The changing incidence of thyroid cancer

Thyroid nodules: diagnosis and management

Thyroid nodules are common. Their importance lies in the need to assess thyroid function, degree of and future risk of mass effect, and exclude thyroid cancer, which occurs in 7-15% of thyroid nodules. There are four key components to thyroid nodule assessment: clinical history and examination, serum thyroid stimulating hormone (TSH) measurement, ultrasound and, if indicated, fine-needle aspiration (FNA). If the serum TSH is suppressed, a thyroid scan with ⁹⁹Tc can distinguish between a solitary hot nodule, a toxic multinodular goitre or, less commonly, thyroiditis or Graves' disease within a coexisting nodular thyroid. Scintigraphically cold nodules are evaluated in the same way as in the setting of normal or elevated serum TSH levels. Thyroid ultrasonography should be performed only for palpable goitre and thyroid nodules and by specialists with expertise in thyroid sonography. Routine thyroid cancer screening is not recommended, except in high risk individuals, as the detection of early thyroid cancer has not been shown to improve survival. FNA may be performed for nodules ≥ 1.0 cm depending on clinical and sonographic risk factors for thyroid cancer. FNA specimens should be read by an experienced cytopathologist and be reported according to the Bethesda Classification System. Molecular analysis of indeterminate FNA samples has potential to better discriminate benign from malignant nodules and thus guide management. Surgery is indicated for FNA findings of malignancy or indeterminate cytology when there is a high risk clinical context. Surgery may also be indicated for suspicion of malignancy; larger nodules, especially with symptoms of mass effect; and in some patients with thyrotoxicosis.

Expression of WD Repeat Domain 5 (WDR5) is Associated with Progression and Reduced Prognosis in Papillary Thyroid Carcinoma

Background

The WD repeat domain 5 (WDR5) is an essential component of methyltransferase complexes. The expression of WDR5 has been reported in several types of malignancy. This study aimed to investigate the expression of the WDR5 gene and protein in a human papillary carcinoma cell line in vitro, including the use WDR5 gene silencing, and the expression of the WDR5 protein in papillary thyroid carcinoma tissue, and clinicopathological characteristics including overall survival (OS).

Material/Methods

The role of WDR5 in proliferation and migration of the human papillary thyroid carcinoma cell line, KTC-1, was investigated using the cell counting kit-8 (CCK-8) assay and transwell assay after silencing WDR5 expression. Expression levels of WDR5 in 84 patients with papillary thyroid carcinoma were detected using immunohistochemistry. The correlation between WDR5 expression and clinicopathological features was analyzed using the chi-squared test. The prognostic role of WDR5 was evaluated by univariate analysis with the log-rank test, and by multivariate analysis with the Cox regression model.

Results

WDR5 expression promoted the proliferation and migration of the KTC-1 cells. In tumor tissue from patients with papillary thyroid carcinoma, low expression and high expression levels of WDR5 were found in 72.6% and 27.4%, respectively. Increased expression of WDR5 was significantly associated with lymphatic invasion and reduced survival rates. WDR5 expression was an independent negative prognostic biomarker.

Conclusions

Expression of WDR5 promoted cell proliferation and migration in vitro and was associated with reduced prognosis in patients with papillary thyroid carcinoma.

Antiproliferative Effects of Cynaropicrin on Anaplastic Thyroid Cancer Cells

BACKGROUND

The sesquiterpene lactone cynaropicrin, a major constituent of the artichoke leaves extracts, has shown several biologic activities in many preclinical experimental models, including anti-proliferative effects.

OBJECTIVE

Herein we evaluated the effects of cynaropicrin on the growth of three human anaplastic thyroid carcinoma cell lines, investigating the molecular mechanism underlying its action.

METHOD

MTT assay was used to evaluate the viability of CAL-62, 8505C and SW1736 cells, and flow cytometry to analyse cell cycle distribution. Western blot was performed to detect the levels of STAT3 phosphorylation and NFkB activation. Antioxidant effects were analyzed by measuring the reactive oxygen species and malonyldialdehyde dosage was used to check the presence of lipid peroxidation.

RESULTS

Viability of CAL-62, 8505C and SW1736 cells was significantly reduced by cynaropicrin in a dose- and time-dependent way, with an EC50 of about 5 µM observed after 48 h of treatment with the compound. Cellular growth inhibition was accompanied both by an arrest of the cell cycle, mainly in the G2/M phase, and the presence of a significant percentage of necrotic cells. After 48 h of treatment with 10 µM of cynaropicrin, a reduced nuclear expression of NFkB and STAT3 phosphorylation were also revealed. Moreover, we observed an increase in lipid peroxidation, without any significant effect on the reactive oxygen species production.

CONCLUSION

These results demonstrate that cynaropicrin reduces the viability and promotes cytotoxic effects in anaplastic thyroid cancer cells associated with reduced NFkB expression, STAT3 phosphorylation and increased lipid peroxidation. Further characterization of the properties of this natural compound may open the way for using cynaropicrin as an adjuvant in the treatment of thyroid cancer.

Impact of thyroiditis on 131I uptake during ablative therapy for differentiated thyroid cancer

CONTEXT

Differentiated thyroid cancer (DTC) is usually treated by thyroidectomy followed by radioiodine ablation and generally has a good prognosis. It may now be possible to limit the amount of treatment without impacting on efficacy. It is not known whether coexistent thyroiditis impacts on radioiodine uptake or on its potential efficacy, but this could provide a rationale for modification to current therapeutic protocols.

DESIGN

This was a retrospective cohort study of radioiodine uptake on imaging after radioiodine ablation for DTC in patients with and without concurrent thyroiditis. All patients with histologically confirmed DTC treated with radioiodine ablation after thyroidectomy in a single centre from 2012 to 2015 were included. The primary outcome assessed was the presence of low or no iodine uptake on post-ablation scan, as reported by a nuclear medicine physician blinded to the presence or absence of thyroiditis.

RESULTS

One hundred thirty patients with available histopathology results were included. Thyroiditis was identified in 42 post-operative specimens and 15 of these patients had low or no iodine uptake on post-ablation scan, compared to only 2 of 88 patients without thyroiditis (P < 0.0001) with further data analysis dividing the groups by ablation activity received (1100 MBq or 3000 MBq).

CONCLUSIONS

Concurrent thyroiditis may impair the uptake of radioactive iodine in management of DTC. Given that patients with DTC and thyroiditis already have a good prognosis, adopting a more selective approach to this step in therapy may be indicated. Large, longitudinal studies would be required to determine if omitting radioactive iodine therapy from those patients with concurrent thyroiditis has a measurable impact on mortality from thyroid cancer.

Comparing the Sensitivity and Specificity of Two-Dimensional Shear Wave Elastography and Fine Needle Aspiration in Determining Malignant Thyroid Nodules

Background

Malignancy in thyroid nodules is a common clinical problem, and epidemiological studies have shown that it is increasing. Since malignancy is a very important problem in treating patients and misdiagnosis leads to many physical and financial damages, the importance of diagnostic methods becomes more important. Hence, the aim of this study was to investigate the sensitivity and specificity of the two dimensional-shear wave elastography (2D-SWE) diagnostic method in comparison with fine-needle aspiration (FNA) in determining the malignant thyroid nodules.

Materials and Methods

This study is cross-sectional which was performed on 57 thyroid nodules are proven by conventional ultrasound. Afterward, 2D-SWE images were taken with the help of a superSonic ultrasound machine. Then, FNA was performed from the thyroid nodules and the specimens were evaluated in a single specialized thyroid pathology center. The results of conventional sonography and 2D-SWE were compared with histopathologic results as a gold standard method. The elasticity quantity was recorded by measuring the amount of the appropriate quantities by a recording machine and analyzed using the SPSS and MedCalc software.

Results

From 57 nodules studied, 50 nodules were evaluated with benign diagnosis and 7 nodules with the malignant diagnosis. Among all the parameters recorded by the machine, SWE. ratio provided the highest surface area under the curve and the highest sensitivity and specificity with 0.94, 100% and 84%, respectively, and a cut-off point of 1.7.

Conclusion

The 2D-SWE method and the conventional ultrasound can be good references for decision making about with the thyroid nodules.

