Long-term risks for thyroid cancer and other neoplasms after exposure to radiation

Genetic Alterations in Papillary Thyroid Carcinoma With Hashimoto's Thyroiditis： ANK3, an Indolent Maintainer of Papillary Thyroid Carcinoma

Hashimoto’s thyroiditis (TH) is a risk factor for the occurrence of papillary thyroid carcinoma (PTC), which is considered to be the most common type of thyroid cancer. In recent years, the prevalence of PTC with TH has been increasing, but little is known about the genetic alteration in PTC with TH. This study analyzed the mutation spectrum and mutation signature of somatic single nucleotide variants (SNV) for 10 non-tumor and tumor pair tissues of PTC with TH using whole-exome sequencing. The ANK3 protein expression was evaluated by immunohistochemistry in PTC with TH and PTC samples. Moreover, the functional role of ANK3 in PTC cells was determined by CCK-8 proliferation assay, colony formation assays, cell cycle analysis, cell invasion and migration and in vivo study through overexpression assay. Our results showed three distinct mutational signatures and the C>T/G>A substitution was the most common type of SNV. Gene-set enrichment analysis showed that most of the significantly mutated genes were enriched in the regulation of actin cytoskeleton signaling. Moreover, NCOR2, BPTF, ANK3, and PCSK5 were identified as the significantly mutated genes in PTC with TH, most of which have not been previously characterized. Unexpectedly, it was found that ANK3 was overexpressed in cytoplasm close to the membrane of PTC cells with TH and in almost all PTC cases, suggesting its role as a diagnostic marker of PTC. Ectopic expression of ANK3 suppressed invasion and migration, increased apoptosis of B-CPAP and TPC-1 cells. Moreover, our findings revealed that enhanced ANK3 expression inhibits growth of PTC cells both in vitro and in vivo. Ectopic expression of ANK3 significantly enhanced E-cadherin protein expression and inhibited PTC progression, at least in part, by suppression of epithelial-mesenchymal transition (EMT). Our study shows that ANK3 exerts an anti-oncogenic role in the development of PTC and might be an indolent maintainer of PTC.

Imaging of Complications of Chemoradiation

Chemoradiation for head and neck cancer is associated with a variety of early and late complications. Toxicities may affect the aero-digestive tract (mucositis, salivary gland injury), regional osseous and cartilaginous structures (osteoradionecrosis (ORN) and chondronecrosis), vasculature (progressive radiation vasculopathy and carotid blow out syndromes), and neural structures (optic neuritis, myelitis, and brain injury). These may be difficult to distinguish from tumor recurrence on imaging, and may necessitate the use of advanced MRI and molecular imaging techniques to reach the correct diagnosis. Secondary radiation-induced malignancies include thyroid cancer and a variety of sarcomas that may manifest several years after treatment. Checkpoint inhibitors can cause a variety of adverse immune events, including autoimmune hypophysitis and encephalitis.

Thyroid cancer in the Democratic Republic of the Congo: Frequency and risk factors

BACKGROUND

The prevalence of thyroid cancer is increasing steadily in most countries, partly due to better, earlier diagnosis. However, there is little data for developing countries, where the technical platform is often very limited, especially in Africa.

OBJECTIVES

To assess the frequency of thyroid cancer in the Democratic Republic of the Congo (DRC) and to analyze the epidemiological, clinical, and ultrasound risk factors.

MATERIAL AND METHODS

This is a multicenter cross-sectional study of 594 patients operated on for a thyroid mass from 2005 to 2019, in 35 centers in the DRC and for whom histopathological analyses were performed.

RESULTS

The frequency of thyroid cancers in our cohort was 20%, mostly in patients over the age of 40 (62% of patients). These cancers were mainly diagnosed at the clinical stage, due to the presence of palpable masses. Papillary cancer was the most common (67.2% of patients), followed by follicular cancer (28% of cases). We found a high prevalence of anaplastic cancer (7.6%). These frequencies are probably the consequence of the fact that histopathological analyses are not systematically performed in the DRC, but mostly on tissues that the thyroid surgeons suspect to be malignant. Age ≥60 years, the presence of adenopathies upon palpation or on ultrasound, the solid nature and hypoechogenicity of nodules, the presence of macronodules and calcifications were the factors independently associated with the diagnosis of cancer in the study population.

CONCLUSIONS

In this first study performed in the DRC, we have found that thyroid cancer is common. It is mainly detected at clinical stages, with patients over the age of 40 years and women being the most affected. The histopathology distribution differs from that in developed countries, with a lower prevalence of papillary cancer and a higher prevalence of the anaplastic type. In developing countries, it appears necessary to introduce the use of more precise diagnostic tools for thyroid cancer and also, to reinforce the improvement of known, controllable risk factors such as iodine deficiency.

Association of Parental Consanguinity With Papillary Thyroid Carcinoma: A Case-Control Study

CONTEXT

Papillary thyroid carcinoma (PTC) is the most common type of nonmedullary thyroid carcinoma. Uncommonly, PTC is associated with multiple genetic alterations and chromosomal abnormalities and displays familial patterns of inheritance. Parental consanguinity increases susceptibility to many genetic disorders.

OBJECTIVE

This work aimed to investigate the association of parental consanguinity with PTC.

METHODS

This case-control study of PTC patients compared with healthy controls took place in a tertiary referral hospital. We recruited 200 PTC patients who were managed at the endocrinology outpatient clinics of the Jordan University Hospital, and we recruited 515 healthy controls from a nonclinical setting. We interviewed all participants and collected sociodemographic data. We reviewed the family pedigrees of each participant four generations back and excluded any participant who was related. We established whether the parents of each participant were first cousins, first cousins once removed, second cousins, or unrelated. We then used binary logistic regression to assess the association of parental consanguinity with PTC adjusted for age, sex, smoking status, body mass index, and parental education.

RESULTS

We recruited 715 participants. The numbers of PTC patients and healthy controls were 200 (28.0%) and 515 (72.0%), respectively. The rate of parental consanguinity was 25.5% in PTC patients and 12.2% in healthy controls. Parental consanguinity was significantly associated with PTC (adjusted odds ratio, 2.60; 95% CI, 1.63-4.17; P < .001).

CONCLUSION

Parental consanguinity is a risk factor for PTC. Our findings should be considered during familial risk assessment and genetic counseling, especially in populations with high rates of consanguinity.

Risk perception of the pre-distribution of stable iodine to guardians of children living around the Genkai Nuclear Power Plant, Saga Prefecture, Japan

Iodine thyroid blocking (ITB) is effective for preventing childhood thyroid cancer when radioactive iodine is released into the environment during a nuclear power plant accident. Japan employs the pre-distribution of stable iodine (PDSI) to residents living near nuclear power plants; however, the number of residents who have actually received stable iodine to date remains limited. The aim of this study was to evaluate the profile of guardians of children living around the Genkai Nuclear Power Plant (GNPP) in Japan. We distributed self-administered questionnaires regarding perception of risks associated with administration of stable iodide to approximated 400 guardians of children aged 0-6 in 10 kindergartens located in four municipalities. We obtained responses from 286 guardians, and after excluding invalid responses, 247 were included in the analysis. Logistic regression analysis revealed that living within 5 km of the GNPP (odds ratio [OR] = 4.48, 95% confidence interval [CI]: 2.43-8.24), awareness of preferential implementation of ITB to children (OR = 3.33, 95%CI: 1.78-6.22), and awareness of the prophylaxis booklet published by the local government (OR = 2.53, 95%CI: 1.37-4.68) were independently associated with PDSI for children. The main reasons for not receiving PDSI were "anxiety about the side effects of stable iodine" (40.2%), "distrust of the effectiveness of SI" (23.5%), "complicated procedures for receiving stable iodine" (15.7%) and "missed the date for receiving stable iodine" (8.8%). In the case of ITB implementation during a nuclear emergency, it is necessary to clarify the risk perceptions of guardians and adapt risk communication accordingly.

