BMI, diet and female reproductive factors as risks for thyroid cancer: a systematic review

Obesity and thyroid cancer: unraveling the connection through a systematic review and meta-analysis of cohort studies

Background

The relationship between adiposity indicators and thyroid cancer (TC) risk has garnered increasing attention due to the rising prevalence of obesity and its potential impact on cancer incidence. We conducted a comprehensive meta-analysis to investigate this association across various effect measures.

Method

Until July 2022, a comprehensive search of databases was conducted to identify cohort studies that assessed the association between adiposity and the development of TC. Meta-analysis was performed using random effects models. Subgroup analyses were conducted to explore heterogeneity. Publication bias was assessed using Begg's tests.

Results

A systematic literature search identified 27 eligible studies reporting odds ratios (OR), relative risks (RR), or hazard ratios (HR) as effect measures. Pooling the studies irrespective of the effect measure, a significant positive association between adiposity indicators and TC risk was observed, yielding an effect estimate of 1.16 (95% CI 1.12-1.21). The combined effect estimate for OR/RR studies was 1.10 (95%CI 1.04-1.17), while HR studies yielded an effect estimate of 1.20 (95%CI 1.13-1.26). Subgroup analyses revealed associations across different age groups, obesity indices, and regions, with some variations based on effect measure. Meta-regression identified follow-up duration as a confounding factor only in HR studies.

Conclusion

The synthesis of 27 studies with diverse designs and populations underscores a robust positive association between adiposity and TC risk, providing compelling evidence for the potential role of increased adiposity in TC development.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40200-024-01425-3.

Global burden of disease study analysis of thyroid cancer burden across 204 countries and territories from 1990 to 2019

Background

The purpose of this study is to assess the burden of thyroid cancer over the course of 30 years in 204 countries and territories.

Methods

Data from the Global Burden of Disease (GBD) 2019 database was analyzed to extract information on prevalence, deaths, DALYs(disability-adjusted life-years), YLL(years of life los), YLD(years lived with disability), and their corresponding age-standardized rates at global, regional, and national levels. The primary focus of the study was to examine trends in thyroid cancer from 1990 to 2019, specifically looking at the Estimated Annual Percentage Change (EAPC) for ASPR, ASDR, and ASDR. Additionally, the study investigated the relationship between cancer burden and the Socio-Demographic Index (SDI).

Results

Globally, there will be approximately 18.3 million thyroid cancer (TC) cases in 2019; China and the USA are projected to be the most significant with 310,327 and 220,711 cases (16.17 and 14.82 cases per 100,000 people, respectively).Over the period from 1990 to 2019, age-standardized prevalence rates exhibited a global rise, whereas deaths and DALYs saw a decrease(EAPC:1.63, -0.15- -0.14, respectively). Significantly, the age-standardized prevalence rate increased in 21 GBD regions, affecting 195 out of 204 countries or territories. Over the studied period, thyroid cancer cases, deaths, and DALYs were consistently higher among females than males. Furthermore, a higher Socio-demographic Index was associated with increased age-standardized prevalence rates.

Association of hormonal and reproductive factors with differentiated thyroid cancer risk in women: a pooled prospective cohort analysis

BACKGROUND

The incidence of differentiated thyroid cancer (DTC) is higher in women than in men but whether sex steroid hormones contribute to this difference remains unclear. Studies of reproductive and hormonal factors and thyroid cancer risk have provided inconsistent results.

METHODS

Original data from 1 252 907 women in 16 cohorts in North America, Europe, Australia and Asia were combined to evaluate associations of DTC risk with reproductive and hormonal factors. Multivariable-adjusted Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

During follow-up, 2142 women were diagnosed with DTC. Factors associated with higher risk of DTC included younger age at menarche (<10 vs 10-11 years; HR, 1.28; 95% CI, 1.00-1.64), younger (<40; HR, 1.31; 95% CI, 1.05-1.62) and older (≥55; HR, 1.33; 95% CI, 1.05-1.68) ages at menopause (vs 40-44 years), ever use of menopausal hormone therapy (HR, 1.16; 95% CI, 1.02-1.33) and previous hysterectomy (HR, 1.25; 95% CI, 1.13-1.39) or bilateral oophorectomy (HR, 1.14; 95% CI, 1.00-1.29). Factors associated with lower risk included longer-term use (≥5 vs <5 years) of oral contraceptives (HR, 0.86; 95% CI, 0.76-0.96) among those who ever used oral contraception and baseline post-menopausal status (HR, 0.82; 95% CI, 0.70-0.96). No associations were observed for parity, duration of menopausal hormone therapy use or lifetime number of reproductive years or ovulatory cycles.

CONCLUSIONS

Our study provides some evidence linking reproductive and hormonal factors with risk of DTC. Results should be interpreted cautiously considering the modest strength of the associations and potential for exposure misclassification and detection bias. Prospective studies of pre-diagnostic circulating sex steroid hormone measurements and DTC risk may provide additional insight.

Association between oil spill clean-up work and thyroid cancer: Nine years of follow-up after the Hebei Spirit oil spill accident

In 2007, an unprecedented oil spill occurred in Taean, Korea. Although crude oil contains chemicals that could increase thyroid cancer risk, few studies have examined the long-term effects of oil exposure during clean-up and thyroid cancer incidence. We investigated the long-term thyroid cancer incidence among participants involved in clean-up work. 1798 participants engaged in at least two surveys since the baseline was tracked from 2008 to 2018. Participants reported the days they participated in oil clean-up works and cancer diagnoses. Cox proportional hazard models were used to estimate the hazard ratios between clean-up work duration and thyroid cancer. Over the 9-year follow-up, 30 thyroid cancer cases were diagnosed. A positive association was observed between clean-up duration and thyroid cancer risk. This effect was more pronounced among residents living <50 m from traffic roads. Our results indicate that crude oil clean-up work participation may increase the thyroid cancer risk.

Role of Mediterranean diet in endocrine diseases: a joint overview by the endocrinologist and the nutritionist

PURPOSE

The purpose of this review is to examine the current evidence on the potential role of Mediterranean diet (MD) in the prevention and management of endocrine disorders and to highlight the importance of interdisciplinary collaboration between endocrinologists and nutritionists.

METHODS

A literature search was conducted using PubMed and Google Scholar databases to identify relevant studies published in English. Studies were selected based on their relevance to the role of MD in the prevention and management of endocrine disorders. The search terms included "Mediterranean diet," "endocrine disorders," "thyroid disorders," "gonadal disorders," and "neuroendocrine tumors".

RESULTS

The studies reviewed suggest that MD may have a beneficial effect in the prevention and management of various endocrine disorders, including thyroid disorders, gonadal disorders, and neuroendocrine tumors. MD has been associated with decreased risk of nodular thyroid disease and thyroid cancer, improved male and female reproductive health, and a potential role in the management of neuroendocrine tumors. MD's anti-inflammatory and antioxidant properties, as well as its high levels of phytochemicals, may play a role in its beneficial effects.

CONCLUSION

Interdisciplinary collaboration between endocrinologists and nutritionists is essential for the optimal management of endocrine disorders, including the potential role of MD in their prevention and management. While further research is needed, the current evidence suggests that MD may have a protective effect against endocrine disorders, and its incorporation into dietary recommendations may be beneficial.

The Relationship between Thyrotropin Serum Concentrations and Thyroid Carcinoma

Thyroid Stimulating Hormone (TSH) is a hormone secreted by the pituitary gland and plays a role in regulating the production and secretion of thyroid hormones by the thyroid gland. This precise feedback loop is essential for maintaining a harmonious balance of thyroid hormones in the body, which are vital for numerous physiological processes. Consequently, TSH serves as a significant marker in assessing thyroid function, and deviations from normal TSH levels may indicate the presence of a thyroid disorder. Thyroid cancer (TC) is the malignant tumor within the endocrine system. In recent years, numerous experts have dedicated their efforts to discovering efficacious biomarkers for TC. These biomarkers aim to improve the accurate identification of tumors with a poor prognosis, as well as facilitate active monitoring of tumors with a more favorable prognosis. The role of TSH in the thyroid gland underscores its potential influence on the occurrence and progression of TC, which has garnered attention in the scientific community. However, due to the limited scope of clinical research and the dearth of high-quality foundational studies, the precise impact of TSH on TC remains unclear. Consequently, we present a comprehensive review of this subject, aiming to offer a valuable reference for future research endeavors.

Clinicopathological profile and management of thyroid carcinoma: a Sub-Saharan country experience

BACKGROUND

In Sudan, there is limited knowledge on the epidemiology, clinical characteristics and pathological patterns of thyroid cancer. To address this shortcoming, we studied the clinical, pathological and treatment patterns of thyroid cancer at the National Cancer Institute ‒ University of Gezira (NCI-UG), Sudan.

METHODS

We performed a retrospective health facility-based study of patients with thyroid cancer who were treated at NCI-UG from January 2009 to December 2017.

