussions (39/54, 72%). Additional needs included information about uncertainty, lived experience, and costs. Providers (n=10) reported needing interventions that address misinformation (9/10, 90%), foster realistic expectations (9/10, 90%), and address mistrust in clinical trials (5/10, 50%). Additional needs included provider tools that support shared decision making. Both groups recommended designing a web-based patient decision aid that can be tailored to (64/64, 100%) and delivered on a hospital website (53/64, 83%), focuses on quality of life (45/64, 70%), and provides step-by-step guidance (43/64, 67%). The study team identified best practices to meet each need, which are presented in the proposed decision support design guide.

CONCLUSIONS

Patients, families, and providers report multifaceted decision support needs during the chronic phase of cancer. Web-based patient decision aids that provide tailored support over time and explicitly address uncertainty, quality of life, realistic expectations, and effects on families are needed.

Long Non-coding RNA RUNDC3A-AS1 Promotes Lung Metastasis of Thyroid Cancer via Targeting the miR-182-5p/ADAM9

Long non-coding RNAs (lncRNAs) have been identified as influential indicators in variety of malignancies. Among which, LncRNA RUNDC3A-AS1 is reported to upregulate in thyroid cancer. However, the expression pattern and the pathological function of lncRNA RUNDC3A-AS1 in thyroid cancer is unclear. In this study, we examined the expression levels of lncRNA RUNDC3A-AS1 in the thyroid cancer tissues and cell lines via RT-qPCR analysis. The effects of RUNDC3A-AS1 on thyroid cancer cell metastasis were detected by transwell chamber assay, scratch assay in vitro and lung metastasis model in vivo. The results indicated that RUNDC3A-AS1 was highly expressed in the thyroid cancer tissues and cell lines. Functionally, knockdown of RUNDC3A-AS1 could repress the migration and invasion of thyroid cancer cells in vitro, and inhibit thyroid cancer metastasis to lung in vivo. Mechanistically, RUNDC3A-AS1 served as an inhibitor of miR-182-5p in tumor tissues and cell lines. RUNDC3A-AS1 inhibited the expression of miR-182-5p to increase the expression level of ADAM9, thus further aggravating the malignancy of thyroid cancer. Therefore, the RUNDC3A-AS1/miR-182-5p/ADAM9 axis may be a potential therapeutic target for the treatment of thyroid cancer metastasis.

Medullary thyroid cancer: molecular factors, management and treatment

Medullary thyroid cancer (MTC) is an infrequent neuroendocrine tumor, which amounts to 3–5% of all thyroid malignancies. Approximately 75–80% of MTCs are sporadic neoplasms. The rest of 20–25% are familial cases that belong to multiple endocrine neoplasia (MEN) syndromes, specifically MEN2 and MEN3. These cases of familial MTC are attributed to an activating germline mutation of a tyrosine kinase receptor gene, the rearranged during transfection (RET) proto-oncogene, located on chromosome 10q11.21. These mutations are also found in some cases of sporadic MTC. This review sets forth in summary the accepted guidelines and approaches regarding diagnosis, management, and treatment of MTC. Surgical resection is the standard care, and an early, prophylactic intervention is performed in genetic cases. Further investigation and understanding of the molecular pathways involved in the growth and advancement of MTC is required in order to provide efficient therapy in cases of progressive disease.

Long non-coding RNA LINC00488 facilitates thyroid cancer cell progression through miR-376a-3p/PON2

Objective: Long non-coding RNAs (lncRNAs) recently have been identified as influential indicators in a variety of malignancies. The aim of the present study was to identify a functional lncRNA LINC00488 and its effects on thyroid cancer in the view of cell proliferation and apoptosis.

Methods: In order to evaluate the effects of LINC00488 on the cellular process of thyroid cancer, we performed a series of in vitro experiments, including cell counting kit-8 (CCK-8) assay, EdU (5-ethynyl-2′-deoxyuridine) assay, flow cytometry, transwell chamber assay, Western blot and RT-qPCR. The target gene of LINC00488 was then identified by bioinformatics analysis (DIANA and TargetScan). Finally, a series of rescue experiments was conducted to validate the effect of LINC00488 and its target genes on proliferation, migration, invasion and apoptosis of thyroid cancer.

