Impact of enhanced detection on the increase in thyroid cancer incidence in the United States: review of incidence trends by socioeconomic status within the surveillance, epidemiology, and end results registry, 1980-2008

Thyroid Cancer Incidence in Bulgaria before and after the Introduction of Universal Salt Iodization: An Analysis of the National Cancer Registry Data

Background

Thyroid cancer is the most common malignancy of the endocrine system and it has become the fastest growing cancer among women. The suspected risk factors include increased exposure to ionizing radiation during childhood, environmental pollutants, possible iodine deficiency, and excessive iodine exposure.

Aims

To analyze the thyroid cancer incidence between 1980 and 2013 in Bulgaria and to determine the incidence rate before and after the introduction of universal salt iodization in 1994 in regions with different iodine deficiency levels.

Study Design

Retrospective cohort.

Methods

The study was a retrospective analysis of the total number of thyroid cancer cases with all histological types in Bulgaria (thyroid cancer, ICD10 code C73), diagnosed between 01/01/1980 and 31/12/2013, and retrieved from the anonymous cancer registry database of the Bulgarian National Cancer Registry. Age-standardized rates of thyroid cancer per 100,000 persons were calculated for each year of the periods mentioned below by sex and age, utilizing the WHO world reference populations with a special statistical module of the Bulgarian National Cancer Registry’s software CancerRegBG, 2011. Incidence rates were reported by age, sex, and period of diagnosis (1980-86, 1987-93, 1994-99, 2000-2006, 2007-2013). Trends among males and females were analyzed separately, as well as by age category: 0-19, 20-44, 45-64, and 65+. Annual percentage changes of age-standardized incidence rates were analyzed by Joinpoint regression to determine trends using the Joinpoint statistical software SEER* Stat Software, Version 4.1.1, 2014.

Results

The age-standardized rates of thyroid cancer in Bulgaria has been increasing since 1990, being higher among women compared to men (4.68 vs 2.81). The highest age-standardized rates of thyroid cancer was observed in women in the 2007-2013 period. The only significant joinpoint was recorded in 1990 for females and in 1991 for males. The highest incidence rates was in the Smolyan district, a region with historically existing iodine deficiency and relatively high post-Chernobyl radiation exposure.

Conclusion

Our results showed that, in different regions, the age-standardized thyroid cancer rates between endemic and non-endemic differ greatly depending on the radiation dose from the Chernobyl accident. The role of iodine intake in thyroid cancer remains uncertain, but iodine deficiency could be a contributing factor to the increased risk of thyroid cancer.

Papillary thyroid carcinoma with a high tumor mutation burden has a poor prognosis

BACKGROUND

Tumor mutation burden (TMB) as a prognostic marker for immunotherapy has shown prognostic value in many cancers. However, there is no systematic investigation on TMB in papillary thyroid carcinoma (PTC).

METHODS

Based on the somatic mutation data of 487 PTC patients from The Cancer Genome Atlas (TCGA), TMB was calculated, and we classified the samples into high-TMB (H-TMB) and low-TMB (L-TMB) groups. Bioinformatics methods were used to explore the characteristics and potential mechanism of TMB in PTC.

RESULTS

High TMB predicts shorter progression-free survival (PFS) (P < 0.001). TMB was positively correlated with age, stage, tumor size, metastasis, the male sex and tall cell PTC. Compared to the L-TMB group, the H-TMB group presented with lower immune cell infiltration, a higher proportion of tumor-promoting immune cells (M0 macrophages, activated dendritic cells and monocytes) and a lower proportion of antitumor immune cells (M1 macrophages, CD8⁺ T cells and B cells). Additionally, the characteristics displayed by different TMB groups were not driven by critical driver mutations such as BRAF and RAS.

CONCLUSIONS

PTC patients with high TMB have a worse prognosis. By stratifying PTC patients according to their TMB, advanced PTC patients who are candidates for immunotherapy could be selected.

Immune Cell Confrontation in the Papillary Thyroid Carcinoma Microenvironment

Background

Papillary thyroid cancer has been associated with chronic inflammation. A systematic understanding of immune cell infiltration in PTC is essential for subsequent immune research and new diagnostic and therapeutic strategies.

Methods

Three different algorithms, single-sample gene set enrichment analysis (ssGSEA), immune cell marker and CIBERSORT, were used to evaluate immune cell infiltration levels (abundance and proportion) in 10 data sets (The Cancer Genome Atlas [TCGA], GSE3467, GSE3678, GSE5364, GSE27155, GSE33630, GSE50901, GSE53157, GSE58545, and GSE60542; a total of 799 PTC and 194 normal thyroid samples). Consensus unsupervised clustering divided PTC patients into low-immunity and high-immunity groups. Weighted gene coexpression network analysis (WGCNA) and gene set enrichment analysis (GSEA) were used to analyze the potential mechanisms causing differences in the immune response.

Results

Compared with normal tissues, PTC tissues had a higher overall immune level and higher abundance levels and proportions of M2 macrophages, Tregs, monocytes, neutrophils, dendritic cells (DCs), mast cells (MCs), and M0 macrophages. Compared with early PTC, advanced PTC showed higher immune infiltration and higher abundance levels and proportions of M2 macrophages, Tregs, monocytes, neutrophils, DCs, MCs, and M0 macrophages. Compared to the low-immunity group, the high-immunity group exhibited more advanced stages, larger tumor sizes, greater lymph node metastases, higher tall-cell PTCs, lower follicular PTC proportions, more BRAF mutations, and fewer RAS mutations. Epstein-Barr virus (EBV) infection was the most significantly enriched Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway for key module genes.

Conclusions

In human PTC, M2 macrophages, Tregs, monocytes, neutrophils, DCs, MCs, and M0 macrophages appear to play a tumor-promoting role, while M1 macrophages, CD8+ T cells, B cells, NK cells, and T follicular helper (TFH) cells (including eosinophils, γδ T cells, and Th17 cells with weak supporting evidence) appear to play an antitumor role. During the occurrence and development of PTC, the overall immune level was increased, and the abundance and proportion of tumor-promoting immune cells were significantly increased, indicating that immune escape had been aggravated. Finally, we speculate that EBV may play an important role in changing the immune microenvironment of PTC tumors.

MRI-based radiomics analysis to predict preoperative lymph node metastasis in papillary thyroid carcinoma

Background

The aim of the present study was to develop a magnetic resonance imaging (MRI) radiomics model and evaluate its clinical value in predicting preoperative lymph node metastasis (LNM) in patients with papillary thyroid carcinoma (PTC).

Methods

Data of 129 patients with histopathologically confirmed PTC were retrospectively reviewed in our study (90 in training group and 39 in testing group). 395 radiomics features were extracted from T2 weighted imaging (T2WI), diffusion weighted imaging (DWI) and T1 weighted multiphase contrast enhancement imaging (T1C+) respectively. Minimum redundancy maximum relevance (mRMR) was used to eliminate irrelevant and redundant features and least absolute shrinkage and selection operator (LASSO), to additionally select an optimized features' subset to construct the radiomics signature. Predictive performance was validated using receiver operating characteristic curve (ROC) analysis, while decision curve analyses (DCA) were conducted to evaluate the clinical worth of the four models according to different sequences. A radiomics nomogram was built using multivariate logistic regression model. The nomogram's performance was assessed and validated in the training and validation cohorts, respectively.

Results

Seven key features were selected from T2WI, five from DWI, ten from T1C+ and seven from the combined images. The scores (Rad-scores) of patients with LNM were significantly higher than patients with non-LNM in both the training cohort and the validation cohort. The combined model performed better than the T2WI, DWI, and T1C+ models alone in both cohorts. In the training cohort, the area under the ROC (AUC) values of T2WI, DWI, T1C+ and combined features were 0.819, 0.826, 0.808, and 0.835, respectively; corresponding values in the validation cohort were 0.798, 0.798, 0.789, and 0.830. The clinical utility of the combined model was confirmed using the radiomics nomogram and DCA.

Conclusions

MRI radiomic model based on anatomical and functional MRI images could be used as a non-invasive biomarker to identify PTC patients at high risk of LNM, which could help to develop individualized treatment strategies in clinical practice.

Bioinformatics analysis of the clinical value and potential mechanisms of AHNAK2 in papillary thyroid carcinoma

BACKGROUND

AHNAK2 has been recently reported as a biomarker in many cancers. However, a systematic investigation of AHNAK2 in papillary thyroid carcinoma (PTC) has not been conducted.