RESULTS

A total of 139 patients with thyroid cancer were identified during the study period. Tumors were more common among women (69%). Goiter was the main presenting symptom (85%). The most common type of thyroid cancer was follicular carcinoma (41%), followed by papillary carcinoma (24%), then anaplastic carcinoma (20%). The mean age of the women was 56.3 years (SD ± 14.7), compared to 52.5 years (SD ± 16.6) for the men. The frequencies of stage I, II, III, and IV were 17%, 22%, 16%, and 45%, respectively. Different types of thyroidectomies were performed in 79% of the cases, lobectomy in 4%, and no surgery in 17%. Only 28% of the cases received radioactive iodine. Palliative chemotherapy and radiotherapy were prescribed to 17% and 37% of the cases, respectively.

CONCLUSION

Thyroid cancer is more prevalent among women and most patients present at later stages. The dominance of follicular type suggests that the majority of this population is iodine-deficient.

Women consuming oral contraceptives containing cyproterone acetate and ethinylestradiol show a higher risk of thyroid cancer than nonusers

This study explored whether the risk of thyroid cancer in Asian women is associated with consumption of oral contraceptives (Diane-35). We conducted a population-based, retrospective cohort study using the Taiwan National Health Insurance Research Database. From the database, 9865 women aged 18 to 65 years who were prescribed Diane-35 between 2000 and 2012 were included in the Diane-35 group, and 39,460 women who were not prescribed Diane-35 were included in the comparison group and were frequency-matched by age and index year. Both groups were followed until 2013 to calculate the incidence of thyroid cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazard model. The median (standard deviation) follow-up duration was 7.08 (3.63) and 7.04 (3.64) years in the Diane-35 and the comparison group, respectively. The incidence of thyroid cancer was 1.80-fold higher in the Diane-35 group than in the comparison group (2.72 vs 1.51 per 10,000 person-years). The cumulative incidence of thyroid cancer was significantly higher in the Diane-35 group than in the comparison group (log-rank test, P = .03). An elevated hazard ratio of thyroid cancer was observed in the Diane-35 group than in the comparison group (HR: 1.91, 95% CI: 1.10-3.30). In subgroup analysis, patients aged 30 to 39 years showed a higher hazard ratio of developing thyroid cancer after consuming Diane-35 than those in the comparison group (HR: 5.58, 95% CI: 1.84-16.91). The study provides evidence that women aged 30 to 39 years consuming Diane-35 are at increased risk of thyroid cancer. Nevertheless, a larger population with a longer follow-up may be necessary to confirm causality.

Sexual disparity and the risk of second primary thyroid cancer: a paradox

BACKGROUND

Despite extensive research on sex differences in primary thyroid cancer, there is a lack of data on the role of sex in the risk of developing second primary thyroid cancer (SPTC). We aimed to investigate the risk of SPTC development according to patient sex, with an emphasis concerning previous malignancy location as well as age.

METHODS

Cancer survivors diagnosed with SPTC were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The SEER*Stat software package obtained standardized incidence ratios (SIR) and absolute excess risks of subsequent thyroid cancer development.

RESULTS

Data for 9,730 (62.3%) females and 5,890 (37.7%) males were extracted for a total of 15,620 SPTC individuals. Asian/Pacific Islanders had the highest incidence of SPTC [SIR =2.67, 95% confidence interval (CI): 2.49-2.86]. The risk of SPTC was higher in males (SIR =2.01, 95% CI: 1.94-2.08) than when compared to females (SIR =1.83, 95% CI: 1.79-1.88; P<0.001). Head and neck tumors had significantly higher SIRs for SPTC development in males when compared to females.

CONCLUSIONS

Survivors of primary malignancies have an increased risk SPTC, especially males. Our work suggests that oncologists and endocrinologists may consider the need for increased surveillance of both male and female patients given their increased risk of SPTC.

Role of breast cancer screening in the overdiagnosis of thyroid cancer: results from a cross-sectional nationwide survey

BACKGROUND

South Korea has the highest incidence of thyroid cancer worldwide, raising questions regarding the possibility of overdiagnosis. Examining the factors affecting thyroid cancer screening is crucial in elucidating the reasons for this unusually high incidence of thyroid cancer. Therefore, in the present study, we investigated the association between breast cancer screening and thyroid cancer screening to determine the potential role of breast cancer screening in the overdiagnosis of thyroid cancer in South Korea.

METHODS

We analyzed the data of women aged > 30 years who were enrolled in the 2014 Korean National Cancer Screening Survey. Self-reported breast cancer screening behavior was categorized as follows: no screening, mammography only, ultrasonography only, and both ultrasonography and mammography. Thyroid cancer screening behavior was categorized as follows: those who had or had not undergone ultrasonography screening. Logistic regression analysis was used to examine the associations between breast and thyroid cancer screening behaviors.

RESULTS

Of the 2270 participants, a total of 569 (25.1%) were screened for thyroid cancer. Those who underwent only mammography, only ultrasonography, or both mammography and ultrasonography were more likely to be screened for thyroid cancer than those who did not undergo breast cancer screening (odds ratio [OR]: 1.47, 95% confidence interval [CI] 1.06-2.04; OR 2.71, 95% CI 1.83-4.02; OR 2.75, 95% CI 1.99-3.80, respectively).

CONCLUSIONS

Our findings indicate that thyroid cancer screening in Korea is likely to be performed on an opportunistic basis. Therefore, a nationwide public health and medical initiative is needed to curb the unnecessary use of thyroid screening in the asymptomatic general population.

Incidence and mortality of thyroid cancer in 50 countries: a joinpoint regression analysis of global trends

PURPOSE

To evaluate the incidence and mortality trend of thyroid cancer, and compare its global incidence trends among different countries by age group and sex.

METHODS

Data on age-standardized incidence and mortality rate of thyroid cancer among 50 countries were collected from the Cancer Incidence in Five Continents Volume XI; the Surveillance, Epidemiology, and End Results Program (SEER), the National Cancer Institute; the Nordic Cancer Registries (NORDCAN), and the WHO mortality database. The Average Annual Percent Change (AAPC) of the incidence and mortality trends was calculated by joinpoint regression analysis.

RESULTS

The age-standardized incidence of thyroid cancer was 3.1 and 10.1 cases per 100,000 persons in men and women, respectively. The incidence of thyroid cancer increased in most countries among individuals irrespective of age groups, and increased in populations aged <40 years in several countries, including Korea (male: AAPC 25.3, 95% C.I. 22.3-28.4, p < 0.001; female: AAPC 18.5, 95% C.I. 16.2-20.9, p < 0.001), Poland (male: AAPC 19.1, 95% C.I. 1.4-39.7, p = 0.036; female: AAPC 13.7, 95% C.I. 7.6-20.2), and China (male: AAPC 18.6, 95% C.I. 12.1-25.5, p < 0.001; female: AAPC 13.3, 95%C.I. 11.5-15.1, p < 0.001).

CONCLUSION

An increasing incidence of thyroid cancer was observed in younger subjects in a majority of countries, highlighting the need for more preventive strategies in this population and possible avoidance of over-diagnosis.

Iodine nutrition and papillary thyroid cancer

Thyroid cancer (TC) is the most frequent endocrine malignancy. The incidence of TC, especially papillary thyroid carcinoma (PTC), has continued to rise all over the world during the past few years, for reasons that are not entirely clear. Though the phenomenon of overdiagnosis is occurring, it is not the sole driver of the substantial increase in incidence. Lifestyle, environmental factors, or complications are considered to be potential risk factors. Among these factors, iodine is a micronutrient that is vital to thyroid function. The effect of iodine intake on PTC has been controversial for many years and the epidemiological or experimental studies provided diametrically opposite conclusions. Combining all these studies, we found that iodine nutrition may affect the overall prevalence, distribution of the histological types, and clinicopathological aggressiveness of TC, especially PTC. However, the available evidence is poor due to the impact of various internal and external related factors. Therefore, this article sums up available results from both epidemiological and experimental studies, future studies are also warranted to expound on the relationship between overall PTC prevalence and iodine intake.

A protective factor against lymph node metastasis of papillary thyroid cancer: Female gender

OBJECTIVE

Papillary thyroid carcinoma (PTC) is the most common pathological type of thyroid cancer, with good prognosis, but the rate of lymph node metastasis (LNM) is high, and the difference between men and women is significant. Therefore, the related risk factors for LNM of PTC based on gender were examined in this study in order to draw attention to gender factor in PTC.

METHODS

We retrospectively analyzed the clinicopathological data of 2103 patients with surgically confirmed PTC at the Fourth affiliated Hospital of Hebei Medical University West Side between January 2016 and December 2019.

