Obesity and the risk of papillary thyroid cancer: a pooled analysis of three case-control studies

Sex-dependent impact of obesity on aggressiveness of papillary thyroid cancer

PURPOSE

To investigate the impact of body mass index (BMI) on the aggressiveness of papillary thyroid cancer (PTC).

METHODS

A total of 1720 PTC patients with total thyroidectomy or lobectomy, from January 2017 to April 2020, were retrospectively evaluated. Based on BMI, they were divided into two groups, as follows: control (CON, < 24 kg/m2) and overweight and obesity (OB, ≥ 24 kg/m2), each sex being analyzed separately.

RESULTS

In the whole cohort, the OB group had significantly higher rates of extrathyroidal extension (21.5 vs. 16.8%, p = 0.013), multifocality (43.2 vs. 37.7%, p = 0.018), and BRAF-V600E mutation (82.9 vs. 79.3%, p = 0.015) than the CON group. In males, the OB group had increased rates of tumor size over 1cm (54.4 vs. 42.7%, p = 0.008), extrathyroidal extension (24.9 vs. 12.4%, p = 0.001), and multifocality (42.7 vs. 33.5%, p = 0.038). The OB group had significantly higher adjusted odds ratios (ORs) of 1.63 (1.14-2.33, p = 0.008), 2.12 (1.26-3.57, p = 0.005), and 1.56 (1.07-2.29, p = 0.022) for tumor size over 1cm, extrathyroidal extension, and multifocality compared with CON. Additionally, overweight and obesity were analyzed alone and the rates of extrathyroidal extension (30/100, 30.0%, p = 0.001) and tumor size over 1cm (65/100, 65.0%, p = 0.001) were significantly higher in the obesity group than in the overweight and CON groups. The obesity group had robust higher adjusted ORs of 2.51(1.50-4.20, p < 0.001), 2.93 (1.50-5.73, p = 0.002) and 1.89 (1.11-3.22, p = 0.020) for tumor size over 1cm, extrathyroidal extension, and multifocality compared with CON.

CONCLUSIONS

Overweight and obesity were predominant independent risk factors for PTC aggressiveness in males. These data indicated that the therapeutic treatment should be based on risk stratification by BMI in males.

Overweight as a biomarker for concomitant thyroid cancer in patients with Graves' disease

The incidence of concomitant thyroid cancer in Graves' disease varies and Graves' disease can make the diagnosis and management of thyroid nodules more challenging. Since the majority of Graves' disease patients primarily received non-surgical treatment, identifying biomarkers for concomitant thyroid cancer in patients with Graves' disease may facilitate planning the surgery. The aim of this study is to identify the biomarkers for concurrent thyroid cancer in Graves' disease patients and evaluate the impact of being overweight on cancer risk. This retrospective cohort study analyzed 122 patients with Graves' disease who underwent thyroid surgery at Seoul St. Mary's Hospital (Seoul, Korea) from May 2010 to December 2022. Body mass index (BMI), preoperative thyroid function test, and thyroid stimulating hormone receptor antibody (TR-Ab) were measured. Overweight was defined as a BMI of 25 kg/m² or higher according to the World Health Organization (WHO). Most patients (88.5%) underwent total or near-total thyroidectomy. Multivariate analysis revealed that patients who were overweight had a higher risk of malignancy (Odds ratios, 3.108; 95% confidence intervals, 1.196-8.831; p = 0.021). Lower gland weight and lower preoperative TR-Ab were also biomarkers for malignancy in Graves' disease. Overweight patients with Graves' disease had a higher risk of thyroid cancer than non-overweight patients. A comprehensive assessment of overweight patients with Graves' disease is imperative for identifying concomitant thyroid cancer.

Nonalcoholic Fatty Liver Disease and the Risk of Thyroid Cancer Among Young Adults in South Korea

CONTEXT

Nonalcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Obesity and metabolic syndrome are known risk factors for thyroid cancer.

OBJECTIVE

We investigated the association between NAFLD and thyroid cancer risk in young adults.

METHODS

This nationwide cohort study included 1 135 967 participants aged 20 to 39 years who underwent 4 consecutive health screenings in South Korea. NAFLD was categorized using the fatty liver index (FLI), as follows: ≥60, 30 to 60, and <30. The cumulative FLI points were defined as the number of times participants had a FLI of ≥30 (0-4).

RESULTS

During a median follow-up of 5.2 years, 4126 participants (0.36%) were newly diagnosed with thyroid cancer. Compared with the participants with an FLI of <30, those with an FLI of 30 to 60 (men: hazard ratio [HR] 1.36 [95% CI, 1.22-1.51] and women: HR 1.44 [1.21-1.70]) and those with an FLI of ≥60 (men: HR 1.71 [1.53-1.92] and women: HR 1.81 [1.46-2.25]) had a significantly higher risk of thyroid cancer. Participants with higher cumulative FLI points had a higher risk of thyroid cancer compared to those with a cumulative FLI point of 0 (P < .001). During the follow-up period, the participants with an increased FLI exhibited an increased risk of thyroid cancer.

CONCLUSION

NAFLD was associated with an increased risk of thyroid cancer in young adults. Repeatedly elevated FLI and progression of NAFLD were associated with an increased risk of thyroid cancer in this study.

Evolving approaches in paediatric thyroid cytopathology: A review

The guidelines for the workup of thyroid nodules have been established in adult populations and secondarily applied to paediatric populations. In particular, The Bethesda System for Reporting Thyroid Cytopathology (TBSRTC) is commonly applied to both adult and paediatric thyroid nodules. However, as paediatric nodules have distinct molecular drivers and behavioural trajectories, there is renewed interest in diagnostic and management strategies that are paediatric specific. Here, we review key differences between paediatric and adult thyroid cancer and recent literature evaluating the use of TBSRTC in paediatric populations.

Thyroid cancer burden and risk factors in China from 1990-2019: a systematic analysis using the global burden of disease study

Background

Thyroid cancer (TC) is the most common endocrine system malignancy with a rapidly increasing incidence in China. Epidemiological data on TC at the national level are lacking. This study aimed to quantify the TC disease burden in China between 1990 and 2019 and evaluate the current status and trends of the disease burden attributed to a high body mass index (HBMI).

Methods

The 2019 Global Burden of Disease Study dataset was used to explore the TC disease burden. Age-standardized rates of incidence (ASIR), prevalence (ASPR), deaths (ASDR), and disability-adjusted life years (DALYs) were considered and the estimated annual percentage change (EAPC) was calculated as a measure of the average change in age-standardized rates. The trend in TC-related mortality and DALYs attributed to an HBMI, accounting for different age groups and sexes, was examined.

Results

Between 1990 and 2019, the ASDR and DALYs for TC decreased by 0.02/100000 and 1.17/100000, respectively. The ASPR and ASIR increased by 9.88/100000 and 1.04/100000, respectively. The EAPC for ASDR, age-standardized rates of DALYs, ASPR, and ASIR were 0.06 (95% CI: -0.09, 0.21), -0.20 (95% CI: -0.31, -0.10), 3.52 (95% CI: 3.35, 3.68), and 2.73 (95% CI: 2.58, 2.88), respectively. TC-related deaths, DALYs, and their prevalence and incidence in China increased by 118%, 350%, 81%, and 290%, respectively. The disease burden of TC was higher among male than female patients in different age groups, with varying distributions. The disease burden attributed to HBMI gradually increased over the past 30 years according to age-standardized DALYs, particularly in male patients.

Conclusion

The TC burden has increased in China over the past 30 years, and population aging poses a challenge to TC prevention and control. HBMI has become an important factor in the TC disease burden and further research should focus on reducing the disease burden among Chinese male patients with TC.

Clinical characteristics and therapeutic response of differentiated thyroid carcinoma with obesity and diabetes

BACKGROUND

The effects of obesity and diabetes on the clinical outcomes of differentiated thyroid cancer (DTC) remain unclear.

OBJECTIVES

To explore the association between obesity and diabetes with pathological features and therapeutic response of DTC.