RESULTS

AHNAK2 is overexpressed in PTC tissues and could be an independent prognostic factor. AHNAK2 expression was significantly high in patients with advanced stage, advanced T classification, lymph node metastasis, increased BRAF mutations and decreased RAS mutations. Cell adhesion-, cell junction-, and immune-related pathways were the most frequently noted in gene set enrichment analysis. AHNAK2 expression in PTC was positively correlated with immune infiltration and negatively correlated with AHNAK2 methylation. AHNAK2 expression was significantly positively correlated with tumor progression and poor overall survival (OS) in pan-cancer patients.

CONCLUSIONS

AHNAK2 is a good biomarker for the diagnosis and prognosis of PTC. AHNAK2 may promote thyroid cancer progression through cell adhesion-, cell junction-, and immune-related pathways. Methylation may act as an upstream regulator to inhibit the expression and biological function of AHNAK2. Additionally, AHNAK2 has broad prognostic value in pan-cancer.

METHODS

Based on The Cancer Genome Atlas (TCGA) data, we screened AHNAK2-related genes through weighted gene coexpression network analysis and explored the clinical value and the potential mechanism of AHNAK2 in PTC by multiomics analysis.

Changes in the Demographic and Clinicopathological Characteristics of Thyroid Cancer: A Population-Based Investigation in Algeria, 1993-2013

Over the last three decades, the incidence of thyroid cancer has increased worldwide. The reasons for this increase remain controversial. In Algeria, however, to date, information on thyroid cancer has been limited to a hospital-based case series. We analyzed data from a population-based cohort study in Oran District, Algeria, to describe demographic and clinicopathological characteristics of patients diagnosed with thyroid cancer between 1993 and 2013. Medical records and pathology reports of thyroid cancer patients who had surgery were reviewed. Changes in demographic and clinicopathological features over the 21-year period are described. During the study period, thyroid cancer was diagnosed in 1248 women (86.5%, mean age 43.7 ± 15.2 years) and 195 men (23.4%, mean age 48.1 ± 15.9 years). Most cases (83.1% for women and 69.8% for men) sought a diagnosis following a self-neck check. The most common histologic types were papillary (58.3%), follicular (29.7%), anaplastic (4.1%), and medullary (0.8%) carcinomas. The incidence of papillary carcinomas significantly increased (p < 0.001) while the incidence of other histologic types significantly decreased over time. Tumor size overall significantly decreased (p < 0.001) while the frequency of small (≤20 mm) and larger (>20 mm) carcinomas significantly increased (p < 0.05). The frequency of thyroid cancers with capsular effractions and angioinvasions also decreased over time. Thyroid cancer incidence in Algeria has increased substantially in line with international trends with changes in clinical practice being a possible contributing factor. However, the increasing papillary-to-follicular cancer ratio may be due to changes in iodine nutrition status in Algeria. Further research, including exploration of biological and molecular features of thyroid cancer, will enable a better understanding of risk factors and etiopathogenetic mechanisms.

The Benefit of Primary Tumor Surgical Resection in Distant Metastatic Carcinomas of the Thyroid

OBJECTIVES/HYPOTHESIS

Thyroid cancer with distant metastasis (TCDM) at diagnosis has significantly worse survival rates when compared to localized/regional thyroid cancer. This study sought to report on the characteristics of patients presenting with TCDM and the potential survival advantage of surgical resection.

STUDY DESIGN

Data were acquired from the Surveillance, Epidemiology, and End Results (SEER) database with cases from 2004 to 2015.

METHODS

TCDM cases (n = 2,558) were identified from the SEER database. The Bonferroni correction was applied for multivariate analysis. Kaplan-Meier analysis was utilized to obtain disease-specific survival (DSS) rates. Cox regression analysis was utilized to identify independent factors significantly associated with survival.

RESULTS

The average age of diagnosis of TCDM was 62.0 (±17.5) years. Patients were predominantly white (74.6%), female (54.6%), in a relationship (56.0%), and between ages 36 and 80 years (76.4%). Cases consisted of papillary (57.2%), follicular (16.0%), medullary (8.9%), anaplastic (17.9%) TCDM histological variants. Overall 1-, 5-, and 10-year DSS rates were 72.0%, 56.8%, and 43.8%, respectively. Anaplastic and medullary variants had the worst 10-year DSS (0% and 25.5%, respectively). Patients who underwent surgical resection only and surgical resection with radiation were 49% and 59% less likely to die, respectively. Treatment, age, histology, T staging, relationship status, and metastasis site were determined to be significant predictors of survival.

CONCLUSIONS

Surgical resection with radiation was found to be a significant predictor of survival after applying the Bonferroni correction for all thyroid cancer variants except medullary. To increase survival, surgical intervention should be recommended in patients who are deemed to be medically tolerant of surgery.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:1026-1034, 2021.

Thyroid Cancer Incidence Trends in the United States: Association with Changes in Professional Guideline Recommendations

Background: Overdiagnosis is the leading factor contributing to the rapid increase in thyroid cancer incidence of the last decades. During this period, however, thyroid cancer incidence has not been increasing at a constant pace. We hypothesized that changes in the slope of the incidence trends curve, called joinpoints, could be associated with changes in clinical practice guideline recommendations. Methods: Data were obtained from the initial nine registries of the Surveillance, Epidemiology, and End Results (SEER) Program. Thyroid cancer incidence was analyzed from 1975 to 2016. Joinpoints in thyroid cancer incidence trends and clinical variables were correlated with significant changes in clinical practice recommendations. Results: Incidence rate trends of medullary and anaplastic thyroid cancer were constant during the study period. Among papillary thyroid cancers (PTCs), three main joinpoints were identified, mainly driven by changes in incidence trends of smaller cancers. First, acceleration followed by two deceleration periods in thyroid cancer incidence coincident in time with the release of American Thyroid Association guidelines in 1996, 2009, and 2015. In 1996, the use of thyroid ultrasound and fine needle aspiration biopsy for the evaluation of thyroid nodules was described; and in 2009 and 2015, higher size thresholds for the biopsy of thyroid nodules were set. For the follicular variant of PTC, a joinpoint was observed around 1988, when the histological diagnosis of this entity was revised in the World Health Organization classification; and another one in 2015 coinciding with the proposal to remove the term carcinoma from noninvasive follicular-pattern tumors with papillary-like nuclear features which contributed to drive down the overall thyroid cancer incidence. Follicular thyroid cancer incidence was affected as well by changes in the guidelines, but to a lesser extent, and it was fairly stable during the study period. Conclusions: This study suggests that thyroid cancer incidence trends have been shaped, in large part, but not completely, by changes in professional guideline recommendations.

Evaluation of Medical Surveillance and Incidence of Post-September 11, 2001, Thyroid Cancer in World Trade Center-Exposed Firefighters and Emergency Medical Service Workers

IMPORTANCE

Elevated incidence rates of thyroid cancer among World Trade Center (WTC)-exposed individuals may be associated with the identification of asymptomatic cancers during medical surveillance.

OBJECTIVE

To examine the association between WTC exposure and thyroid cancer among Fire Department of the City of New York (hereafter, Fire Department) rescue/recovery workers as well as the association with medical surveillance.

DESIGN, SETTING, AND PARTICIPANTS

This closed-cohort study classified the method of detection (asymptomatic and symptomatic) of thyroid cancers in 14 987 men monitored through the Fire Department-WTC Health Program diagnosed from September 12, 2001, to December 31, 2018. Age-, sex-, and histologic-specific Fire Department incidence rates were calculated and compared with demographically similar men in Olmsted County, Minnesota, from the Rochester Epidemiology Project using age-standardized rates, relative rates (RRs), and 95% CIs. The secondary analysis was restricted to papillary carcinomas.

EXPOSURES

World Trade Center exposure was defined as rescue/recovery work at the WTC site from September 11, 2001, to July 25, 2002.

MAIN OUTCOMES AND MEASURES

The outcomes evaluated comprised (1) number of incident thyroid cancers and their detection method categorizations in the Fire Department and Rochester Epidemiology Project cohorts; (2) Fire Department, Rochester Epidemiology Project, and Surveillance, Epidemiology, and End Results-21 age-standardized incidence rates of thyroid cancer; and (3) RRs comparing Fire Department and Rochester Epidemiology Project overall and by detection method categorization.