RESULTS

LNM was detected in 1124 of the 2103 cases of PTC. Logistic regression analysis showed that LNM was associated with age (p < 0.001, OR:0.547), gender (p < 0.001, OR:2.609), tumor diameter (p < 0.001, OR:2.995), bilaterality (p=0.003, OR:1.683), and extrathyroid extension (p < 0.001, OR:1.657). After propensity score matching, female gender (p < 0.001, OR: 0.393) remained an independent factor of LNM in patients with PTC. LNM in men was only associated with diameter (p < 0.001, OR: 3.246). LNM in woman was associated with menopausal history (p = 0.012, OR=0.684), reproductive history (p < 0.001, OR=0.360), abortion history (p = 0.011, OR=0.725), tumor diameter >1 cm (p < 0.001, OR=2.807), bilaterality (p =0.006, OR:1.728), and extrathyroid extension (p < 0.001, OR=1.879).

CONCLUSION

Although the invasion is high in female patients, the rate of LNM is significantly reduced due to the influence of sex hormones and reproductive factors. For female patients of childbearing age who were not pregnant and did not have children, it is suggested to take a positive attitude towards their lymph nodes.

Epidemiological, Clinical, Ultrasonographic and Cytological Characteristics of Thyroid Nodules in an Afro-Caribbean Population: A Series of 420 Patients

Simple Summary

This study describes the epidemiological, clinical and ultrasound characteristics of malignancy in thyroid nodules and evaluates the value of cytology in the diagnosis of malignancy in an Afro-Caribbean population. Our results revealed that none of the standard ultrasound criteria of malignancy were significantly predictive of cancer, but hypoechogenicity and central vascularity were frequently found in malignant nodules. These results could increase awareness and guide practitioners in their diagnostic approach and management of thyroid nodules in Afro-Caribbean populations. Bethesda system-based cytology revealed low sensitivity in analyzing the risk of malignancy in this population. The high prevalence of papillary microcarcinomas may explain the inconclusive ultrasound and cytological results.

Abstract

The incidence of thyroid cancer is increasing worldwide. The aim of this study is to describe the epidemiological, clinical and ultrasound characteristics of malignancy in thyroid nodules and to evaluate the predictive value of the Bethesda system for thyroid cytology in the diagnosis of malignancy in an Afro-Caribbean population. We conducted a retrospective study in Martinique involving 420 patients with a diagnosis of thyroid nodules between 2011 and 2014. Of the 192/420 (45.7%) patients operated on for thyroid nodules, 9% had thyroid cancer. All patients with thyroid cancer were obese women with a mean age of 50 years. The final histological examination revealed papillary microcarcinomas in 61% of cases and papillary carcinomas in 39% of cases. Thyroid cytology alone had a low sensitivity (22.2%) and positive predictive value (15.4%) for the diagnosis of malignancy, with a good specificity (91.1%) and negative predictive value (94.2%). None of the standard ultrasound criteria of malignancy were significantly predictive of cancer, but hypoechogenicity and central vascularity were frequently found in malignant nodules. These epidemiological, clinical and ultrasound results could increase awareness and guide practitioners in their diagnostic approach and management of thyroid nodules in an Afro-Caribbean population. Bethesda system-based cytology revealed lower sensitivity in analyzing the risk of malignancy in this population. The high prevalence of papillary microcarcinomas may explain the inconclusive ultrasound and cytological results.

ASF1B: A Possible Prognostic Marker, Therapeutic Target, and Predictor of Immunotherapy in Male Thyroid Carcinoma

Background

Thyroid carcinoma (TC) is the most common malignant endocrine tumor worldwide. Several studies have documented that male patients with TC have a higher rate of metastasis and disease recurrence than female patients. However, the mechanism underlying this observation is not completely clear. The goal of our research was to investigate the potential key candidate genes and pathways related to TC progression in male patients at the molecular level.

Methods

A total of 320 samples were obtained from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. Hub genes were screened out using weighted gene coexpression network analysis (WGCNA) and a protein–protein interaction (PPI) network analysis. Survival analysis was used to identify hub genes associated with disease-free survival (DFS) rates. Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression (ESTIMATE) data were used to assess the relationship between hub genes and immune cell infiltration. The molecular mechanism and biological functions of hub genes were explored using RT-qPCR, Western blot, Cell Counting Kit-8 Assay, flow cytometry, Transwell assays, and scratch assays.

Results

Forty-seven hub genes were identified, and the survival analysis demonstrated that anti-silencing function 1B (ASF1B) was the sole independent risk factor for poor DFS in male TC patients. Possible associations between the results from the ESTIMATE analysis showed that the ASF1B expression level was related to the ESTIMATE score, immune score, and T-cell regulatory (Treg) infiltration level. Through in vitro cell function experiments, we verified that knockdown of ASF1B inhibited KTC-1 cell proliferation, promoted cell apoptosis, and blocked cell cycle. The silencing of ASF1B reduced protein kinase B (AKT), phospho-AKT (p-AKT), and forkhead box p3 (FOXP3) in KTC-1 cells. Moreover, FOXP3 overexpression markedly restored the cell migration, invasion, and proliferation abilities repressed by ASF1B knockdown.

Conclusions

Our results indicate that ASF1B can be considered a prognostic marker, therapeutic target, and predictor of immunotherapy response in male thyroid cancer patients. However, further in-depth studies are required to validate this finding.

Hypertension and Obesity: Risk Factors for Thyroid Disease

Thyroid disease instances have rapidly increased in the past few decades; however, the cause of the disease remains unclear. Understanding the pathogenesis of thyroid disease will potentially reduce morbidity and mortality rates. Currently, the identified risk factors from existing studies are controversial as they were determined through qualitative analysis and were not further confirmed by quantitative implementations. Association rule mining, as a subset of data mining techniques, is dedicated to revealing underlying correlations among multiple attributes from a complex heterogeneous dataset, making it suitable for thyroid disease pathogenesis identification. This study adopts two association rule mining algorithms (i.e., Apriori and FP-Growth Tree) to identify risk factors correlated with thyroid disease. Extensive experiments were conducted to reach impartial findings with respect to knowledge discovery through two independent digital health datasets. The findings confirmed that gender, hypertension, and obesity are positively related to thyroid disease development. The history of I₁₃₁ treatment and Triiodothyronine level can be potential factors for evaluating subsequent thyroid disease.

The relationship between urinary iodine concentration and papillary thyroid cancer: A systematic review and meta-analysis

BACKGROUND

The effect of iodine on papillary thyroid cancer (PTC) has been controversial for many years. Since urinary iodine is an effective indicator of iodine intake, some recent epidemiological studies have described the relationship between urinary iodine concentration (UIC) and PTC.

METHODS

We searched PubMed, Embase, Cochrane Library, and Web of Science for case-control studies about UIC and PTC published before September 2022. Results are presented as the overall odds ratio (OR) and 95% confidence intervals (CI).

RESULTS

According to the analysis of the included studies, excessive iodine intake (UIC≥300ug/L) was positively associated with the occurrence of PTC patients compared with healthy controls (OR4.05, 95%CI 1.64-10.02, P=0.002). Meanwhile, adequate iodine exposure (100≤UIC&lt;200ug/L) may play a protective role in the occurrence of PTC compared with healthy individuals (OR 0.36, 95%CI 0.14-0.91, P=0.03) while the difference in the prevalence of insufficient iodine intake (UIC&lt;100ug/L) and iodine above requirements (200≤UIC&lt;300ug/L) among the two groups were not significant (deficiency: OR 0.38, 95%CI 0.13-1.16, P=0.09; above requirements: OR 0.92, 95%CI 0.40-2.10, P=0.84). After comparing the UIC levels of PTC patients with those of other thyroid diseases, we found that there was also no significant difference in the incidence of different levels of UIC in the two groups (excessive: OR 1.25, 95%CI 0.87-1.80, P=0.22; above requirements: OR 0.93, 95%CI 0.77-1.14, P=0.49; adequate: OR 0.96, 95%CI 0.78-1.17, P=0.67; deficiency: OR 1.02, 95%CI 0.86-1.22, P=0.80). The result of this meta-analysis also did not support the relationship between UIC and the BRAF mutation and lymph node metastasis (LNM) of PTC patients. Besides, we also found that studies on the relationship between urinary iodine and PTC may be influenced by the way UIC was measured.

CONCLUSION

The 10 case-control included studies involved a total of 6,544 participants. The results of this meta-analysis showed excessive iodine intake, that is, UIC≥300ug/L was associated with the occurrence of PTC but not with BRAF mutation and LNM while adequate iodine intake (100≤UIC&lt;200ug/L) may be one of the protective factors for PTC.

Association of Metabolic Health and Central Obesity With the Risk of Thyroid Cancer: Data from the Korean Genome and Epidemiology Study

BACKGROUND

It is unknown whether the risk of thyroid cancer differs among metabolically healthy/unhealthy, normal-weight, or obese women. We aimed to assess the association of metabolic health and obesity with thyroid cancer risk.