METHODS

Patients were categorized based on body mass index (BMI) and glycemic status. Compare the correlation between BMI and glycemic status with pathological features and therapeutic response of DTC. To analyze the independent risk factors for the aggressiveness of DTC.

RESULTS

The proportion of patients with bilateral tumors was higher in the overweight, obese and diabetes group (P = 0.001, 0.045). The overweight group demonstrated a higher TNM stage (P = 0.004), while the T and TNM stages were higher in the diabetes group (P = 0.032, 0.000). The probability of distant metastasis increases by 37.4% for each unit of BMI increase (odds ratio (OR) = 1.374, CI 95% 1.061-1.778, P < 0.05). The BMI of Biochemical Incomplete Response (BIR) is significantly higher than that of Excellent Response (ER) (P = 0.015), the fasting plasma glucose (FPG) of Structural Incomplete (SIR) was significantly higher than that of ER and BIR (P = 0.030, 0.014).

CONCLUSION

Obesity and diabetes have effect on DTC aggressiveness. BMI and FPG have correlation with the therapeutic response of DTC patients.

Prepregnancy Body Mass Index and Risk of Differentiated Thyroid Cancer: A Prospective Cohort Study of More than 440,000 Danish Women

Background: High body mass index (BMI) has previously been associated with increased risk of differentiated thyroid cancer (DTC); however, only few studies have investigated the association with BMI in a large cohort assessed at a young age and with sufficient data on confounding factors. We assessed the association between excess body weight and the risk of DTC and papillary thyroid cancer (PTC) in a large cohort of young Danish women with substantial confounder control. Methods: We included all parous Danish women registered with a prepregnancy BMI ≥18.5 kg/m² during 2004-2016 in the Danish Medical Birth Registry in the study population. Cox proportional hazards regression models were used to estimate the hazard ratios (HRs) with confidence intervals (CIs) of DTC according to BMI. In subanalyses, we investigated PTC as a separate group. Analyses were adjusted for calendar time, education, smoking status, benign thyroid disease (BTD), type II diabetes, parity, and oral contraceptive use. In addition, we examined the association with increasing BMI stratified for previous BTD. Results: A total of 443,403 women were included in the study population, and the median age at baseline was 30.0 years. Altogether, 463 women were diagnosed with DTC during follow-up. Excess body weight was associated with a higher rate of DTC (overweight, BMI 25-29.9 kg/m²: HR = 1.54; CI 1.25-1.90. Obese, BMI ≥30 kg/m²: HR = 1.32; CI 1.00-1.75) compared with normal weight. Results were similar in PTC. In addition, we found an increased rate of DTC with increasing BMI, when investigating BMI as a continuous variable per 5 kg/m² increase (HR = 1.17; CI 1.07-1.27). The results were similar in women without previous BTD. Conclusions: Our study confirms that excess body weight is associated with an increased incidence of DTC and PTC in women.

ABCA1-Mediated EMT Promotes Papillary Thyroid Cancer Malignancy through the ERK/Fra-1/ZEB1 Pathway

Papillary thyroid cancer (PTC) is the most prevalent histological type of thyroid cancer (TC) worldwide. Although tumor metastasis occurs in regional lymph nodes, distant metastasis (DM) may also occur. Radioactive iodine (RAI) therapy is an effective treatment for TC; however, resistance to RAI occurs in patients with DM. Therefore, in this study, we investigated the efficacy of DM-related biomarkers as therapeutic targets for PTC therapy. ABCA1 expression was higher in aggressive BCPAP cells than in other PTC cells in terms of migration and invasion capacity. The knockdown of ABCA1 substantially decreased the expression of the epithelial-mesenchymal transition (EMT) marker, N-cadherin, and EMT regulator (ZEB1), resulting in suppressed migration and invasion of BCPAP cells. ABCA1 knockdown also reduced ERK activity and Fra-1 expression, which correlated with the effects of an ERK inhibitor or siRNA-mediated inhibition of ERK or Fra-1 expression. Furthermore, ABCA1-knocked-down BCPAP cells suppressed cell migration and invasion by reducing Fra-1 recruitment to Zeb1 promoter; lung metastasis was not observed in mice injected with ABCA1-knocked-down cells. Overall, our findings suggest that ABCA1 regulates lung metastasis in TC cells.

Dietary selenium intake and thyroid cancer risk in postmenopausal women

OBJECTIVE

It has been suggested that higher selenium intake and consumption of supplements protect against several cancers. To our knowledge, epidemiologic evidence is rare and inconsistent on the association of selenium level and the risk for thyroid cancer. Therefore, the aim of this study was to examine the association between selenium intake and thyroid cancer risk in postmenopausal women using the Women's Health Initiative (WHI) database.

METHODS

The WHI recruited 161 808 postmenopausal women 50 to 79 y of age between September 1, 1993 and December 31, 1998. The present study included 147 348 women 63.15 y of age (SD = 7.21) at baseline. The main exposure was baseline total selenium intake including dietary selenium measured by food frequency questionnaire (FFQ) and supplemental selenium. The outcome was thyroid cancer, which was adjudicated by trained physicians. Cox proportional hazard models were used to analyze the association.

RESULTS

During a mean follow-up of 16.4 y until September 30, 2020, 442 thyroid cancer cases were identified. There was no significant association between total selenium intake and thyroid cancer risk after adjusting for multiple covariates (highest versus lowest quartile: hazard ratio [HR], 0.88; 95% confidence interval [CI], 0.60-1.29). Association between total selenium intake and the risk for papillary thyroid cancer was also not significant (highest versus lowest quartile: HR, 1.02; 95% CI, 0.66-1.52).

CONCLUSIONS

The present data did not support that either total or dietary selenium intake was associated with the risk for thyroid cancer or the papillary subtype in postmenopausal women ages 50 to 79 y in the United States.

Hormonal Crosstalk Between Thyroid and Breast Cancer

Differentiated thyroid cancer and breast cancer account for a significant portion of endocrine-related malignancies and predominately affect women. As hormonally responsive tissues, the breast and thyroid share endocrine signaling. Breast cells are responsive to thyroid hormone signaling and are affected by altered thyroid hormone levels. Thyroid cells are responsive to sex hormones, particularly estrogen, and undergo protumorigenic processes upon estrogen stimulation. Thyroid and sex hormones also display significant transcriptional crosstalk that influences oncogenesis and treatment sensitivity. Obesity-related adipocyte alterations-adipocyte estrogen production, inflammation, feeding hormone dysregulation, and metabolic syndromes-promote hormonal alterations in breast and thyroid tissues. Environmental toxicants disrupt endocrine systems, including breast and thyroid homeostasis, and influence pathologic processes in both organs through hormone mimetic action. In this brief review, we discuss the hormonal connections between the breast and thyroid and perspectives on hormonal therapies for breast and thyroid cancer. Future research efforts should acknowledge and further explore the hormonal crosstalk of these tissues in an effort to further understand the prevalence of thyroid and breast cancer in women and to identify potential therapeutic options.

Repeated Low High-Density Lipoprotein Cholesterol and the Risk of Thyroid Cancer: A Nationwide Population- Based Study in Korea

BACKGROUND

High-density lipoprotein cholesterol (HDL-C) plays an important role in the reverse cholesterol transport pathway and prevents atherosclerosis-mediated disease. It has also been suggested that HDL-C may be a protective factor against cancer. However, an inverse correlation between HDL-C and cancer has not been established, and few studies have explored thyroid cancer.

METHODS

The study participants received health checkups provided by the Korean National Health Insurance Service from 2009 to 2013 and were followed until 2019. Considering the variability of serum HDL-C level, low HDL-C level was analyzed by grouping based on four consecutive health checkups. The data analysis was performed using univariate and multivariate Cox proportional hazard regression models.

RESULTS

A total of 3,134,278 total study participants, thyroid cancer occurred in 16,129. In the crude model, the hazard ratios for the association between repeatedly measured low HDL-C levels and thyroid cancer were 1.243, 1.404, 1.486, and 1.680 (P for trend <0.01), respectively, which were significant even after adjusting for age, sex, lifestyle factors, and metabolic diseases. The subgroup analysis revealed that low HDL-C levels likely had a greater impact on the group of patients with central obesity (P for interaction= 0.062), high blood pressure (P for interaction=0.057), impaired fasting glucose (P for interaction=0.051), and hyperlipidemia (P for interaction=0.126).