RESULTS

Seventy-two post-9/11 Fire Department cases of thyroid cancer were identified. Among the 65 cases (90.3%) with a categorized detection method, 53 cases (81.5%) were asymptomatic and 12 cases (18.5%) were symptomatic. Median (interquartile range) age at diagnosis was 50.2 (44.0-58.6) vs 46.6 (43.9-52.9) years for asymptomatic vs symptomatic cases. Associated primarily with asymptomatic cancers, the overall age-standardized incidence of Fire Department thyroid cancers (24.7; 95% CI, 17.4-52.3) was significantly higher than the Rochester Epidemiology Project (10.4; 95% CI, 8.5-12.7) and Surveillance, Epidemiology, and End Results-21 (9.1; 95% CI, 9.0-9.1) per 100 000 person-years. Furthermore, the RR of thyroid cancer among symptomatic men in Fire Department cases was not significantly different from that of men in the Rochester Epidemiology Project (0.8; 95% CI, 0.4-1.5); however, the rate of asymptomatic cancers was more than 3-fold that of the Rochester Epidemiology Project rate (RR, 3.1; 95% CI, 2.1-4.7).

CONCLUSIONS AND RELEVANCE

Excess asymptomatic thyroid cancer in Fire Department WTC-exposed rescue/recovery workers is apparently attributable to the identification of occult lesions during medical surveillance. Among WTC-exposed cohorts and the general population, these findings appear to have important implications for how thyroid cancer incidence rates are interpreted and how diagnoses should be managed.

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.

With High-Risk Factors, Total Thyroidectomy is Preferred for Thyroid Cancer

INTRODUCTION

Based on thyroid cancer data from patients treated in Liaocheng People's Hospital in 2017, with Chinese national and regional characteristics, in this study we addressed the controversy of which initial thyroid surgical mode, lobectomy or total thyroidectomy, is most effective.

PATIENTS AND METHODS

Clinical and pathological data from 552 patients with thyroid cancer, who were initially diagnosed and treated surgically, were collected from the Department of Thyroid Surgery. Among them, 40 patients underwent endoscopic surgery, with resection including lobectomy + central lymph node dissection of the affected lobe, while 512 cases underwent total thyroidectomy + central lymph node dissection.

RESULTS

The metastasis rate for all patients was 59.42%. Further, among patients with bilateral or multiple tumors or capsule invasion, the proportions who developed metastatic disease were 63.54% and 71.19% and 67.46%, respectively. Meanwhile, the incidence of contralateral accidental malignancy was 7.25% after postoperative paraffin pathology.

DISCUSSION

Rates of neck lymph node metastasis are high, particularly among patients with risk factors for poor prognosis. It is recommended that, among patients with risk factors, initial treatment should comprise at least total thyroidectomy + central lymph node dissection in China, to avoid the risks associated with secondary surgery and effects on patient quality of life.

Neuropilin-2 promotes growth and progression of papillary thyroid cancer cells

OBJECTIVE

Neuropilin-2 (NRP2) is a coreceptor of vascular endothelial growth factor-C/D (VEGF-C/D) and plays the important role in the development of lymphatic endothelial cells, as well as neuronal development. NRP2 is known to affect aggressiveness by increasing expression in various human cancers, but the role of NRP2 in thyroid cancer is not fully understood. The purpose of this study was to investigate the NRP2 expression and its role in regulating the tumor aggressiveness in the papillary thyroid carcinoma (PTC).

METHODS

The NRP2 expression and its clinicopathologic correlation to PTC was determined using the data from the 262 PTC patients at a tertiary referral medical center and The Cancer Genome Atlas (TCGA) database. The potential role of NRP2 in modulating tumor growth, invasion, and metastasis in PTC was examined by using small interfering RNA (siRNA)-mediated knockdown of NRP2.

RESULTS

High expression of NRP2 was significantly associated with capsular invasion, lymphovascular invasion, lymph node metastasis, 5 or more metastatic lymph nodes, and recurrence in PTC patients. In TCGA data, the higher NRP2 expression group was significantly associated with extrathyroid extension, lymph node metastasis, and BRAF^V600E mutation. The siRNA mediated knockdown of NRP2 in the PTC cells reduced the cell proliferation, migration and invasion. We also have confirmed that NRP2 knockdown suppressed epithelial-mesenchymal transition (EMT) by regulating AKT and ERK phosphorylation signaling pathways.

CONCLUSION

Our results suggest that NRP2 regulates tumor progression in PTC and may act as a predictive factor for aggressiveness of PTC.

The sentinel lymph node biopsy technique in papillary thyroid carcinoma: The issue of false-negative findings

BACKGROUND

The management of papillary thyroid carcinoma (PTC) is changed after introduction of sentinel lymph node biopsy (SNB) technique for nodal staging. Some debate still surrounds the accuracy of this procedure in terms of wide heterogeneity of sentinel lymph node detection and false-negative findings.

AIM

to identify the key issues which make it difficult the usefulness of SNB in PTC.

METHODS

A comprehensive computer literature search of meta-analyses published in PubMed/MEDLINE and Cochrane library database until June 30, 2019 was conducted. We used a search algorithm based on this combination of terms: (i) "thyroid neoplasm" or "thyroid cancer" or "thyroid carcinoma" or "thyroid malignancy" or "meta-analysis" or "systematic review") AND (ii) "sentinel lymph node biopsy".

RESULTS

Comparing 4 written meta-analyses published in the literature, the diagnostic performance of SNB technique in PTC has been summarized. Relatively high false-negative rates (FNR) were reported for each SNB methods: vital-dye (VD: 12.7%; 7%; 0-38%), 99mTc-nanocolloid planar lymphoscintigraphy with the use of intraoperative hand-held gamma probes (LS: 11.3%; 16%; 0-40%), combined LS with VD (LS+VD: 0%; 0-17%), LS with the additional contribution of preoperative SPECT/CT (7-8%).

CONCLUSION

Evidence-based data about the diagnostic performance of SNB in PTC are increasing. The nuclear medicine community should reach a consensus on the operational definition of the SLN to better guide the surgeon in identifying the lymph nodes most likely contain metastatic cells. Standardization of SLN identification, removal and analysis are required.

Nutritional status and follicular-derived thyroid cancer: An update

The incidence of differentiated thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more intensive thyroid nodule screening and more sensitive diagnostic procedures. Several environmental factors have changed with sufficient rapidity in the same time frame and may represent credible candidates for this increase. They include modified iodine intake, lifestyle-associated risk factors, exposure to various toxic compounds, pollutants and xenobiotics, nutritional deficiencies, eating habits and comorbidities. Foremost, nutritional patterns have gained high interest as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this narrative review is to focus on the relationship between thyroid cancer and nutritional factors, dietary habits and obesity. Low iodine intake has been associated to increased risk of thyroid cancer, favoring the development of more aggressive histotypes. Moreover, correction of iodine deficiency can shift thyroid cancer subtypes toward less aggressive forms, without affecting the overall risk for cancer. Actually, evidence regarding the association between selenium and vitamin D deficiency and thyroid cancer is very limited, despite their well-known anti-cancer potentials, and the clinical usefulness of their supplementation is still uncertain in this setting. Albeit the relationship between single foods and thyroid cancer is difficult to examine, fish and iodine-rich foods, vegetables, and fruits might exert protective effects on thyroid cancer risk. Conversely, no clear association has been found for other foods to date. Lastly, a clear association between obesity and the risk of thyroid cancer, with more aggressive behavior, seems to emerge from most studies, likely involving variations in thyroid function and chronic inflammation mediated by cytokines, insulin, leptin and adiponectins. Although no definite association between dietary factors and thyroid cancer has been firmly established so far, some nutritional patterns, together with excessive weight, seem to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. These effects may play an additive role to the well-established one exerted by environmental carcinogens, such as pollutants and radiation exposure.