Long non-coding RNA ANRIL polymorphisms in papillary thyroid cancer and its severity

Background: Long non-coding RNAs are likely to have a role in the pathogenesis of many diseases, including cancer. We hypothesised an effect of certain ANRIL single nucleotide polymorphisms (SNPs) in papillary thyroid cancer. Methods: Genomic ANRIL SNPs in rs11333048, rs4977574, rs1333040 and rs10757274 were determined in 134 papillary thyroid cancer patients and 155 age- and sex-matched controls. Results: None of the ANRIL SNPs were individually linked to papillary thyroid cancer. However, the AAAC haplotype (A from rs11333048, A from rs4977574, A from rs1333040 and C from rs10757274, respectively) showed a protective effect from papillary thyroid cancer whilst the CAAC and CAGT haplotypes were associated with cancer. The rs1333048 CC variant was more frequent in patients with larger tumour size (≥1 cm) in a recessive model (OR 3.4 [95%CI, 1.1-11], P = 0.035). The rs4977574 AC variant was associated with smaller tumour size in an over-dominant model (OR 0.4 [95%CI, 0.2-1.0], P = 0.041). SNPs in rs10757274 (AA: p = 0.045) and rs1333040 (CC: p = 0.019) are linked to a lower likelihood of III-IV cancer stages in dominant or codominant models. Conclusions: Certain haplotypes of ANRIL SNPs are associated with papillary thyroid cancer. ANRIL rs1333048 and rs4977574 variants were associated with larger and smaller tumour sizes, respectively. rs10757274 and rs1333040 variants might lead to lower III-IV cancer stages. These SNPs may be important in the diagnosis of this form of thyroid cancer.

Clinical characteristics, surgical approach, BRAFV600E mutation and sodium iodine symporter expression in pediatric patients with thyroid carcinoma

Objectives Thyroid cancer is the most common endocrine neoplasm in childhood. There are few studies characterizing pediatric population in Colombia. We intend to detail the clinical, histological characteristics, BRAFV600E mutational status and NIS (sodium-iodine symporter) expression of children with papillary thyroid carcinoma (PTC) managed at Hospital de La Misericordia. Methods Medical records of the Department of Pediatric Surgery and Pathology from 2009 to 2018 were scrutinized in search of cases of differentiated thyroid carcinoma. A descriptive analysis was made. Paraffin embedded tumoral tissue was recovered to assess BRAF V600E mutational status by PCR and NIS expression by immunohistochemistry. Results Sixteen patients were selected, 81.2% were girls. Average age of presentation was 11.8 years. Only one patient had previous radiation exposure. Most frequent symptom was cervical adenopathy with a mean time of 29.2 weeks before diagnosis. 93.7% underwent total thyroidectomy and lymphadenectomy. 62.5% were PTC combining both classic and follicular pattern. 6.25% cases had BRAFV600E mutation and 25% showed NIS focal reactivity. Conclusions We found greater female predominance, lower percentage of risk factors described and a high percentage of patients requiring aggressive surgical treatment. We consider important to contemplate thyroid cancer as a differential diagnosis of cervical lymph node enlargement in children. Diagnosis can be challenging in benign and indeterminate categories of the FNA cytology and biomolecular profiles such as BRAF and NIS could be determinant in guiding treatment. More studies with larger sample size, complete genetic analysis, evaluation to iodine response and long term follow up are required.

Thyroid cancer risk factors and Pakistani University students' awareness towards its preventive practice

OBJECTIVES

Thyroid Cancer is one of the rarest cancers but its prevalence has been increasing worldwide for the last couple of decades.

METHODS

The data collection tool was designed to assess knowledge, awareness, perception, and attitude towards preventive practices of thyroid cancer in Pakistani university students. The data were collected over a duration of six months and a total number of 3722 students participated.

RESULTS

The knowledge of risk factors of thyroid cancer was an important parameter of this study. The students who knew all the early signs of thyroid cancer were 28.7%. In this study, the independent variables such as age, gender, demographic location, and financial status were found to be highly significant with knowledge, attitude towards warning signs of cancer, and the perception of students about developing thyroid cancer.

CONCLUSIONS

The participants were found to have poor knowledge about early signs of thyroid cancer. The study participants perception, behavior, and attitude towards preventive practices of thyroid cancer were found inadequate and appropriate measures on a National level should be taken to enhance the knowledge about preventive practices of thyroid cancer. Increasing knowledge and awareness shall help decrease the overall morbidity and mortality linked with thyroid carcinomas and thyroid diseases.

African Head and Neck Society Clinical Practice guidelines for thyroid nodules and cancer in developing countries and limited resource settings

BACKGROUND

International thyroid nodule and cancer management guidelines generally fail to take into account potential limitations in diagnostic and treatment resources.

METHODS

Thyroid cancer specialists from the African Head and Neck Society and American Head & Neck Society Endocrine Section developed guidelines for diagnosis and management of thyroid nodules and cancer in low resource settings. Recommendations were based on literature review and expert opinion, with level of evidence defined.

RESULTS

Using the ADAPTE process, diagnostic and treatment algorithms were adapted from the National Comprehensive Cancer Network (NCCN). Low resource settings were simulated by systematically removing elements such as availability of laboratory testing, hormone replacement, imaging, and cytopathology from NCCN guidelines.

CONCLUSIONS

Successful management of thyroid nodules and cancer in low resource settings requires adaptation of treatment methodologies. These guidelines define specific scenarios where either more or less aggressive intervention for thyroid pathology may be advisable based on limited available resources.

Among Individuals Irradiated for Benign Conditions in Childhood, Developing Thyroid Cancer Does Not Affect All-Cause Survival

Background: Whether radiation-induced thyroid cancer affects survival rates has not been clearly elucidated. Survival could be affected by the thyroid cancer itself, its treatment, or by being a sign of susceptibility to other cancers. The objective of the current study was to determine if the development of thyroid cancer is associated with a differential survival in radiation-exposed individuals. Methods: We conducted a matched prospective cohort mortality follow-up study based on data from a cohort of 4296 individuals who were irradiated predominantly for enlarged tonsils during their childhood (between 1939 and 1962) and were prospectively followed since 1974. The study matched an irradiated subject who developed (was exposed to) thyroid cancer (a "case") and two irradiated subjects, who had not developed (were not exposed to) thyroid cancer ("controls") by the time of case incidence. The two controls were randomly matched to cases by sex, year of birth, age at radiation treatment, and radiation dose. Then, using a stratified Cox analysis, we compared survival time from the date of thyroid cancer diagnosis or time of selection to either date of death or the end of the observation period (December 31, 2016). Vital status and causes of death were determined using the National Death Index (1979-2016), the Social Security Death Index (1974-1979), and study files. Cause of death was categorized as cardiovascular, malignancy, or other. Results: A total of 1008 subjects were included in the analysis, including 353 thyroid cancer cases. At the end of the study period, 162 of 655 (24.7%) of individuals without thyroid cancer had died compared with 100 of 353 (28.3%) of the subjects with thyroid cancer. The hazard ratio (HR) for all-cause mortality, comparing the thyroid cancer cases to controls, was close to unity (HR = 1.01 [0.77-1.33]). HRs remained insignificant after eliminating matched sets with microcarcinomas, defined as tumor size <10 mm (HR = 1.39 [0.96-2.03]). Distribution of the causes of death taking into account age and the time of observation differed between cases and controls (p < 0.05). Neither increased cardiovascular-related nor malignancy-related mortality was associated with radiation-induced thyroid cancer. Conclusions: Among individuals irradiated for benign conditions in childhood, development of thyroid cancer was not associated with decreased all-cause survival.

MicroRNA-384 Inhibits the Progression of Papillary Thyroid Cancer by Targeting PRKACB

Background

Growing evidence shows that dysregulation of miRNAs plays a significant role in papillary thyroid cancer (PTC) tumorigenesis and development. The abnormal expression of miR-384 has been acknowledged in the proliferation or metastasis of some cancers. However, the function and the underlying mechanism of miR-384 in PTC progression remain largely unknown.