CONCLUSION

Repeatedly measured low HDL-C levels can be considered a risk factor for cancer as well as vascular disease. Low HDL-C levels were associated with the risk of thyroid cancer, and this correlation was stronger in a metabolically unhealthy population.

Insulin and cancer: a tangled web

For a century, since the pioneering work of Otto Warburg, the interwoven relationship between metabolism and cancer has been appreciated. More recently, with obesity rates rising in the U.S. and worldwide, epidemiologic evidence has supported a link between obesity and cancer. A substantial body of work seeks to mechanistically unpack the association between obesity, altered metabolism, and cancer. Without question, these relationships are multifactorial and cannot be distilled to a single obesity- and metabolism-altering hormone, substrate, or factor. However, it is important to understand the hormone-specific associations between metabolism and cancer. Here, we review the links between obesity, metabolic dysregulation, insulin, and cancer, with an emphasis on current investigational metabolic adjuncts to standard-of-care cancer treatment.

Impaired Glucose Metabolism, Anti-Diabetes Medications, and Risk of Thyroid Cancer

Simple Summary

An epidemiologic link exists between obesity, insulin resistance, diabetes, and some cancers, such as breast cancer and colon cancer. The prevalence of obesity and diabetes is increasing, and additional epidemiologic data suggest that there may be a link between obesity and risk of thyroid abnormalities. Factors that may link obesity and diabetes with thyroid proliferative disorders include elevated circulating levels of insulin, increased body fat, high blood sugars, and exogenous insulin use. However, mechanisms underlying associations of obesity, diabetes, and thyroid proliferative disorders are not yet fully understood. The present manuscript reviews and summarizes current evidence of mechanisms and epidemiologic associations of obesity, insulin resistance, and use of anti-diabetes medications with benign and malignant proliferative disorders of the thyroid.

Abstract

The prevalence of obesity is progressively increasing along with the potential high risk for insulin resistance and development of type 2 diabetes mellitus. Obesity is associated with increased risk of many malignancies, and hyperinsulinemia has been proposed to be a link between obesity and cancer development. The incidence of thyroid cancer is also increasing, making this cancer the most common endocrine malignancy. There is some evidence of associations between obesity, insulin resistance and/or diabetes with thyroid proliferative disorders, including thyroid cancer. However, the etiology of such an association has not been fully elucidated. The goal of the present work is to review the current knowledge on crosstalk between thyroid and glucose metabolic pathways and the effects of obesity, insulin resistance, diabetes, and anti-hyperglycemic medications on the risk of thyroid cancer development.

The association of obesity with thyroid carcinoma risk

Background

The prevalence of obesity and an increased incidence of thyroid carcinoma (TC) threaten public health in parallel on a global scale. Sufficient evidence supports excess body fatness in thyroid carcinogenesis, and the role and anthropometric markers of obesity have been causally associated with the rising risk of TC.

Methods

A literature search was conducted in PubMed. Studies focused on the effect of obesity in TC.

Results

This review mainly discusses the global incidence and prevalence of obesity‐related TC. We also review the role of obesity in TC and potential clinical strategies for obesity‐related TC.

Conclusions

Excess body fatness in early life and TC survival initiate adverse effects later in life.

The incidence of thyroid cancer has been increasing in the last decades all over the world. Such a steady growth cannot be entirely attributable to more sensitive diagnostic procedures. Obesity has increased with sufficient rapidity in the same time frame and may as possible promoters and modifiable risk factors for thyroid cancer in recent years. The aim of this review was to focus on the relationship between obesity and the risk of thyroid cancer. Obesity seems to play a relevant role in thyroid cancer carcinogenesis as well as in its severity and aggressiveness. The possible underlying mechanism is involved chronic inflammation mediated by cytokines, leptin, and adiponectins.

Influence of Obesity Parameters on Different Regional Patterns of Lymph Node Metastasis in Papillary Thyroid Cancer

OBJECTIVE

Obesity increases risk of thyroid cancer. However, the association between obesity and the progression of papillary thyroid cancer (PTC) remains controversial. This retrospective study aimed to explore the relationship between obesity and regional patterns of lymph node metastasis (LNM) in PTC.

METHODS

We retrospectively reviewed data from 1015 patients with PTC. We calculated obese parameters, such as body mass index (BMI), body fat percentage (BFP), and body surface area (BSA). Logistic regression models were used to assess associations between obese parameters and the rate of lymph node metastasis (LNM), number of LNM, pattern of LNM, and lymph node ratio (LNR).

RESULTS

Higher BMI was not associated with different regional patterns of LNM in PTC. In men with PTC, high BFP was an independent predictor of total LNM, central lymph node metastasis (CLNM), total lateral lymph node metastasis (LLNM), multiple lateral lymph node metastasis, and simultaneous metastasis in lateral compartment. In addition, male patients with high BFP had higher central LNR and higher number of CLNM. For women, high BSA was an independent predictor of LLNM and level IV metastasis. Female patients with high BSA had higher number of CLNM.

CONCLUSION

BFP and BSA, possibly influenced by gender, were positively associated with the number and risk of LNM in different regions of PTC patients. However, BMI was not the predictor for aggressiveness of PTC in terms of LNM. Clinical decision-making for regional LNM in PTC patients should consider the factor of obesity.

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.

Body mass index and weight gain after middle adulthood are associated with risk of papillary thyroid cancer: A case-control study

BACKGROUND

It is unclear whether weight change after middle adulthood influences the risk of thyroid cancer. The aim of this study was to investigate associations between the risk of papillary thyroid cancer (PTC) and body mass index (BMI) and weight change after middle adulthood (age 35).

METHODS

A matched case-control study based on three hospitals included 516 pairs of cases newly diagnosed with PTC and controls. Current height and weight after defecation in the morning were measured by trained nurses. During measurement, all subjects were requested to wear lightweight clothing and no shoes. Weight at age 35 was self-reported. BMI and weight change were modeled as continuous and categorical variables. Conditional and unconditional logistic regression models were used to estimate the odds ratio (OR) and 95% confidence interval (95%CI) for the association between BMI and weight change after middle adulthood and PTC.

RESULTS

After adjustment for covariates, measured BMI at the time of current diagnosis was positively associated with PTC (OR 1.16, 95%CI 1.10-1.21). According to WHO BMI guidelines for Asia-Pacific populations, the OR (95%CI) for PTC risk in obesity was 2.99 (1.92-4.67) compared to normal weight (p-trend <0.001). Moreover, PTC was positively associated with BMI at age 35; the OR (95%CI) for PTC risk per unit increase in BMI was 1.06 (1.02-1.11). Compared to stable weight (changed <0.5 kg/year), weight gain ≥1.0 kg/year after middle adulthood was positively associated with PTC (OR 2.57, 95%CI 1.39-4.76, p-trend <0.001). Compared to maintaining non-overweight status, the PTC risk was significantly increased in those individuals who gained weight and became overweight after middle adulthood (OR 3.82, 95%CI 2.50-5.85).

CONCLUSION

This study showed that high BMI and obesity were positively associated with increased risk of PTC, and weight gain after middle adulthood also could elevate the PTC risk.

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.

Transcriptome analysis discloses dysregulated genes in normal appearing tumor-adjacent thyroid tissues from patients with papillary thyroid carcinoma

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. The molecular characteristics of histologically normal appearing tissue adjacent to the tumor (NAT) from PTC patients are not well characterized. The aim of this study was to characterize the global gene expression profile of NAT and compare it with those of normal and tumor thyroid tissues. We performed total RNA sequencing with fresh frozen thyroid tissues from a cohort of three categories of samples including NAT, normal thyroid (N), and PTC tumor (T). Transcriptome analysis shows that NAT presents a unique gene expression profile, which was not associated with sex or the presence of lymphocytic thyroiditis. Among the differentially expressed genes (DEGs) of NAT vs N, 256 coding genes and 5 noncoding genes have been reported as cancer genes involved in cell proliferation, apoptosis, and/or tumorigenesis. Bioinformatics analysis with Ingenuity Pathway Analysis software revealed that “Cancer, Organismal Injury and Abnormalities, Cellular Response to Therapeutics, and Cellular Movement” were major dysregulated pathways in the NAT tissues. This study provides improved insight into the complexity of gene expression changes in the thyroid glands of patients with PTC.