Circular RNA Profiling Reveals Exosomal circ_0006156 as a Novel Biomarker in Papillary Thyroid Cancer

Circular RNAs (circRNAs) are a class of noncoding RNAs that are broadly expressed in various biological cells and function in regulating gene expression. However, the molecular mechanisms that link circRNAs with progression of papillary thyroid carcinoma (PTC) are not well understood. In the present study, the function of circ_0006156 (circFNDC3B) was investigated in human PTC cells. First, we detected the expression of circFNDC3B in PTC tissues and PTC cell lines by RT-PCR. A luciferase reporter assay and AGO2-RNA immunoprecipitation (RIP) was used to confirm the relationship between circFNDC3B and microRNA (miR)-1178. PTC cells were stably transfected with small interfering RNA (siRNA) against circFNDC3B, and cell proliferation, migration, and invasion were detected to evaluate the effect of circFNDC3B in PTC, while tumorigenesis was assayed in nude mice. In this study, circFNDC3B was observed to be upregulated in PTC tissues and cell lines. Knockdown of circFNDC3B inhibited cell proliferation and promoted cell apoptosis in PTC cells. Bioinformatics analysis predicted that there is a circFNDC3B/miR-1178/Toll-like receptor 4 (TLR4) axis in PTC. The dual-luciferase reporter system validated the direct interaction of circFNDC3B, miR-1178, and TLR4. Furthermore, circFNDC3B facilitates PTC progression in vivo. Importantly, we demonstrated that circFNDC3B was upregulated in serum exosomes from PTC patients. In summary, our study demonstrated that circFNDC3B modulates PTC progression through the miR-1178/TLR4 pathway. Our findings indicated that circFNDC3B may serve as a promising therapeutic target for the treatment of PTC patients.

Posttraumatic stress disorder and incidence of thyroid dysfunction in women

BACKGROUND

Abnormal thyroid function is prevalent among women and has been linked to increased risk of chronic disease. Posttraumatic stress disorder (PTSD) has been linked to thyroid dysfunction in some studies; however, the results have been inconsistent. Thus, we evaluated trauma exposure and PTSD symptoms in relation to incident thyroid dysfunction in a large longitudinal cohort of civilian women.

METHODS

We used data from 45 992 women from the ongoing Nurses' Health Study II, a longitudinal US cohort study that began in 1989. In 2008, history of trauma and PTSD were assessed with the Short Screening Scale for Diagnostic and Statistical Manual of Mental Disorders, fourth edition, PTSD, and incident thyroid dysfunction was determined by participants' self-report in biennial questionnaires of physician-diagnosed hypothyroidism and Graves' hyperthyroidism. The study period was from 1989 to 2013. Proportional hazard models were used to estimate multivariable-adjusted hazard ratios and 95% confidence intervals (CIs) for incident hypothyroidism and Graves' hyperthyroidism.

RESULTS

In multivariable-adjusted models, we found significant associations for PTSD only with hypothyroidism [p-trend <0.001; trauma with no PTSD symptoms, 1.08 (95% CI 1.02-1.15); 1-3 PTSD symptoms, 1.12 (95% CI 1.04-1.21); 4-5 PTSD symptoms, 1.23 (95% CI 1.13-1.34); and 6-7 PTSD symptoms, 1.26 (95% CI 1.14-1.40)]. PTSD was not associated with risk of Graves' hyperthyroidism (p-trend = 0.34). Associations were similar in sensitivity analyses restricted to outcomes with onset after 2008, when PTSD was assessed.

CONCLUSIONS

PTSD was associated with higher risk of hypothyroidism in a dose-dependent fashion. Highlighted awareness for thyroid dysfunction may be especially important in women with PTSD.

Upregulation of the long non-coding RNA FOXD2-AS1 is correlated with tumor progression and metastasis in papillary thyroid cancer

BACKGROUND

Mounting evidence has shown that long non-coding RNAs (lncRNAs) play critical regulation roles in the progression of various cancers. However, the biological role and clinical value of lncRNA FOXD2-AS1 in papillary thyroid cancer (PTC) remain to be elucidated.

METHODS

The expression of FOXD2-AS1 in PTC tissues and cell lines was evaluated by RT-qPCR and in situ hybridization. The association between FOXD2-AS1 expression levels and clinicopathologic features was analyzed through tissue microarray. The biological function of FOXD2-AS1 in PTC cells was determined both in vitro through CCK-8, EdU staining, colony formation and cell invasion assays and in vivo through a xenograft tumor model. Functional and pathway enrichment analysis were also conducted to analyze the molecular mechanism.

RESULTS

FOXD2-AS1 was significantly upregulated in PTC tissues, and high FOXD2-AS1 expression was positively associated with malignant potential factors in PTC patients. In addition, high level of FOXD2-AS1 expression was an unfavorable independent prognostic biomarker for patients with PTC. Moreover, we found that knockdown of FOXD2-AS1 could effectively inhibit PTC cell proliferation and invasion in vitro and suppress tumor growth of PTC in vivo. Bioinformatics analysis indicated that activation of cell cycle and apoptosis pathways might be involved in the oncogenic function of FOXD2-AS1 in PTC. Moreover, we demonstrated that FOXD2-AS1 directly interacted with miR-185-5p as miRNA sponge and overexpression of FOXD2-AS1 partially reversed the suppressive effect of miR-185-5p in TPC cells.

CONCLUSION

Our findings suggest FOXD2-AS1 functions as an oncogene and promotes the tumor progression and metastasis in PTC, which might serve as a promising prognostic biomarker and potential therapeutic target for PTC patients.

Recurrent Papillary Thyroid Carcinoma to the Cervical Lymph Nodes: Outcomes of Compartment-Oriented Lymph Node Resection

INTRODUCTION

Recurrence of papillary thyroid carcinoma after initial treatment is challenging. Surgical reintervention is recommended, but cure after surgery in uncertain and surgical morbidity may be high. This study evaluates the effect of compartment-oriented lymph node dissection (LND) on clinical and biochemical cure rate as well as the related complications.

PATIENTS AND METHODS

All patients who underwent LND for recurrent papillary thyroid carcinoma between 2000 and 2015 were included. Demography, the extent of the initial surgery, usage of ¹³¹I, the pattern of recurrence, diagnosis, details of the surgical reintervention, histological findings, surgical morbidity, and clinical and biochemical outcomes were analyzed.

RESULTS

There were 11 (12.7%) males and 75 (87.2%) females with a mean age of 42.8 ± 14.6 years. Seventy-seven patients had undergone total thyroidectomy and in 67 (77.9%) some type of LN resection. In 76 (88.3%), ¹³¹I was administered after the initial surgery. We localized suspicious lymph nodes by US in all patients, and metastases were documented before surgery by FNA in 63. Seven (8.13%) patients underwent central LND, 63 (73.2%) lateral LND and 16 (18.6%) both, central and lateral LND. Major complications occurred in 6 patients (6.9%). Sixty-two (72.0%) patients received ¹³¹I after surgery. A second surgical re-exploration was performed in 30 (34.8%) patients, and 7 patients required 3 or more additional LND. In a mean follow-up of 59.4 ± 39 months, 51 (59.3%) patients are clinically, radiologically and biochemically free of disease.

CONCLUSIONS

In this series, compartment-oriented lymph node resection of recurrent papillary thyroid carcinoma leads to a final clinical and biochemical disease-free status of 59.3% with 6.9% of major complications.

Incidence of thyroid cancer in Puerto Rico and the US by racial/ethnic group, 2011-2015

BACKGROUND

Puerto Rico has the highest incidence rate of thyroid cancer (TC) in the Americas and the third highest rate worldwide. The purpose of this study was to compare the burden of TC between the population of PR and United States (US) non-Hispanic Whites (NHW), non-Hispanic Blacks (NHB), and US Hispanics (USH) during the period 2011-2015.

METHODS

TC data for the period 2011-2015 was obtained from the Puerto Rico Central Cancer Registry (PRCCR) and the Surveillance Epidemiology and Ends Results Program (SEER) 18 Registries Research Data. TC was categorized in: papillary carcinoma (PTC), and other TC histologic types. Data was analyzed by sex, age groups, and histologic type. Racial/ethnic differences by sex, age, and histologic types were assessed using the Standardized Rate Ratio (SRR) and its 95% CI.

RESULTS

During the period 2011-2015 there were 5175 and 65,528 cases of TC diagnosed in PR and the US, respectively. The overall age-adjusted incidence rate of PTC was almost two-fold higher in PR than in the US (25.8/100,000 vs. 12.9/100,000). Among PR women, the incidence rate of PTC was 40.0/100,000 compared to 19.4/100,000 in US. PR women had 83% increased risk of being diagnosed with PTC than NHW women, a 2.25-fold increased risk than USH, and 3.45-fold increased risk than NHB women. For men, PR had 34% increased risk of being diagnosed with PTC than NHW men, 2.2-fold increased risk than USH men, and 3.2-fold higher risk than in NHB men.