Results: Our findings revealed that LINC00488 was highly expressed in thyroid cancer cell lines (BCPAP, BHP5-16, TPC-1 and CGTH-W3) and promoted the proliferation, migration and invasion, while inhibited the apoptosis of thyroid cancer cells (BCPAP and TPC-1). The results of bioinformatics analysis and dual luciferase reporter gene assay showed that LINC00488 could directly bind to miR-376a-3p and down-regulated the expression level of miR-376a-3p. In addition, Paraoxonase-2 (PON2) was a target gene of miR-376a-3p and negatively regulated by miR-376a-3p. Rescue experiment indicated that LINC00488 might enhance PON2 expression by sponging miR-376a-3p in thyroid cancer.

Conclusion: Taken together, our study revealed that lncRNA LINC00488 acted as an oncogenic gene in the progression of thyroid cancer via regulating miR-376a-3p/PON2 axis, which indicated that LINC00488-miR-376a-3p-PON2 axis could serve as novel biomarkers or potential targets for the treatment of thyroid cancer.

Efficacy and Safety of Vandetanib in Progressive and Symptomatic Medullary Thyroid Cancer: Post Hoc Analysis From the ZETA Trial

PURPOSE

We conducted a post hoc analysis of the vandetanib phase III trial involving patients with advanced medullary thyroid cancer (MTC) to assess the efficacy and safety of vandetanib in patients with progressive and symptomatic MTC. The primary objective of the analysis was to determine progression-free survival (PFS) of these patients.

PATIENTS AND METHODS

Eligible patients from the ZETA trial were divided into 4 disease severity subgroups: progression and symptoms, symptoms only, progression only, and no progression and no symptoms assessed at baseline. PFS, determined from objective tumor measurements performed by the local investigator, overall survival (OS), time to worsening of pain (TWP), and objective response rate (ORR) were evaluated.

RESULTS

Of the 331 patients in this trial, 184 had symptomatic and progressive disease at baseline. In this subgroup, results were similar in magnitude to those observed in the overall trial for PFS (hazard ratio [HR], 0.43; 95% CI, 0.28 to 0.64; P < .0001), OS (HR, 1.08; 95% CI, 0.72 to 1.61; P = .71), and TWP (HR, 0.67; 95% CI, 0.43 to 1.04; P = .07), and the observed adverse events were consistent with the known safety profile of vandetanib. In this subgroup, the ORR was 37% in the treatment arm versus 2% in the placebo arm.

CONCLUSION

Vandetanib demonstrated clinical benefit—specifically, increased PFS—in patients with symptomatic and progressive MTC.

Kinase Inhibitors in the Treatment of Thyroid Cancer: Institutional Experience

Although most patients with thyroid cancer have a favorable clinical course, some patients develop a more aggressive type of cancer and exhibit more rapid disease progression with worse prognosis. Those patients usually exhibit mutations of proteins such as tyrosine kinase enzymes that play a significant role in regulation of tumor proliferation and spreading. Development of targeted therapies is based on the inhibition of mutated kinases which are involved in the MAPK signaling pathway. The aim of this study was to present the initial results of clinical experience with kinase inhibitors in patients with metastatic differentiated thyroid cancer (DTC), poorly differentiated thyroid cancer (PDTC), and medullary thyroid cancer (MTC) who exhibited rapid disease progression. A total of 17 adult patients (11 women, mean age 53.3 years) managed for progressive, metastatic disease were included in the study. Twelve patients with DTC and PDTC were previously tested for BRAF mutations, of whom nine that had tumor tissue negative for the BRAF V600E mutation received sorafenib, while three patients with tumors harboring the BRAF V600E mutation were treated with vemurafenib. Patients with MTC were treated with sunitinib, vandetanib, and sorafenib. Two patients with tumors harboring the BRAF mutation treated with vemurafenib showed restoration of radioiodine uptake. Most of patients showed significant improvement in disease status but of limited duration until disease progression. Although there was an improvement in progression-free survival, future research has to achieve a greater and longer-lasting response, probably by utilizing combined targeted therapy.

The prognostic value of lymph node ratio in Medullary thyroid carcinoma: A multi-center study

INTRODUCTION

The lymph node ratio (LNR), which represents the proportion of metastatic lymph nodes resected, has been found to be a prognostic variable in several cancers, but data for Medullary thyroid carcinoma (MTC) are sparse. The aim of this study was to determine the value of the LNR in predicting outcome in patients with MTC.