Oestrogen receptor alpha in papillary thyroid carcinoma: association with clinical features and BRAFV600E mutation

BACKGROUND

Papillary thyroid cancer cells can express oestrogen receptor alpha, which is encoded by the ESR1 gene and may bind to oestrogen to induce the occurrence and development of papillary thyroid cancer. The BRAFV600E mutation is also an important biomarker for the occurrence and progression of papillary thyroid cancer. However, the association between the BRAFV600E mutation and oestrogen receptor alpha expression has not been identified. This study aims to investigate the association between ESR1 expression and the BRAFV600E mutation and its clinical significance.

METHODS

Oestrogen receptor alpha and BRAFV600E proteins were detected by immunohistochemical staining of formalin-fixed paraffin-embedded thyroid tissues from 1105 patients with papillary thyroid cancer at our institution. Messenger RNA expression counts of ESR1 and clinicopathologic information were obtained from The Cancer Genome Atlas database.

RESULTS

Oestrogen receptor alpha protein expression was significantly associated with BRAFV600E protein. The positive rate of oestrogen receptor alpha protein in papillary thyroid cancer patients was significantly higher in males, younger patients and patients with the multifocal type. In papillary thyroid cancer patients with positive BRAFV600E protein, oestrogen receptor alpha expression was significantly correlated with central lymph node metastasis. Data from the The Cancer Genome Atlas database also suggested that the ESR1 messenger RNA level was associated with the BRAFV600E mutation. Furthermore, classification analysis performed according to a tree-based classification method demonstrated that higher ESR1 messenger RNA expression indicated poorer overall survival in papillary thyroid cancer patients with the BRAFV600E mutation.

CONCLUSIONS

The percentage of BRAFV600E mutations is increased in patients with higher ESR1 messenger RNA levels, and the BRAFV600E protein might be co-expressed with oestrogen receptor alpha, which could be an indicator of cervical lymph node metastasis and poor overall survival in patients with papillary thyroid cancer.

Association of BMI with Clinicopathological Features of Papillary Thyroid Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Papillary thyroid cancer (PTC) is the most common subtype of thyroid cancer. The incidence of PTC is rising in tandem with an obesity epidemic. Associations have been demonstrated between increased body mass index (BMI) and worse oncological outcomes in a number of malignancies. However, research on this topic in PTC to date has been inconsistent, often due to limited data. This study aimed to measure the association between BMI and potentially adverse clinicopathological features of PTC.

METHODS

A meta-analysis of studies reporting outcomes after surgical treatment of PTC was performed. PubMed, Embase and the Cochrane Library were searched systematically to identify studies which provided data on BMI and clinicopathologic features of PTC. Relevant data were extracted and synthesis performed using adjusted odds ratios where available and crude values when not. Data were analysed by inverse variance using random and fixed effects models.

RESULTS

Data on 35,237 patients from 15 studies met the criteria for inclusion. Obesity was associated with larger tumour size (MD = 0.17 cm [0.05, 0.29]), increased rates of multifocality (OR = 1.41 [1.16, 1.70]), extrathyroidal extension (OR = 1.70 [1.39, 2.07]) and nodal spread (OR = 1.18 [1.07, 1.30]). Associations were more pronounced as BMI increased. There was no association between BMI and bilaterality, vascular invasion or metastatic spread.

CONCLUSION

Increased BMI is significantly associated with multiple potentially adverse features of PTC. The effect on long-term oncological outcomes requires further evaluation.

Apolipoprotein A1 is negatively associated with male papillary thyroid cancer patients: a cross-sectional study of single academic center in China

BACKGROUND

Papillary thyroid cancer (PTC) is the most common type of thyroid cancer and the incidence of PTC has continued to increase over the past decades. Many studies have shown that obesity is an independent risk factor for PTC and obese PTC patients tend to have a relative larger tumor size and higher grade of tumor stage. Obesity is associated with disordered lipid metabolism and the relationship between serum lipids and PTC remains unclear. Therefore, this study aimed to investigate the association between serum lipid level and PTC.

METHODS

We retrospectively analyzed 1018 PTC patients diagnosed and treated in our hospital, all these cases were first diagnosed with PTC and had complete clinical information including ultrasound reports before surgery, serum lipid (CHOL, TG, HDL-c, LDL-c, Apo-A1, Apo-B, Apo-E) results, surgical records and pathological reports.

RESULTS

None of these lipid markers were associated with tumor size in the whole cohort and in the female group. In the male group, on crude analysis, Apo-A1 showed a marginally association with tumor size, [OR = 0.158 (0.021-1.777)], p = 0.072. After adjusting for age and multifocality, Apo-A1 showed a significant association with tumor size [OR = 0.126 (0.016-0.974)], p = 0.047. This association become more apparent in a young male subgroup, [OR = 0.051 (0.005-0.497)], p = 0.009. CHOL, TG, HDL-c, LDL-c, Apo-B, Apo-E did not show significant association with tumor size. As for LNM, neither in the male group nor in the female group were found to be associated with any serum lipid biomarkers.

CONCLUSION

As PTC incidences continues to increase, our findings demonstrated a negatively association between PTC and apoA-1 in male PTC patients, which may contribute to further investigation concerning diagnosing and preventing this most common type of thyroid cancer.

Obesity and Overweight Are Associated with Minimal Extrathyroidal Extension, Multifocality and Bilaterality of Papillary Thyroid Cancer

Epidemiological studies have shown a strong association between high body mass index (BMI) and papillary thyroid cancer (PTC). We assessed the clinical and histopathological features of PTC in patients with a higher BMI and compared them to analogous parameters in PTC patients with a normal BMI. We retrospectively analyzed 5021 medical records of patients admitted and surgically treated for thyroid tumors in one center between 2008 and 2018. Finally, we extracted data from 523 adult patients with PTC and stratified patients into two groups according to BMI: Group 1 with BMI < 25 kg/m² and Group 2 with BMI ≥ 25 kg/m². Data stratification was performed to estimate the association of overweight and obesity with clinical and histopathological features of PTC in both univariable and multivariable binary logistic regression analyses. Overall, compared to patients with a normal BMI, overweight and obese patients had a greater risk of minimal extrathyroidal extension (minimal ETE), multifocality and bilaterality of PTC (p < 0.001 for all). Analysis did not show that BMI was significantly associated with the more advanced tumor-node-metastasis (TNM) stage (p = 0.894). Obesity and overweight were significantly associated with higher aggressiveness of PTC. When considering various management options for PTC patients, these findings regarding overweight and obesity should be taken into consideration during the decision-making process.

Genetic variants and risk of thyroid cancer among Iranian patients

The definition of an exclusive panel of genetic markers is of high importance to initially detect among this review population. Therefore, we gave a summary of each main genetic marker among Iranian patients with thyroid cancer for the first time which were classified based on their cellular function. Due to the results, a significant relationship was found between SNP in codons 194, 280, and 399 (XRCC1), Allele 3434Thr (XRCC7), GC or CC genotype 31, G/C (Survivin), 399G>A (XRCC1), Tru9I (vitamin D receptor), G-D haplotype (MDM2), TT genotype, -656 G/T (IL-18), TAGTT haplotype (IL-18), G allele in +49 A>G (CTLA-4), +7146 G/A (PD-1.3), +7785 C/T (PD-1.5), rs1143770 (let7a-2), rs4938723 (pri-mir-34b/c) genes, and thyroid cancers. Moreover, SNP in 677C-->T (MTHFR), GG genotype Asp1312Gly (thyroglobulin), 2259C>T (Rad52), R188H, (XRCC2), T241M (XRCC3) had higher risks of thyroid cancer and lower risks were observed in -16 Ins-Pro (p53), rs3742330 (DICER1). At last, the protective effects were explored in 127 CC genotype (IL-18), rs6877842 (DROSHA). Conduct further studies on the types of DNA repair gene polymorphisms with a larger number in the thyroid cancer using modern methods such as SNP array so that these genes could be used as a biomarker in prediction, diagnosis, and treatment of thyroid cancer. This review presents for the first time a summary of important genetic markers in Iranian patients with thyroid cancer.