Identifying gene modules of thyroid cancer associated with pathological stage by weighted gene co-expression network analysis

Thyroid cancer is the most common type of endocrine tumor. The TNM classification remains a standard for treatment determination and predicting prognosis in thyroid cancer. The genes modules associated with the progression of papillary thyroid carcinoma (PTC) were not clear. We applied a weighted gene co-expression network analysis (WGCNA) and differential expression analysis to systematically identified co-expressed gene modules and hub genes associated with PTC progression based on The Cancer Genome Atlas (TCGA) PTC transcriptome sequencing data. An independent validation cohort, GSE27155, was used to evaluate the preservation of gene modules. We identified two co-expressed genes modules associated with progression of PTC. Enrichment analysis indicated that the two modules were enriched in angiogenesis and extracellular matrix organization. DCN, COL1A1, COL1A2, COL5A2 and COL3A1 were hub genes in the co-expressed network. We systematically identified co-expressed gene modules and hub genes associated with PTC progression for the first time, which provided insights into the mechanisms underlying PTC progression and some potential targets for the treatment of PTC.

Clinicopathological predictors of occult lateral neck lymph node metastasis in papillary thyroid cancer: A meta-analysis

BACKGROUND

This meta-analysis aimed to identify the clinicopathological factors that could predict the risk of occult lateral neck lymph node metastasis (OLLNM) in N0/N1a papillary thyroid cancer (PTC).

METHODS

A literature search of PubMed, Web of Science, OvidSP, and Chinese National Knowledge Infrastructure databases was performed using relevant keywords. Specific odds ratios and confidence intervals were calculated.

RESULTS

The final analysis included 15 studies with a total of 5342 patients. OLLNM was found to be significantly associated with some clinicopathological features, including age <45 years, male sex, extrathyroidal extension, tumor location in the upper pole, tumor size >10 mm, positive central lymph node metastasis, number of central lymph node metastasis ≥3, and vascular invasion.

CONCLUSIONS

Fine-needle aspiration (FNA) cytology or FNA-Tg test might be an appropriate and reasonable intervention in the patients with N0/N1a PTC with an increased risk of OLLNM.

A novel microfluidic device capable of maintaining functional thyroid carcinoma specimens ex vivo provides a new drug screening platform

BACKGROUND

Though the management of malignancies has improved vastly in recent years, many treatment options lack the desired efficacy and fail to adequately augment patient morbidity and mortality. It is increasingly clear that patient response to therapy is unique to each individual, necessitating personalised, or 'precision' medical care. This demand extends to thyroid cancer; ~ 10% patients fail to respond to radioiodine treatment due to loss of phenotypic differentiation, exposing the patient to unnecessary ionising radiation, as well as delaying treatment with alternative therapies.

METHODS

Human thyroid tissue (n = 23, malignant and benign) was live-sliced (5 mm diameter × 350-500 μm thickness) then analysed or incorporated into a microfluidic culture device for 96 h (37 °C). Successful maintenance of tissue was verified by histological (H&E), flow cytometric propidium iodide or trypan blue uptake, immunohistochemical (Ki67 detection/ BrdU incorporation) and functional analysis (thyroxine [T4] output) in addition to analysis of culture effluent for the cell death markers lactate dehydrogenase (LDH) and dead-cell protease (DCP). Apoptosis was investigated by Terminal deoxynucleotidyl transferase dUTP nick end labelling (TUNEL). Differentiation was assessed by evaluation of thyroid transcription factor (TTF1) and sodium iodide symporter (NIS) expression (western blotting).

RESULTS

Maintenance of gross tissue architecture was observed. Analysis of dissociated primary thyroid cells using flow cytometry both prior to and post culture demonstrated no significant change in the proportion of viable cells. LDH and DCP release from on-chip thyroid tissue indicated that after an initial raised level of release, signifying cellular damage, detectable levels dropped markedly. A significant increase in apoptosis (p < 0.01) was observed after tissue was perfused with etoposide and JNK inhibitor, but not in control tissue incubated for the same time period. No significant difference in Ki-67 positivity or TTF1/NIS expression was detected between fresh and post-culture thyroid tissue samples, moreover BrdU positive nuclei indicated on-chip cellular proliferation. Cultured thyroid explants were functionally viable as determined by production of T4 throughout the culture period.

CONCLUSIONS

The described microfluidic platform can maintain the viability of thyroid tissue slices ex vivo for a minimum of four days, providing a platform for the assessment of thyroid tissue radioiodine sensitivity/adjuvant therapies in real time.

Thyroid cancer risks among medical radiation workers in South Korea, 1996-2015

BACKGROUND

Thyroid cancer rates, especially among children, are known to be increased by radiation exposure. However, little is known about the impact of chronic low-dose radiation exposure on thyroid cancer risk in adulthood. This study examined radiation effects on thyroid cancer rates as well as an overall evaluation of thyroid cancer risk among medical radiation workers.

METHODS

Data on all diagnostic medical radiation workers enrolled in the national dosimetry registry between 1996 and 2011 were linked with the cancer registry data through 2015. Standardized incidence ratios (SIRs) were used to compare the observed cancer incidence rates in this population to those for the general population while internal comparisons were used to estimate relative risks (RRs) for occupational history and excess relative risks (ERRs) were used to quantify the radiation dose-response relationship.

RESULTS

Overall, 827 thyroid cancer cases were reported among 93,922 medical radiation workers. Thyroid cancer SIRs were significantly higher than expected for both men (SIR 1.72, 95% confidence interval [CI] 1.53 to 1.91) and women (SIR 1.18, 95% CI 1.08 to 1.28). However, RRs for thyroid cancer by job title and duration of employment showed no particular pattern among diagnostic medical radiation workers. There were no indications of a significant dose effect on thyroid cancer rates for either men (ERR/100 mGy 0.07, 95% CI -0.38 to 0.53) or women (ERR/100 mGy -0.13, 95% CI -0.49 to 0.23). The findings were similar for different job titles or when limited to workers employed for at least one year.

CONCLUSIONS

While thyroid cancer incidence rates among Korean medical radiation workers were somewhat higher than those in the general population, there was no significant evidence that this increase was associated with occupational radiation dose. Additional follow-up together with consideration of other risk factors should provide useful information on thyroid cancer rates in this cohort.

Transoral Endoscopic Thyroidectomy for Thyroid Cancer

The prevalence of low-risk differentiated thyroid cancer (DTC) is dramatically increasing because of superior diagnostic imaging technologies. Remote-access endoscopic thyroidectomy is becoming more popular for the lack of a noticeable neck scar. Transoral endoscopic thyroidectomy, vestibular approach (TOETVA) is the only technique that could be called a true scarless surgery; however, there is a scarcity of long-term studies about its safety and feasibility. Because thyroid cancer is a slow-growing lesion, with adequate follow-up and surveillance, TOETVA is a surgical procedure for the management of low-risk DTC without any difference of surgical and oncological outcome.

Understanding Pathways to the Diagnosis of Thyroid Cancer: Are There Ways We Can Reduce Over-Diagnosis?

BACKGROUND

The incidence of thyroid cancer has rapidly increased, and ecological evidence suggests this is due in some part to over-diagnosis. Understanding pathways to diagnosis could help determine whether unnecessary diagnosis can be avoided.

METHODS

A population-based sample (n = 1007) of thyroid cancer patients diagnosed between July 2013 and August 2016 was recruited from Queensland, Australia (response rate 67%). Information from structured telephone interviews was used to describe diagnostic pathways for thyroid cancer, to investigate factors associated with diagnostic pathways, and to assess the most prevalent modes of diagnoses by which the lowest-risk, potentially over-diagnosed thyroid cancers (intrathyroidal microcarcinomas) are detected.

RESULTS

Only 38% of participants presented with symptoms potentially related to thyroid cancer. Older age at diagnosis was associated with a lower prevalence of symptomatic diagnosis (prevalence ratio [PR] = 0.46 [confidence interval (CI) 0.31-0.68] for 70-79 vs. <30 years), as was frequent medical contact, while living in rural/regional areas was associated with a higher prevalence of symptomatic diagnosis (PR = 1.17 [CI 1.00-1.37] for rural/regional areas vs. major cities). Symptomatic diagnosis also occurred more for those whose tumors had adverse histopathological features (larger size, lymph node involvement, lymphovascular invasion). The likelihood of diagnosis of intrathyroidal microcarcinomas was greatest for those having surgical resection or monitoring for benign thyroid disease (PR = 3.87 [CI 2.81-5.32] and PR = 2.21 [CI 1.53-3.18], respectively).

CONCLUSIONS

A minority of newly detected thyroid cancer cases were diagnosed because of symptoms. Access to medical care and factors related to cancer aggressiveness were associated with how diagnoses occurred. The likelihood of diagnosing the lowest-risk thyroid cancers was higher in situations related to management of other thyroid conditions. Adherence to thyroid management guidelines could reduce some thyroid cancer over-diagnosis, but ultimately better diagnostic tools are needed to differentiate between indolent cancers and those of clinical significance.