CONCLUSION

Further research is needed to understand this disparity in the island. This research should address the extent of overdiagnosis in PR, the role of health insurance status and insurance type, characteristics of the healthcare delivery system as well as the role of patient and environmental factors.

Impact of Rurality on National Trends in Thyroid Cancer Incidence and Long-Term Survival

PURPOSE

Thyroid cancer incidence is rising, possibly secondary to increased imaging and surveillance. Based on rural access to care disparities, we hypothesized that incidence would be greater in urban compared to rural counties with no significant difference in long-term survival.

METHODS

An observational study was performed on thyroid cancer patients using Surveillance Epidemiology and End Results data (2000-2012). Age-adjusted incidence rates, incidence rate ratios, and survival rates were calculated across rural-urban designations.

FINDINGS

Incidence rates were 11.2, 9.8, and 10.1 per 100,000 for urban, rural-adjacent, and rural-nonadjacent counties, respectively. Statistically significantly lower incidence was noted in rural-adjacent and rural-nonadjacent compared to urban areas. Five-year and 10-year survival was significantly lower in rural-nonadjacent counties compared to urban counties.

CONCLUSIONS

Higher incidence and increased long-term survival for thyroid cancer were noted in urban areas compared to rural areas. It is uncertain if rural-urban differences in long-term survival reflect health care disparities, differences in therapy, or other origins.

Trends in pediatric thyroid cancer incidence in the United States, 1998-2013

BACKGROUND

Pediatric differentiated thyroid cancer (DTC) rates have increased over time in the United States and worldwide. Improvements in imaging for the diagnosis of DTC have been hypothesized as a potential driver of these increases. This study stratifies temporal trends in pediatric DTC by stage and tumor size to assess whether rates of large, late-stage cancers, which are likely to be clinically meaningful, are increasing over time.

METHODS

Age-standardized incidence rates (ASRs) of DTC and annual percent changes (APCs) in primary DTC rates were estimated for 0- to 19-year-olds with data from 39 US cancer registries during 1998-2013.

RESULTS

During 1998-2013, 7296 cases of DTC were diagnosed (6652 papillary cases and 644 follicular cases). APCs of pediatric DTCs significantly increased by 4.43%/y [95% CI, 3.74%/y-5.13%/y], primarily because of increases in papillary histologies. Increasing trends were observed for children aged 10 to 19 years for both sexes and for non-Hispanic whites, non-Hispanic blacks, and Hispanics. Rates increased significantly over the time period for all tumor stages (APC_localized , +4.06%/y [95% CI, 2.84%/y-5.29%/y]; APC_regional , +5.68%/y [95% CI, 4.64%/y-6.73%/y]; APC_distant , +8.55%/y [95% CI, 5.03%/y-12.19%/y]) and across tumor sizes (APC_<1 cm , +9.46%/y [95% CI, 6.13%/y-12.90%/y]; APC_1-2 cm , +6.92%/y [95% CI, 4.31%/y-9.60%/y]; APC_>2 cm , +4.69%/y [95% CI, 2.75%/y-6.67%/y]).

CONCLUSIONS

Significantly increasing rates of DTC over time among 10- to 19-year-olds in the United States are unlikely to be entirely explained by increases in medical surveillance during childhood because rates of large and late-stage DTC are increasing over time. Future studies should examine environmental and other factors that may be contributing to rising DTC rates.

Evaluation of MEDAG gene expression in papillary thyroid microcarcinoma: associations with histological features, regional lymph node metastasis and prognosis

Papillary thyroid microcarcinoma accounts for a large proportion of papillary thyroid carcinoma, especially among new cases. Many  PTMC patients have regional lymph node metastasis, with some experiencing recurrence and even death. However, the risk factors and mechanism by which PTMC relates to these factors are unknown. In this study, differentially expressed genes were identified with microarray from The Cancer Genome Atlas, followed by analysis using the Kyoto Encyclopedia of Genes and Genomes. Immunohistochemistry, immunofluorescence, western blot and Oil Red O staining were carried out to evaluate expression levels and functional alterations. Mesenteric Estrogen Dependent Adipogenesis expression was observed in almost all cases of papillary thyroid microcarcinomas, and the location of expression was associated with histological subtype. High expression was correlated with metastasis and poor disease-free survival. Furthermore, the enrichment analysis indicated that Mesenteric Estrogen Dependent Adipogenesis expression may be associated with metabolic reprogramming to influence metastasis and prognosis. These findings contribute to a better understanding of how Mesenteric Estrogen Dependent Adipogenesis affects metastasis and the prognosis of papillary thyroid microcarcinoma patients and suggest that Mesenteric Estrogen Dependent Adipogenesis expression may be a novel prognostic marker in these patients. 

A review of incidence and mortality of colorectal, lung, liver, thyroid, and bladder cancers in Iran and compared to other countries

In Iran, a developing country in southwest Asia, an epidemiologic transition is underway from communicable to noncommunicable diseases. In Iran, cancer is the second largest group of chronic non-communicable diseases (NCDs) and the third most common cause of death following heart disease, accidents and other natural phenomena. There are some studies reporting an increasing trend in the incidence and mortality rate of a variety of cancers in Iran. Therefore, controlling and preventive interventions pertaining to cancers must be a main priority for health policy and it is recommended that the high-risk population receive earlier screening. In this review, incidence and mortality of colorectal, lung, liver, thyroid, and bladder cancers in Iran are reported.

Thyroid Cancer in Ecuador, a 16 years population-based analysis (2001-2016)

BACKGROUND

Thyroid cancer is the most frequent endocrine neoplasia worldwide. Information from Andean countries is scarce. In Ecuador there is no reports available of the epidemiology of this type of cancer. The aim of this study is to present the epidemiology and the burden of disease of thyroid cancer.

METHODS

This is a cross-sectional population-based analysis of thyroid cancer epidemiology in Ecuador from 2001 to 2016. The variables studied were the overall mortality rate, socio-demographics characteristics of the hospitalized patients, geographical trends and the burden of thyroid cancer in Ecuador. All the data was obtained from the official records reported by the Ministry of Public Health's and retrieved from the public databases of the Vital Statistics Deaths and Births Databases and the National Institute of Census and Statistics (INEC).

RESULTS

In Ecuador, over a period of 16 years from 2001 to 2016 a total of 23,632 hospital admissions were reported, which caused 1539 deaths due thyroid cancer. Data demonstrated an annual mean of 1477 cases, which caused 96 deaths per year in average. The annual incidence fluctuated from 3 in 2001 to 22 in 2016 per 100,000 inhabitants. Women were 5 times more likely than men to have thyroid cancer. The average length of stay for both sexes were 4 days. The mortality attributable to thyroid cancer represent less than 0.3% of all cancer deaths.

CONCLUSION

Ecuador has one of the highest rates of thyroid cancer in Latin America, ranking first among women in Latin America. Although this cancer is frequent, mortality rate is relatively low. As this is the first national report of thyroid cancer in the country, a further analysis of the pathological variants and the grading of this neoplasia is needed.

Application of deep learning to the diagnosis of cervical lymph node metastasis from thyroid cancer with CT

PURPOSE

To develop a deep learning-based computer-aided diagnosis (CAD) system for use in the CT diagnosis of cervical lymph node metastasis (LNM) in patients with thyroid cancer.

METHODS

A total of 995 axial CT images that included benign (n = 647) and malignant (n = 348) lymph nodes were collected from 202 patients with thyroid cancer who underwent CT for surgical planning between July 2017 and January 2018. The datasets were randomly split into training (79.0%), validation (10.5%), and test (10.5%) datasets. Eight deep convolutional neural network (CNN) models were used to classify the images into metastatic or benign lymph nodes. Pretrained networks were used on the ImageNet and the best-performing algorithm was selected. Class-specific discriminative regions were visualized with attention heatmap using a global average pooling method.

RESULTS

The area under the ROC curve (AUROC) for the tested algorithms ranged from 0.909 to 0.953. The sensitivity, specificity, and accuracy of the best-performing algorithm were all 90.4%, respectively. Attention heatmap highlighted important subregions for further clinical review.

CONCLUSION

A deep learning-based CAD system could accurately classify cervical LNM in patients with thyroid cancer on preoperative CT with an AUROC of 0.953. Whether this approach has clinical utility will require evaluation in a clinical setting.