Trends in Childhood Thyroid Cancer incidence in Korea and Its Potential Risk Factors

BACKGROUND

Although the incidence of thyroid cancer had been increasing until a few years ago, a decrease has been observed in the last years, probably due to the reduction of the screening tests in Korea. Childhood thyroid cancer has been increasing in the past with the same trend as in adults, but there have been few reports on recent trends. We analyzed the trends of thyroid cancer in Korean children and related factors.

METHODS

From national statistics and cancer register database, the data of age-specific incidence rate in Korean childhood thyroid cancer from 1999 to 2017 was obtained, and levels of seaweed intake, the number of computed tomography (CT) and neck ultrasonography (US), obesity prevalence rate, and smoking and alcohol consumption rates in children were analyzed.

RESULTS

The age-specific incidence of thyroid cancer in Korean children has increased in both genders between 1999 and 2017 (2.0 in 1999 vs. 7.2 in 2017, per population of 100,000), especially in the age group of 14-18 years (1.5 in 1999 vs. 5.5 in 2017, per population of 100,000). During the same period, levels of seaweed intake, number of CT scans and neck US, and prevalence of obesity in children increased significantly, while childhood smoking and alcohol consumption rates decreased.

CONCLUSION

Unlike the adult thyroid cancer in Korea, childhood thyroid cancer continues to increase, and the cause might be accompanied by actual increases due to the environmental factors such as excessive iodine intake, exposure to medical radiation, and increased obesity prevalence as well as the screening effect.

Thyroid Receptor Antagonism of Chemicals Extracted from Personal Silicone Wristbands within a Papillary Thyroid Cancer Pilot Study

Research suggests that thyroid cancer incidence rates are increasing, and environmental exposures have been postulated to be playing a role. To explore this possibility, we conducted a pilot study to investigate the thyroid disrupting bioactivity of chemical mixtures isolated from personal silicone wristband samplers within a thyroid cancer cohort. Specifically, we evaluated TRβ antagonism of chemical mixtures extracted from wristbands (n = 72) worn by adults in central North Carolina participating in a case-control study on papillary thyroid cancer. Sections of wristbands were solvent-extracted and analyzed via mass spectrometry to quantify a suite of semivolatile chemicals. A second extract from each wristband was used in a bioassay to quantify TRβ antagonism in human embryonic kidney cells (HEK293/17) at concentrations ranging from 0.1 to 10% of the original extract (by volume). Approximately 70% of the sample extracts tested at a 1% extract concentration exhibited significant TRβ antagonism, with a mean of 30% and a range of 0-100%. Inhibited cell viability was noted in >20% of samples that were tested at 5 and 10% concentrations. Antagonism was positively associated with wristband concentrations of several phthalates, organophosphate esters, and brominated flame retardants. These results suggest that personal passive samplers may be useful in evaluating the bioactivities of mixtures that people contact on a daily basis. We also report tentative associations between thyroid receptor antagonism, chemical concentrations, and papillary thyroid cancer case status. Future research utilizing larger sample sizes, prospective data collection, and measurement of serum thyroid hormone levels (which were not possible in this study) should be utilized to more comprehensively evaluate these associations.

Obesity and the prevention of thyroid cancer: Impact of body mass index and weight change on developing thyroid cancer - Pooled results of 24 million cohorts

BACKGROUND

Body weight may be a modifiable risk factor predisposing to different cancers. To establish a potential impact of weight change on thyroid cancer risk, we conducted a meta-analysis to evaluate the effect of body mass index (BMI) and weight change over time as a risk of developing thyroid cancer (TC).

METHODS

A systematic search was performed up to February 25, 2020. Pooled relative risk (RR) were estimated using fixed and random models. Heterogeneity between articles was examined using Q-test and I² index. Evaluation of publication bias was conducted with Egger's regression test.

RESULTS

A total of 31 studies including 24,489,477 cohorts were eligible. Pooled analysis revealed that normal and underweight cohorts were associated with a decreased risk of TC (RR = 0.68, 95%CI = 0.65-0.71, p < 0.001) and (RR = 0.92, 95%CI = 0.91-0.93, p < 0.001), respectively. In contrast, overweight and obese cohorts were more likely to develop TC (RR = 1.26, 95%CI = 1.24-1.28, p < 0.001 and RR = 1.50, 95%CI = 1.45-1.55, p < 0.001, respectively). Obesity was associated with higher risk of developing TC among women (RR = 1.29, 95%CI = 1.14-1.46, p < 0.001), but not men (RR = 1.25, 95%CI = 0.97-1.62, p = 0.08). Furthermore, weight gain increased the risk of developing TC (RR = 1.18, 95%CI = 1.14-1.22, p < 0.001), while weight loss decreased the risk (RR = 0.89, 95%CI = 0.85-0.93, p < 0.001). Results showed similar trends of weight change effect in both males and females.

CONCLUSIONS

Obesity is associated with higher risk of developing TC in women. However, maintaining a healthy weight is associated with reduced risk of TC in both women and men. Shifting our practice to include weight control strategies will help lead to cancer prevention.

Obesity Is Associated with BRAFV600E-Mutated Thyroid Cancer

Background: Thyroid cancer incidence has increased in many parts of the world since the 1980s, as has the prevalence of obesity. Evidence suggests that people with greater body size have higher thyroid cancer risk. However, it is unclear whether this association is causal or is driven by over-diagnosis of indolent cancers, because overweight/obese people use health services more frequently than those of normal weight, thus conferring greater opportunity for incidental diagnosis. Assessing whether obesity is associated with higher-risk thyroid cancers might help clarify this issue. Methods: We recruited 1013 people diagnosed with thyroid cancer between 2013 and 2016 and 1057 population controls, frequency matched by sex and age group. We used logistic regression to assess the association between body mass index (BMI) and overall thyroid cancer risk as well as by tumor BRAF mutational status as a marker of potentially higher-risk cancer. Results: Overall, obesity was associated with greater risk of thyroid cancer (odds ratio [OR] = 1.72; 95% confidence interval [CI 1.37-2.16] for obese vs. normal BMI). The association with obesity was significantly stronger for BRAF-mutation positive than BRAF-negative papillary thyroid cancers (PTCs; OR = 1.71 [CI 1.17-2.50] for BRAF-positive vs. BRAF-negative cancers). The increased risks associated with overweight/obesity did not vary by histological subtypes or presence/absence of adverse tumor histologic features. Conclusions: Greater risk of BRAF-mutated PTCs among those with high BMI suggests that the association may not merely reflect greater health care service use and indicates an independent relationship between obesity and clinically important thyroid cancer.

Metabolic Syndrome and the Risk of Thyroid Cancer: A Nationwide Population-Based Cohort Study

Background: The association of metabolic syndrome and its components with the risk of thyroid cancer is unclear. Thus, we conducted a large-scale, nationwide, population-based, cohort study to investigate this relationship. Methods: We studied 9,890,917 adults without thyroid cancer from the Korean National Health Insurance health checkup database from January 1 to December 31, 2009. Individuals with at least three of the following five components were diagnosed with metabolic syndrome: abdominal obesity, hypertriglyceridemia, low high-density lipoprotein-cholesterol levels, elevated blood pressure, and hyperglycemia. Multivariate Cox proportional hazards models were used to estimate thyroid cancer risk. Results: During the average 7.2 years of follow-up, 77,133 thyroid cancer cases were newly identified. The thyroid cancer risk was higher in the metabolic syndrome group than in the nonmetabolic syndrome group (hazard ratio [HR] 1.15 [95% confidence interval, CI 1.13-1.17]). The association between metabolic syndrome and thyroid cancer risk was significant in the obese group (HR 1.10 [CI 1.07-1.13]) and not in the nonobese group (HR 1.002 [CI 0.98-1.03]). The effect of metabolic syndrome on the risk of thyroid cancer differs according to obesity (p for interaction = 0.017). People with all five components of metabolic syndrome had a 39% higher risk than those without any components (HR 1.39 [CI 1.33-1.44]). The higher risk of thyroid cancer in people with all five components was significant in the obese group (HR 1.29 [CI 1.21-1.38]), but not in the nonobese group (HR 1.06 [CI 0.98-1.14]). There was a significant interaction between the number of metabolic syndrome components and obesity (p for interaction <0.0001). For the combined effect of obesity and metabolic syndrome on the risk of thyroid cancer, obese men with metabolic syndrome had the highest risk of thyroid cancer compared with those without (HR 1.58 [CI 1.52-1.64]), but obese women with metabolic syndrome did not. Conclusions: Metabolic syndrome was associated with an increased risk of thyroid cancer in the Korean general population. Metabolic syndrome had a more significant risk of thyroid cancer in the obese group. Metabolic syndrome and obesity were associated with a higher risk of thyroid cancer in men but not in women.