Human telomerase reverse transcriptase in papillary thyroid cancer: gene expression, effects of silencing and regulation by BET inhibitors in thyroid cancer cells

PURPOSE

Mutations in TERT promoter have been detected in the more aggressive papillary thyroid cancers (PTCs). To elucidate the role of TERT as an eligible molecular target in these tumors, the expression of hTERT was analyzed in a series of PTCs and the effects of both pharmacological and RNA-interference-induced hTERT silencing were investigated in two human PTC cell lines (K1 and BCPAP).

METHODS

The expression levels of hTERT mRNA and protein were evaluated by real-time PCR and western blot assays, respectively. Effects of hTERT silencing on PTC cell lines were analyzed by MTT, migration and western blot assays. Pharmacological inhibition of hTERT was performed using two bromodomain and extra-terminal (BET) inhibitors, JQ1 and I-BET762.

RESULTS

hTERT expression results increased in 20 out of 48 PTCs, including tumors either positive or negative for the presence of hTERT promoter and/or BRAF mutations. In K1 and BCPAP cells, hTERT silencing determined a reduction in cell viability (~50% for K1 and ~70%, for BCPAP, vs control) and migration properties that were associated with a decrease of AKT phosphorylation and β-Catenin expression. Moreover, hTERT mRNA levels were down-regulated by two BET inhibitors, JQ1 and I-BET762, which at the same dosage (0.5 and 5 µM) reduced the growth of these thyroid cancer cells.

CONCLUSIONS

These findings demonstrate that hTERT may represent an excellent therapeutic target in subgroups of aggressive PTCs.

Metabolic Obesity Phenotypes and Thyroid Cancer Risk: A Cohort Study

BACKGROUND

No cohort studies have evaluated the effect of obesity on the incidence of thyroid cancer according to metabolic health status. Therefore, this study examined the association of body mass index (BMI) and metabolic health status with thyroid cancer risk.

METHODS

A cohort study was performed involving 255,051 metabolically healthy (MH) and metabolically unhealthy (MUH) adults free of thyroid cancer at baseline who were followed for a median of 5.3 years. A parametric proportional hazard model was used to estimate the adjusted hazard ratio (aHR) and confidence interval (CI).

RESULTS

During 1,402,426.3 person-years of follow-up, 2927 incident thyroid cancers were identified. Among men, the multivariable aHR for thyroid cancer comparing obesity, defined as a BMI ≥25 kg/m², with a BMI of 18.5-22.9 kg/m² was 1.47 [CI 1.12-1.93] in MH individuals, whereas the corresponding HR in MUH individuals was 1.26 [CI 1.03-1.53]. Among women, the corresponding HR in MH individuals was 1.05 [CI 0.80-1.36], whereas the corresponding HR in MUH individuals was 1.43 [CI 1.22-1.69]. Increasing quartiles of waist circumference were positively associated with risk of thyroid cancer in MUH men and women (p for trend <0.005) but not in MH individuals.

CONCLUSIONS

In both MH and MUH men, obesity was associated with an increased risk of incident thyroid cancer, indicating excessive adiposity per se as an independent risk factor for thyroid cancer. Conversely, women with MUH obesity but not MH obesity were found to have an increased risk of thyroid cancer, indicating that obesity with accompanying metabolic abnormalities may affect thyroid cancer risk in women.

Evolving Understanding of the Epidemiology of Thyroid Cancer

The incidence of thyroid cancer worldwide has increased significantly over the past 3 decades, due predominantly to an increase in papillary thyroid cancer. Although most of these cancers are small and localized, population-based studies have documented a significant increase in thyroid cancers of all sizes and stages, in addition to incidence-based mortality for papillary thyroid cancer. This suggests that the increasing incidence of thyroid cancer is due in large part to increasing surveillance and overdiagnosis, but that there also appears to be a true increase in new cases of thyroid cancer.

Epigallocatechin-3-gallate inhibits the growth and increases the apoptosis of human thyroid carcinoma cells through suppression of EGFR/RAS/RAF/MEK/ERK signaling pathway

Background

Thyroid cancer is the most common type of endocrine malignancy and the incidence rate is rapidly increasing worldwide. Epigallocatechin-3-gallate (EGCG) could suppress cancer growth and induce apoptosis in many types of cancer cells. However, the mechanism of action of EGCG on the growth of human thyroid carcinoma cells has not been fully illuminated.

Methods

Cell proliferation and viability were detected by EdU and MTS assays. Cell cycle distribution was measured by flow cytometry. Migration and invasion were evaluated by scratch and transwell assays. Apoptotic levels were detected by TUNEL staining and western blotting. The protein levels of EGFR/RAS/RAF/MEK/ERK signaling pathway were detected by western blotting. The in vivo results were determined by tumor xenografts in nude mice. The in vivo proliferation, tumor microvessel density, and apoptosis were detected by immunohistochemistry.

Results

EGCG inhibited the proliferation, viability, and cell cycle progression in human thyroid carcinoma cells. EGCG decreased the migration and invasion, but increased the apoptosis of human thyroid carcinoma cells. EGCG reduced the protein levels of phospho (p)-epidermal growth factor receptor (EGFR), H-RAS, p-RAF, p-MEK1/2, and p-extracellular signal-regulated protein kinase 1/2 (ERK1/2) in human thyroid carcinoma cells. EGCG inhibited the growth of human thyroid carcinoma xenografts by inducing apoptosis and down-regulating angiogenesis.

Conclusions

EGCG could reduce the growth and increase the apoptosis of human thyroid carcinoma cells through suppressing the EGFR/RAS/RAF/MEK/ERK signaling pathway. EGCG can be developed as an effective therapeutic agent for the treatment of thyroid cancer.

Correlations of lncRNAs with cervical lymph node metastasis and prognosis of papillary thyroid carcinoma

Background

Cervical lymph node metastasis is an important prognostic indicator for papillary thyroid carcinoma (PTC) and affects treatment strategies for PTC. lncRNAs essentially contribute to the biological functions of tumors. This study aimed to identify the lncRNAs associated with cervical lymph node metastasis and prognosis of PTC and their potential pathophysiological mechanisms.

Materials and methods

PTC-associated lncRNAs were selected from The Cancer Genome Atlas database, and correlations among lncRNAs, lymph node metastasis, tumor staging, and prognosis of PTC were analyzed in silico. These correlations were then validated through quantitative reverse transcription PCR (qRT-PCR) and immunohistochemistry (IHC).

Results

In silico analysis showed that FAM95B1 and UCA1 were significantly correlated with cervical lymph node metastasis, tumor staging, and PTC prognosis (P<0.05). qRT-PCR analysis revealed high UCA1 expression in PTC tissues and correlations between UCA1 expression levels and cervical lymph node metastasis and tumor staging in PTC, that is, higher UCA1 expression resulted in poorer PTC prognosis. IHC analysis revealed that a high expression of UCA1 was accompanied by a high expression of metastasis-related proteins (MMP-2 and MMP-9), thereby validating the correlation of UCA1 expression with metastasis.

Conclusion

FAM95B1 and UCA1 expression was significantly correlated with the occurrence and progression of PTC. The expression levels of UCA1 significantly affected the prognosis of PTC patients and were significantly correlated with tumor staging and cervical lymph node metastasis.

I-131 uptake in the breast from fat necrosis

Radioactive iodine I-131 whole-body scintigraphy is used to monitor thyroid cancer metastases after total thyroidectomy. We present a case of a woman who was diagnosed with papillary thyroid cancer and underwent a total thyroidectomy. I-131 scintigraphy revealed abnormal accumulation of radioactive iodine in the right breast causing concern for thyroid cancer metastasis. Mammographic studies confirmed that the abnormal radiotracer accumulation was due to fat necrosis in the breast. I-131 uptake in fat necrosis is a poorly understood process that is not clearly defined in the literature. This case highlights that false-positive uptake of I-131 can mimic metastases of thyroid carcinoma.