Methods

Real-time PCR was conducted to detect miR-384 expression in 58 cases of PTC and their adjacent noncancerous tissues. MTT, soft agar assay Transwell assay, and wound-healing assay were carried out to explore the biological function of miR-384 in PTC cell lines of BCPAP and K1. Bioinformatics analysis, dual-luciferase reporter assay, western blot, and functional complementation analysis were conducted to explore the target gene of miR-384. Moreover, Spearman's correlation analysis was conducted to reveal the correlation between miR-384 and PRKACB mRNA in PTC.

Results

The expression of miR-384 decreased obviously in PTC, especially in the tumors with lymph node metastasis or larger tumor size. The ectopic upregulation of miR-384 significantly suppressed PTC progression, and the inhibition of miR-384 had the opposite effects. Moreover, PRKACB gene was confirmed as the target of miR-384.

Conclusion

The study suggests that miR-384 serves as a tumor suppressor in PTC progression by directly targeting the 3′-UTR of PRKACB gene.

Leukocyte Telomere Length and Risk of Papillary Thyroid Carcinoma

CONTEXT

Telomere length may contribute to predisposition to papillary thyroid cancer (PTC).

OBJECTIVE

To test this hypothesis, we examined the association between leukocyte telomere length and PTC risk.

DESIGN/SETTING

Case-control study in a Chinese Han population.

PARTICIPANTS/INTERVENTION

A total of 1200 PTC cases and 1201 age- and sex-matched healthy controls were included in the study. ORs and 95% CIs were calculated by logistic regression.

RESULTS

Short relative telomere length (RTL) was significantly associated with elevated risk of PTC (OR = 1.61, 95% CI = 1.35 to 1.92; P = 1.30 × 10-7). Interestingly, when individuals were categorized into four groups on the basis of quartile distribution of relative telomere length (RTL) in controls, we observed a reverse U-shaped association between telomere length and PTC risk. Compared with those in the first (the longest) quartile as the reference group, ORs (95% CIs) were 5.61 (4.04 to 7.78) (P = 6.10 × 10-25), 9.33 (6.78 to 12.83) (P = 6.99 × 10-43), and 1.23 (0.83 to 1.81) (P = 0.300) for individuals in the second, third, and fourth (the shortest) quartiles, respectively. This reverse U-shaped relationship was more apparent in younger individuals.

CONCLUSIONS

Our findings suggest that RTL is significantly associated with susceptibility to PTC. There is an obvious reverse U-shaped association between telomere length and PTC risk. Telomere length may be a potential pronouncing biomarker to identify individuals with a high risk of developing PTC.

Stable Iodine Distribution Among Children After the 2011 Fukushima Nuclear Disaster in Japan: An Observational Study

CONTEXT

Intake of stable iodine helps prevent childhood thyroid cancer in nuclear emergencies, but there is limited case information.

OBJECTIVE

We identified the intake rate and the factors associated with no intake among children who did not take stable iodine after the Fukushima disaster.

DESIGN

Retrospective observational study.

SETTING

Data were obtained from thyroid cancer screenings performed from August through November 2017.

PARTICIPANTS

Children in Miharu Town, Fukushima, Japan.

INTERVENTION

No intervention.

MAIN OUTCOME MEASURES

We performed multilevel logistic regression analysis at the regional and individual levels. We qualitatively examined the reasons for no intake of stable iodine based on closed- and open-ended questions.

RESULTS

The rate of distribution was 94.9%, but the intake rate was only 63.5%. Intake was lower in those aged 0 to 2 years compared with those aged ≥3 years (OR, 0.21; 95% CI, 0.11 to 0.36). Parents' intake was positively associated with their children's intake (OR, 61.0; 95% CI, 37.9 to 102.9). The variance partition coefficient for regions was 0.021, suggesting that the intake of stable iodine was more likely affected by individual than by regional factors. Closed-ended questions showed that the main reason for avoiding intake was concern about safety. Open-ended questions for other reasons revealed issues related to the distribution method, information about the effects and adverse effects of iodine, and instructions for iodine intake. There were no symptomatic adverse effects claimed to the town.

CONCLUSIONS

The distribution and consumption of stable iodine occurred in Miharu Town after the Fukushima disaster. To prepare for future nuclear emergencies, it is important to explain to both children and parents the need for intake of stable iodine, particularly among young children.

Factors contributing to the resistance of the thyrocyte to hydrogen peroxide

We studied the mechanism that may explain the relative resistance of thyrocytes to H₂O₂ compared to other cell types. Ability to degrade H₂O₂, glutathione peroxidase (GPx) activity, heme oxygenase-1 (HO-1) expression, cell survival and capacity to repair DNA damage after H₂O₂ exposure or irradiation were measured in human thyrocytes in primary culture and compared to the values obtained in human T-cells and different cell lines. Compared to other cell types, thyrocytes presented a low mortality rate after H₂O₂ exposure, rapidly degraded extracellular H₂O₂ and presented a high basal seleno-dependent GPx activity. Only in thyrocytes, H₂O₂ up-regulated GPx activity and expression of HO-1 mRNA. These effects were not reproduced by irradiation. DNA damage caused by H₂O₂ was more slowly repaired than that caused by irradiation and not repaired at all in T-cells. Our study demonstrates that the thyrocyte has specific protective mechanisms against H₂O₂ and its mutagenic effects.

A Case of Functional Metastatic Follicular Thyroid Carcinoma that Presented with Hip Fracture and Hypercalcemia

Thyroid follicular cancers are one of the thyroid gland cancers. This cancer can lead to metastases to various areas of the body. We describe a patient with thyroid follicular carcinoma who after total thyroidectomy had severe hypercalcemia, increased creatinine, and thyrotoxicosis due to extensive bone metastases. The patient was a 52-year-old man who had femoral neck fracture as the first manifestation of thyroid cancer. He was hospitalized for some time after orthopedic measures because of thyrotoxicosis and deep-venous thrombosis. The study found that the origin of metastatic lesions was thyroid follicular cancer, leading to extensive bone metastases. After administering of methimazole and control of thyrotoxicosis, he was subjected to total thyroidectomy. Methimazole was discontinued immediately after surgery. One month after surgery, ultrasound confirmed that the thyroid was completely removed. However, T3 (triiodothyronine) remained high; besides the patient had hypercalcemia and increased creatinine due to dehydration. The patient was retreated with methimazole due to thyrotoxicosis, and for hypercalcemia fluid therapy, intravenous zoledronic acid was prescribed. These measures led to the normalization of creatinine and glomerular filtration rate. The purpose of introducing this case report was that these symptoms are a rare manifestation of functional metastases of follicular thyroid carcinoma after total thyroidectomy. Bone metastases of follicular thyroid carcinoma may be functional and are lytic that can lead to hypercalcemia and its complications.

Anaplastic lymphoma kinase (ALK) gene rearrangements in radiation-related human papillary thyroid carcinoma after the Chernobyl accident

Childhood radiation exposure has been associated with increased papillary thyroid carcinoma (PTC) risk. The role of anaplastic lymphoma kinase (ALK) gene rearrangements in radiation‐related PTC remains unclear, but STRN‐ALK fusions have recently been detected in PTCs from radiation exposed persons after Chernobyl using targeted next‐generation sequencing and RNA‐seq. We investigated ALK and RET gene rearrangements as well as known driver point mutations in PTC tumours from 77 radiation‐exposed patients (mean age at surgery 22.4 years) and PTC tumours from 19 non‐exposed individuals after the Chernobyl accident. ALK rearrangements were detected by fluorescence in situ hybridisation (FISH) and confirmed with immunohistochemistry (IHC); point mutations in the BRAF and RAS genes were detected by DNA pyrosequencing. Among the 77 tumours from exposed persons, we identified 7 ALK rearrangements and none in the unexposed group. When combining ALK and RET rearrangements, we found 24 in the exposed (31.2%) compared to two (10.5%) in the unexposed group. Odds ratios increased significantly in a dose‐dependent manner up to 6.2 (95%CI: 1.1, 34.7; p = 0.039) at Iodine‐131 thyroid doses >500 mGy. In total, 27 cases carried point mutations of BRAF or RAS genes, yet logistic regression analysis failed to identify significant dose association. To our knowledge we are the first to describe ALK rearrangements in post‐Chernobyl PTC samples using routine methods such as FISH and IHC. Our findings further support the hypothesis that gene rearrangements, but not oncogenic driver mutations, are associated with ionising radiation‐related tumour risk. IHC may represent an effective method for ALK‐screening in PTCs with known radiation aetiology, which is of clinical value since oncogenic ALK activation might represent a valuable target for small molecule inhibitors.