KEY POINTS

• A deep learning-based CAD system could accurately classify cervical lymph node metastasis. The AUROC for the eight tested algorithms ranged from 0.909 to 0.953. • Of the eight models, the ResNet50 algorithm was the best-performing model for the validation dataset with 0.953 AUROC. The sensitivity, specificity, and accuracy of the ResNet50 model were all 90.4%, respectively, in the test dataset. • Based on its high accuracy of 90.4%, we consider that this model may be useful in a clinical setting to detect LNM on preoperative CT in patients with thyroid cancer.

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.

Epidemiology of Thyroid Cancer: A Review of the National Cancer Database, 2000-2013

Objective  To show the recent trends in thyroid cancer in the United States, elucidate the characteristics of stage IV thyroid cancer, and consider the effects of diagnostic testing on the rising incidence of thyroid cancer. Design  A retrospective population-based study conducted using the National Cancer Database from 2000-2013 (NCDB). Demographics of patients presenting with stage IV thyroid cancer were compared to patients presenting with all other stages using the chi-square testing. The incidence rates were examined with the trend graphs. Results  When compared to stages I-III, there was an increased incidence of stage IV thyroid cancer in: Medicare, lower level of education, lower income, advanced age, male sex, increased number of comorbidities, further distance from a treatment facility, and medullary/anaplastic histology. The incidence of thyroid cancer increased from 7.1 per 100,000 in 2000 to 17.6 per 100,000 in 2013. During this same time period, stage IV disease increased 1 per 100,000. The increase in the incidence of thyroid cancer was almost entirely due to an increase in papillary cancer. Conclusions  The United States has continued to see a rise in the incidence of thyroid cancer over the last decade, largely due to the detection of papillary cancers. During this same time, the incidence of stage IV thyroid cancer increased as well. Because early diagnosis and treatment of an increasing number of potentially lethal cancers should lead to a decrease in metastatic disease, we suggest that the increasing incidence of thyroid cancer in the United States is due to overdiagnosis and that more aggressive disease is not being removed by early detection.

Active and Passive Smoking, BRAFV600E Mutation Status, and the Risk of Papillary Thyroid Cancer: A Large-Scale Case-Control and Case-Only Study

PURPOSE

The association between tobacco smoking and thyroid cancer remains uncertain. We evaluated the associations of active and passive smokingwith the risk of papillary thyroid cancer (PTC), the most common type of thyroid cancer, and with the BRAFV600E mutation, the most common oncogenic mutation in PTC related to poor prognosis.

Materials and Methods

We conducted this study with newly diagnosed PTC patients (n=2,142) and community controls (n=21,420) individually matched to cases for age and sex. Information on active and passive smoking and potential confounders were obtained from structured questionnaires, anthropometric measurements, and medical records. BRAFV600E mutation status was assessed in PTC patients. We evaluated the associations of active and passive smoking with PTC and BRAFV600E mutation risk using conditional and unconditional logistic regression models, respectively.

RESULTS

We did not find associations between exposure indices of active and passive smoking and PTC risk in both men and women, except for the association between current smoking and lower PTC risk. Cumulative smoking ≥ 20 pack-years was associated with lower BRAFV600E mutation risk in male PTC patients (odds ratio [OR], 0.55; 95% confidence interval [CI], 0.30 to 1.00). The CI for the association was wider in female PTC patients (OR, 0.23; 95% CI, 0.02 to 2.62), possibly owing to a smaller sample size in this stratum.

CONCLUSION

We did not find consistent associations between active and passive smoking and PTC risk. Cumulative smoking ≥ 20 pack-years was associated with lower BRAFV600E mutation risk in male PTC patients.

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.

Higher incidence of screening-related cancers in the employed population

Background

Employment may confound the risk of a cancer diagnosis in both directions. We hypothesized that a higher baseline rate of employment among cancer patients may explain the lack of association between a cancer diagnosis and later unemployment in many studies.

Aims

To assess the unemployment rate among cancer patients before diagnosis compared with a matched cancer-free control group.

Methods

Using data from the Israeli National Central Bureau of Statistics 1995 census (persons aged between 15 and 60 years old), the Israeli Tax Authority database and the Israel Cancer Registry, cancer patients (diagnosed between the years 2000 and 2007 and alive at 2011) were compared with matched cancer-free controls.

Results

There were 8797 cancer patients and 26166 cancer-free controls. We found that, in general, cancer was not associated with unemployment 2 years before diagnosis (adjusted odds ratio [OR] = 0.96, 95% confidence interval [CI] 0.90-1.009, P = NS) after adjustment for age, gender, ethnicity, educational years and residential socioeconomic position. However, the diagnoses associated with screening (breast, prostate, colorectal and cervix cancers) were inversely associated with unemployment 2 years before diagnosis (adjusted OR = 0.90, 95% CI 0.84-0.97, P < 0.01).

Conclusions

The results from the current study suggest that a higher baseline rate of employment among cancer patients, mainly those who were diagnosed with screening-associated cancers, explains false negative results in previous studies assessing cancer survivors' work issues.

THYROGLOBULIN AS A TUMOR MARKER IN DIFFERENTIATED THYROID CANCER - CLINICAL CONSIDERATIONS

SUMMARY – Initial treatment of the majority of patients with differentiated thyroid cancer (DTC) includes total thyroidectomy. Postoperative ablation therapy with radioactive iodine (I-131) is indicated in all high-risk patients, however, there is disagreement regarding its use in low- and intermediate-risk patients. Over the last few decades, thyroglobulin (Tg) has been established as the primary biochemical tumor marker for patients with DTC. Thyroglobulin can be measured during thyroid hormone therapy or after thyroid-stimulating hormone (TSH) stimulation, through thyroid hormone withdrawal or the use of human recombinant TSH. In many studies, the cut-off value for adequate Tg stimulation is a TSH value ≥30 mIU/L. However, there is an emerging body of evidence suggesting that this long-established standard should be re-evaluated, bringing this threshold into question. Recently, a risk stratification system of response to initial therapy (with four categories) has been introduced and Tg measurement is one of the main components. The relationship between the Tg/TSH ratio and the outcome of radioiodine ablation has also been studied, as well as clinical significance of serum thyroglobulin doubling-time. The postoperative serum Tg value is an important prognostic factor that is used to guide clinical management, and it is the most valuable tool in long term follow-up of patients with DTC.

Incidence and Survival of Thyroid Cancer in Children, Adolescents, and Young Adults in Denmark: A Nationwide Study from 1980 to 2014

BACKGROUND

Thyroid cancer constitutes a major and increasing proportion of head and neck cancers in children and adolescents. The purpose of this study was to determine the incidence and survival of thyroid cancer in Danish patients aged 0-24 years from 1980 to 2014.

METHODS

Patients aged 0-24 years registered with primary thyroid cancer in the Danish Cancer Registry or the Danish Pathology Data Bank during 1980-2014 were included. Crude incidence rates and age-adjusted incidence rates (AAIR) per 100,000, average annual percent change (AAPC), and overall survival (OS) were evaluated in relation to sex, histopathological tumor type, age at diagnosis, and year of diagnosis.

RESULTS

A total of 297 thyroid cancer patients (72% female, 72% papillary carcinoma) were identified. The AAIR per 100,000 increased significantly from 0.36 in 1980 to 0.97 in 2014, with an AAPC of 2.9%. There was no significant increase in incidence among children and adolescents (0-17 years). However, among young adults (18-24 years), a significant increase in incidence was observed (AAPC 3.7%). The incidence of thyroid cancer increased with age from 0.05 among infants aged 0 years to 1.73 among young adults aged 24 years. Female patients and papillary carcinoma showed significant increase in incidence (AAPC 3.3% and 3.2%), whereas male patients and other histopathological tumor types showed no change. The 15-year OS was 99%. The lowest 15-year OS was observed among patients with medullary carcinomas at 96%. There was no significant difference in OS between groups based on histopathological tumor type, and there was no significant change in OS over time.

CONCLUSION

In this nationwide study, no change in OS was observed, but a significant increase was seen in the incidence of thyroid cancer among young adults (aged 18-24 years), mainly attributed to an increase among females and patients with papillary carcinoma. No increase in incidence was seen among children and adolescents. These findings demonstrate the excellent prognosis for children and adolescents diagnosed with thyroid cancer.