The Emerging Role of Estrogens in Thyroid Redox Homeostasis and Carcinogenesis

Reactive oxygen species (ROS) are the most critical class of free radicals or reactive metabolites produced by all living organisms. ROS regulate several cellular functions through redox-dependent mechanisms, including proliferation, differentiation, hormone synthesis, and stress defense response. However, ROS overproduction or lack of appropriate detoxification is harmful to cells and can be linked to the development of several diseases, such as cancer. Oxidative damage in cellular components, especially in DNA, can promote the malignant transformation that has already been described in thyroid tissue. In thyrocyte physiology, NADPH oxidase enzymes produce large amounts of ROS that are necessary for hormone biosynthesis and might contribute to the high spontaneous mutation rate found in this tissue. Thyroid cancer is the most common endocrine malignancy, and its incidence is significantly higher in women than in men. Several lines of evidence suggest the sex hormone estrogen as a risk factor for thyroid cancer development. Estrogen in turn, besides being a potent growth factor for both normal and tumor thyroid cells, regulates different mechanisms of ROS generation. Our group demonstrated that the thyroid gland of adult female rats exhibits higher hydrogen peroxide (H₂O₂) production and lower enzymatic antioxidant defense in comparison with male glands. In this review, we discuss the possible involvement of thyroid redox homeostasis and estrogen in the development of thyroid carcinogenesis.

Predictive Factors of Recurrence for Multifocal Papillary Thyroid Microcarcinoma With Brafv600e Mutation: A Single Center Study of 1,207 Chinese Patients

Background: The American Thyroid Association (ATA) guidelines risk stratify Braf^v600e mutated multifocal papillary thyroid microcarcinoma (BMPTMC) into different recurrence risk groups by the extent of extrathyroidal extension (ETE). These findings and modifications for BMPTMC need to be verified in additional studies. Methods: A retrospective cohort study was conducted in BMPTMC patients who underwent total thyroidectomy (TT) and central lymph node dissection (CLND) from 2008 to 2013. Overall, 1,207 patients were included, and predictive factors were identified by univariate and multivariate analysis over a mean 7.5-year follow up. Results: BMPTMC with ETE to capsule shows the same recurrence rate (3.8%) with intrathyroidal BMPTMC. Moreover, BMPTMC with ETE only to strap muscle, which belongs to high-risk group according to ATA guideline, shows relatively lower recurrence rate (13.3%) compared with some intermediate risk categories such as cN1 and >5 pN1. Multivariate analysis using a Cox proportional hazards regression model shows that total tumor diameter (TTD) is associated with significantly higher recurrence for BMPTMC with or without other risk factors (Hazard Ratio (HRO) = 9.86 [95%CI 5.35-18.20], p = 0.00; HRO = 2.32 [95%CI 1.12-4.85], p = 0.02; respectively), while Hashimoto thyroiditis (HT) is found to be protective against the recurrence (HRO = 0.51 [95%CI 0.33-0.79], p = 0.00; HRO = 0.47 [95%CI 0.25-0.89], p = 0.02; respectively). Conclusions: Taken together, capsular ETE and gross ETE to the strap muscles did not have the expected significant influence on recurrence for Chinese BMPTMC patients who underwent TT and CLND. Rather than the extent of ETE, TTD and the lack of HT were identified as predictors for recurrence among BMPTMC with or without other risk factors (vascular invasion, cN1, pN1>5, pN1>3 cm).

Decreased staging of differentiated thyroid cancer in patients with chronic lymphocytic thyroiditis

PURPOSE

The biological association between chronic lymphocytic thyroiditis (CLT) and differentiated thyroid cancer (DTC) has not been elucidated yet. The aim of the study was to assess whether the presence of CLT exerts any influence on clinical or histological presentation of DTC.

METHODS

Nine hundred and seven consecutive patients with DTC treated in the years 1998-2016 were divided into two groups according to the presence or absence of concomitant CLT. The statistical differences were analysed.

RESULTS

Out of 907 patients included in the study, 331 were diagnosed with DTC and CLT (studied group), while 576 patients with DTC but without CLT constituted a control group. The distribution of papillary and follicular thyroid cancer did not differ. In CLT group, the prevalence of pT1 was greater than for pT2-pT4 DTC (P = 0.0003; OR = 1.69, 95% CI 1.27-2.24) compared to controls (68.3 vs. 56.1%, respectively). The presence of multifocal lesions was similar. The thyroid capsule infiltration without extrathyroidal invasion (P < 0.0001; OR = 0.21, 95% CI 0.14-0.31) was more frequent in the studied group, unlike extracapsular invasion, which was significantly more often present in patients with DTC but without CLT (P = 0.004; OR = 1.66; 95% CI 1.17-2.34) as well as nodal involvement (P = 0.048; OR = 0.65, 95% CI 0.42-0.99).

CONCLUSIONS

The collected data indicate a protective role of CLT in preventing the spread of the DTC. The presence of CLT might limit tumour growth to the primary site.

Identification and Validation of Core Genes Involved in the Development of Papillary Thyroid Carcinoma via Bioinformatics Analysis

BACKGROUND

Papillary thyroid carcinoma (PTC) is a common endocrine malignant neoplasm, and its incidence increases continuously worldwide in the recent years. However, efficient clinical biomarkers were still deficient; the present research is aimed at exploring significant core genes of PTC.

METHODS

We integrated three cohorts to identify hub genes and pathways associated with PTC by comprehensive bioinformatics analysis. Expression profiles GSE33630, GSE35570, and GSE60542, including 114 PTC tissues and 126 normal tissues, were enrolled in this research. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were utilized to search for the crucial biological behaviors and pathways involved in PTC carcinogenesis. Protein-protein interaction (PPI) network was constructed, and significant modules were deeply studied.

RESULTS

A total of 831 differentially expressed genes (DEGs) were discovered, comprising 410 upregulated and 421 downregulated genes in PTC tissues compared to normal thyroid tissues. PPI network analysis demonstrated the interactions between those DEGs, and top 10 pivotal genes (TGFB1, CXCL8, LRRK2, CD44, CCND1, JUN, DCN, BCL2, ACACB, and CXCL12) with highest degree of connectivity were extracted from the network and verified by TCGA dataset and RT-PCR experiment of PTC samples. Four of the hub genes (CXCL8, DCN, BCL2, and ACACB) were linked to the prognosis of PTC patients and considered as clinically relevant core genes via survival analysis.

CONCLUSION

In conclusion, we propose a series of key genes associated with PTC development and these genes could serve as the diagnostic biomarkers or therapeutic targets in the future treatment for PTC.

KAT5 promotes invasion and metastasis through C-MYC stabilization in ATC

Anaplastic thyroid cancer (ATC) is an aggressive cancer with poor clinical prognosis. However, mechanisms driving ATC aggressiveness is not well known. Components of the DNA damage response (DDR) are frequently found mutated or aberrantly expressed in ATC. The goal of this study is to establish the functional link between histone acetyltransferase lysine (K) acetyltransferase 5 (KAT5, a critical DDR protein) and ATC invasiveness using clinical, in vitro and in vivo models. We analyzed the expression of KAT5 by immunohistochemistry and assessed its relationship with metastasis and overall survival in 82 ATC patients. Using cellular models, we established functional connection of KAT5 expression and C-MYC stabilization. We then studied the impact of genetically modified KAT5 expression on ATC metastasis in nude mice. In clinical samples, there is a strong correlation of KAT5 expression with ATC metastasis (P = 0.0009) and overall survival (P = 0.0017). At the cellular level, upregulation of KAT5 significantly promotes thyroid cancer cell proliferation and invasion. We also find that KAT5 enhances the C-MYC protein level by inhibiting ubiquitin-mediated degradation. Further evidence reveals that KAT5 acetylates and stabilizes C-MYC. Finally, we prove that altered KAT5 expression influences ATC lung metastases in vivo. KAT5 promotes ATC invasion and metastases through stabilization of C-MYC, demonstrating it as a new biomarker and therapeutic target for ATC.

Health-Related Complications of Acromegaly-Risk of Malignant Neoplasms

The issue of increased risk of benign and malignant neoplasms in patients with acromegaly remains the topic of debate from many years and was addressed by numerous studies. Many of them have shown increase in the cancer incidence. Among particular types of malignancies, thyroid, colorectal, and breast cancer are most commonly indicated as associated with acromegaly. Single reports denoted increase in prevalence of neoplasms of other organs such as kidney, bone or central nervous system. Cardiovascular and respiratory tract disorders were traditionally consider as main causes of mortality in acromegalic patients, accounting for about 60 and 25% of deaths, respectively. However, according to a number of studies published over the current decade cancer became the most important cause of deaths. Aim of the current article was to review the literature concerning the risk of malignant neoplasms in acromegaly and its clinical implications.

Lung Metastasis in Pediatric Thyroid Cancer: Radiological Pattern, Molecular Genetics, Response to Therapy, and Outcome

CONTEXT

Lung metastases are common in pediatric thyroid cancer (TC). We present an analysis of a series of lung metastases in pediatric TC.

PATIENTS AND METHODS

Data from 20 patients (16 females, 4 males; median age, 14.5 years; range 10 to 18 years) were analyzed. The tumors included differentiated TC in 19 patients and poorly differentiated TC in 1 patient.