Thyroid cancer risk in the Swedish AMORIS study: the role of inflammatory biomarkers in serum

Chronic inflammation is one of the underlying risks associated with thyroid cancer. We ascertained the association between commonly measured serum biomarkers of inflammation and the risk of thyroid cancer in Swedish Apolipoprotein-related MORtality RISk (AMORIS) study. 226,212 subjects had baseline measurements of C-reactive protein, albumin and haptoglobin. Leukocytes were measured in a subgroup of 63,845 subjects. Associations between quartiles and dichotomized values of inflammatory markers and risk of thyroid cancer were analysed using multivariate Cox proportional hazard models. 202 individuals were diagnosed with thyroid cancer during a mean follow-up of 19.6 years. There was a positive association between lower albumin levels and risk of developing thyroid cancer [Hazard Ratio for albumin ≤ 40 g/L: 1.50 (95% Confidence Interval = 1.04-2.16)]. When stratified by a metabolic score, we observed similar association for albumin with higher HR among those with metabolic score ≥ 1, as compared to those with metabolic score of 0 [HR 1.98 (95% CI = 1.11-3.54) vs 1.17 (95% CI = 0.72-1.89)] (P = 0.19). Apart from albumin, none of the serum markers of inflammation studied showed a link with the risk of developing thyroid cancer-suggesting that the role of inflammation may be more complicated and requires assessment of more specialised measurements of inflammation.

Imaging and Screening of Thyroid Cancer

Ultrasound is the first-line diagnostic tool for diagnosis of thyroid diseases. The low aggressiveness of many thyroid cancers coupled with high sensitivity of sonography can lead to cancer diagnosis and treatment with no effect on outcomes. Ultrasound is recognized as the most important driver of thyroid cancer overdiagnosis. Ultrasound should not be used as a general screening tool and should be reserved for patients at high risk of thyroid cancer and in the diagnostic management of incidentally discovered thyroid nodules. With prescreening risk stratification and application of consensus criteria for nodule biopsy, the value of the diagnostic ultrasound can be maximized.

MicroRNA-335 is downregulated in papillary thyroid cancer and suppresses cancer cell growth, migration and invasion by directly targeting ZEB2

MicroRNAs (miRs) are a group of short, endogenous, non-protein-coding and single-stranded RNAs that regulate gene expression by binding to the 3'-untranslated region (3'UTR) of mRNAs, which results in their degradation or translational repression. The aim of the present study was to investigate the expression and function of miR-335 in human papillary thyroid cancer (PTC). Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to quantify the relative miR-335 expression levels in PTC tissues and cell lines. The effect of miR-335 on the proliferation, migration and invasion of PTC cells was assessed by an MTT assay, and transwell migration and invasion assays, respectively. Dual-luciferase reporter assays were employed to explore whether miR-335 directly targeted the 3'UTR of the potential target gene zinc finger E-box binding homeobox 2 (ZEB2). RT-qPCR and western blotting were adopted to assess the effect of miR-335 on the mRNA and protein expression of ZEB2. RT-qPCR revealed that miR-335 was downregulated in PTC tissues and cell lines. The MTT assay and transwell migration and invasion assays demonstrated that the overexpression of miR-335 significantly inhibited the proliferation, migration and invasion of PTC cells. ZEB2 was identified as a direct target of miR-335 with computational analysis, which was confirmed with a dual-luciferase reporter assay, RT-qPCR and western blotting. The knockdown of ZEB2 significantly inhibited the proliferation, migration and invasion of PTC cells, indicating that ZEB2 may be a functional target of miR-335. Taken together, these findings suggested that miR-335 functioned as a tumor suppressor and suppressed the growth and metastatic behavior of PTC cells by targeting ZEB2.

Application of rodes software to experimental biokinetic data for dose assessment in mice and rats

H Miloudi, M Locatelli, G Autret, D Balvay, A Desbrée, E Blanchardon, J M Bertho: application of RODES software to experimental biokinetic data for dose assessment in mice and rats. In support of experimental studies of chronic, long-term contamination in rodents, voxel-based computer models were built representing adult mice and juvenile, adult and elderly rats of both sexes. RODES software was created to calculate absorbed radiation doses to organs with these specific anatomical models. Absorbed doses were then calculated starting from previously published biokinetic data. Whole body doses showed less than 5% differences between calculation with RODES and calculation with the ICRP Publication 108 model for long term exposure to ⁹⁰Sr of mice. Similar results were obtained for long term exposure to ¹³⁷Cs. Dose distribution for ⁹⁰Sr internal contamination also showed that the dose to the skeleton is six fold more as compared to the whole body dose while radiation dose to other organs is less than the mean whole body dose. These results underline the importance of using specific anatomical models according to the age and the sex of experimental animals.

MicroRNA-150 targets Rho-associated protein kinase 1 to inhibit cell proliferation, migration and invasion in papillary thyroid carcinoma

Thyroid cancer is the most prevalent malignant tumor of the endocrine organs and accounts for one third of all head and neck tumors. Dysregulation of microRNAs is well‑known to contribute to the development of various cancers, including papillary thyroid carcinoma (PTC), which accounts for 80‑90% of all thyroid cancer cases. The present study aimed to investigate the expression, functional roles of microRNA‑150 (miR‑150) and its direct target gene in PTC. miR‑150 expression in PTC tissues and cell lines was analyzed by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). After transfection with miR‑150 mimics, cell proliferation, migration and invasion was analyzed by MTT and Transwell assays, respectively. Bioinformatics analysis was performed to investigate the potential target genes of miR‑150, which were then confirmed by luciferase reporter assay, RT‑qPCR and western blotting. Functional assays were also applied to investigate the effects of endogenous Rho‑associated protein kinase 1 (ROCK1) in PTC. miR‑150 was demonstrated to be significantly downregulated in PTC tissues and cell lines. In addition, reduced miR‑150 expression was obviously correlated with TNM stage and lymph node metastasis in PTC patients. Restoration of miR‑150 expression significantly inhibited PTC cell proliferation, migration and invasion in vitro. Furthermore, ROCK1 was identified as a direct target gene of miR‑150. Therefore, ROCK1 knockdown may serve tumor suppressive functions in PTC, induced by miR‑150 overexpression. In conclusion, miR‑150 overexpression in PTC may inhibit growth and metastasis of PTC cells. miR‑150/ROCK1‑based targeted therapy may be a potential strategy for the treatment of PTC.

Assessment of Nutritional Status of Iodine Through Urinary Iodine Screening Among Local Children and Adolescents After the Fukushima Daiichi Nuclear Power Plant Accident

BACKGROUND

Iodine deficiency is an important modifier of the risk of thyroid cancer following irradiation. However, little information is available on the prevalence of iodine deficiency in Fukushima and its surroundings after the Fukushima Daiichi nuclear power plant accident that occurred in March 2011.

METHODS

In order to assess urinary iodine concentrations (UIC) and the prevalence of iodine deficiency and to elucidate any associations between demographic characteristics and UIC levels among children and adolescents aged ≤18 years at the time of the accident in Fukushima Prefecture and its surroundings, the data on voluntary UIC testing conducted by Hirata Central Hospital, Fukushima, were evaluated.

RESULTS

A total of 4410 children and adolescents with a median age of 10 years at examination underwent UIC testing between October 2012 and October 2015. Calculated for all the participants, the median UIC level was 204 μg/L (range 25-21,100 μg/L). There were 133 (3.0%), 732 (16.6%), and 1472 (33.4%) participants with UIC levels of <50, <100, or ≥300 μg/L, respectively. Based on the World Health Organization criteria for nutritional iodine status, no participants were severely iodine deficient (<20 μg/L), but 16.6% of the population were mildly (50-100 μg/L) or moderately (20-50 μg/L) iodine deficient. While no significant difference in UIC was noted between those who did and did not increase dietary iodine intake after the accident (p = 0.93), there were significant differences by year (p < 0.01), school level (p < 0.001), and residential area at the time of the accident (p < 0.001).