A sorafenib-sparing effect in the treatment of thyroid carcinoma cells attained by co-treatment with a novel isoflavone derivative and 1,25 dihydroxyvitamin D3

BACKGROUND

Sorafenib improves progression-free survival in patients with progressive radioactive iodine-refractory differentiated thyroid carcinoma, but causes severe side effects. Estrogens may accelerate thyroid carcinoma cell growth. Our group recently reported that isoflavone derivative 7-(O)-carboxymethyl daidzein conjugated to N-t-boc-hexylenediamine (cD-tboc), a novel anti-estrogenic compound, retards the growth of both thyroid carcinoma cell lines and cultured human carcinoma cells. Vitamin D receptor (VDR) is expressed in malignant cells and responds to 1,25 dihydroxyvitamin D3 (1.25D) by decreased proliferative activity in vitro. The purpose of this study was to examine the effects of vitamin D metabolites (VDM) on the expression of estrogen receptors (ERs), VDR, and 1OHase mRNA, and to evaluate the inhibitory effect of low doses of sorafenib in combination with cDtboc and VDM on cell proliferation in cultured human papillary thyroid carcinoma (PTC).

METHODS

In 19 cultured PTC specimens and 19 normal thyroid specimens, harvested during thyroidectomies from the same patients, expression levels of ERα, ERβ, VDR, and 1 alpha-hydroxylase (1OHase) mRNA (by quantitative real-time PCR) were determined at baseline and after treatment with VMD. Cell proliferation was determined by measurement of ³[H] thymidine incorporation after treatment with sorafenib alone, sorafenib with added 1.25D or cD-tboc, and sorafenib with both 1.25D and cD-tboc added.

RESULTS

1,25D increased mRNA expression of all tested genes in the malignant and normal thyroid cells, while the ERα mRNA of the normal cells was unaffected. 1.25D dose-dependently inhibited cell proliferation in the malignant cells. The inhibitory effect of sorafenib on cell proliferation in the malignant cells was amplified after the addition of cDtboc and 1.25D, such that the maximal inhibition was not only greater, but also had been attained at a 10-fold lower concentration of sorafenib (20 μg/ml). This inhibition was similar to that of the generally used concentration of sorafenib (200 μg/ml) alone.

CONCLUSIONS

The demonstration that low concentrations of cDtboc and 1.25D markedly amplify the inhibitory effect of sorafenib on the growth of human PTC supports the use of a 10-fold lower concentration of sorafenib. The findings may promote a new combination treatment for progressive radioactive iodine-refractory PTC.

Nutritional and Environmental Factors in Thyroid Carcinogenesis

Several epidemiological studies suggest an increased incidence of thyroid carcinoma (TC) in recent years, especially for the papillary histotype (PTC), suggesting that specific carcinogens might promote molecular abnormalities that are typical of PTC. The increased incidence is probably attributed to more intensive and sensitive diagnostic procedures, even if recent data suggest that various toxic elements could explain the phenomenon. Ionizing radiation exposure represents the most accepted risk factor for differentiated thyroid cancer that includes both the follicular and papillary histotypes. In this review, we examined the other environmental carcinogens that play a role in TC, such as eating habits, living in volcanic areas, and xenobiotic elements. Among eating habits, iodine intake represents one of the more discussed elements, because its deficiency is associated with follicular thyroid carcinomas (FTCs), while its progressive increment seems to be responsible for PTC. The gas, ash, and lava emissions of volcanoes are composed of various toxic compounds that pollute ground water, vegetables, and animals, contaminating humans via the food chain. Finally, the risk of developing PTC has also been associated with exposure of the population to xenobiotics in the environment or in the home. Their carcinogenic effects are probably caused by their accumulation, but additional studies are necessary to better understand the mechanisms of action.

Comparison of treatment efficacy 1 and 2 years after thyroid remnant ablation with 1110 versus 5550 MBq of iodine-131 in patients with intermediate-risk differentiated thyroid cancer

BACKGROUND

Radioiodine ablation may be associated with improved survival in patients with intermediate-risk follicular cell differentiated thyroid cancer (FCDTC). The aim of this study was to compare ablation efficacy of 1110 versus 5500 MBq of iodine-131 (I) in FCDTC patients with intermediate risk.

METHODS

Thirty-nine patients with intermediate-risk FCDTC (T3N0, T1-2N1b and T1-3N1a) were treated with 1110 MBq of I and compared with 43 age-matched and sex-matched patients who received 5550 MBq of I. Patients with invasive histology, extensive lymph node involvement, and preablation thyroglobulin (Tg) of more than 100 ng/ml were excluded from the study. All patients underwent total or near total thyroidectomy with or without lymph node dissection. Response to treatment was evaluated 1 and 2 years after I treatment.

RESULTS

We studied four male and 78 female patients, age range 21-69 years. Preablation Tg level was 12.7±17.8 and 15.8±22.6 ng/ml in patients in the low-dose and high-dose groups, respectively (P=0.48). Anti-Tg antibody level as well as T and N staging were not significantly different in the two groups (P>0.2). One and 2 years after treatment, an excellent response was noted in 19 and 22 patients in the low-dose group and in 16 and 23 patients in the high-dose group, respectively (P>0.3). Using logistic regression analysis, preablation Tg was the only significant factor in the prediction of an incomplete response 2 years after therapy.

CONCLUSION

1110 MBq of I was as effective as 5550 MBq of I in the treatment of FCDTC patients with intermediate risk 1 and 2 years after therapy.

Age greater than 60 years portends a worse prognosis in patients with papillary thyroid cancer: should there be three age categories for staging?

Background

Age is an important prognostic factor in papillary thyroid cancer (PTC), with better survival observed in patients < 45 years of age, regardless of stage. Although the impact of increasing age on PTC-related survival is well-known, previous studies have focused on survival relative to age 45 years only. As the number of patients entering their 7th decade of life increases, PTC-related survival in this demographic becomes increasingly important. Survival in patients ≥ 60 years specifically compared to other groups has not previously been examined. We sought to determine whether age ≥ 60 years is an adverse prognostic factor for disease-specific survival and recurrence in patients with PTC.

Methods

The California Cancer Registry database was linked to inpatient and ambulatory patient records from the Office of Statewide Health Planning and Development for the years 2000–2011. This linked database was queried for patients diagnosed with papillary thyroid cancer and treated with surgery. We then identified prognostic factors related to both 5-year and 10-year disease-specific survival and disease-free survival in patients ≤ 45, 45–59, and ≥ 60 years. Multivariable Cox proportional hazard models were created to test the effect of age ≥ 60 on disease-specific and disease-free survival, controlling for clinical, treatment, and demographic factors.

Results

The final cohort included 15,675 patients. Of the group, 46.3% were between 18 and 44 years of age, 33.6% were 45–59 years, and 20.1% were ≥ 60. Univariate analysis showed that compared to other groups, patients ≥ 60 were more likely to be male (p < 0.001), present with tumors > 5 cm (p < 0.001), more likely to have metastatic disease (p < 0.001), less likely to receive radioactive iodine (p < 0.001), and more likely to receive external beam radiation therapy (p < 0.001). In multivariable Cox proportional hazards models for 5 and 10-year disease-free survival, age ≥ 60 was associated with higher risk of disease at 5 and 10-years (HR 2.3 and 1.9 respectively, p < 0.001). Similar results were observed for 5 and 10-year disease-specific survival (HR 38.0 and 30.0 respectively, p < 0.001) after controlling for gender, race, co-morbidity, stage, surgical procedure, radioactive iodine, insurance, and hospital volume.

Conclusions

Patients ≥ 60 years of age have worse DSS and DFS after a diagnosis of PTC, across all stages of disease. Given that patients over the age of 45 years have progressively worse survival as they age, these data support having three age groups, 18–44 years of age, 45–59 years, and ≥ 60 as an independent predictor of survival and recurrence to current staging guidelines.

Thyroid cancer: trends in incidence, mortality and clinical-pathological patterns in Zhejiang Province, Southeast China

Background

Thyroid cancer is the most common malignant disease of the endocrine system. Previous studies indicate a rapid increase in the incidence of thyroid cancer in recent decades, and this increase has aroused the great public concern. The aim of this study was to analyze the trends in incidence, mortality and clinical-pathological patterns of thyroid cancer in Zhejiang province.

Methods

Population-based incidence and mortality rates of thyroid cancer were collected from eight cancer registries in Zhejiang from 2000 to 2012. The incidence and mortality rates were age-standardized to Segi’s world population. A Joinpoint model was used to examine secular trends in age-adjusted thyroid cancer rates with the Joinpoint Regression Program Version 4.0.0. Thyroid cancer patients were recruited from Zhejiang Cancer Hospital from 1972 to 2014. Patient demographics, tumor histology and tumor size were compared among the different periods of 1972–1985, 1986–1999 and 2000–2014.