Association between adipokines and thyroid carcinoma: a meta-analysis of case-control studies

Background

The incidence of thyroid carcinoma is increasing all over the world. Some studies have suggested that the change of adipokines expression can induce thyroid carcinoma. However, other studies have come to the opposite conclusion. Therefore, we studied the relationship between adipokines and thyroid carcinoma.

Methods

Databases—PubMed, Cochrane Library, SinoMed, CNKI, Wanfang, and clinical trial registries were searched. A meta-analysis was then performed through a fixed or random-effects model to calculate I values for heterogeneity analysis.

Results

Twenty-nine articles were finally included for analysis. The level of serum tumor necrosis factor-alpha (TNF-α) [standardized mean difference (SMD) =1.31, 95% confidence interval (95% CI): 0.35 to 2.28, I² = 98%, P = 0.008] and the ratio of TNF-α immunoreactivity in tissues [odds ratios (OR) =6.36, 95% CI: 1.92 to 21.05, I² = 66%, P = 0.002] in thyroid carcinoma are significantly higher than those in control. The serum interleukin-6 (IL-6) in patients with thyroid carcinoma is higher than that in control (SMD = 1.04, 95% CI: 0.40 to 1.67, I² = 96%, P = 0.001). There is no significant difference of the ratio of IL-6 immunoreactivity in tissues between carcinoma and control (OR = 1.23, 95% CI: 0.62 to 2.43, I² = 86%, P = 0.55). The ratio of leptin immunoreactivity in tissues is significantly associated with the risk of thyroid carcinoma (OR = 12.21, 95% CI: 3.36 to 44.40, I² = 85%, P < 0.00001). However, after analyzing the expression level of serum adiponectin in three studies, no significant difference is found between thyroid carcinoma and the control (P = 0.81).

Conclusions

Adipokines (TNF-α, IL-6 and leptin) show a strong relationship between elevated concentrations (in serum and/or tissue) and thyroid carcinoma. However, the association between adiponectin and thyroid carcinoma needs further research.

Serum Adiponectin and Progranulin Level in Patients with Benign Thyroid Nodule or Papillary Thyroid Cancer

BACKGROUND

Obesity is associated with thyroid cancer risk. Adiponectin has insulin-sensitizing and anti-inflammatory effects, while progranulin is associated with inflammation and tumorigenesis. We investigated serum adiponectin and progranulin levels in patients with benign thyroid nodule (benign group) and papillary thyroid cancer (PTC; PTC group). The associations between these levels and the clinicopathological features of PTC were evaluated.

METHODS

We included 157 patients who underwent thyroid surgery (17% of benign and 83% of PTC group). Clinicopathological features including size, lymph node metastasis, extrathyroidal extension (ETE), multifocality, American Thyroid Association risk stratification were evaluated.

RESULTS

The age was 42.0 years, and 69% were female. Serum adiponectin and progranulin levels were 6.3 μg/mL and 101.5 ng/mL in the benign group and 5.4 μg/mL and 106.1 ng/mL in the PTC group, respectively (P=0.6 and P=0.4, respectively). Serum adiponectin levels showed no significant differences according to clinicopathological features of PTC. The proportions of patients with primary tumor size &gt;1 cm were 3%, 5%, 8%, and 8% according to serum progranulin level quartiles, respectively (P=0.03). The proportions of patients with microscopic/gross ETE were 8%/0%, 9%/1%, 11%/1%, and 11%/2% according to serum progranulin level quartiles, respectively. Median serum progranulin level was significantly higher in patients with PTC &gt;1 cm than in patients with papillary thyroid microcarcinoma (P=0.04, 115.3 ng/mL and 104.7 ng/mL, respectively).

CONCLUSION

Serum adiponectin and progranulin levels showed no significant difference between benign and PTC groups. Increased serum progranulin levels were significantly associated with PTC &gt;1 cm and microscopic and gross ETE.

Potential Impact of BMI on the Aggressiveness of Presentation and Clinical Outcome of Differentiated Thyroid Cancer

BACKGROUND

Obesity is a risk factor for several cancers, including differentiated thyroid cancer (DTC). Moreover, it has also been investigated as a potential risk factor for aggressiveness of DTC, but the data gathered so far are conflicting. The aim of our study was to evaluate the relationship between body mass index (BMI), aggressiveness of DTC at diagnosis, and clinical outcome.

METHODS

We evaluated 1058 consecutive DTC patients treated with total thyroidectomy and enrolled at the time of first radioactive iodine (131I) treatment. Patients were divided into 4 groups based on their BMI: underweight (< 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2), and obese (≥ 30 kg/m2). Histological aggressiveness of DTC at the time of diagnosis and clinical outcome according to 2015 American Thyroid Association (ATA) guidelines were evaluated.

RESULTS

No differences in histological features, ATA risk of recurrence, activity of 131I administered and prevalence of 131I avid metastatic disease after first131I treatment, have been demonstrated among the groups. Furthermore, at the end of follow up (median = 5.7 years), no differences were evident in the number of further treatments performed as well as in the clinical response.

CONCLUSIONS

In our study group of Caucasian subjects, we could not demonstrate any association between BMI and aggressiveness of DTC, neither at the time of diagnosis nor during follow-up. These data indicate that postsurgical assessment and therapeutic attitude for treatment and follow-up of DTC should be based on the class of risk applied to the general population, with no concern for BMI.

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 BRAF^V600E 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.

Adiposity and the risk of thyroid nodules with a high-suspicion sonographic pattern: a large cross-sectional epidemiological study

Background

To our knowledge, no previous studies have evaluated the association between obesity and the risk of thyroid nodules with a high-suspicion sonographic pattern defined by the 2015 American Thyroid Association management guidelines for adult patients with thyroid nodules and differentiated thyroid cancers. In this large cross-sectional epidemiological study, we investigated whether a positive association existed between anthropometric measurements and the risk of thyroid nodules.

Methods

In total, 10,504 individuals from two towns in northern China were enrolled between May to September 2016. The height and weight were measured and the body mass index (BMI), body fat percentage (BFP), and body surface area (BSA) were calculated. A logistic regression model was used to estimate age-, sex-, and study site-adjusted odds ratios (ORs) and confidence intervals (CIs) for each of the anthropometric measurements with respect to the risk of thyroid nodules.

Results

The final analyses included 9,096 participants, among whom 3,614 (39.7%) had thyroid nodules and 365 (4.0%) had thyroid nodules with a high-suspicion sonographic pattern. An increased risk of any thyroid nodules was associated with greater height, weight, BFP, and BSA in both men and women. Compared with the lowest quartile of BFP, the ORs for the highest quartile were 1.33 (95% CI: 1.09-1.62) in women and 1.89 (95% CI: 1.35-2.65) in men. An increased risk of thyroid nodules with a high-suspicion sonographic pattern was associated with greater weight, BMI, BFP, and BSA in both men and women. Compared with the lowest quartile of BFP, the ORs for the highest quartile were 2.19 (95% CI: 1.32-3.64) in women and 3.10 (95% CI: 1.31-7.36) in men.