METHODS

The Korean Genome and Epidemiology Study is a population-based prospective cohort study. Data were obtained from 173,343 participants (age {greater than or equal to}40 years) enrolled from 2004 to 2013. Obese participants were those with body mass index (BMI) {greater than or equal to}25 kg/m2. Participants with abnormalities in three of these indices were considered metabolically unhealthy: triglycerides, blood pressure, high-density lipoprotein cholesterol (HDL-cholesterol), waist circumference (WC), and fasting glucose levels. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for thyroid cancer risk associated with metabolic health and obesity.

RESULTS

Compared to non-obese women without metabolic abnormalities, metabolically unhealthy women, either normal-weight or obese, had an increased risk of thyroid cancer (HR [95% CI]=1.57[1.02-2.40] and 1.71[1.21-2.41], respectively). Significant association was not observed in men. Thyroid cancer risk was higher among non-obese women with high WC ({greater than or equal to}85 cm; HR [95% CI]=1.62[1.03-2.56]) than in non-obese women with low WC, and in obese women with low HDL-cholesterol (<50 mg/dL; HR[95% CI]=1.75[1.26-2.42]) compared to non-obese women with high HDL-cholesterol.

CONCLUSIONS

Metabolically unhealthy women or women with central adiposity may be at an increased thyroid cancer risk despite normal BMI.

IMPACT

This study suggests that women with central obesity and metabolically abnormality despite normal BMI may constitute a target group for thyroid cancer prevention and control programs.

Sex Bias in Differentiated Thyroid Cancer

Differentiated thyroid cancers are more frequent in women than in men. These different frequencies may depend on differences in patient's behavior and in thyroid investigations. However, an impact on sexual hormones is likely, although this has been insufficiently elucidated. Estrogens may increase the production of mutagenic molecules in the thyroid cell and favor the proliferation and invasion of tumoral cells by regulating both the thyrocyte enzymatic machinery and the inflammatory process associated with tumor growth. On the other hand, the worse prognosis of thyroid cancer associated with the male gender is poorly explained.

Novel Inhibitor-Based Therapies for Thyroid Cancer-An Update

Thyroid cancers (TCs) are the most common tumors of the endocrine system and a constant rise in the number of TC cases has been observed for the past few decades. TCs are one of the most frequent tumors in younger adults, especially in women, therefore early diagnosis and effective therapy are especially important. Ultrasonography examination followed by fine needle biopsy have become the gold standard for diagnosis of TCs, as these strategies allow for early-stage detection and aid accurate qualification for further procedures, including surgical treatment. Despite all the advancements in detection and treatment of TCs, constant mortality levels are still observed. Therefore, a novel generation line of targeted treatment strategies is being developed, including personalized therapies with kinase inhibitors. Recent molecular studies on TCs demonstrate that kinase inhibitor-based therapies might be considered as the most promising. In the past decade, new kinase inhibitors with different mechanisms of action have been reported and approved for clinical trials. This review presents an up-to-date picture of new approaches and challenges of inhibitor-based therapies in treatment of TCs, focusing on the latest findings reported over the past two years.

A two-microRNA signature predicts the progression of male thyroid cancer

In various cancers, microRNAs (miRNAs) are abnormally expressed, including thyroid cancer (TC). In recent years, the incidence of TC has increased annually around the world. Compared with female patients, male TC patients are more likely to have a postoperative recurrence and lymph node metastasis, and hence need second treatments. However, the molecular biological processes underlying this phenomenon are not understood. Therefore, we collected data on miRNA expression and clinical information of male TC patients from The Cancer Genome Atlas (TCGA) database. Differentially expressed miRNAs were identified between male TC tissues and matched normal tissues. The Kaplan–Meier method, univariate and multivariate Cox regressions, and receiver operating characteristic curve analyses were performed to assess the association between miRNAs and the disease-free survival of male TC patients. Gene Ontology (GO) and the Kyoto Encyclopaedia of Gene and Genome (KEGG) enrichment analyses were then used to explore the function of miRNA target genes. Furthermore, we evaluated the ability of the miRNA biomarker to predict survival in female TC patients. As a result, a total of 118 differentially expressed miRNAs were identified, including 25 upregulated and 93 downregulated miRNAs. Among them, miR-451a and miR-16-1-3p were confirmed to be independent prognostic factors for the disease-free survival rate. The target genes of miR-451a and miR-16-1-3p were identified, and functional analysis showed that these genes were enriched in 25 Go and KEGG accessions, including cell signal transduction, motor adhesion, phagocytosis, regulation of transcription, cell proliferation, angiogenesis, etc. Neither miR-451a and miR-16-1-3p, nor a prediction model based on both miRNAs effectively predicted survival in female TC patients. In conclusion, both miR-451a and miR-16-1-3p may play important roles in the processes of male TC. The two-miRNA signature involving miR-1258 and miR-193a may serve as a novel prognostic biomarker for male TC patients.

Impact of healthcare services on thyroid cancer incidence among World Trade Center-exposed rescue and recovery workers

BACKGROUND

A recent study of World Trade Center (WTC)-exposed firefighters and emergency medical service workers demonstrated that elevated thyroid cancer incidence may be attributable to frequent medical testing, resulting in the identification of asymptomatic tumors. We expand on that study by comparing the incidence of thyroid cancer among three groups: WTC-exposed rescue/recovery workers enrolled in a New York State (NYS) WTC-medical monitoring and treatment program (MMTP); WTC-exposed rescue/recovery workers not enrolled in an MMTP (non-MMTP); and the NYS population.

METHODS

Person-time began on 9/12/2001 or at enrollment in a WTC cohort and ended at death or on 12/31/2015. Cancer data were obtained through linkages with 13 state cancer registries. We used Poisson regression to estimate rate ratios (RRs) and 95% confidence intervals (CIs) for MMTP and non-MMTP participants. NYS rates were used as the reference. To estimate potential changes over time in WTC-associated risk, change points in RRs were estimated using profile likelihood.

RESULTS

The thyroid cancer incidence rate among MMTP participants was more than twice that of NYS population rates (RR = 2.31; 95% CI = 2.00-2.68). Non-MMTP participants had a risk similar to NYS (RR = 0.96; 95% CI = 0.72-1.28). We observed no change points in the follow-up period.

CONCLUSION

Our findings support the hypothesis that no-cost screening (a benefit provided by WTC-MMTPs) is associated with elevated identification of thyroid cancer. Given the high survival rate for thyroid cancer, it is important to weigh the costs and benefits of treatment, as many of these cancers were asymptomatic and may have been detected incidentally.

Evaluation of Gender Inequity in Thyroid Cancer Diagnosis: Differences by Sex in US Thyroid Cancer Incidence Compared With a Meta-analysis of Subclinical Thyroid Cancer Rates at Autopsy

IMPORTANCE

Thyroid cancer is more common in women than in men, but the associated causes of these differences are not fully understood.

OBJECTIVE

To compare sex-specific thyroid cancer rates in the US to the prevalence of subclinical thyroid cancer at autopsy.

DATA SOURCES

Data on thyroid cancer incidence and mortality by sex among US adults (≥18 years) were extracted from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program (SEER) data for 1975 to 2017. Embase, PubMed, and Web of Science databases were searched for studies on the prevalence of subclinical thyroid cancer at autopsy of men and women, from inception to May 31, 2021.

STUDY SELECTION

The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline was used to perform a systematic search for articles reporting the prevalence of subclinical thyroid cancer in autopsy results of both women and men. Of 101 studies identified, 8 studies containing 12 data sets met inclusion criteria; ie, they examined the whole thyroid gland, stated the number of thyroids examined, and reported results by sex. Excluded studies reported thyroid cancer in Japan after the atomic bombs or Chernobyl after the nuclear disaster; did not examine the whole thyroid gland or had incomplete information on thyroid examination methods; or did not report rates by sex.

DATA EXTRACTION AND SYNTHESIS

Thyroid cancer incidence and mortality data by sex, histologic type, and tumor size were extracted from SEER. The inverse variance heterogeneity model was used to meta-analyze the prevalence and the odds ratio of subclinical thyroid cancer by sex from 8 studies (12 data sets) on thyroid cancer prevalence in autopsy results.

MAIN OUTCOMES AND MEASURES

Incidence and mortality of thyroid cancer, by histologic type and tumor size; prevalence of thyroid cancer in autopsy results.

RESULTS

In 2017, 90% of thyroid cancers diagnosed were papillary thyroid cancer (PTC) and in 2013 to 2017, the women to men incidence ratio for small (≤2 cm) PTC was 4.39:1. The incidence ratio approached 1:1 as cancer type lethality increased. The ratio of thyroid cancer mortality by gender was 1.02:1 and remained stable from 1992 to 2017. Results of the meta-analysis showed that the pooled autopsy prevalence of subclinical PTC was 14% in women (95% CI, 8%-20%) and 11% in men (95% CI, 5%-18%). The pooled odds ratio of subclinical PTC in women compared with men was 1.07 (95% CI, 0.80-1.42).