RESULTS

Lung metastasis presented with three distinct radiological patterns: lung uptake on diagnostic radioactive iodine whole body scan (DxWBS) only in 3 patients (15%); lung uptake on DxWBS and CT scan as micrometastases (≤1 cm) in 16 patients (80%); and lung uptake on DxWBS and CT scan as macrometastases (>1 cm) in 1 patient (5%). Iodine-131 therapies were administered to all patients (median, three; range one to eight) with a median cumulative administered activity of 317.5 mCi (range, 109 to 682 mCi). None of the patients achieved a complete response but the biochemical response was substantial. During a median follow-up period of 8.2 years (range, 0.75 to 16.3 years), 1 patient (5%) died, 1 patient (5%) had a biochemically incomplete response, 2 patients (10%) had an indeterminate response, 1 patient (5%) had progressive structural disease, and 14 patients (70%) had stable structural disease. Mutational testing of 10 of 20 tumors revealed only two PIK3CA mutations in a single tumor.

CONCLUSIONS

Lung metastases are common in pediatric TC and present most frequently with bilateral radioiodine-avid micrometastases. Known single point mutations in adult TC are rare in pediatric TC. The biochemical response to iodine-131 can be substantial but resolution of structural abnormalities is rare.

Radioactive Iodine Therapy in Patients with Differentiated Thyroid Cancer: Study of External Dose Rate Attenuation Law and Individualized Patient Management

BACKGROUND

Therapy with radioactive iodine (¹³¹I) is a well established treatment method for postsurgical differentiated thyroid carcinoma (DTC). A fixed discharge time is generally set, regardless of individual differences in residual body radioactivity (RBA). This study aimed to investigate the RBA of each patient to find the attenuation law and to identify underlying factors in order to predict the time point for a safe, scientifically sound discharge plan.

METHODS

A total of 231 DTC patients undergoing ¹³¹I treatment were all treated with 3.7 GBq (100 mCi) of ¹³¹I. RBA was estimated by measuring the external body dose rate (EDR) at a distance of 1 m from the body surface between 0 and 72 hours after oral administration of ¹³¹I. Data from each patient were used to establish a time-EDR value (h-μSv/h) curve. Software was developed to predict the time when a patient's dose equivalent meets the national safety standard by including six time points between 40 and 60 hours. Several factors that might affect that time were analyzed.

RESULTS

The EDR attenuation law in patients could be described with a double exponential decay model, and the cutoff value was set as 23.3 μSv/h, upon which the predictive software was developed. Student's t-test showed there was no statistical difference between predicted values and the actual measured values (p > 0.05). Correlation analysis found that serum thyroglobulin, total triiodothyronine, total thyroxine, free triiodothyronine, free thyroxine, thyrotropin, 2- and 24-hour iodine uptake rate of the thyroid, scores of ^99mTc-pertechnetate thyroid scan, scores of ¹³¹I whole-body scan, scores of ultrasound scan, and gastrointestinal residues were associated with attenuation speed. A further multiple linear regression analysis found that 24-hour iodine uptake (X₁), residual thyroid grading by ¹³¹I whole-body scan (X₂), blood free triiodothyronine (X₃) and free thyroxine (X₄) predominantly influenced the decline of the EDR. The regression equation was Ŷ = 2.091X₁ + 6.370X₂ + 4.529X₃ + 2.466X₄ - 8.614 (F = 44.03, p < 0.01).

CONCLUSIONS

An effective and convenient method was created to measure and predict the individual safety time for discharge. This could play a significant role not only for scientific hospital discharge planning, rational use of medical resources, and better individualized management, but also in public radiation protection.

Targeting mitochondria with Au–Ag@Polydopamine nanoparticles for papillary thyroid cancer therapy

A mitochondria-targeted and exocytosis inhibition strategy of polydopamine-coated inorganic nanoparticles for enhanced papillary thyroid cancer therapy is demonstrated.

A Monocentric Retrospective Study about the Correlation between Histology and Cytology of Thyroid Indeterminate Nodules Classified as TIR 3A and TIR 3B, according to 2014 Italian Consensus for Classification and Reporting of Thyroid Cytology

BACKGROUND

In 2014, the Italian Consensus for Classification and Reporting of Thyroid Cytology (ICCRTC) reviewed the previous cytological classification proposed in 2007 including the subdivision of TIR 3 category into low risk (TIR 3A) and high risk (TIR 3B). In Italian literature, different rates of malignancy have been correlated to these subcategories.

OBJECTIVES

The aim of the study is to present our experience on this subclassification for the assessment of the malignancy risk of indeterminate thyroid nodules. We correlated the subdivision into TIR 3A and TIR 3B with the histological report by highlighting the rates of malignancy detected in the two subcategories. On the one hand, we aimed to check if the groups are associated with a real and significant difference risk of malignancy. On the other hand, we evaluated the use of this subdivision in the choice of the appropriate treatment.

STUDY DESIGN

This is a retrospective review of all the patients with an indeterminate nodule who underwent US-FNA and had surgery at ASL Città di Torino between January 2005 and May 2018.

RESULTS

150 patients have been analyzed for the research; 62 (41.3%) had a malignant histological report. Rates of malignancy between TIR 3A (20.8%) and TIR 3B (60.3%) were significantly different (p < 0.0001). The subclassification had high sensitivity (75.8%; CI 63.3-85.8%) and NPV (79.3%; CI 68-87.8%) and low specificity (64.8%; CI 53.9-74.7%) and PPV (60.3; CI 48.5-71.2%). The measurement of the accuracy (AUC = 0.7) classified the test as "moderately accurate." Conclusions. Obtained data show a great rate of false negative (20.8%) and limited AUC (0.7). According to our logistic regression, we argue that the 2014 subclassification into TIR 3A and TIR 3B should be considered for the choice of patient treatment, but at the same time, we believe that the association with other screening tests is necessary to increase the accuracy in the future.

MiR-19a Overexpression in FTC-133 Cell Line Induces a More De-Differentiated and Aggressive Phenotype

In recent years, microRNAs (miRNAs) have received increasing attention for their important role in tumor initiation and progression. MiRNAs are a class of endogenous small non-coding RNAs that negatively regulate the expression of several oncogenes or tumor suppressor genes. MiR-19a, a component of the oncogenic miR-17-92 cluster, has been reported to be highly expressed only in anaplastic thyroid cancer, the most undifferentiated, aggressive and lethal form of thyroid neoplasia. In this work, we evaluated the putative contribution of miR-19a in de-differentiation and aggressiveness of thyroid tumors. To this aim, we induced miR-19a expression in the well-differentiated follicular thyroid cancer cell line and evaluated proliferation, apoptosis and gene expression profile of cancer cells. Our results showed that miR-19a overexpression stimulates cell proliferation and alters the expression profile of genes related to thyroid cell differentiation and aggressiveness. These findings not only suggest that miR-19a has a possible involvement in de-differentiation and malignancy, but also that it could represent an important prognostic indicator and a good therapeutic target for the most aggressive thyroid cancer.

MiR-let-7e inhibits invasion and magration and regulates HMGB1 expression in papillary thyroid carcinoma

Thyroid cancer keeps rapidly increasing worldwide and the most frequent type is papillary thyroid carcinoma (PTC). MicroRNAs (miRNAs) are proved dysregulated in many types of malignancies, including thyroid cancer. Although miR-let-7e has been implicated in several types of cancer regulation, relatively little is known about the function of miR-let-7e in PTC. In this study, we showed that the overexpression of miR-let-7e or knockdown of high mobility group box 1 (HMGB1) inhibited cell migration and invasion. MiR-let-7e downregulates HMGB1 expression by directly targeting the HMGB1 3'-UTR. Furthermore, HMGB1 reintroduction reversed the anti-proliferation, anti-migration, and anti-invasion roles of miR-let-7e. miR-let-7e might function as a tumor suppressor in papillary thyroid carcinoma through HMGB1. Therefore, our study demonstrates that miR-let-7e plays an important role in papillary thyroid carcinoma progression and might represent a new potential therapeutic target for treatment.

Beyond the Spinal Canal

Cross-sectional spinal imaging is common, and extraspinal findings are often incidentally identified during interpretation. Although some of these findings may cause symptoms that mimic a spinal disorder, the majority are entirely asymptomatic and incidental. It is essential that the radiologist not only identify those abnormalities that may have clinical significance but also recognize those that are clinically irrelevant and thereby prevent patients from being subjected to further unnecessary, expensive and potentially harmful interventions. This article focuses on those abnormalities that are commonly encountered and provides practical guidance for follow-up and management based on current recommendations.