MATERIALS AND METHODS

A retrospective multicenter study design of 107 patients with MTC who underwent total thyroidectomy with neck dissection between 1984 and 2016. The association of LNR with patient and tumor characteristics and prognostic factors was evaluated.

RESULTS

Study population consisted of 53.3% female, mean age at diagnosis was 50.3 ± 18.4 years; 16.8% had inherited MTC. LNR was positively correlated with tumor size (p = 0.018) and inversely correlated with age at diagnosis (p = 0.024). A higher LNR was associated with extrathyroidal extension (p < 0.001), multifocality (p = 0.001), bilateral tumor (p = 0.002), distant metastases (p < 0.001), and tumor recurrence (OR = 14.7, p < 0.001). LNR was also correlated to postoperative calcitonin levels (p < 0.001) and carcinoembryonic antigen (p = 0.011). LNR >0.1 was associated with shorter disease-specific survival in patients at risk: tumor larger than 20 mm at diagnosis (p = 0.013), sporadic MTC (p = 0.01), and age above 40 years at diagnosis (p = 0.004). Cox multivariate survival analysis revealed LNR as the only significant independent factor for disease free survival (p = 0.005).

CONCLUSIONS

This study showed that LNR correlates well with patient and tumor characteristics and prognostic variables. We suggest that LNR should be considered an important parameter for predicting outcome in MTC.

Medullary thyroid cancer: epidemiological pattern and factors contributing to recurrence and metastasis

INTRODUCTION

Medullary thyroid carcinoma (MTC) is a neuroendocrine thyroid carcinoma with parafollicular C cell differentiation. It can occur in either sporadic or hereditary form. Surgery is still the only curative treatment. The efficacy of chemotherapy and radiotherapy is poor.

METHODS

This was a retrospective study of 31 patients treated surgically for MTC in our oncology centre at Mansoura University between January 2008 and February 2019.

RESULTS

The mean age at diagnosis was 39.9 years. The median pathological size was 4cm. Multifocal disease was found in 12 patients and extrathyroid extension in 3 cases. Twenty patients were pathologically node positive. The median number of positive lymph nodes was four. Seven cases were metastatic at diagnosis. Local recurrence occurred in six individuals while distant recurrence occurred only in one. The median time from surgery to local recurrence was 12 months. The estimated mean disease free survival was 56.5 months. Disease free survival was significantly related to age, metastasis and side of nodal spread.

CONCLUSIONS

In our study cohort, the disease occurred predominantly in women and younger patients. Age, distant metastasis and nodal spread were the most significant prognostic factors. This study has also demonstrated that prognosis is not only affected by nodal involvement but also by side of involvement. The role of hemithyroidectomy in node negative unifocal disease with a small tumour size warrants further investigation.

Multiple Auer Rods in Fine-Needle Aspiration Smears of Medullary Thyroid Carcinoma: An Unusual Finding

Background

Medullary thyroid carcinoma (MTC) is a rare tumor. Fine-needle aspiration (FNA) cytology is a popular method for the preoperative diagnosis of MTC.

Case Report

A 45-year-old man was referred to our center for a palpable thyroid nodule. Ultrasound-guided FNA was carried out for the patient. Cytology slides showed many isolated and small clusters of round to oval cells, some with a moderate amount of cytoplasm and red cytoplasmic granules. Rare cells showed multiple red Auer rods. Histology confirmed the diagnosis of MTC.

Conclusion

Cytologic findings of MTC in FNA are variable, and several rare cytologic findings have been reported. Cytoplasmic red granules are one of the usual findings, whereas detection of cells containing multiple Auer rods is an unusual finding, which has not been reported so far.

Lymph Node Metastases of Medullary Thyroid Cancer: Role of Calcitonin in the Washout Fluid of Fine-Needle Aspiration

INTRODUCTION

The diagnostic value of calcitonin (CT) measurement in fine-needle aspirate washout (FNA-CT) for medullary thyroid cancer (MTC) lymph node (LN) metastases remains to be determined. It may increase the diagnostic sensitivity, but data on this subject is sparse.

OBJECTIVE

Our study aimed to evaluate the utility of FNA-CT in the diagnosis of LN metastases of MTC.