CONCLUSIONS AND RELEVANCE

This cohort study and meta-analysis found that the belief that women get thyroid cancer more often than men is an oversimplification. The gender disparity is mostly confined to the detection of small subclinical PTCs, which are equally common in both sexes at autopsy but identified during life much more often in women than men. As the lethality of the cancer type increases, the ratio of detection by gender approaches 1:1. This phenomenon may be associated with gender differences in health care utilization and patterns of clinical thinking and can harm both women, who are subject to overdetection, and men, who may be at risk of underdetection.

Global burden of thyroid cancer and its attributable risk factors in 204 countries and territories from 1990 to 2019

Background

To investigate the burden of thyroid cancer and its attributable risk factors in 204 countries and territories during 30 years.

Methods

We extracted data from the Global Burden of Disease (GBD) 2019 database, including incidence, mortality, disability‐adjusted life‐years (DALYs), and the attributable risk factors of thyroid cancer from 1990 to 2019. Estimated annual percentage changes (EAPC) were calculated to assess the changes in age‐standardized incidence rate (ASIR), age‐standardized mortality rate (ASMR), and age‐standardized DALYs rate (ASDR). We also examined the associations between cancer burden and the sociodemographic index (SDI).

Results

The global new cases, death, and DALYs of thyroid cancer in 2019 were 233 847 (95% UI: 211 637–252 807), 45 576 (95% UI: 41 290‐48 775), and 1 231 841 (95% UI: 1 113 585–1 327 064), respectively. From 1990 to 2019, the ASIR of thyroid cancer showed an upward trend (EAPC = 1.25), but ASMR (EAPC = −0.15) and ASDR (EAPC = −0.14) decreased. The burden of thyroid cancer varied at regional and national levels, but the association between ASIR and SDI was positive. We found that the burden of thyroid cancer was mainly concentrated in females and that the age of onset tended to be younger. The proportion of DALYs from thyroid cancer attributable to high body‐mass index was higher in high SDI regions, especially in males.

Conclusions

The global incidence of thyroid cancer has continued to increase in the past three decades. The high body‐mass index as an important risk factor for thyroid cancer deserves greater attention, especially in high SDI regions.

Analysis of the Association between Female Medical History and Thyroid Cancer in Women: A Cross-Sectional Study Using KoGES HEXA Data

The purpose of this study was to evaluate the association between female medical history and thyroid cancer. Methods: Data from the Korean Genome and Epidemiology Study were collected from 2004 to 2016. Among a total of 1303 participants with thyroid cancer and 106,602 control (non-thyroid cancer) participants, the odds ratios (ORs) with 95% confidence intervals (CIs) of hysterectomy, oophorectomy, use of oral contraceptives, and number of children were evaluated. Results: The adjusted OR of hysterectomy for thyroid cancer was 1.73 (95% CI = 1.48-2.01, p < 0.001) in the minimally adjusted model. The adjusted ORs for thyroid cancer were 1.89 (95% CI = 1.06-3.37, p = 0.031), 0.89 (95% CI = 0.83-0.94, p < 0.001), and 0.85 (95% CI = 0.73-0.99, p = 0.040) for bilateral oophorectomy, number of children, and use of oral contraceptives, respectively, in the fully adjusted model. In the subgroup analysis, the adjusted ORs of bilateral oophorectomy were significant in the younger age (OR = 3.62, 95% CI = 1.45-9.03, p = 0.006), while the number of children was significant in the older age (OR = 0.86, 95% CI = 0.80-0.93, p < 0.001). Conclusions: The ORs of hysterectomy and bilateral oophorectomy were significantly higher in the thyroid cancer group in the younger age group. The adjusted ORs of the number of children were significantly low in the older age group.

Projected lifetime cancer risk from cone-beam computed tomography for orthodontic treatment

Objective

To estimate the projected cancer risk attributable to diagnostic cone-beam computed tomography (CBCT) performed under different exposure settings for orthodontic purposes in children and adults.

Methods

We collected a list of CBCT machines and their specifications from 38 orthodontists. Organ doses were estimated using median and maximum exposure settings of 105 kVp/156.8 mAs and 130 kVp/200 mAs, respectively. The projected cancer risk attributable to CBCT procedures performed 1-3 times within 2 years was calculated for children (aged 5 and 10 years) and adult (aged 20, 30, and 40 years) male and female patients.

Results

For maximum exposure settings, the mean lifetime fractional ratio (LFR) was 14.28% for children and 0.91% for adults; this indicated that the risk to children was 16 times the risk to adults. For median exposure settings, the mean LFR was 5.25% and 0.58% for children and adults, respectively. The risk of cancer decreased with increasing age. For both median and maximum exposure settings, females showed a higher risk of cancer than did males in all age groups. Cancer risk increased with an increase in the frequency of CBCT procedures within a given period.

Conclusions

The projected dental CBCT-associated cancer risk spans over a wide range depending on the machine parameters and image acquisition settings. Children and female patients are at a higher risk of developing cancer associated with diagnostic CBCT. Therefore, the use of diagnostic CBCT should be justified, and protective measures should be taken to minimize the harmful biological effects of radiation.

Reproductive Factors and Risk of Thyroid Cancer in Women: An Analysis in the Nurses' Health Study II

BACKGROUND

The incidence of thyroid cancer in women is increasing at an alarming rate, with greatest risk in the reproductive years. Establishing relationships of hormonally related reproductive factors with thyroid cancer has been difficult. We aimed to elucidate potential risk factors for thyroid cancer in a large cohort of women.

METHODS

Among 116,228 women in the Nurses' Health Study II followed from 1989 to 2013, 620 cases of thyroid cancer were identified. We examined reproductive and hormone-related factors, including age at menarche, age at menopause, parity, oral contraceptive use, and postmenopausal hormone therapy use. Pregnancy, reproductive years, and months of breastfeeding were used as surrogate markers for exposure to endogenous reproductive hormones. We used multivariable Cox models to calculate relative risks and 95% confidence intervals for the associations between these factors and risk of thyroid cancer.

RESULTS

Number of reproductive years of 41 years or more was associated with more than double the risk of thyroid cancer compared with 30 years or fewer (relative risk, 2.20; 95% confidence interval, 1.19-4.06). The other variables analyzed (parity number, months of breastfeeding, age at menarche, menopausal status, and postmenopausal hormone therapy) were not associated with the risk of thyroid cancer. Women who entered menopause at age 45 years or older had a higher risk of thyroid cancer compared with women who entered menopause at a younger age. This result did not reach statistical significance; however, there was a linear trend between later age at menopause and increased risk of thyroid cancer (p_trend = .009).

CONCLUSIONS

This study used a unique large, longitudinal dataset to assess thyroid cancer risk factors and potential confounders over an extended time frame. Our key finding suggests increased risk of thyroid cancer may be associated with a variety of indicators of longer reproductive years. The Nurses' Health Study II has provided new insights into the hormonal risks associated with thyroid cancer.

Diet as a possible influencing factor in thyroid cancer incidence: the point of view of the nutritionist

The incidence of differentiated thyroid cancer has increased in the last decades all over the world. Different environmental factors are possible perpetrators of this exponential growth. Nutritional factors are among the main environmental factors studied for thyroid cancer in recent years. This review aims to overview the main dietary factors involved in thyroid cancer risk, providing specific nutrition recommendations from the endocrinological Nutritionist point of view. Among the single food, fish and shellfish are the primary natural source of iodine, selenium and vitamin D in the human diet. These nutrients are essential for the synthesis of thyroid hormones; however, their consumption is not consistently related to thyroid cancer risk. The high intake of fruit and vegetables, probably due to their vitamin and antioxidant content, shows a weak inverse association with thyroid cancer risk. Alcohol, meat, or other food groups/nutrients showed no significant effect on thyroid cancer. In conclusion, to date, no definite association among dietary factors, specific dietary patterns, and thyroid cancer, and its clinical severity and aggressiveness have been found. However, it is essential to underline that in the future, prospective studies should be carried out to precisely evaluate the qualitative and quantitative intake of nutrients by patients to establish with more confidence a potential correlation between food intake and the occurrence and development of thyroid cancer.

Trend dynamics of thyroid cancer incidence among China and the U.S. adult population from 1990 to 2017: a joinpoint and age-period-cohort analysis

BACKGROUND

Thyroid cancer (TC) is the most common malignant disease of the endocrine system. Based on the previously published reports, the incidence of TC has been increasing in the past 25 years, and the reason for the increase is not yet clear. The present study aims to reveal the long-term trends and age-period-cohort effects for the incidence of TC in China and the U.S. from 1990 to 2017.

METHODS

We examined the trends of TC incidence and the average annual percentage change (AAPC) of rate using the Joinpoint regression analysis in the two countries, for the different genders (men/women) in the Global Burden of Disease (GBD 2017). We further used an age-period-cohort model to analyze age-period-cohort effects on TC incidence.