Activation of CXCL5-CXCR2 axis promotes proliferation and accelerates G1 to S phase transition of papillary thyroid carcinoma cells and activates JNK and p38 pathways

C-X-C motif chemokine ligand 5 (CXCL5) is initially identified to recruit neutrophils by interacting with its receptor, C-X-C motif chemokine receptor 2 (CXCR2). Our prior work demonstrated that the expression levels of CXCL5 and CXCR2 were higher in the papillary thyroid carcinoma (PTC) tumors than that in the non-tumors. This study was performed to further investigate how this axis regulates the growth of PTC cells. B-CPAP cells (BRAF^V600E) and TPC-1 cells (RET/PTC rearrangement) expressing CXCR-2 were used as in vitro cell models. Our results showed that the recombinant human CXCL5 (rhCXCL5) promoted the proliferation of PTC cells. rhCXCL5 accelerated the G1/S transition, upregulated the expression of a group of S (DNA synthesis) or M (mitosis)-promoting cyclins and cyclin-dependent kinases (CDKs), and downregulated CDK inhibitors in PTC cells. The CDS region of homo sapiens CXCL5 gene was inserted into an eukaryotic expression vector to mediate the overexpression of CXCL5 in PTC cells. The phosphorylation of c-Jun N-terminal kinases (JNK) and p38, and the nuclear translocation of c-Jun were enhanced by CXCL5 overexpression, whereas attenuated by CXCR2 antagonist SB225002. Additionally, CXCL5/CXCR2 axis, JNK and p38 pathway inhibitors, SB225002, SP600125 and SB203580, suppressed the growth of PTC cells overexpressing CXCL5 in nude mice, respectively. Collectively, our study demonstrates a growth-promoting effect of CXCL5-CXCR2 axis in PTC cells in vitro and in vivo.

Thyroid Cancer Epidemiology in South Spain: a population-based time trend study

PURPOSE

Thyroid cancer (TC) is the most common malignant disease of the endocrine system. The aim of this study was to analyze incidence and mortality trends of TC (C73 according to ICD-O-3) in Granada (Southern Spain) during the period 1985-2013, by sex, age, and histological type.

METHODS

This is a population-based cross-sectional study. Incidence data were obtained from the population-based Cancer Registry of Granada. All newly diagnosed cases of thyroid cancer over the period 1985-2013 were included. Joinpoint regression analysis with age-standardized rates were used to estimate annual percentage change (APC), CI 95% and turning points in trends. Results are presented by sex, age group, and histological type.

RESULTS

During the study period there were 1265 diagnosed cases of TC in Granada (72.6% in women). Incidence trends significantly increased in both men (APC: + 5.4%) and women (APC: + 4.7%). The most common histological types in both sexes were papillary (74.8%) and follicular (16.8%). The incidence has increased during the study period mainly due to papillary carcinoma, which has increased annually around 6% in both sexes. TC mortality trend during this period decreased in men (APC: -0.3%) and women (APC: -2.3%).

CONCLUSION

Our data showed an increasing trend in incidence of thyroid cancer in Granada, especially in women between 55-64 years. Mortality showed a slight decrease trend during the study period in both sexes. Papillary carcinoma was the most common histological type, with an increase of the relative weight of papillary microcarcinomas. Our study is in accordance with the European and worldwide trends in thyroid cancer incidence and mortality and sex differences.

Thyroid surgery for differentiated thyroid cancer - recent advances and future directions

Population-based studies have demonstrated that an increasing number of incidental thyroid nodules are being identified. The corresponding increase in thyroid-based diagnostic procedures, such as fine-needle aspiration biopsy, has in part led to an increase in the diagnoses of thyroid cancers and to more thyroid surgeries being performed. Small papillary thyroid cancers account for most of this increase in diagnoses. These cancers are considered to be low risk because of the excellent patient outcomes, with a 5-year disease-specific survival of >98%. As a result, controversy remains regarding the optimal management of newly diagnosed differentiated thyroid cancer, as the complications related to thyroidectomy (primarily recurrent laryngeal nerve injury and hypoparathyroidism) have considerable effects on patient quality of life. This Review highlights current debates, including undertaking active surveillance versus thyroid surgery for papillary thyroid microcarcinoma, the extent of thyroid surgery and lymphadenectomy for low-risk differentiated thyroid cancer, and the use of molecular testing to guide decision-making about whether surgery is required and the extent of the initial operation. This Review includes a discussion of current consensus guideline recommendations regarding these topics in patients with differentiated thyroid cancer. Additionally, innovative thyroidectomy techniques (including robotic and transoral approaches) are discussed, with an emphasis on patient preferences around decision-making and outcomes following thyroidectomy.

Meta-analysis of microarray datasets identify several chromosome segregation-related cancer/testis genes potentially contributing to anaplastic thyroid carcinoma

AIM

Anaplastic thyroid carcinoma (ATC) is the most lethal thyroid malignancy. Identification of novel drug targets is urgently needed.

MATERIALS & METHODS

We re-analyzed several GEO datasets by systematic retrieval and data merging. Differentially expressed genes (DEGs) were filtered out. We also performed pathway enrichment analysis to interpret the data. We predicted key genes based on protein-protein interaction networks, weighted gene co-expression network analysis and genes' cancer/testis expression pattern. We also further characterized these genes using data from the Cancer Genome Atlas (TCGA) project and gene ontology annotation.

RESULTS

Cell cycle-related pathways were significantly enriched in upregulated genes in ATC. We identified TRIP13, DLGAP5, HJURP, CDKN3, NEK2, KIF15, TTK, KIF2C, AURKA and TPX2 as cell cycle-related key genes with cancer/testis expression pattern. We further uncovered that most of these putative key genes were critical components during chromosome segregation.

CONCLUSION

We predicted several key genes harboring potential therapeutic value in ATC. Cell cycle-related processes, especially chromosome segregation, may be the key to tumorigenesis and treatment of ATC.

Total thyroidectomy's association with survival in papillary thyroid cancers and the high proportion of total thyroidectomy in low-risk patients: Analysis of Korean nationwide data

BACKGROUND

Papillary thyroid cancer has an excellent prognosis, but the appropriate level of treatment is controversial. We compared survival between total thyroidectomy and less-than-total thyroidectomy, and examined the proportion of patients with papillary thyroid cancer in Korea undergoing total thyroidectomy.

METHODS

A nationwide sample of 5,230 papillary thyroid cancer patients was included (total thyroidectomy: 4,262, less-than-total thyroidectomy: 968). Using multivariate Cox regression, we compared overall survival and cause-specific survival by the extent of thyroidectomy (total thyroidectomy versus less-than-total thyroidectomy) for a 1:1 optimal match via the propensity score and for the total study population. We also compared overall survival by extent of thyroidectomy and the proportion of total thyroidectomy in different risk groups using papillary thyroid cancer staging systems.

RESULTS

We saw no difference in overall survival by extent of thyroidectomy in the propensity score matched population and the total study population (hazard ratio for less-than-total thyroidectomy 0.82, 95% confidence interval 0.52-1.29; hazard ratio for less-than-total thyroidectomy 1.03, 95% confidence interval 0.71-1.48, respectively). Similarly, there were no differences in thyroid cancer-specific survival by extent of thyroidectomy. None of the different risk groups showed differences in overall survival by surgical extent, although total thyroidectomy improved overall survival in older females with larger tumors. The proportion of papillary thyroid cancer patients who received a total thyroidectomy was 80% or greater regardless of risk group classification.

CONCLUSION

Total thyroidectomy had no survival advantage over less-than-total thyroidectomy in Korean papillary thyroid cancer patients except in a specific high-risk group. 80% or more of low-risk papillary thyroid cancer patients received a total thyroidectomy. These results suggest that further patient-centered treatment which considers both quality of life and clinical outcome is needed.

Genetic polymorphism contributes to 131I radiotherapy-induced toxicities in patients with differentiated thyroid cancer

AIM

To investigate the association between SNPs in DNA damage response pathways and toxicities following ¹³¹I radiotherapy of differentiated thyroid cancer (DTC). Materials & methods: We identified 22 functional SNPs of genes in DNA damage response pathways. MassArray was used to sequence SNP genotypes in 203 DTC patients. Hardy-Weinberg equilibrium and the associations between the two alleles of each SNP and toxicity reactions were evaluated using χ² analysis.