Conclusions

Our results demonstrated that BFP was the most pronounced anthropometric factor associated with an increased risk of any thyroid nodules and thyroid nodules with a high-suspicion sonographic pattern.

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.

Breast Cancer After Treatment of Differentiated Thyroid Cancer With Radioiodine in Young Females: What We Know and How to Investigate Open Questions. Review of the Literature and Results of a Multi-Registry Survey

Published studies on the risk of radiation-induced second primary malignancy (SPM) after radioiodine treatment (RAI) of differentiated thyroid cancer (DTC) refer mainly to patients treated as middle-aged or older adults and are not easily generalizable to those treated at a younger age. Here we review available literature on the risk of breast cancer as an SPM after RAI of DTC with a focus on females undergoing such treatment in childhood, adolescence, or young adulthood. Additionally, we report the results of a preliminary international survey of patient registries from academic tertiary referral centers specializing in pediatric DTC. The survey sought to evaluate the availability of sufficient patient data for a potential international multicenter observational case-control study of females with DTC given RAI at an early age. Our literature review identified a bi-directional association of DTC and breast cancer. The general breast cancer risk in adult DTC survivors is low, ~2%, slightly higher in females than in males, but presumably lower, not higher, in those diagnosed as children or adolescents than in those diagnosed at older ages. RAI presumably does not substantially influence breast cancer risk after DTC. However, data from patients given RAI at young ages are sparse and insufficient to make definitive conclusions regarding age dependence of the risk of breast cancer as a SPM after RAI of DTC. The preliminary analysis of data from 10 thyroid cancer registries worldwide, including altogether 6,449 patients given RAI for DTC and 1,116 controls, i.e., patients not given RAI, did not show a significant increase of breast cancer incidence after RAI. However, the numbers of cases and controls were insufficient to draw statistically reliable conclusions, and the proportion of those receiving RAI at the earliest ages was too low.In conclusion, a potential international multicenter study of female patients undergoing RAI of DTC as children, adolescents, or young adults, with a sufficient sample size, is feasible. However, breast cancer screening of a larger cohort of DTC patients is not unproblematic for ethical reasons, due to the likely, at most slightly, increased risk of breast cancer post-RAI and the expected ~10% false-positivity rate which potentially produced substantial "misdiagnosis."

Obesity and risk of differentiated thyroid cancer: A large-scale case-control study

OBJECTIVE

Recently, the incidence of thyroid cancer as well as obesity has dramatically increased worldwide. Whether obesity contributes to the development of differentiated thyroid cancer (DTC) remains controversial. We evaluated the relationship between anthropometric measurements and DTC risk.

DESIGN/PATIENTS/MEASUREMENTS

A large frequency-matched case-control study based on hospital data was performed. A total of 10 668 DTC patients and 11 858 controls were enrolled. Body mass index (BMI), body surface area (BSA) and body fat percentage (BF%) were calculated. An unconditional logistic regression model was applied.

RESULTS

The univariate analysis showed a significant increase in DTC risk with increased height, weight, BMI, BSA and BF%. The multivariate analysis also showed a positive relationship. Based on the Chinese BMI (CN-BMI) classification, for women of all ages, the ORs for DTC risk in overweight and obesity were 1.151 (1.037-1277) and 1.292 (1.092-1.528), respectively. For men under 50, the ORs were 1.221 (1.014-1.469) and 1.520 (1.202-1.923), respectively, but the ORs for men over 50 were not significant. Additionally, BSA showed a significant association with DTC risk for both sexes under 50 (P = .02 and P < .001). BF% remained significant only for women under 50 (P = .003). However, for both sexes over 50, neither BSA nor BF% was significantly associated with DTC risk. Based on The World Health Organization BMI (WHO-BMI) classification, for all women and men over 50, the results were consistent with CN-BMI. For men under 50, BF%, but not BMI, showed a significant association with DTC risk.

CONCLUSION

BMI, BSA and BF% were positively correlated with the risk of DTC, which was potentially affected by age and sex.

Association of obesity with the clinicopathological features of thyroid cancer in a large, operative population: A retrospective case-control study

We aimed to investigate the association between excess body mass index (BMI) and papillary thyroid cancer (PTC) in an operative population, and the impact of higher BMI on clinicopathological aggressiveness of PTC.Charts of 10,844 consecutive patients with thyroid nodules undergoing partial or total thyroidectomy between 1993 and 2015 were reviewed. Patients diagnosed with PTC were stratified in 4 groups: BMI < 18.5 (underweight), 18.5 ≤ BMI < 24 (normal-weight), 24 ≤ BMI < 28 (overweight) and BMI ≥ 28(obese). The impacts of high BMI on prevalence and clinicopathological parameters of PTC were retrospectively analyzed in both univariate and multivariate binary logistic regression analysis.For every 5-unit increase in body mass, the odds of risk-adjusted malignance increased by 36.6%. The individuals who were obese and overweight were associated with high risk of thyroid cancer [odds ratio (OR)= 1.982, P < .001; OR= 1.377, P < .001; respectively] compared to normal weight patients, and this positive association was found in both genders. Obesity was independent predictors for tumors larger than 1 cm (OR = 1.562, P < .001) and multifocality (OR = 1.616, P < .001). However, there was no difference in cervical lymph node (LN) metastasis among BMI groups. Crude analysis showed BMI was associated with advanced tumor-node-metastasis (TNM) stage (relative risk, approximately 1.23 per 5 BMI units, P < .001), but this association disappeared after adjusting for confounding factors.Obesity was significantly associated with the risk of PTC in a large, operative population. Higher BMI was significantly associated with larger tumor size and multifocal tumor.

Cholesterol and 27-hydroxycholesterol promote thyroid carcinoma aggressiveness

Cholesterol mediates its proliferative and metastatic effects via the metabolite 27-hydroxycholesterol (27-HC), at least in breast and endometrial cancer. We determined the serum lipoprotein profile, intratumoral cholesterol and 27-HC levels in a cohort of patients with well-differentiated papillary thyroid carcinoma (PTC; low/intermediate and high risk), advanced thyroid cancers (poorly differentiated, PDTC and anaplastic thyroid carcinoma, ATC) and benign thyroid tumors, as well as the expression of genes involved in cholesterol metabolism. We investigated the gene expression profile, cellular proliferation, and migration in Nthy-ori 3.1 and CAL-62 cell lines loaded with human low-density lipoprotein (LDL). Patients with more aggressive tumors (high-risk PTC and PDTC/ATC) showed a decrease in blood LDL cholesterol and apolipoprotein B. These changes were associated with an increase in the expression of the thyroid’s LDL receptor, whereas 3-hydroxy-3-methylglutaryl-CoA reductase and 25-hydroxycholesterol 7-alpha-hydroxylase were downregulated, with an intratumoral increase of the 27-HC metabolite. Furthermore, LDL promoted proliferation in both the Nthy-ori 3.1 and CAL-62 thyroid cellular models, but only in ATC cells was its cellular migration increased significantly. We conclude that cholesterol and intratumoral accumulation of 27-HC promote the aggressive behavior process of PTC. Targeting cholesterol metabolism could be a new therapeutic strategy in thyroid tumors with poor prognosis.

Physical Activity and Thyroid Cancer Risk: A Case-Control Study in Catania (South Italy)

Background: The health benefits of physical activity are well established, but the association between physical activity and thyroid cancer remains poorly understood. The aim of the study was to investigate the relationship between physical activity and thyroid cancer in order to determine type, frequency, and duration of exercise needed to maximize prevention. Method: Cases, diagnosed from January 2009 to July 2018, and controls were enrolled at the University Hospital “Policlinico-Vittorio Emanuele” of Catania (South Italy). Logistic regression models were used to estimate the crude and adjusted odds ratios (ORs) and their 95% confidence intervals. Results: A total of 106 cases (91.2% papillary type) and 217 controls were enrolled. Physical activity was rare in Catania (32.8%) and was not correlated to risk of total thyroid cancer (OR: 0.997; 95% CI: 0.515–1.929). Conversely, walking every day for at least 60 minutes reduced the risk of thyroid cancer (OR: 0.357; 95% CI: 0.157–0.673). Conclusions: Our study showed that daily walking duration was associated with lower risk of thyroid cancer using a case-control study. Unfortunately, the frequency of physical activity often declines with age, particularly among the elderly, thus more research on physical activity adherence is needed to determine which approaches are most effective in promoting sustained physical activity participation.