RESULTS

The ASIR of China increased markedly with AAPC of 4.5% (95% confidence interval (CI): 4.0, 5.0%) and 1.8% (1.6, 2.0%) for men and women during 1990-2017. The ASIR of the U. S increased by 1.4% (1.0, 1.8%) and 1.3% (0.9, 1.7%) for men and women from 1990 to 2017.TC increased with the age and period. Aging was one of the most influential factors of TC in China. The age effect increased markedly in the U.S. compared with China. The period effect showed an increase in China while that tended to grow steadily during 1990-2017 in the U.S. The cohort effect peaked in 1963-1967 birth cohorts for men and women in China and declined consistently in the birth cohort in the U.S.

CONCLUSION

From 1990 to 2017, due to ionizing radiation and over-diagnosis, age-standardized TC incidence rates in both genders rose in China and the U.S. The standardized incidence rate of women is higher than that of men. It is necessary to provide women with reasonable prevention and protection measures for TC. We need to apply for health services and screening to reduce ionizing radiation.

Differential expression of Vitamin D binding protein in thyroid cancer health disparities

Thyroid cancer incidence, recurrence, and death rates are higher among Filipino Americans than European Americans. We propose that vitamin D binding protein (DBP) with multifunctionality with ethnic variability plays a key role within different ethnicities. In this study, we determined the correlation between differential DBP expression in tumor tissues and cancer staging in Filipino Americans versus European Americans. We assayed DBP expression by immunohistochemistry and analyzed the data with confocal microscopy on 200 thyroid cancer archival tissue samples obtained from both ethnicities. DBP-stable knockdown/gain-in-function assays were done by using DBP-shRNA/DBP-cDNA-expression in vitro. The majority of Filipino Americans presented with advanced tumor staging. In contrast, European Americans showed early staging and very few advanced tumors. A significantly low to no DBP staining was detected and correlated to the advanced staging in Filipino Americans. On the contrary, in the tumor tissues derived from European Americans, moderate to strong DBP staining was detected and correlated to early staging. When downregulation of the DBP gene in papillary thyroid cancer (PTC) cell lines was observed, tumor proliferation and migration were enhanced. On the other hand, the upregulation of the DBP gene decreased cell proliferation and migration in PTC cells. In conclusion, we determined a differential expression of an essential biological molecule (DBP) is linked to cancer staging in thyroid cancer health disparities in two ethnicities. Loss-of-DBP/gain-in-DBP-function influenced tumor progression. A future study is underway to determine the DBP regulation and its downstream pathways to elucidate strategies to eliminate the observed thyroid cancer health disparities.

Trends in incidence and histological pattern of thyroid cancer in Ho Chi Minh City, Vietnam (1996-2015): a population-based study

BACKGROUND

The burden and trend of thyroid cancer in Vietnam have not been well documented. This study aimed to investigate the trends in incidence and histological pattern of thyroid cancer in Ho Chi Minh City from 1996 to 2015.

METHODS

A population-based study retrieved data from the Ho Chi Minh City Cancer Registry during 1996-2015. Trends in the incidence of thyroid cancer were investigated based on age, gender, and histology for each 5-year period. Annual percentage change (APC) in incidence rates was estimated using Joinpoint regression analysis.

RESULTS

In the study period, there were 5953 thyroid cancer cases (men-to-women ratio 1:4.5) newly diagnosed in Ho Chi Minh City with the mean age of 42.9 years (±14.9 years). The age-standardized incidence rate of thyroid cancer increased from 2.4 per 100,000 during 1996-2000 (95% confidence interval [95% CI]: 2.2-2.6) to 7.5 per 100,000 during 2011-2015 (95% CI: 7.3-7.9), corresponded to an overall APC of 8.7 (95% CI 7.6-9.9). The APC in men and women was 6.2 (95% CI: 4.2-8.2) and 9.2 (95% CI: 8.0-10.4), respectively. The incidence rate in the < 45 years age group was the highest diagnosed overall and increased significantly in both men (APC 11.0) and women (APC 10.1). Both genders shared similar distribution of subtype incidences, with papillary thyroid cancer constituted the most diagnosed (73.3% in men and 85.2% in women). The papillary thyroid cancer observed a markedly increase overall (APC of 10.7 (95% CI 9.3-12.0)).

CONCLUSIONS

There were appreciable increases in the age-standardized incidence rate of thyroid cancer in both genders, mainly contributed by the papillary subtype. The age of patients at diagnosis decreased gradually. The widespread utilization of advanced diagnostic techniques and healthcare accessibility improvement might play a potential role in these trends. Further investigations are needed to comprehend the risk factors and trends fully.

Study of Essential and Toxic Metal Imbalances in the Scalp Hair of Thyroid Cancer Patients in Comparison with Healthy Donors

Thyroid cancer is among the most common type of head and neck cancer; diet, age, gender and environmental factors play vital roles in its malignancy. The present study was carried out to assess the imbalances in the contents of trace metals due to onset and progression of thyroid cancer. Scalp hair was used as matrix for the evaluation of toxic and trace metals. Quantification of the metals was done through atomic absorption spectrometry. In comparison with healthy subjects, the thyroid cancer patients revealed significantly higher median levels of Mn (71%), Co (64%), Cr (55%), K (49%), Fe (45%), Mg (42%), Pb (36%), Na (30%), and Ni (26%), while the median level of Zn was considerably lower in the patients. The correlation coefficients among the metals in the patients demonstrated significantly different communal relationships compared with the healthy counterparts. Multivariate methods exhibited noticeably dissimilar apportionment among the metals in the patients than the controls. Significant disparities in the metal levels were also noticed for various types (anaplastic thyroid cancer, follicular thyroid cancer, papillary thyroid cancer, and medullary thyroid cancer) as well as stages (I, II, III, and IV) among the thyroid cancer patients. Majority of the metals revealed perceptible disparities in their contents based on gender, habitat, dietary habits, and smoking habits of the patients and controls. Overall, the study showed significantly divergent distribution and associations of the essential and toxic metal levels in the scalp hair of the patients in comparison with the levels in controls.

Menstrual, reproductive and hormonal factors and thyroid cancer: a hospital-based case-control study in China

BACKGROUND

There have been considerable studies on the effects of reproductive factors on thyroid cancer risk, while findings are inconsistent. In this analysis, we aimed to investigate the associations between menstrual, reproductive and hormonal factors with thyroid cancer occurrence in a population of Chinese women.

METHODS

Using data from a 1:1 matched case-control study performed between 2015 and 2017 in Zhejiang Province of China, a second analysis of 2261 pairs of female subjects was conducted. The possible effects for thyroid cancer were evaluated in logistic regression models by odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Later age at first pregnancy (for > 25 vs. ≦ 20 years, OR: 0.47, 95% CI 0.23-0.96) and longer duration of breast feeding (for 6-12 vs. ≦ 6 months, OR: 0.49, 95% CI 0.24-0.98) were significantly associated with decreased occurrence of thyroid cancer, while no trend was observed. Stratified by age at enrollment, only the association with duration of breast feeding remained significant, but limited to younger women (≦ 50 years).

CONCLUSIONS

Our results suggested that women with later age at first pregnancy or longer breast feeding duration were less likely to have thyroid cancer. These findings supported an influence role of reproductive factors in thyroid cancer risk.

Association Between Aggressive Clinicopathologic Features of Papillary Thyroid Carcinoma and Body Mass Index: A Systematic Review and Meta-Analysis

BACKGROUND

The association between adiposity and papillary thyroid carcinoma (PTC) has been reported in several studies, but its association with aggressive clinicopathologic features is not well-recognized. Our aim is to systematically review the literature to identify whether adiposity, expressed through Body Mass Index (BMI), is related to aggressive clinicopathologic features such as tumor-node-metastasis (TNM) stage, extrathyroidal extension (ETE), lymph node (LN) metastasis and multifocality in patients with PTC.

METHODS

A systematic search for articles was performed using the PubMed, EBSCO, and Cochrane Library for all articles published in English until December 2020. Specific keywords such as "papillary thyroid carcinoma", "Body Mass Index", "clinicopathologic features" were used in the search strategy. Two independent reviewers screened all retrieved articles based on predefined inclusion and exclusion criteria. Meta-analysis was performed in the studies that reported crude and adjusted odds ratios (OR). The methodological quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

A total of 11 retrospective cohort studies involving 26,196 participants included. Our findings showed that elevated BMI was significantly associated with ETE in both overweight (OR 1.26, 95% CI: 1.09-1.44) and obesity group (OR 1.45, 95% CI:1.26-1.64). Elevated BMI was also significantly associated with multifocality in overweight patients (OR 1.17, 95% CI:1.10-1.24) and obese patients (OR 1.45, 95% CI:1.29-1.62). Also, obesity was significantly associated with increased tumor size (OR 1.77, 95% CI:1.52-2.03) and with LN metastasis (OR 1.28, 95% CI: 1.12-1.44), whereas being overweight was significantly associated with advanced TNM stage (OR 1.55, 95% CI:1.27-1.83).

CONCLUSION

Our results provide strong evidence for the association between higher BMI and ETE, multifocality, and tumor size. Further studies with a larger number of participants are required to elucidate further the association of increased BMI with advanced TNM stage and LN metastasis.