CONCLUSIONS

This study demonstrates that the children and adolescents examined had a sufficient amount of iodine during the period 1.5-4.5 years after the nuclear accident. In addition to the differences in the scale and the countermeasures undertaken between the Fukushima and Chernobyl accidents, differences in dietary iodine intake might have played an additional role in resulting in the reportedly different radiation doses to the thyroid between the two nuclear accidents.

Pediatric Exposures to Ionizing Radiation: Carcinogenic Considerations

Children are at a greater risk than adults of developing cancer after being exposed to ionizing radiation. Because of their developing bodies and long life expectancy post-exposure, children require specific attention in the aftermath of nuclear accidents and when radiation is used for diagnosis or treatment purposes. In this review, we discuss the carcinogenic potential of pediatric exposures to ionizing radiation from accidental, diagnostic, and therapeutic modalities. Particular emphasis is given to leukemia and thyroid cancers as consequences of accidental exposures. We further discuss the evidence of cancers that arise as a result of radiotherapy and conclude the review with a summary on the available literature on the links between computer tomography (CT) and carcinogenesis. Appropriate actions taken to mitigate or minimize the negative health effects of pediatric exposures to ionizing radiation and future considerations are discussed.

Onco-lncRNA HOTAIR and its functional genetic variants in papillary thyroid carcinoma

The role of long noncoding RNA (lncRNA) HOX transcript antisense RNA (HOTAIR) and its functional single nucleotide polymorphisms (SNPs) in papillary thyroid carcinoma (PTC) is still largely unclear. Therefore, we investigated the involvement of lncRNA HOTAIR and its three haplotype-tagging SNPs (htSNPs) in PTC. There was higher expression of HOTAIR in PTC tissues compared to normal tissues. A series of gain-loss assays demonstrated that HOTAIR acts as a PTC oncogene via promoting tumorigenic properties of PTC cells. Additionally, the functional HOTAIR rs920778 genetic variant was a PTC susceptibility SNP. Subjects with the HOTAIR rs920778 TT genotype had an odds ratio (OR) of 1.88, 1.25 and 1.61 (P = 6.0 × 10(-6), P = 0.028 and P = 3.2 × 10(-5)) for developing PTC in Shandong, Jiangsu and Jilin case-control sets compared with subjects with the CC genotype. This statistically significant associations were only found between the rs920778 genetic polymorphism and PTC risk in females but not in males. The allele-specific regulation on HOTAIR expression by the rs920778 SNP was confirmed both in vitro and in vivo. Our results demonstrate that functional SNPs influencing lncRNA regulation may explain a part of PTC genetic basis.

NADPH oxidases: new actors in thyroid cancer?

Hydrogen peroxide (H2O2) is a crucial substrate for thyroid peroxidase, a key enzyme involved in thyroid hormone synthesis. However, as a potent oxidant, H2O2 might also be responsible for the high level of oxidative DNA damage observed in thyroid tissues, such as DNA base lesions and strand breakages, which promote chromosomal instability and contribute to the development of tumours. Although the role of H2O2 in thyroid hormone synthesis is well established, its precise mechanisms of action in pathological processes are still under investigation. The NADPH oxidase/dual oxidase family are the only oxidoreductases whose primary function is to produce reactive oxygen species. As such, the function and expression of these enzymes are tightly regulated. Thyrocytes express dual oxidase 2, which produces most of the H2O2 for thyroid hormone synthesis. Thyrocytes also express dual oxidase 1 and NADPH oxidase 4, but the roles of these enzymes are still unknown. Here, we review the structure, expression, localization and function of these enzymes. We focus on their potential role in thyroid cancer, which is characterized by increased expression of these enzymes.

Neutron radiation therapy for advanced thyroid cancers

PURPOSE

The aim of this study was to review institutional outcomes for advanced thyroid cancers treated with fast neutron radiation therapy (FNRT) and photon radiation therapy (RT).

METHODS AND MATERIALS

In all, 62 consecutive patients were analyzed. Fifty-nine had stage IV disease. Twenty-three were treated with FNRT and 39 with photon RT. Median follow-up was 14 months. The primary endpoint was overall survival (OS).

RESULTS

There was no significant difference in median OS between FNRT and photon RT (26 vs 16 months; P = .49). Patients with well-differentiated histologies had superior median OS with photon RT (17 vs 69 months; P = .04). There was a nonsignificant trend toward improved OS with FNRT for medullary and anaplastic histologies.

CONCLUSIONS

Outcomes in this study are in line with historical results. There is an apparent detriment in OS with FNRT for well-differentiated histologies and a trend toward improved OS with medullary and anaplastic histologies that warrants further investigation.

Patients exposed to diagnostic head and neck radiation for the management of shunted hydrocephalus have a significant risk of developing thyroid nodules

PURPOSE

External radiation to the head and neck can lead to an increased incidence of thyroid nodules. We investigated whether patients requiring repeated head and neck imaging for the management of shunted hydrocephalus had a higher incidence of ultrasound-detected thyroid nodules compared to reports of comparable age.

METHODS

Patients treated at our institution for shunted hydrocephalus from 1990 to 2003 were contacted. Enroled patients underwent a thyroid ultrasound. Demographic data and radiation exposure history were obtained retrospectively.

RESULTS

Thyroid nodules were identified sonographically in 15/112 patients (13.6 %). Patients with thyroid nodules were older (mean 24.3 ± 7.6 years) than those without (mean 18.4 ± 8.0 years) (p = 0.005). Those with a detectable thyroid nodule had a longer follow up time compared to those who did not (mean 21.9 ± 5.5 vs. 15.1 ± 7 years, respectively) (p = 0.018).

CONCLUSION

Patients with shunted hydrocephalus are exposed to substantial head and neck radiation from diagnostic imaging and have a higher incidence of thyroid nodules detected by ultrasonography. These patients should be provided ongoing surveillance for detection of thyroid nodules and the possibility of malignancy.

Functional evaluation of TERT-CLPTM1L genetic variants associated with susceptibility of papillary thyroid carcinoma

TERT is the catalytic subunit of telomerase which plays an essential part in cellular immortality by maintaining telomere integrity. TERT is commonly over-expressed in human malignancies, indicating its key role in cell transformation. The chromosome 5p15.33 TERT-CLPTM1L region has been associated with susceptibility of multiple cancers via a genome-wide association approach. However, the involvement of this locus in papillary thyroid carcinoma (PTC) etiology is still largely unknown. We analyzed 15 haplotype-tagging single nucleotide polymorphisms (htSNPs) of the TERT-CLPTM1L region in a two stage case-control design. After genotyping 2300 PTC patients and frequency-matched 2300 unaffected controls, we found that TERT rs2736100 genetic variant is significantly associated with elevated PTC risk. Ex vivo reporter gene assays indicated that the PTC susceptibility rs2736100 polymorphism locating in a potential TERT intronic enhancer has a genotype-specific effect on TERT expression. Correlations between rs2736100 genotypes and tissue-specific TERT expression supported the regulatory function of this genetic variant in vivo. Our data demonstrated that the functional TERT rs2736100 SNP as a novel genetic component of PTC etiology. This study, together with recent studies in other cancers, unequivocally establishes an essential role of TERT in cancers.