RESULTS

Ataxia-telangiectasia mutated (ATM) rs620815 T-allele carriers were at increased risk of ¹³¹I radiation-induced gastrointestinal reaction compared with C allele carriers. TNFα rs1800629 GA genotype may increase the incidence of neck pain compared with GG genotype. Furthermore, TNFα rs1800629, ATM rs11212570, NF-κβ rs230493, and TGF-β rs1800469, rs2241716 were associated with throat pain following ¹³¹I radiotherapy.

CONCLUSION

The identified SNPs might serve as novel biomarkers for DTC treated with ¹³¹I radiotherapy.

Routine thyroglobulin, neck ultrasound and physical examination in the routine follow up of patients with differentiated thyroid cancer-Where is the evidence?

PURPOSE

Patients with differentiated thyroid cancer (DTC) typically have a favourable prognosis and recurrence as late as 45 years after diagnosis has been reported. International clinical guidelines for monitoring recommend routine thyroglobulin, ultrasound and physical examination for the detection of recurrence. The aim of this review was to systematically review whether routine monitoring using thyroglobulin (Tg), neck ultrasound and physical examination for recurrence in differentiated thyroid cancer patients is effective in improving patient survival and/or quality of life.

METHODS

Primary studies were retrieved via a comprehensive search of three electronic bibliographic databases (PubMed, Web of Science Core Collection and Cochrane Library) without time restriction. Eligible studies must have reported on disease-free patients with DTC subject to long-term routine surveillance. The primary and secondary outcomes of interest were overall survival (or other survival parameters) and quality of life, respectively.

RESULTS

Literature searches yielded 5529 citations, which were screened by two reviewers. 241 full texts were retrieved. No randomised controlled trials or two-arm cohort studies on the effectiveness of any of the three specified interventions were identified. However, three 'single-arm' studies reporting long-term follow-up outcomes in patients undergoing regular surveillance were identified and appraised.

CONCLUSIONS

This review highlights a lack of empirical evidence to support current use of routine surveillance in DTC. Although early detection is possible, routine surveillance may lead to unnecessary intervention.

Diagnosis and Management of Hypothyroidism: Addressing the Knowledge-Action Gaps

Hypothyroidism presents a large epidemiological burden in India. As a result of subtle and nonspecific clinical symptoms and signs, the condition often goes undiagnosed and is not adequately treated when it is detected. There is heterogeneity in the diagnostic and treatment approaches to hypothyroidism. As a result of the physiological changes in thyroid hormones with age and illness, it is important to tailor the diagnosis and management of this condition in specific populations including pregnant women, infants, children, geriatric patients, and those with comorbid conditions. Enhanced understanding and education of physicians and patients can help to improve the outcomes of treatment in hypothyroidism which should be focused on patient-centered care. Policies and reforms should be crafted and implemented at the national level to curb public health challenges of hypothyroidism. This publication summarizes the recommendations of a national advisory board meeting to identify and bridge the gaps in understanding of the diagnosis and treatment of hypothyroidism in India. As a complement to clinical judgment, these recommendations will foster the diagnosis and management of hypothyroidism in the community and clinics for the benefit of the patients.

FUNDING

Merck Ltd, India.

Potent effects of roniciclib alone and with sorafenib against well-differentiated thyroid cancer

Activation of cyclin-dependent kinase activity is frequently observed in many human cancers; therefore, cyclin-dependent kinases that promote cell cycle transition and cell proliferation may be potential targets in the treatment of malignancy. The therapeutic effects of roniciclib, a cyclin-dependent kinase inhibitor for papillary and follicular thyroid cancer (designated as well-differentiated thyroid cancer), were investigated in this study. Roniciclib inhibited cell proliferation in two papillary and two follicular thyroid cancer cell lines in a dose-dependent manner. Roniciclib activated caspase-3 activity and induced apoptosis. Cell cycle progression was arrested in the G2/M phase. Roniciclib treatment in vivo retarded the growth of two well-differentiated thyroid tumors in xenograft models in a dose-dependent fashion. Furthermore, the combination of roniciclib with sorafenib was more effective than either single treatment in a follicular thyroid cancer xenograft model. Acceptable safety profiles appeared in animals treated with either roniciclib alone or roniciclib and sorafenib combination therapy. These findings support roniciclib as a potential drug for the treatment of patients with well-differentiated thyroid cancer.

Young age increases the risk of lymph node positivity in papillary thyroid cancer patients: a SEER data-based study

Introduction

Currently in papillary thyroid cancer (PTC), the correlation between lymph node positivity (LN+) and patient's age at diagnosis is still inconclusive. The aim of this study was to investigate whether younger PTC patients had higher LN+ rates.

Patients and methods

From the 1998-2013 Surveillance, Epidemiology, and End Results database, we analyzed PTC patients with at least 1 LN examined. The patients were divided into 5 groups by age separately for each T stage: ≤30; 31-40; 41-50; 51-60; >60 years.

Results

A total of 46,077 PTC patients were identified, including 8,386 (18.2%) patients aged ≤30 years, 10,971 (23.8%) patients aged 31-40 years, 11,646 (25.3%) patients aged 41-50 years, 8,596 (18.7%) patients aged 51-60 years, and 6,478 (14.1%) patients aged >60 years. In each T stage, LN+ rates were inversely associated with age at diagnosis, which was validated by multivariate logistic regression analysis (p<0.001). In addition, the subset of patients 30 or younger had the highest lymph node ratio compared with other subsets (p<0.001).

Conclusion

We identified that younger PTC patients have an increased predisposition for LN+ regardless of T stage. This finding could help surgeons to select the optimal treatment for younger PTC patients.

Prevalence of papillary thyroid cancer in subacute thyroiditis patients may be higher than it is presumed: retrospective analysis of 137 patients

Background The association of subacute thyroiditis (SAT) and papillary thyroid carcinoma is a rare finding. In this study, we aimed to investigate the prevalence of differentiated thyroid cancer in a cohort of patients followed with the diagnosis of SAT. Patients and methods We retrospectively screened medical records of Endocrinology and Metabolism outpatient clinic in the past 20 years for patients with SAT. Patients with nodules and suspicious ultrasonography findings who underwent fine needle aspiration biopsy (FNAB) and operated due to malignancy risk were identified. Results We identified 137 (100 females, 37 males) patients with reliable records to confirm the diagnosis of SAT. The mean age of female patients was 41.1 ± 9.1 (range, 20-64) and of male patients was 43.0 ± 9.3 (range, 20-65). One or more FNAB was performed in 23 of the patients (16.8%) at the beginning and/or during the follow-up period when needed. Seven patients with suspicious FNAB findings were operated, and histopathological examination of the nodules confirmed the diagnosis of papillary thyroid carcinoma in 6 patients (4.4%). Conclusions Our observations suggesting a relatively higher prevalence of thyroid cancer in a small series of SAT patients warrant further studies to identify the real frequency of differentiated thyroid cancer and its association with inflammatory pathogenesis of SAT. This finding is compatible with the trend of increased thyroid cancer incidence all over the world. A repeat ultrasonography after resolution of clinical and inflammatory findings, and FNAB should be recommended to all patients with suspicious nodules.

GABPA inhibits invasion/metastasis in papillary thyroid carcinoma by regulating DICER1 expression

The ETS family transcription factor GABPA is suggested as an oncogenic element, which is further supported by the recent reporting of it as the sole ETS member to activate the mutant TERT promoter in thyroid carcinomas (TC). However, it remains unclear how GABPA contributes to TC pathogenesis. The present study is designed to address this issue. TERT expression was significantly diminished in TERT promoter-mutated TC cells upon GABPA inhibition. Surprisingly, GABPA depletion led to robustly increased cellular invasion independently of TERT promoter mutations and TERT expression. DICER1, a component of the microRNA machinery, was identified as a downstream effector of GABPA. GABPA facilitated Dicer1 transcription while its depletion reduced Dicer1 expression. The mutation of the GABPA binding site in the DICER1 promoter led to diminished basal levels of DICER1 promoter activity and abolishment of GABPA-stimulated promoter activity as well. The forced DICER1 expression abrogated the invasiveness of GABPA-depleted TC cells. Consistently, the analyses of 93 patients with papillary thyroid carcinoma (PTC) revealed a positive correlation between GABPA and DICER1 expression. GABPA expression was negatively associated with TERT expression and promoter mutations, in contrast to published observations in cancer cell lines. Lower GABPA expression was associated with distant metastasis and shorter overall/disease-free survival in PTC patients. Similar results were obtained for PTC cases in the TCGA dataset. In addition, a positive correlation between GABPA and DICER1 expression was seen in multiple types of malignancies. Taken together, despite its stimulatory effect on the mutant TERT promoter and telomerase activation, GABPA may itself act as a tumor suppressor rather than an oncogenic factor to inhibit invasion/metastasis in TCs and be a useful predictor for patient outcomes.