Identification of Potential lncRNAs and miRNAs as Diagnostic Biomarkers for Papillary Thyroid Carcinoma Based on Machine Learning

BACKGROUND

Papillary thyroid carcinoma (PTC) accounts for most of the proportion of thyroid cancer (TC). The objective of this study was to identify diagnostic, differentially expressed long noncoding RNAs (lncRNAs) and microRNAs (miRNAs), contributing to understanding the epigenetics mechanism of PTC.

METHODS

The data of lncRNA, miRNA, and mRNA were downloaded from the Cancer Genome Atlas (TCGA) dataset, followed by functional analysis of differentially expressed mRNAs. Optimal diagnostic lncRNA and miRNA biomarkers were identified via random forest. The regulatory network between optimal diagnostic lncRNA and mRNAs and optimal diagnostic miRNA and mRNAs was identified, followed by the construction of ceRNA network of lncRNA-mRNA-miRNA. Expression validation and diagnostic analysis of lncRNAs, miRNAs, and mRNAs were performed. Overexpression of ADD3-AS1 was performed in PTC-UC3 cell lines, and cell proliferation and invasion assay were used for investigating the role of ADD3-AS1 in PTC.

RESULTS

A total of 107 differentially expressed lncRNAs, 81 differentially expressed miRNAs, and 515 differentially expressed mRNAs were identified. 11 lncRNAs and 6 miRNAs were regarded as the optimal diagnostic biomarkers for PTC. The epigenetic modifications via the above diagnostic lncRNAs and miRNAs were identified, including MIR181A2HG-FOXP2-hsa-miR-146b-3p, BLACAT1/ST7-AS1-RPS6KA5-hsa-miR-34a-5p, LBX2-AS1/MIR100HG-CDHR3-hsa-miR-34a-5p, ADD3-AS1-PTPRE-hsa-miR-9-5p, ADD3-AS1-TGFBR1-hsa-miR-214-3p, LINC00506-MMRN1-hsa-miR-4709-3p, and LOC339059-STK32A-hsa-miR-199b-5p. In the functional analysis, MMRN1 and TGFBR1 were involved in cell adhesion and endothelial cell migration, respectively. Overexpression of ADD3-AS1 inhibited cell growth and invasion in PTC cell lines.

CONCLUSION

The identified lncRNAs/miRNAs/mRNA were differentially expressed between normal and cancerous tissues. In addition, identified altered lncRNAs and miRNAs may be potential diagnostic biomarkers for PTC. Additionally, epigenetic modifications via the above lncRNAs and miRNAs may be involved in tumorigenesis of PTC.

Association among Body Mass Index, Genetic Variants of FTO, and Thyroid Cancer Risk: A Hospital-Based Case-Control Study of the Cancer Screenee Cohort in Korea

Purpose

Obesity has been determined to be associated with fat mass and obesity-associated (FTO) gene and thyroid cancer risk. However, the effect of combined interactions between obesity and the FTO gene on thyroid cancer needs further investigation. This study aimed to examine whether interactions between body mass index (BMI) and the FTO gene are associated with an increased risk of thyroid cancer.

Materials and Methods

A total of 705 thyroid cancer cases and 705 sex- and age-matched normal controls were selected from the Cancer Screenee Cohort in National Cancer Center, Korea. A conditional logistic regression model was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for the measure of associations and the combined effect of BMI and FTO gene on thyroid cancer.

Results

BMI was associated with an increased risk of thyroid cancer in subclasses of overweight (23–24.9 kg/m²; adjusted OR, 1.50; 95% CI, 1.12 to 2.00) and obese (≥ 25 kg/m²) (adjusted OR, 1.62; 95% CI, 1.23 to 2.14). There were positive associations between the FTO genetic variants rs8047395 and rs8044769 and an increased risk of thyroid cancer. Additionally, the combination of BMI subclasses and FTO gene variants was significantly associated with thyroid cancer risk in the codominant (rs17817288), dominant (rs9937053, rs12149832, rs1861867, and rs7195539), and recessive (rs17817288 and rs8044769) models.

Conclusion

Findings from this study identified the effects of BMI on thyroid cancer risk among individuals carrying rs17817288, rs9937053, rs12149832, rs1861867, rs7195539, and rs8044769, whereas the effects of BMI may be modified according to individual characteristics of other FTO variants.

Dietary habits and thyroid cancer risk: A hospital-based case-control study in Sicily (South Italy)

Several studies have investigated the role of diet as a risk and/or protective factor against thyroid cancer, both considering individual foods, groups of foods and dietary patterns, but the results are not consistent. The aim of the study was to investigate the relationship between dietary habits and thyroid cancer. Cases and controls were recruited at the University Hospital "G. Rodolico" of Catania. The dietary habits were defined through the "Lifestyle Assessment Questionnaire". The frequency of consumption of each food item was reported on a 4-level scale (never, one time a week, 2-3 times a week, every day of the week). We computed the odds ratios (ORs) of thyroid cancer and the corresponding 95% confidence intervals (CIs) according to the median of control group daily intake of each food group, using multiple logistic regression models adjusted for major confounding factors. Starchy foods (OR = 1.39, 95% CI 0.83-2.32), sweets (OR = 1.39, 95% CI 0.81-2.40) and products rich in salt and fat showed a positive association with thyroid cancer risk. Conversely, an inverse association with disease risk was found for vegetables (cruciferous OR = 0.30, 95% CI 0.10-0.92, non cruciferous OR = 0.57 (0.20-1.57) milk and dairy products (OR = 0.68, 95% CI 0.40-1.13) and seafood (OR = 0.68, 95% CI 0.34-1.22). An increased risk was observed for consumption of iodized salts (OR 2.06, 95% CI 1.21-3.51), tea (OR = 1.42, 95% CI 0.84-2.41) and coca-cola (OR = 3.08, 95% CI 1.53-6.20). Finally, our results confirm the protective effect of a daily water intake of 1-2 L, but unfortunately this quantity is usually consumed by about a quarter of the sample. Dietary habits appear to modify the risk of thyroid carcinoma. A diet with a limited consumption of starchy foods, products rich in salt, fat and sugar and a higher consumption of, cruciferous/non-cruciferous vegetables, milk and dairy products and seafood could be protective towards thyroid cancer. Moreover, the water intake should be increased and the actual need to consume iodized salt should be verified for each subject/area. These results warrant further investigations and, if confirmed, they might have important public health implications for the reduction of thyroid cancer through the improvement of dietary habits.

Is There Such a Thing as "Anti-Nutrients"? A Narrative Review of Perceived Problematic Plant Compounds

Plant-based diets are associated with reduced risk of lifestyle-induced chronic diseases. The thousands of phytochemicals they contain are implicated in cellular-based mechanisms to promote antioxidant defense and reduce inflammation. While recommendations encourage the intake of fruits and vegetables, most people fall short of their target daily intake. Despite the need to increase plant-food consumption, there have been some concerns raised about whether they are beneficial because of the various ‘anti-nutrient’ compounds they contain. Some of these anti-nutrients that have been called into question included lectins, oxalates, goitrogens, phytoestrogens, phytates, and tannins. As a result, there may be select individuals with specific health conditions who elect to decrease their plant food intake despite potential benefits. The purpose of this narrative review is to examine the science of these ‘anti-nutrients’ and weigh the evidence of whether these compounds pose an actual health threat.

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.

Thyroid cancer: incidence and mortality trends in China, 2005-2015

PURPOSE

Understanding secular trends of thyroid cancer is critical to plan strategies for cancer prevention and control. Our aim was to estimate the incidence and mortality trends of thyroid cancer in China during 2005-2015.

METHODS

A retrospective cohort evaluation of thyroid cancer cases and deaths during 2005-2015 was performed using population-based data from the Chinese Cancer Registry Annual Report. The incidence and mortality rates of thyroid cancer were stratified by gender, age group (0, 1-4, 5-9, 10-14…80-84, 85-), and area (urban or rural). A Joinpoint regression model was used to examine secular trends.

RESULTS

In China, the age-standardized incidence was 3.21/10⁵ in 2005, and increased to 9.61/10⁵ in 2015. Besides, a significant increase incidence rate was observed with the average annual percent change (AAPC) of 12.4% (95% CI: 10.5%-14.4%) in the period 2005-2015. The age-standardized mortality was 0.30/10⁵ in 2005 and 0.35/10⁵ in 2015, and the AAPC was 2.9% (95% CI: 1.3%-4.5%). For both incidence and mortality, the rates of thyroid cancer were much higher in females than in males, and in urban areas rather than rural areas; however, the rates of increasing trends showed no significant differences. With respect to the highest age-specific rates, it appeared in the age group of 50-54 years old for incidence and in the age group of 80-84 years old for mortality. Notably, the rate of increasing incidence trend was lower in older age groups, especially for people aged 70-79 years old.