Whole exome sequencing identifies lncRNA GAS8-AS1 and LPAR4 as novel papillary thyroid carcinoma driver alternations

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. However, we know little of mutational spectrum in the Chinese population. Thus, here we report the identification of somatic mutations for Chinese PTC using 402 tumor-normal pairs (Discovery: 91 pairs via exome sequencing; validation: 311 pairs via Sanger sequencing). We observed three distinct mutational signatures, evidently different from the two mutational signatures among Caucasian PTCs. Ten significantly mutated genes were identified, most previously uncharacterized. Notably, we found that long non-coding RNA (lncRNA) GAS8-AS1 is the secondary most frequently altered gene and acts as a novel tumor suppressor in PTC. As a mutation hotspot, the c.713A>G/714T>C dinucleotide substitution was found among 89.1% patients with GAS8-AS1 mutations and associated with advanced PTC disease (P = 0.009). Interestingly, the wild-type lncRNA GAS8-AS1 (A713T714) showed consistently higher capability to inhibit cancer cell growth compared to the mutated lncRNA (G713C714). Further studies also elucidated the oncogene nature of the G protein-coupled receptor LPAR4 and its c.872T>G (p.Ile291Ser) mutation in PTC malignant transformation. The BRAF c.1799T>A (p.Val600Glu) substitution was present in 59.0% Chinese PTCs, more frequently observed in patients with lymph node metastasis (P = 1.6 × 10(-4)). Together our study defines a exome mutational spectrum of PTC in the Chinese population and highlights lncRNA GAS8-AS1 and LPAR4 as potential diagnostics and therapeutic targets.

Risk of Thyroid Cancer in Euthyroid Asymptomatic Patients with Thyroid Nodules with an Emphasis on Family History of Thyroid Cancer

Objective

To determine the factors associated with thyroid cancer, focusing on first-degree family history and ultrasonography (US) features, in euthyroid asymptomatic patients with thyroid nodules.

Materials and Methods

This retrospective study included 1310 thyroid nodules of 1254 euthyroid asymptomatic patients who underwent US-guided fine-needle aspiration biopsy between November 2012 and August 2013. Nodule size and clinical risk factors–such as patient age, gender, first-degree family history of thyroid cancer, multiplicity on US and serum thyroid stimulating hormone (TSH) levels–were considered together with US features to compare benign and malignant nodules. Multiple logistic regression analysis was performed to assess the risk of thyroid malignancy according to clinical and US characteristics.

Results

Although all of the clinical factors and US findings were significantly different between patients with benign and malignant nodules, a solitary lesion on US (p = 0.041–0.043), US features and male gender (p < 0.001) were significant independent risk factors for thyroid malignancy in a multivariate analysis. Patient age, a first-degree family history of thyroid cancer and high normal serum TSH levels did not independently significantly increase the risk of thyroid cancer. However, multicollinearity existed between US assessment and patient age, first-degree family history of thyroid cancer and serum TSH values.

Conclusion

Ultrasonography findings should be the primary criterion used to decide the management of euthyroid asymptomatic patients with thyroid nodules. The concept of first-degree family history as a risk factor for thyroid malignancy should be further studied in asymptomatic patients.

No evidence for a decreased risk of thyroid cancer in association with use of metformin or other antidiabetic drugs: a case-control study

Background

Use of metformin has been associated with a decreased cancer risk. We aimed to explore whether use of metformin or other antidiabetic drugs is associated with a decreased risk for thyroid cancer.

Methods

We conducted a case-control analysis (1995 to 2014) using the U.K.-based Clinical Practice Research Datalink (CPRD). Cases had a first-time diagnosis of thyroid cancer, six controls per case were matched on age, sex, calendar time, general practice, and number of years of active history in the database prior to the index date. We assessed odds ratios (ORs) with 95 % confidence intervals (95 % CI), adjusted for body mass index (BMI), smoking, and diabetes mellitus.

Results

In 1229 cases and 7374 matched controls, the risk of thyroid cancer associated with ever use of metformin yielded an adjusted OR of 1.48, 95 % CI 0.86–2.54. The relative risk estimate was highest in long-term (≥30 prescriptions) users of metformin (adjusted OR 1.83, 95 % CI 0.92–3.65), based on a limited number of 26 exposed cases. No such association was found in users of sulfonylurea, insulin, or thiazolidinediones (TZD). Neither a diabetes diagnosis (adjusted OR 1.17, 95 % CI 0.89–1.54), nor diabetes duration >8 years (adjusted OR 1.22, 95 % CI 0.60–2.51) altered the risk of thyroid cancer.

Conclusion

In our observational study with limited statistical power, neither use of metformin nor of other antidiabetic drugs were associated with a decreased risk of thyroid cancer.

Fetal growth and subsequent maternal risk of thyroid cancer

Thyroid cancer has peak incidence among women of reproductive age, and growth factors, which have procarcinogenic properties, may play an important etiologic role. However, the association between fetal growth rate during a woman's pregnancy and her subsequent risk of thyroid cancer has not been previously examined. We conducted a national cohort study of 1,837,634 mothers who had a total of 3,588,497 live-births in Sweden in 1973-2008, followed up for thyroid cancer incidence through 2009. There were 2,202 mothers subsequently diagnosed with thyroid cancer in 36.8 million person-years of follow-up. After adjusting for maternal age, height, weight, smoking, and sociodemographic factors, high fetal growth (birth weight standardized for gestational age and sex) was associated with a subsequent increased risk of thyroid cancer in the mother (incidence rate ratio [IRR] per additional 1 standard deviation, 1.05; 95% CI, 1.01-1.09; p = 0.02). Each 1,000 g increase in the infant's birth weight was associated with a 13% increase in the mother's subsequent risk of thyroid cancer (IRR, 1.13; 95% CI, 1.05-1.22; p = 0.001). These findings appeared to involve both papillary and follicular subtypes, and did not vary significantly by the mother's height, weight or smoking status. In this large national cohort study, high fetal growth during a woman's pregnancy was independently associated with a subsequent increased risk of her developing thyroid cancer. If confirmed, these findings suggest an important role of maternal growth factors in the development of thyroid cancer, and potentially may help facilitate the identification of high-risk subgroups of women.

Quantitative assessment of common genetic variants on FOXE1 and differentiated thyroid cancer risk

Forkhead box E1 encodes the transcription factor FOXE1 (or TTF-2), which together with Homeobox protein NKX2-1, PAX8 and HHEX, are pivotal proteins required for thyroid gland formation, differentiation and function. Recently, genome-wide association studies have identified FOXE1 as a thyroid cancer (TC) susceptibility gene in populations of European descent. After that, a number of studies reported that the rs965513, rs1867277, and rs71369530 polymorphism in FOXE1 has been implicated in TC risk. However, the causal variants remain unknown. To derive a more precise estimation of the relationship, a meta-analysis of 9,828 TC cases and 109,995 controls from 14 case–control studies was performed. Overall, significant results were observed for rs965513 (OR = 1.71, 95% CI: 1.59–1.85, P<10⁻⁵), rs1867277 (OR = 1.64, 95% CI: 1.51–1.78, P<10⁻⁵) and rs71369530 (OR = 2.01, 95% CI: 1.66–2.44, P<10⁻⁵) polymorphism. In the subgroup analysis by ethnicity, we found that rs965513 polymorphism confer high risk for Caucasians with per-allele OR of 1.80 (95% CI: 1.69–1.92, P<10⁻⁵) compared to East Asians of 1.35 (95% CI: 1.09–1.67, P = 0.006). There was strong evidence of heterogeneity, which largely disappeared after stratification by ethnicity. In the subgroup analysis by sample size, and study design, significantly increased risks were found for the polymorphism. In conclusion, this meta-analysis demonstrated that common variations of FOXE1 are a risk factor associated with increased TC susceptibility.

Thyroid dysfunction as an unintended side effect of anticancer drugs

BACKGROUND

Several of the currently used anticancer drugs may variably affect thyroid function, with impairment ranging from modified total but not free concentration of thyroid hormones to overt thyroid disease.

SUMMARY

Cytotoxic agents seem to alter thyroid function in a relatively small proportion of adult patients. Anticancer hormone drugs may mainly alter serum levels of thyroid hormone-binding proteins without clinically relevant thyroid dysfunction. Old immunomodulating drugs, such as interferon-α and interleukin-2, are known to induce variably high incidence of autoimmune thyroid dysfunction. Newer immune checkpoint inhibitors, such as anti-CTLA4 monoclonal antibodies, are responsible for a relatively low incidence of thyroiditis and may induce secondary hypothyroidism resulting from hypophysitis. Central hypothyroidism is a well-recognized side effect of bexarotene. Despite their inherent selectivity, tyrosine kinase inhibitors may cause high rates of thyroid dysfunction. Notably, thyroid toxicity seems to be restricted to tyrosine kinase inhibitors targeting key kinase-receptors in angiogenic pathways, but not other kinase-receptors (e.g., epidermal growth factor receptors family or c-KIT). In addition, a number of these agents may also increase the levothyroxine requirement in thyroidectomized patients.