METHODS

We retrospectively investigated, in our institutional database, 69 consecutive FNA LN cytology from 42 patients who underwent FNA cytology and CT measurement in needle washout for suspicious LN between 2012 and 2017.

RESULTS

From the total of 69 FNA, 30 (43.4%) were performed in patients with personal history of MTC. MTC was detected in 19 FNA cytology (27.5%), and CT was detectable in needle washout in 23 cases (median = 2014 pg/mL; interquartile range = 490-15111 pg/mL). Based on the combined results of FNA-CT and FNA cytology, LN surgical resection was performed in 33 cases (47.8%). Histology reported MTC LN metastases in 21 lesions (63.6%). Regarding the diagnosis of MTC LN metastases, FNA cytology showed sensitivity of 81.8% and specificity of 97.9%, and FNA-CT demonstrated sensitivity of 100% and specificity of 97.9%. We determined through ROC analysis an optimal FNA-CT cut-off value of 23 pg/mL for the diagnosis of LN metastases (sensitivity 100%; specificity 100%).

CONCLUSIONS

FNA-CT may be a valuable diagnostic tool for detection of MTC LN metastases, along with FNA cytology, and it should be included in the clinical workup of neck adenopathies in patients with MTC or with thyroid nodules.

[Imaging of medullary thyroid carcinoma]

BACKGROUND

About 10% of thyroid cancers are medullary thyroid carcinoma (MTC) and can occur sporadically, familially and in the context of type II multiple endocrine neoplasia (MEN). Imaging plays a pivotal role in screening family members and in diagnosis.

DIAGNOSTIC METHODS

Diagnosis is based on ultrasound (US), thyroid scintigraphy, serum calcitonin and carcinoembryonic antigen (CEA) as well as fine needle biopsy. High-resolution US is the most important imaging method for locoregional staging, combined with computed tomography (CT) of the mediastinum. Positron emission tomography (PET-CT) using 18-F-DOPA is particularly suited for suspected occult metastases in case of rising tumor markers in serum.

FINDINGS AND COURSE OF DISEASE

Diagnosis is made based on cytologic findings in a hypoechoic, cold thyroid nodule, combined with an elevation of serum calcitonin and CEA. US is the most important imaging modality during routine follow-up. CT is indicated for suspected mediastinal, lung, or liver metastases. CT should be replaced by MRI as early as possible to prevent significant cumulative radiation doses over time.

RECENT CLINICAL DEVELOPMENTS

Although MTC is curable by surgery only, owing to its radio- and chemoresistance, the disease will often progress only slowly, and even patients with metastases will frequently survive 10 years or longer. For more aggressive variants and late symptomatic stages, targeted drugs that have the potential to indicate stabilization or even a partial remission of the disease are under clinical investigation or already approved.

Thyroid cancer management: from a suspicious nodule to targeted therapy

Thyroid nodules are very common, and their frequency is four to five times higher in women than in men. Most of them are benign, with only a very little percentage revealing a malignant neoplasm. About 50% of thyroid nodules are detected by self-palpation of neck, whereas the other 50% are diagnosed by neck ultrasonography and following fine-needle aspiration. Management of thyroid nodules is very difficult, because benign nodules are prevalent, whereas thyroid carcinoma is uncommon, representing only 1% of all malignancies. A standard diagnostic approach is represented by 'first-level' exams, consisting in neck ultrasonography and serum thyroid-stimulating hormone measurement, followed, only for nodules that are suspicious of malignancy, by 'second-level' exams, consisting of fine-needle aspiration and mutational test, which does detect particular DNA mutations present only in malignant cells. In this review, we will analyze the genetics of thyroid cancer and its heterogeneity, and we will briefly describe the current available diagnostic and therapeutic approaches.