Metabolic Obesity Phenotypes and Thyroid Cancer Risk: A Cohort Study

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Weight change is significantly associated with risk of thyroid cancer: A nationwide population-based cohort study

Obesity is a risk factor for many cancers including breast, esophageal, colon, and thyroid cancer. We aimed to evaluate the association of thyroid cancer with body mass index (BMI), waist circumference (WC), and weight change. This nationwide population-based cohort study included 11,323,006 adults who joined the national health screening program. Weight change was defined as the difference between the weight of the subjects measured during the study period and the weight at the time of four years ago. For evaluating the association between the weight change and the risk of thyroid cancer, subjects without weight change for four years were defined as the reference group. Mean age was 50.1 ± 13.7 years and 44% were female. In total, 50,464 subjects (0.4%) had newly-diagnosed thyroid cancer. After multivariable analyses, the incidence of thyroid cancer increased significantly in subjects with larger WC as well as higher BMI (P < 0.001 and P < 0.001, respectively). In subjects who were lean and became obese, the incidence of thyroid cancers increased significantly (hazard ratio [HR] 1.15 [1.11-1.19]). In subjects who were obese and became lean, the incidence of thyroid cancers decreased significantly (HR 0.89 [0.86-0.93]). These results demonstrated that higher BMI and larger WC were significantly associated with an increased risk of thyroid cancer. Weight gain in lean subjects was associated with an increased risk of thyroid cancer, and weight reduction in subjects with obesity was associated with a decreased risk of thyroid cancer.

Linking obesity-induced leptin-signaling pathways to common endocrine-related cancers in women

Obesity is related to many major diseases and cancers. Women have higher rates of obesity and obesity is linked to commonly occurring cancers in women. However, there is a lack of knowledge of the unique mechanism(s) involved in each type of cancer. The objective of this review is to highlight the need for novel experimental approaches and a better understanding of the common and unique pathways to resolve controversies regarding the role of obesity in cancer. In women, there is a link between hormones and obesity-associated genes in cancer development. Leptin is an obesity-associated gene that has been studied extensively in cancers; however, whether the defect is in the leptin gene or in its signaling pathways remains unclear. Both leptin and its receptor have been positively correlated with cancer progression in some endocrine-related cancers in women. This review offers an up-to-date and cohesive review of both upstream and downstream pathways of leptin signaling in cancer and a comprehensive picture of cancer pathogenesis in light of current evidence of leptin effects in several major types of cancer. This work is intended to aid in the design of better therapeutic strategies for obese/overweight women with cancer.

A case-control study of urinary levels of iodine, perchlorate and thiocyanate and risk of papillary thyroid cancer

BACKGROUND

The incidence of thyroid cancer has recently increased worldwide. With the exception of radiation exposure, the effects of potential risk factors on thyroid cancer incidence remain controversial.

OBJECTIVES

The association between exposure to iodine, perchlorate, and thiocyanate and papillary thyroid cancer (PTC) incidence was evaluated and risk factors were predicted.

METHODS

A pair-matching case-control study was performed including 116 age- and sex-matched PTC cases and 116 non-PTC controls. Iodine, perchlorate, and thiocyanate concentrations in urine specimens were determined by inductively coupled plasma mass spectrometry and ultra-performance liquid chromatography-tandem mass spectrometry. The association between iodine, perchlorate, and thiocyanate urinary concentrations and PTC was evaluated using univariable conditional regression logistic analysis followed by multivariable conditional logistic regression analyses with backward stepwise selection to predict risk factors for PTC.

RESULTS

After adjusting for confounders and creatinine standardization, urinary concentrations of iodine [odds ratio (OR) = 11.01, 95% confidence interval (CI): 1.97-30.52] and perchlorate (OR = 2.27, 95% CI: 1.03-5.03) were associated with the risk of PTC, whereas urinary thiocyanate concentration showed a negative association (OR = 0.24, 95% CI: 0.09-0.65).

CONCLUSIONS

Increased exposure to iodine and perchlorate may affect PTC development, whereas high thiocyanate exposure may have a beneficial effect.

Sex Differences in the Associations of Obesity With Hypothyroidism and Thyroid Autoimmunity Among Chinese Adults

There is an intensive link between obesity and thyroid dysfunction, but this relationship in Asians is still unclear. This study was conducted to define the impact of obesity on risk of hypothyroidism and thyroid autoimmunity among Chinese adults. A population-based, cross-sectional study was carried out, which enrolled a total of 2,808 Chinese adults. To assess the associations of obesity with hypothyroidism and thyroid autoimmunity, odds ratio (ORs) with 95% confidence intervals (95%CIs) were calculated through logistic regression model, and the correlations of body mass index (BMI) with TPOAb and TGAb were also analyzed. Obese females had higher risk of hypothyroidism (22.7 vs. 15.0%; OR = 1.66, 95%CI 1.10–2.53; P = 0.02) and higher risk of subclinical hypothyroidism (22.1 vs. 13.4%; OR = 1.83, 95%CI 1.20–2.80; P = 0.005) than non-obese females. Multivariate logistic regression analysis found significant associations of obesity with hypothyroidism (Adjusted OR = 1.54, 95%CI 1.00–2.38; P = 0.05) and subclinical hypothyroidism (Adjusted OR = 1.69, 95%CI 1.09–2.63; P = 0.02) in females after adjustment for confounding factors. No association between obesity and hypothyroidism was observed in male participants. Spearman's correlation analysis suggested BMI was significantly and positively correlated with TPOAb (Spearman's r = 0.062, P = 0.022) in men but not in women. Linear regression analysis suggested an obviously positive correlation of BMI with TPOAb in men (β = 0.018, P = 0.015) and an obviously negative correlation of BMI with TGAb in women (β = −0.025, P = 0.012), respectively. The study suggests sex differences in the associations of obesity with hypothyroidism and thyroid autoimmunity among Chinese adults. Further studies are needed to better understand the exact mechanism of sex difference in the obesity-thyroid relationship.

The impact of BMI on clinical progress, response to treatment, and disease course in patients with differentiated thyroid cancer

Introduction

Obesity is a serious health problem worldwide, particularly in developed countries. It is a risk factor for many diseases, including thyroid cancer. The relationship between obesity and prognostic factors of thyroid cancer is unclear.

Aims

We sought to ascertain the relationship between body mass index (BMI) and clinicopathological features increasing the risk of poor clinical course, treatment response, and clinical outcome in patients with differentiated thyroid cancer (DTC).

Subjects & methods

The study included 1181 patients with DTC (88% women and 12% men) treated at a single center from 2000 to 2016. BMI before surgery and aggressive clinicopathological features, according to the American Thyroid Initial Risk stratification system, were analyzed. The relationship between BMI and initial risk, treatment response, and final status of the disease was evaluated, incorporating the revised 2015 American Thyroid Association guidelines and the 8^th edition of the American Joint Committee on Cancer/Tumor-Node-Metastasis (AJCC/TNM) staging system. Patients were stratified according to the World Health Organization classification of BMI. Statistical analysis was performed using univariate and multivariate logistic regression analysis.

Results

Median follow-up was 7.7 years (1–16 years). There were no significant associations between BMI and extrathyroidal extension (microscopic and gross), cervical lymph node metastasis, or distant metastasis in univariate and multivariate analyses. BMI did not affect initial risk, treatment response or disease outcome. Obesity was more prevalent in men (p = 0.035) and in patients ≥55 years old (p = 0.001). There was no statistically significant relationship between BMI and more advanced TNM stage in patients ≤55 years old (stage I vs. stage II) (p = 0.266) or in patients >55 years old (stage I–II vs. III–IV) (p = 0.877).

Conclusions

Obesity is not associated with more aggressive clinicopathological features of thyroid cancer. Obesity is not a risk factor for progression to more advanced stages of disease, nor is it a prognostic factor for poorer treatment response and clinical outcome.