CONCLUSIONS

The pathophysiology of thyroid toxicity induced by many anticancer agents is not fully clarified and for others it remains speculative. Thyroid dysfunction induced by anticancer agents is generally manageable and dose reduction or discontinuation of these agents is not required. The prognostic relevance of thyroid autoimmunity, overt and subclinical hypothyroidism induced by anticancer drugs, the value of thyroid hormone replacement in individuals with abnormal thyrotropin following anticancer systemic therapy, and the correct timing of replacement therapy in cancer patients need to be defined more accurately in well-powered prospective clinical trials.

Ultra-rare mutation in long-range enhancer predisposes to thyroid carcinoma with high penetrance

Thyroid cancer shows high heritability but causative genes remain largely unknown. According to a common hypothesis the genetic predisposition to thyroid cancer is highly heterogeneous; being in part due to many different rare alleles. Here we used linkage analysis and targeted deep sequencing to detect a novel single-nucleotide mutation in chromosome 4q32 (4q32A>C) in a large pedigree displaying non-medullary thyroid carcinoma (NMTC). This mutation is generally ultra-rare; it was not found in 38 NMTC families, in 2676 sporadic NMTC cases or 2470 controls. The mutation is located in a long-range enhancer element whose ability to bind the transcription factors POU2F and YY1 is significantly impaired, with decreased activity in the presence of the C- allele compared with the wild type A-allele. An enhancer RNA (eRNA) is transcribed in thyroid tissue from this region and is greatly downregulated in NMTC tumors. We suggest that this is an example of an ultra-rare mutation predisposing to thyroid cancer with high penetrance.

A prospective study of medical diagnostic radiography and risk of thyroid cancer

Although diagnostic x-ray procedures provide important medical benefits, cancer risks associated with their exposure are also possible, but not well characterized. The US Radiologic Technologists Study (1983-2006) is a nationwide, prospective cohort study with extensive questionnaire data on history of personal diagnostic imaging procedures collected prior to cancer diagnosis. We used Cox proportional hazard regressions to estimate thyroid cancer risks related to the number and type of selected procedures. We assessed potential modifying effects of age and calendar year of the first x-ray procedure in each category of procedures. Incident thyroid cancers (n = 251) were diagnosed among 75,494 technologists (1.3 million person-years; mean follow-up = 17 years). Overall, there was no clear evidence of thyroid cancer risk associated with diagnostic x-rays except for dental x-rays. We observed a 13% increase in thyroid cancer risk for every 10 reported dental radiographs (hazard ratio = 1.13, 95% confidence interval: 1.01, 1.26), which was driven by dental x-rays first received before 1970, but we found no evidence that the relationship between dental x-rays and thyroid cancer was associated with childhood or adolescent exposures as would have been anticipated. The lack of association of thyroid cancer with x-ray procedures that expose the thyroid to higher radiation doses than do dental x-rays underscores the need to conduct a detailed radiation exposure assessment to enable quantitative evaluation of risk.

Rising incidence, no change in survival and decreasing mortality from thyroid cancer in The Netherlands since 1989

The incidence of thyroid cancer (TC) is increasing worldwide, partly due to increased detection. We therefore assessed combined trends in incidence, survival and mortality of the various types of TC in The Netherlands between 1989 and 2009. We included all patients ≥15 years with TC, diagnosed in the period 1989-2009 and recorded in The Netherlands Cancer Registry (n=8021). Information on age, gender, date of diagnosis, histological type of tumour and tumour-node-metastasis classification was recorded. Mortality data (up to 1st January 2010) were derived from Statistics Netherlands. Annual percentages of change in incidence, mortality and relative survival were calculated. Since 1989 the incidence of TC increased significantly in The Netherlands (estimated annual percentage change (EAPC)=+1.7%). The incidence rates increased for all age groups (except for females >60 years), papillary tumours (EAPC=+3.5%), T1 and T3 TC (EAPC=+7.9 and +5.8% respectively). Incidence rates decreased for T4 TC (-2.3%) and remained stable for follicular, medullary anaplastic and T2 TC. Five-year relative survival rates remained stable for papillary (88%) and follicular (77%) TC, all age groups and T1-T3 TC (96, 94 and 80% respectively) and somewhat lower for T4 (53%), medullary (65%) and anaplastic TC (5%) in the 2004-2009 period compared with earlier periods. Mortality due to TC decreased (EAPC=-1.9%). TC detection and incidence has been rising in The Netherlands, while mortality rates are decreasing and survival rates remained stable or slightly decreasing.

The polymorphism rs944289 predisposes to papillary thyroid carcinoma through a large intergenic noncoding RNA gene of tumor suppressor type

A genome-wide association study of papillary thyroid carcinoma (PTC) pinpointed two independent SNPs (rs944289 and rs965513) located in regions containing no annotated genes (14q13.3 and 9q22.33, respectively). Here, we describe a unique, long, intergenic, noncoding RNA gene (lincRNA) named Papillary Thyroid Carcinoma Susceptibility Candidate 3 (PTCSC3) located 3.2 kb downstream of rs944289 at 14q.13.3 and the expression of which is strictly thyroid specific. By quantitative PCR, PTCSC3 expression was strongly down-regulated (P = 2.84 × 10(-14)) in thyroid tumor tissue of 46 PTC patients and the risk allele (T) was associated with the strongest suppression (genotype [TT] (n = 21) vs. [CT] (n = 19), P = 0.004). In adjacent unaffected thyroid tissue, the genotype [TT] was associated with up-regulation of PTCSC3 ([TT] (n = 21) vs. [CT] (n = 19), P = 0.034). The SNP rs944289 was located in a binding site for the CCAAT/enhancer binding proteins (C/EBP) α and β. The risk allele destroyed the binding site in silico. Both C/EBPα and C/EBPβ activated the PTCSC3 promoter in reporter assays (P = 0.0009 and P = 0.0014, respectively) and the risk allele reduced the activation compared with the nonrisk allele (C) (P = 0.026 and P = 0.048, respectively). Restoration of PTCSC3 expression in PTC cell line cells (TPC-1 and BCPAP) inhibited cell growth (P = 0.002 and P = 0.019, respectively) and affected the expression of genes involved in DNA replication, recombination and repair, cellular movement, tumor morphology, and cell death. Our data suggest that SNP rs944289 predisposes to PTC through a previously uncharacterized, long intergenic noncoding RNA gene (PTCSC3) that has the characteristics of a tumor suppressor.

Thyroid dysfunction from antineoplastic agents

Unlike cytotoxic agents that indiscriminately affect rapidly dividing cells, newer antineoplastic agents such as targeted therapies and immunotherapies are associated with thyroid dysfunction. These include tyrosine kinase inhibitors, bexarotene, radioiodine-based cancer therapies, denileukin diftitox, alemtuzumab, interferon-α, interleukin-2, ipilimumab, tremelimumab, thalidomide, and lenalidomide. Primary hypothyroidism is the most common side effect, although thyrotoxicosis and effects on thyroid-stimulating hormone secretion and thyroid hormone metabolism have also been described. Most agents cause thyroid dysfunction in 20%-50% of patients, although some have even higher rates. Despite this, physicians may overlook drug-induced thyroid dysfunction because of the complexity of the clinical picture in the cancer patient. Symptoms of hypothyroidism, such as fatigue, weakness, depression, memory loss, cold intolerance, and cardiovascular effects, may be incorrectly attributed to the primary disease or to the antineoplastic agent. Underdiagnosis of thyroid dysfunction can have important consequences for cancer patient management. At a minimum, the symptoms will adversely affect the patient's quality of life. Alternatively, such symptoms can lead to dose reductions of potentially life-saving therapies. Hypothyroidism can also alter the kinetics and clearance of medications, which may lead to undesirable side effects. Thyrotoxicosis can be mistaken for sepsis or a nonendocrinologic drug side effect. In some patients, thyroid disease may indicate a higher likelihood of tumor response to the agent. Both hypothyroidism and thyrotoxicosis are easily diagnosed with inexpensive and specific tests. In many patients, particularly those with hypothyroidism, the treatment is straightforward. We therefore recommend routine testing for thyroid abnormalities in patients receiving these antineoplastic agents.