EF24 (a Curcumin Analog) and ZSTK474 Emphasize the Effect of Cabozantinib in Medullary Thyroid Cancer

XL184 is a small-molecule kinase inhibitor recently included in first-line systemic therapy for patients with advanced, progressive medullary thyroid cancer (MTC). EF24 is a curcumin analog with a high bioavailability, and ZSTK474 is an inhibitor of the phosphatidylinositol 3-kinase signaling pathway. We investigated the effect of these compounds, alone and in combination, in two rearranged during transfection (RET)-mutated TT and MZ-CRC-1 MTC cell lines and in six mostly RET wild-type human MTC primary cultures. Low IC50 values demonstrated the efficacy of the drugs, whereas the combination index revealed an important synergistic effect of combinations of XL184 + ZSTK474 and XL184 + EF24. Cell-cycle changes and the induction of apoptosis or necrosis were modulated by single compounds or combinations thereof. Both XL184 and EF24, alone or combined, were effective in reducing calcitonin secretion. Western blot and in-cell Western analysis showed that the compounds prompted a decrease in general reactivity to phosphorylated antibodies. Our data confirm XL184 alone as the reference drug for RET-mutated MTC, but we also demonstrated that EF24 alone is effective in inhibiting MTC cell viability. We tested the combinations XL184 + ZSTK474 and XL184 + EF24 too, finding that they act synergistically, irrespective of RET mutation status.

Recent Development of Nuclear Molecular Imaging in Thyroid Cancer

Therapies targeting specific tumor pathways are easy to enter the clinic. To monitor molecular changes, cellular processes, and tumor microenvironment, molecular imaging is becoming the key technology for personalized medicine because of its high efficacy and low side effects. Thyroid cancer is the most common endocrine malignancy, and its theranostic radioiodine has been widely used to diagnose or treat differentiated thyroid cancer. This article summarizes recent development of molecular imaging in thyroid cancer, which may accelerate the development of personalized thyroid cancer therapy.

Genotypic characteristics and their association with phenotypic characteristics of hereditary medullary thyroid carcinoma in Korea

BACKGROUND

Hereditary medullary thyroid carcinoma can present as a part of multiple endocrine neoplasia syndrome by rearranged during transfection gene mutation. We evaluated the prevalence of rearranged during transfection gene mutation in patients who have medullary thyroid carcinoma and the correlations of genotype with medullary thyroid carcinoma, pheochromocytoma, and hyperparathyroidism according to the revised American Thyroid Association risk level.

METHODS

A total of 331 patients were diagnosed with medullary thyroid carcinoma, 172 of whom were tested for the rearranged during transfection germline mutation by sequencing of exon 8, 10, 11, and 13-16. These patients were diagnosed during the years 1982-2012 at 2 Korean tertiary hospitals. Patients were analyzed according to the route of diagnosis (screened versus index cases) or the mutational site of rearranged during transfection gene (the American Thyroid Association risk group).

RESULTS

Rearranged during transfection mutation was found in 23.8% of patients tested, showing a decreasing trend with time. The most commonly mutated codon was codon 634 (37.1%), followed by codon 918 (14.3%). rearranged during transfection-positive patients were younger than rearranged during transfection-negative patients, although no other clinicopathologic characteristics differed. Screened cases were younger and had smaller tumors than index cases. Among rearranged during transfection-positive patients, pheochromocytoma manifested in 35.1% and hyperparathyroidism in 7.0%. Notably, pheochromocytoma and hyperparathyroidism emerged at any time after the diagnosis of medullary thyroid carcinoma. The American Thyroid Association risk-group analysis demonstrated that medullary thyroid carcinoma patients in the highest risk group were younger, had larger tumors, and higher disease-specific mortality. Similar results for pheochromocytoma were found, according to the American Thyroid Association risk group, although the results were not significant.

CONCLUSIONS

Korean patients who have medullary thyroid carcinoma showed a similar distribution of rearranged during transfection gene mutation with those in Western countries. The American Thyroid Association risk classification was shown to be useful for pheochromocytoma, as well as for medullary thyroid carcinoma. Familial screening for rearranged during transfection mutation and lifelong monitoring for associated pheochromocytoma should be emphasized in hereditary medullary thyroid carcinoma.

Radioguided hepatic resection with 18F-DOPA in a patient with metastatic medullary thyroid carcinoma

INTRODUCTION

Medullary carcinoma accounts for 1-2% of all thyroid malignancies. 13-20% of patients present with distant metastasis, with 45% of the cases affecting the liver.

CLINICAL CASE

A 50-year-old woman, diagnosed with medullary thyroid carcinoma, was treated with total thyroidectomy and a modified neck dissection in 1999. Two lymph node recurrences in the neck were treated with surgical resection; during surveillance, she developed elevated calcitonin levels, the recurrence site was identified with ¹⁸F-DOPA PET/CT in the liver. Metabolic activity was not associated with a visible lesion in CT, MRI nor ultrasound. Radioguided surgery with ¹⁸F-DOPA allowed an anatomic resection of segments IVb and V.