Results

The age-standardized incidence rate of thyroid cancer in Zhejiang cancer registries was 2.75/10⁵ in 2000, and increased to 19.42/10⁵ in 2012. Additionally, we observed significantly increasing incidence rates with the Annual Percent Change (APC) of 22.86% (95%CI, 19.2%–26.7%). The age-standardized mortality of thyroid cancer in Zhejiang cancer registries was 0.23/10⁵ in 2000 and 0.25/10⁵ in 2012. No significant change in mortality rate was found. We observed a rapid increase in the proportions of papillary thyroid carcinoma (PTC) in 12,508 patients with thyroid carcinoma identified in the Zhejiang Cancer Hospital from 1972 to 2014 while the proportions of poorly differentiated thyroid cancer (PDTC), medullary thyroid carcinoma (MTC) and follicular thyroid carcinoma (FTC) decreased over the decades. In the PTC cases, the proportion of patients with maximum tumor diameter (MTD) < 1 cm dramatically and significantly increased from 0 in 1972–1985 to 32.1% in 2000–2014.

Conclusions

A rapid increase in incidence and a stable trend in mortality of thyroid cancer were found in the distribution of thyroid cancer. Most of the increased incidence was PTC, especially the papillary thyroid microcarcinoma (PTMC) with MTD < 1 cm. This increase in incidence might be due to increased diagnosis with advanced technology.

Contribution of industrial density and socioeconomic status to the spatial distribution of thyroid cancer risk in Hangzhou, China

BACKGROUND

The thyroid cancer (TC) incidence in China has increased dramatically during the last three decades. Typical in this respect is the case of Hangzhou city (China), where 7147 new TC cases were diagnosed during the period 2008-2012. Hence, the assessment of the TC incidence risk increase due to environmental exposure is an important public health matter.

METHODS

Correlation analysis, Analysis of Variance (ANOVA) and Poisson regression were first used to evaluate the statistical association between TC and key risk factors (industrial density and socioeconomic status). Then, the Bayesian maximum entropy (BME) theory and the integrative disease predictability (IDP) criterion were combined to quantitatively assess both the overall and the spatially distributed strength of the "exposure-disease" association.

RESULTS

Overall, higher socioeconomic status was positively correlated with higher TC risk (Pearson correlation coefficient=0.687, P<0.01). Compared to people of low socioeconomic status, people of median and high socioeconomic status showed higher TC risk: the Relative Risk (RR) and associated 95% confidence interval (CI) were found to be, respectively, RR=2.29 with 95% CI=1.99 to 2.63, and RR=3.67 with 95% CI=3.22 to 4.19. The "industrial density-TC incidence" correlation, however, was non-significant. Spatially, the "socioeconomic status-TC" association measured by the corresponding IDP coefficient was significant throughout the study area: the mean IDP value was -0.12 and the spatial IDP values were consistently negative at the township level. It was found that stronger associations were distributed among residents mainly on a stripe of land from northeast to southwest (consisting mainly of sub-district areas). The "industrial density-TC" association measured by its IDP coefficient was spatially non-consistent.

CONCLUSIONS

Socioeconomic status is an important indicator of TC risk factor in Hangzhou (China) whose effect varies across space. Hence, socioeconomic status shows the highest TC risk effect in sub-district areas.

Independent predictors and lymph node metastasis characteristics of multifocal papillary thyroid cancer

The multifocal papillary thyroid cancer (PTC), with more aggressive and poorer prognosis, is not rare in papillary histotype. Few studies evaluated risk factors and lymph node metastasis in multifocal PTC. The aim of this present study focusing on risk factors and lymph node metastasis characteristics in multifocal PTC was excepted to assist clinical decisions regarding surgery.It was a retrospective study. The 1249 consecutive patients with PTC were reviewed. Of these, 570 patients who met the criteria were selected: 285 with solitary papillary thyroid cancer and 285 with multifocal PTC. The risk factors and lymph node metastasis in multifocal PTC were investigated by univariate and multivariate analysis.Multifocal PTC showed a higher positive rate of capsular invasion, extrathyroidal extension, tumor size >10 mm, pathological T classification, N+ stage, local recurrence, and radioactive iodine ablation (RAI). Capsular invasion (hazard ratio [HR], 1.589; 95% confidence interval [CI],1.352-1.984), advanced pathological T classification (HR, 3.582; 95% CI, 2.184-5.870), and pathological N+ stage (HR, 1.872; 95% CI, 1.278-2.742) were related to increased risk of multifocality and there was a significant increased HR for central neck compartment involvement in male sex (HR, 2.694; 95% CI, 1.740-4.169), advanced pathological T classification (HR, 2.403; 95% CI, 1.479-3.907) and multifocality (HR, 1.988; 95% CI, 1.361-2.906).There is a significant association between capsular invasion, advanced pathological T classification, N+ stage, and multifocal PTC. Total thyroidectomy plus prophylactic bilateral central lymph node dissection should be recommended during surgery due to a stronger predilection for level VI lymph node metastasis in multifocal PTC.

Growing incidence of thyroid carcinoma in recent years: Factors underlying overdiagnosis

There is an increasing incidence of well-differentiated thyroid cancer worldwide. Much of the increase is secondary to increased detection of small, low-risk tumors, with questionable clinical significance. This review addresses the factors that contribute to the increasing incidence and considers environmental, and patient-based and clinician-led influences. Articles addressing the causes of the increased incidence were critically reviewed. A complex interplay of environmental, medical, and social pressures has resulted in increased awareness of the thyroid disease risk, increased screening of thyroid cancers, and increased diagnosis of thyroid cancers. Although there is evidence to suggest that the true disease incidence may be changing slightly, most of the increase is related to factors that promote early diagnosis of low-risk lesions, which is resulting in a significant phenomenon of overdiagnosis. An improved understanding of these pressures at a global level will enable healthcare policymakers to react appropriately to this challenge in the future.

How Many Contralateral Carcinomas in Patients with Unilateral Papillary Thyroid Microcarcinoma are Preoperatively Misdiagnosed as Benign?

BACKGROUND

The decision to perform a total thyroidectomy (TT) for unilateral papillary thyroid microcarcinoma (PTMC) with nodules in the contralateral lobe remains controversial. The aim of this study was to investigate the rate of contralateral carcinomas that are preoperatively misdiagnosed as benign.

METHODS

From October 2011 to October 2015, a total of 347 patients with unilateral PTMC and contralateral benign nodules who were treated with a TT at a single institution were enrolled. All patients underwent preoperative fine needle aspiration and ultrasonography (US). Clinicopathological features such as age, sex, laterality, tumor size, central lymph node metastases, capsular invasion, TgAb and TPOAb levels, Hashimoto's thyroiditis, nodule number in both lobes according to preoperative US, and primary carcinoma number in the final postoperative pathology report were all analyzed to investigate the rate and predictive factors of contralateral carcinoma.

RESULTS

A total of 100 patients (28.9 %) were diagnosed with papillary thyroid carcinoma in the contralateral lobe. A multivariate analysis showed that tumor size, nodule number in the contralateral lobe, and multifocality of the primary tumor were all independent predictive factors of contralateral carcinoma in patients with unilateral PTMC and contralateral benign nodules.

CONCLUSIONS

According to our findings, the rate at which contralateral carcinomas are preoperatively misdiagnosed as benign is 28.9 %. A TT is essential for unilateral PTMC with a primary tumor size >5 mm, multifocal primary carcinomas or multifocal benign nodules in the contralateral lobe.

Comparison of the effectiveness of ultrasound elastography with that of conventional ultrasound for differential diagnosis of thyroid lesions with suspicious ultrasound features

Ultrasound elastography (USE) has been used for quantitative imaging since the early 1990s. The aim of the present study was to compare the effectiveness of USE with that of conventional ultrasound in the differential diagnosis of benign vs. malignant thyroid nodules. USE was performed on 150 thyroid nodules in 123 patients. USE demonstrated a lower grade of elasticity (grade I/II) in 86% of benign nodules and a decreased strain ratio (2.30±1.01) compared with malignant nodules. USE of malignant nodules exhibited a higher grade of elasticity (grade III/IV) in 90% of nodules and an increased strain ratio (6.39±2.50). The results of the present study indicate that USE and strain ratio may be useful in the differential diagnosis of thyroid nodules.