The loss of the p53 activator HIPK2 is responsible for galectin-3 overexpression in well differentiated thyroid carcinomas

Background

Galectin-3 (Gal-3) is an anti-apoptotic molecule involved in thyroid cells transformation. It is specifically overexpressed in thyroid tumour cells and is currently used as a preoperative diagnostic marker of thyroid malignancy. Gal-3 expression is downregulated by wt-p53 at the transcriptional level. In well-differentiated thyroid carcinomas (WDTCs) there is an unexplained paradoxical concomitant expression of Gal-3 and wt-p53. HIPK2 is a co-regulator of different transcription factors, and modulates basic cellular processes mainly through the activation of wt-p53. Since we demonstrated that HIPK2 is involved in p53-mediated Gal-3 downregulation, we asked whether HIPK2 deficiency might be responsible for such paradoxical Gal-3 overexpression in WDTC.

Methodology/Principal Findings

We analyzed HIPK2 protein and mRNA levels, as well as loss of heterozygosity (LOH) at the HIPK2 locus (7q32-34), in thyroid tissue samples. HIPK2 protein levels were high in all follicular hyperplasias (FHs) analyzed. Conversely, HIPK2 was undetectable in 91.7% of papillary thyroid carcinomas (PTCs) and in 60.0% of follicular thyroid carcinomas (FTCs). HIPK2 mRNA levels were upregulated in FH compared to normal thyroid tissue (NTT), while PTC showed mean HIPK2 mRNA levels lower than FH and, in 61.5% of cases, also lower than NTT. We found LOH at HIPK-2 gene locus in 37.5% of PTCs, 14.3% of FTCs and 18.2% of follicular adenomas. To causally link these data with Gal-3 upregulation, we performed in vitro experiments, using the PTC-derived K1 cells, in which HIPK2 expression was manipulated by RNA interference (RNAi) or plasmid-mediated overexpression. HIPK2 RNAi was associated with Gal-3 upregulation, while HIPK2 overexpression with Gal-3 downregulation.

Conclusions/Significance

Our results indicate that HIPK2 expression and function are impaired in WDTCs, in particular in PTCs, and that this event explains Gal-3 overexpression typically observed in these types of tumours. Therefore, HIPK2 can be considered as a new tumour suppressor gene for thyroid cancers.

Thyroid cancer in older men

This article reviews most common types of thyroid cancer focusing on older males worldwide. Thyroid carcinoma is the most common endocrine malignancy. It includes tumour types that range from localised papillary carcinomas to lethal anaplastic disease. Among elderly population, male gender seems to be highly correlated with the risk and aggressiveness of thyroid cancer. Early diagnosis and urgent aggressive treatment are important for aging patients. This article includes numerous studies which evaluate prevalence, morbidity and mortality of thyroid cancer in older males.

Clinical experiences with radiation induced thyroid cancer after chernobyl

The risk of developing thyroid cancer increases considerably after exposure to external or internal radiation, especially in children below the age of 10. After the Chernobyl reactor accident, the yearly incidence of childhood thyroid cancer in Belarus increased to approximately 40 per 1.000.000 in girls and to roughly 20 per 1.000.000 in boys compared to approximately 0.5 cases per 1.000.000 prior to the accident. Typically, young children with thyroid cancer after radiation exposure present in ≈95% of the cases as papillary cancers, in ≈50% as invasive tumors growing outside the thyroid capsule, in ≈65% with lymph node metastases and in ≈15% with distant metastases. A joint Belarusian-German project starting in April 1993 that combined treatment with surgery and radioiodine was organized in 237 selected children from Belarus who were exposed to the Chernobyl fallout and had advanced stages of thyroid cancer. The study group included 141 girls and 96 boys. Their median age at the time of the accident was 1.7 years; whereas the median age at the time of diagnosis was 12.4 years. With the exception of two cases with follicular histology, the majority of the patients had been diagnosed with papillary thyroid cancers. In 63%, the tumor had grown outside the thyroid capsule and invaded the tissue of the neck (pT4). Nearly all of the selected cases (96%) showed-up with lymph node metastases (pN1) and 43% of the patients with distant metastases mainly to the lungs (pM1). In 58% of the children, complete remissions of thyroid cancer could be achieved until December 31st 2010 and in 34% of the children, stable partial remissions; in the remaining 8% of the patients, partial remissions were observed. The risk of radiation-induced thyroid cancer increased considerably in children and adolescents who were affected by the Chernobyl reactor accident. In spite of the fact, that thyroid cancers in young children seem to behave more aggressively than in older patients, the results of combined treatment with thyroidectomy, radioiodine therapy and thyroid hormone replacement are excellent.

Thyroid cancer risk 40+ years after irradiation for an enlarged thymus: an update of the Hempelmann cohort

Although ionizing radiation is a known carcinogen, the long-term risk from relatively higher-dose diagnostic procedures during childhood is less well known. We evaluated this risk indirectly by assessing thyroid cancer incidence in a cohort treated with "lower-dose" chest radiotherapy more than 55 years ago. Between 2004 and 2008, we re-surveyed a population-based cohort of subjects treated with radiation for an enlarged thymus during infancy between 1926 and 1957 and their unexposed siblings. Thyroid cancer occurred in 50 irradiated subjects (mean thyroid dose, 1.29 Gy) and in 13 nonirradiated siblings during 334,347 person-years of follow-up. After adjusting for attained age, Jewish religion, sex and history of goiter, the rate ratio for thyroid cancer was 5.6 (95% CI: 3.1-10.8). The adjusted excess relative risk per gray was 3.2 (95% CI: 1.5-6.6). The adjusted excess absolute risk per gray was 2.2 cases (95% CI: 1.4-3.2) per 10,000 person-years. Cumulative thyroid cancer incidence remains elevated in this cohort after a median 57.5 years of follow-up and is dose-dependent. Although the incidence appeared to decrease after 40 years, increased risk remains a lifelong concern in those exposed to lower doses of medical radiation during early childhood.

Exposing the thyroid to radiation: a review of its current extent, risks, and implications

Radiation exposure of the thyroid at a young age is a recognized risk factor for the development of differentiated thyroid cancer lasting for four decades and probably for a lifetime after exposure. Medical radiation exposure, however, occurs frequently, including among the pediatric population, which is especially sensitive to the effects of radiation. In the past, the treatment of benign medical conditions with external radiation represented the most significant thyroid radiation exposures. Today, diagnostic medical radiation represents the largest source of man-made radiation exposure. Radiation exposure related to the use of computerized tomography is rising exponentially, particularly in the pediatric population. There is direct epidemiological evidence of a small but significant increased risk of cancer at radiation doses equivalent to computerized tomography doses used today. Paralleling the increasing use of medical radiation is an increase in the incidence of papillary thyroid cancer. At present, it is unclear how much of this increase is related to increased detection of subclinical disease from the increased utilization of ultrasonography and fine-needle aspiration, how much is due to a true increase in thyroid cancer, and how much, if any, can be ascribed to medical radiation exposure. Fortunately, the amount of radiation exposure from medical sources can be reduced. In this article we review the sources of thyroid radiation exposure, radiation risks to the thyroid gland, strategies for reducing radiation exposure to the thyroid, and ways that endocrinologists can participate in this effort. Finally, we provide some suggestions for future research directions.

Surgical management of well-differentiated thyroid cancer: state of the art

Nonmedullary well-differentiated thyroid cancer (WDTC) comprises a group of tumors including papillary thyroid carcinoma (PTC) and follicular thyroid carcinoma (FTC), with Hürthle cell carcinoma being a subtype of follicular carcinoma. This article reviews the epidemiology, pathogenesis, preoperative and diagnostic evaluation, imaging, and staging of WDTC. Different approaches to therapy and follow-up care are discussed. The prognosis for WDTC remains good and most patients can expect to be cured of their disease.