CONCLUSION

A rapid increase in incidence and a moderate increase in mortality of thyroid cancer were observed from 2005 to 2015 in our study. Effective measures and tailored programs should be taken to curb the growth trend and reduce the disease burden.

Combinatorial Therapies in Thyroid Cancer: An Overview of Preclinical and Clinical Progresses

Accounting for about 2% of cancers diagnosed worldwide, thyroid cancer has caused about 41,000 deaths in 2018. Despite significant progresses made in recent decades in the treatment of thyroid cancer, many resistances to current monotherapies are observed. In our complete review, we report all treatments that were tested in combination against thyroid cancer. Many preclinical studies investigating the effects of inhibitors of the MAPK and PI3K pathways highlighted the importance of mutations in such signaling pathways and their impacts on the subsequent efficacy of targeted therapies, thus reinforcing the need of more personalized therapeutic strategies. Our review also points out the multiple possibilities of combinatory strategies, particularly using therapies targeting proliferation, survival, angiogenesis, and in combination with conventional treatments such as chemotherapies. In any case, resistances to anticancer therapies always develop through the activation of alternative signaling pathways. Combinatory treatments aim to blockade such mechanisms, which are gradually decrypted, thus offering new perspectives for the future. The preclinical and clinical aspects of our review allow us to have a global opinion of the different therapeutic options currently evaluated in combination and to be aware about new perspectives of treatment of thyroid cancer.

Adolescent overweight and obesity and the risk of papillary thyroid cancer in adulthood: a large-scale case-control study

This study aimed to investigate the association between adolescent overweight and obesity and PTC risk in adulthood. We conducted a case-control study in the Republic of Korea with 1,549 PTC patients and 15,490 controls individually matched for age and sex. We estimated body mass index (BMI) at age 18 years from self-reported weight at this age. Compared with BMI < 23.0 at age 18 years, BMI ≥ 25.0 at age 18 years was associated with higher PTC risk (odds ratio [OR] = 4.31, 95% confidence interval [CI]: 3.57, 5.22). The association between BMI ≥ 25.0 at age 18 years and PTC risk was stronger among men (OR = 6.65, 95% CI: 4.78, 9.27) than among women (OR = 3.49, 95% CI: 2.74, 4.43), and stronger among individuals with current BMI ≥ 25.0 (OR = 8.21, 95% CI: 6.34, 10.62) than among those with current BMI < 25.0 (OR = 2.21, 95% CI: 1.49, 3.27). Among PTC patients, BMI ≥ 25.0 at age 18 years was associated with extra-thyroidal extension and T stage ≥2, but not with N stage ≥1 or BRAFV600E mutation. Adolescent overweight and obesity was associated with higher risk of PTC in adulthood. Our results emphasise the importance of weight management in adolescence to decrease the PTC risk.

Markers of immune activation: novel biomarkers to predict the early-warning indicator of patients with papillary thyroid carcinoma

Background

Papillary thyroid carcinoma (PTC) is an indolent tumor that is exploding with increasing thyroid nodules (TN). Environmental carcinogens, lifestyle changes increased the incidence of thyroid carcinoma. With the development of B-ultrasound imaging, more and more thyroid cancer has been found. There has been a debate about whether thyroid cancer is overtreated.

Methods

The expression of T cell subsets and plasma cytokines in 191 patients, including 79 patients with PTC (PTC group), 58 patients with thyroid nodules (TN group) and 54 healthy individuals (HP group) were analyzed by flow cytometry.

Results

High levels of natural killer cells (NK) were detected in PTC and TN groups than in HP group. High activities of CD8⁺HLA-DR⁺ and CD8⁺CD38⁺ showed a gradual upward trend from HP group to PTC group. The rise in the levels of TNF-α in PTC patients’ was evident when compared with HP group. CD8⁺CD38⁺ showed a significant correlation with lymph node metastasis. CD8⁺CD38⁺ co-expression was higher in Nx stage than N₀ stage, while the proportion of IL-10 was dramatically decreased in the Nx stage.

Conclusions

These results indicated that CD8⁺CD38⁺ might act as a biomarker of PTC lymph node metastasis. The combination of CD8⁺HLA-DR⁺, CD8⁺CD38⁺ and TNF-α can be used as useful biomarkers for the early-warning indicator of PTC.

Associations of urinary phthalate metabolites with risk of papillary thyroid cancer

Some studies have revealed thyrotoxicity of phthalates; however, associations of phthalate exposure with papillary thyroid cancer (PTC) remain unclear. We conducted a pair-matching case-control study of 111 PTC cases and 111 age- and sex-matched non-PTC controls to examine associations between urinary concentrations of phthalate metabolites and PTC. Phthalate metabolites were determined in fasting urine specimens by ultra-performance liquid chromatography - tandem mass spectrometry (UPLC-MS/MS). After adjusting for potential confounders and other phthalate metabolites, the concentrations of the sum of di (2-ethylhexly) phthalate (DEHP) metabolites in urine were positively associated with PTC [odds ratio (OR) = 5.35; 95% confidence interval (CI): 1.61-17.83], suggesting the effect of phthalates exposure on PTC development. The findings require confirmation.

Contemporary Debates in Adult Papillary Thyroid Cancer Management

An ever-increasing population of patients with papillary thyroid cancer is engaging with health care systems around the world. Numerous questions about optimal management have arisen that challenge conventional paradigms. This is particularly the case for patients with low-risk disease, who comprise most new patients. At the same time, new therapies for patients with advanced disease are also being introduced, which may have the potential to prolong life. This review discusses selected controversial issues in adult papillary thyroid cancer management at both ends of the disease spectrum. These topics include: (i) the role of active surveillance for small papillary cancers; (ii) the extent of surgery in low-risk disease (lobectomy vs total thyroidectomy); (iii) the role of postoperative remnant ablation with radioiodine; (iv) optimal follow-up strategies in patients, especially those who have only undergone lobectomy; and (v) new therapies for advanced disease. Although our current management is hampered by the lack of large randomized controlled trials, we are fortunate that data from ongoing trials will be available within the next few years. This information should provide additional evidence that will decrease morbidity in low-risk patients and improve outcomes in those with distant metastatic disease.

Prediagnostic BMI and thyroid cancer incidence in the PLCO trial

Aim: To assess the correlation between prediagnostic BMI and thyroid cancer risk within the prostate, lung, colorectal and ovary (PLCO) trial. Methods: PLCO trial participants without a history of thyroid cancer before study enrollment who have complete information about prediagnostic BMI were included. Multivariable Cox regression analyses were conducted to assess the impact of prediagnostic BMI on thyroid cancer risk. Results: Higher BMI at the time of the study enrollment was associated with a higher thyroid cancer risk (hazard ratio: 1.046; p < 0.01). Furthermore, compared with a normal to normal prediagnostic BMI trajectory, both normal to overweight as well as normal to obese trajectories were associated with a higher thyroid cancer risk (p = 0.04 and p = 0.03, respectively). Conclusion: Higher BMI at the time of study entry as well as an increasing prediagnostic BMI trajectory are associated with a higher thyroid cancer risk.

When should antithyroid drug therapy to reduce the relapse rate of hyperthyroidism in Graves' disease be discontinued?

OBJECTIVE

The use of antithyroid drug (ATD) therapy in patients with Graves' disease (GD) hyperthyroidism has been increasing, but ATD therapy is associated with a higher relapse rate. We aimed to evaluate clinical factors for predicting relapse of GD after ATD therapy.

METHODS

Patients (n = 149) with newly diagnosed GD who achieved remission of hyperthyroidism after ATD therapy (≥6 months) were followed up for >18 months after ATD withdrawal. We evaluated the predictive factors of relapse during a median of 6.9 years of follow-up.

RESULTS

Disease relapse occurred in 52 patients (34.9%). By multivariate analyses, a duration of the minimum maintenance dose therapy (MMDT) of <6 months was a significant factor in disease relapse (hazard ratio [HR], 2.58; 95% confidence interval [CI], 1.47-4.52; p < 0.001), and a T3/free T4 (fT4) ratio > 120 at ATD withdrawal was significantly more frequent in patients with relapse (HR 2.43; 95% CI, 1.36-4.34; p = 0.002). In the prediction-of-relapse model, the likelihood of relapse was greater in the high-risk group, which had a short MMDT duration and a T3/fT4 ratio ≥120 (HR, 5.81; 95% CI, 2.52-13.39; p < 0.001) and the intermediate-risk group, which had a short MMDT duration or a T3/fT4 ratio < 120 (HR, 2.77; 95% CI, 1.26-6.13; p < 0.001), than in the low-risk group, which had a long MMDT duration and a T3/fT4 ratio < 120.

CONCLUSION

An MMDT longer than 6 months and a high T3/fT4 ratio at ATD withdrawal were independent predictors of relapse in patients who achieved initial remission after ATD for GD. These factors could be used to determine the optimal time to withdraw ATD during the treatment of GD hyperthyroidism.