Copper Chelation as Targeted Therapy in a Mouse Model of Oncogenic BRAF-Driven Papillary Thyroid Cancer

Purpose: Sixty percent of papillary thyroid cancers (PTC) have an oncogenic (V600E) BRAF mutation. Inhibitors of BRAF and its substrates MEK1/2 are showing clinical promise in BRAFV600E PTC. PTC progression can be decades long, which is challenging in terms of toxicity and cost. We previously found that MEK1/2 require copper (Cu) for kinase activity and can be inhibited with the well-tolerated and economical Cu chelator tetrathiomolybdate (TM). We therefore tested TM for antineoplastic activity in BRAFV600E -positive PTC.Experimental Design: The efficacy of TM alone and in combination with current standard-of-care lenvatinib and sorafenib or BRAF and MEK1/2 inhibitors vemurafenib and trametinib was examined in BRAFV600E-positive human PTC cell lines and a genetically engineered mouse PTC model.Results: TM inhibited MEK1/2 kinase activity and transformed growth of PTC cells. TM was as or more potent than lenvatinib and sorafenib and enhanced the antineoplastic activity of sorafenib and vemurafenib. Activated ERK2, a substrate of MEK1/2, overcame this effect, consistent with TM deriving its antineoplastic activity by inhibiting MEK1/2. Oral TM reduced tumor burden and vemurafenib in a BrafV600E -positive mouse model of PTC. This effect was ascribed to a reduction of Cu in the tumors. TM reduced P-Erk1/2 in mouse PTC tumors, whereas genetic reduction of Cu in developing tumors trended towards a survival advantage. Finally, TM as a maintenance therapy after cessation of vemurafenib reduced tumor volume in the aforementioned PTC mouse model.Conclusions: TM inhibits BRAFV600E -driven PTC through inhibition of MEK1/2, supporting clinical evaluation of chronic TM therapy for this disease. Clin Cancer Res; 24(17); 4271-81. ©2018 AACR.

Predictors of Neck Reoperation and Mortality After Initial Total Thyroidectomy for Differentiated Thyroid Cancer

BACKGROUND

In an era of rising differentiated thyroid cancer incidence, the rate and impact of neck reoperation may inform the intensity of earlier interventions and surveillance. This study sought to define predictors of neck reoperation and to assess its impact on survival.

METHODS

Using the California Cancer Registry linked to the California Office of Statewide Health Planning and Development records, a retrospective cohort study was performed of 24,230 patients with total or near-total thyroidectomy for papillary or follicular thyroid cancer between 1991 and 2008 and follow-up through 2013. The primary outcome was neck reoperation 91 days to 5 years after the initial thyroid surgery. Using logistic and Cox proportional hazards regression, the impact of sociodemographics, tumor staging, and hospital thyroid cancer surgery volume on neck reoperation and survival was determined.

RESULTS

Neck reoperation was identified in 1231 (5.1%) patients in increasing odds from 1991 to 2008. In multivariable models, male sex, papillary thyroid cancer, and advancing tumor stage were associated with neck reoperation. Among men, neck reoperation was associated with Asian/Pacific Islander (odds ratio [OR] = 1.44 [confidence interval (CI) 1.07-1.94]) race/ethnicity. Among women, neck reoperation was associated with younger age (15-34 years; OR = 1.50 [CI 1.17-1.92] versus ≥55 years), and Asian/Pacific Islander (OR = 1.24 [CI 1.02-1.51]) or Hispanic (OR = 1.20 [CI 1.00-1.44]) race/ethnicity. After controlling for baseline characteristics, neck reoperation predicted worse thyroid cancer-specific survival (hazard ratio = 4.26 [CI 3.50-5.19]). The effect differed between men and women, and was most pronounced among women who received radioiodine in initial treatment (hazard ratio = 8.32 [CI 6.14-11.27]).

CONCLUSIONS

Neck reoperation is becoming increasingly frequent and is strongly predictive of mortality. Advancing tumor stage, Asian/Pacific Islander race/ethnicity, male sex, as well as younger age and Hispanic ethnicity among women predict a higher risk for neck reoperation and subsequent mortality, reflecting a higher risk of persistent or more biologically aggressive disease.

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

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

Hypoxia Increases Thyroid Cancer Stem Cell-Enriched Side Population

Introduction

Hypoxic stress is a feature of rapidly growing thyroid tumours. Cancer progression is thought to be driven by a small population of tumour cells possessing stem cell properties. Hypoxia-inducible factors (HIFs) are important mediators of hypoxia. Both HIF-1alpha and HIF-2alpha have been reported to be expressed in thyroid cancers. There is growing evidence that the HIF pathway plays a significant role in the maintenance of thyroid cancer stem cells (CSC).

Methodology

We have isolated thyroid CSC from a papillary thyroid cancer-derived cell line (BCPAP) and an anaplastic thyroid cancer-derived cell line (SW1736) as side population (SP) cells (a putative stem cell population) and treated them with cobalt chloride (II) to induce hypoxia.

Results and discussion

We observed an increase in the SP of cells within the thyroid cancer cell lines following induction of hypoxia.

Ginsenoside Rg3 Inhibition of Thyroid Cancer Metastasis Is Associated with Alternation of Actin Skeleton

Ginsenoside Rg3, a bioactive constituent from Panax ginseng, is a worldwide well-known traditional Chinese medicine used as a tonic. It also has good antitumor activity by inhibiting tumors metastasis. Tumor metastasis is a high risk in thyroid cancer. However, the effect and molecular mechanism underlying the antimetastatic activity of Rg3 in thyroid cancer have not been reported. In our study, we found that Rg3 inhibited the growth of thyroid cancer in vitro and in vivo and significantly inhibited metastasis of thyroid cancer. Rg3 apparently inhibited the migration and invasion in four papillary thyroid cancer (PTC) cells (TPC-1, BCPAP, C643, and Ocut-2c cells) and pulmonary metastasis in lung metastasis model of C643 cells in nude mice. We further found that a possible mechanism of Rg3 inhibiting thyroid cancer cells metastasis was associated with inhibiting cells actin skeleton function. Rg3 inhibited lamellipodia formation and induced microspike formation by inhibiting Rho GTPase in thyroid cancer cells. Rg3 decreased the levels of Rac-1 and Cdc42 proteins. In addition, Rg3 decreased the expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 proteins in four thyroid cancer cells. The results that Rg3 remarkably inhibited the expression of vascular endothelial growth factor-C (VEGF-C) protein in PTC cells and VEGF-A protein in anaplastic thyroid cancer (ATC) cells and decreased the staining of CD31 in PTC and ATC tumors hinted that Rg3 might inhibit the lymph node metastasis in PTC and angiogenesis in ATC. These studies suggested that Rg3 might be a useful agent for the treatment of metastatic thyroid cancers.

Thyroid cancer risk in airline cockpit and cabin crew: a meta-analysis

BACKGROUND

Airline crew are exposed to ionizing radiation as part of their occupation and have a documented increased risk of melanoma and cataracts. However, whether their occupation predisposes them to an increased risk of thyroid cancer is not established. The purpose of this systematic review and meta-analysis was to assess the risk of thyroid cancer in airline cockpit and cabin crew compared with the general population.

METHODS

The MEDLINE database accessed via PubMed and Cochrane Database were searched. We included cohort studies reporting the standardized incidence ratio (SIR) or standardized mortality ratio (SMR) of thyroid cancers in any flight-based occupation.

RESULTS

Of the 1777 citations retrieved in PubMed, eight studies with a total of 243,088 aircrew members and over 3,334,114 person-years of follow-up were included in this meta-analysis. No relevant studies were identified on Cochrane Database. The overall summary SIR of participants in any flight-based occupation was 1.11 (95% CI, 0.79-1.57; p = 0.613; 6 records). The summary SIR for cockpit crew was 1.21 (95% CI, 0.75-1.95; p = 0.383; 4 records) and the summary SIR for cabin crew was 1.00 (95% CI, 0.60-1.66; p = 0.646; 2 records). The overall summary standardized mortality ratio for airline crew was 1.19 (95% CI, 0.59-2.39; p = 0.773; 2 records).

CONCLUSION

Airline crew were not found to have a significantly elevated risk of thyroid cancer incidence or mortality relative to the general population. Future research should capitalize on the growing occupational cohort dataset and employ innovative methods to quantify lifetime radiation exposure to further assess thyroid cancer risk in airline crew.