DISCUSSION

In patients with medullary carcinoma and elevated calcitonin during surveillance, ¹⁸F-DOPA PET/CT is an option to evaluate the site of recurrence. Radioguided resection was feasible in this patient, whose hepatic recurrence was not visible with any other imaging method.

CONCLUSION

Radioguided hepatic resection with ¹⁸F-DOPA in metastatic medullary thyroid carcinoma is feasible when the recurrence site is not anatomically identified by any other imaging studies.

Shikonin Inhibites Migration and Invasion of Thyroid Cancer Cells by Downregulating DNMT1

Background

Shikonin is a component of Chinese herbal medicine. The aim of this study was to investigate the effects of shikonin on cell migration of papillary thyroid cancer cells of the TPC-1 cell line in vitro and expression levels of the phosphate and tensin homolog deleted on chromosome 10 (PTEN) and DNA methyltransferase 1 (DNMT1) genes.

Material/Methods

The Cell Counting Kit-8 (CCK-8) assay was performed to evaluate the proliferation of TPC-1 papillary thyroid cancer cells, and the normal thyroid cells, HTori-3, in vitro. A transwell motility assay was used to analyze the migration of TPC-1 cells. Western blot was performed to determine the expression levels of PTEN and DNMT1 genes. A methylation-specific polymerase chain reaction (PCR) (MSP) assay was used to evaluate the methylation of PTEN.

Results

Following treatment with shikonin, the cell survival rate of TPC-1 cells decreased in a dose-dependent manner; the inhibitory effects on HTori-3 cells were less marked. Shikonin inhibited TPC-1 cell migration and invasion in a dose-dependent manner. The methylation of PTEN was suppressed by shikonin, which also reduced the expression of DNMT1 in a dose-dependent manner, and increased the expression of PTEN. Overexpression of DNMT1 promoted the migration of TPC-1 cells and the methylation of PTEN. Levels of protein expression of PTEN in TPC-1 cells treated with shikonin decreased, and were increased by DNMT1 knockdown.

Conclusions

Shikonin suppressed the expression of DNMT1, reduced PTEN gene methylation, and increased PTEN protein expression, leading to the inhibition of TPC-1 cell migration.

Evaluation of in vitro and in vivo activity of a multityrosine kinase inhibitor, AL3810, against human thyroid cancer

Thyroid cancer is the most common type of endocrine neoplasia. Despite recent breakthroughs in treatment of the disease, the treatment of advanced, progressive thyroid cancers remains challenging with limited therapeutic options available. In this study, we evaluated a novel and orally bioavailable small-molecule multiple tyrosine kinases inhibitor, AL3810, in preclinical models of thyroid cancer in vitro and in vivo. AL3810 (2-5 μmol/L) dose-dependently inhibited the proliferation of human thyroid cancer cell lines TT, SW579 and TPC-1 in vitro with IC₅₀ values ranging from 0.59 to 7.03 μmol/L. Specifically, this agent dose-dependently arrested the thyroid cancer cells in the G₁ phase and induced apoptosis. Furthermore, AL3810 dose-dependently inhibited the migration and invasion of SW579 and TPC-1 cells in vitro. In SW579 and TT xenograft models, oral administration of AL3810 (5-20 mg·kg^-1·d^-1) for 21 d potently inhibited the tumor growth; immunohistochemical staining revealed that the antitumor activity of AL3810 was closely correlated with its anti-angiogenesis effect, as evidenced by a dose-dependent reduction of microvessels in tumor tissues. To assess the therapeutic potential of AL3810 in treating thyroid cancer involving RET gene fusion, we showed that AL3810 (1-10 μmol/L) dose-dependently inhibited the proliferation of RET-driven Baf3 cell line Baf3-CCDC6-RET, and the auto-phosphorylation of RET in these cells. Our data suggest that AL3810 is a promising agent for the treatment of thyroid cancer.

A label-free electrochemical immunosensor based on gold nanoparticles and graphene oxide for the detection of tumor marker calcitonin

A label-free ultrasensitive electrochemical immunosensor has been designed for the detection of calcitonin, a medullary thyroid carcinoma tumor marker.