Risk Factors for Thyroid Cancer: A Hospital-Based Case-Control Study in Korean Adults

Thyroid Malignancy in Patients Who Underwent Thyroidectomy for Multinodular Goiter and Solitary Thyroid Nodule

PURPOSE

Worldwide, incidence of thyroid malignancy is increasing. The purpose of this study was to evaluate the pattern and magnitude of nodule types.

METHODS

A cross-sectional retrospective study was performed at Saint Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia, among patients who underwent thyroidectomy from May 2018 to June 2022. Data were extracted using a structured format. Descriptive statistics were performed using SPSS version 26 software. Results were presented in terms of percentages and frequencies.

RESULTS

During a 4-year period, 1,476 patients had thyroidectomies and histopathologic information of 212 malignant cases was studied. Within multinodular goiter (MNG), thyroid cancer accounted for 69.8% (n = 148) of patients, whereas in solitary nodules, it accounted for 30.2%. From the total, 160 participants (75.5%) were female, and the female:male ratio was 3.1 (mean, 41.72; ± standard deviation [SD], 16.44) years, and age range of 12-88 years versus men, who have a mean of 44.71 (±SD, 14.91) years and an age range of 21-78 years. The mean age of male cases with solitary nodule and MNG was 40.6 and 46.5 years, respectively. The most frequent cancer in both types of nodules, accounting for 59% of patients, was papillary carcinoma, which was found in 64% of solitary nodules and 57.4% of multinodular nodules. Overall, 14.1% of tumors had multiple centers (17.4% in multinodular nodules and 6.9% in solitary nodules). In 7.1% of patients, microcarcinoma (<1 cm) was found, with papillary carcinoma accounting for 91.7% of the total.

CONCLUSION

Compared with men, women with cancer typically manifested at a younger age. Males with malignancy in solitary nodules had a lower mean age than those with MNGs. The most frequent and significant cause of multicentric presentation is papillary carcinoma.

Thyroid Cancer Prevalence, Risk Exposure, and Clinical Features Among Transgender Female Veterans

Purpose

Transgender women experience higher-than-average rates of multiple medical conditions. Thyroid cancer occurs more frequently in those assigned female at birth than in those assigned male at birth. We sought to characterize thyroid cancer among transgender female veterans.

Methods

We reviewed charts of veterans who were (1) seen in Veterans Affairs clinics across the United States from July 2017 to December 2022, (2) had an International Classification of Diseases, revision 10, diagnosis code for thyroid cancer, and (3) had an International Classification of Diseases, revision 10, diagnosis code for gender dysphoria or were assigned male at birth and ever had a prescription for estrogens. Charts of cisgender veterans were also reviewed for comparison.

Results

Compared with calculated estimates of 0.641% (95% CI, 0.572-0.724) among cisgender females and 0.187% (95% CI, 0.156-0.219) among cisgender males, the measured prevalence among transgender female veterans was 0.341% (34/9988). Average age at thyroid cancer diagnosis in this population was 53.8 (± SEM 2.61) years. A total of 32.3% (11/34) of these patients had extrathyroidal disease at diagnosis.

Discussion

To our knowledge, this study represents the first report of thyroid cancer prevalence among transgender women in the United States. Risk exposure among all transgender veterans including further assessment of the possible contributions of obesity, smoking, and gender-affirming hormone therapy are important future analyses.

Current and future of immunotherapy for thyroid cancer based on bibliometrics and clinical trials

BACKGROUND

Thyroid cancer is a leading endocrine malignancy, with anaplastic and medullary subtypes posing treatment challenges. Existing therapies have limited efficacy, highlighting a need for innovative approaches.

METHODS

We analyzed 658 articles and 87 eligible clinical trials using bibliometric tools and database searches, including annual publication and citation trends, were executed using Web of Science, CiteSpace, and VOS Viewer.

RESULTS

Post-2018, there is a surge in thyroid cancer immunotherapy research, primarily from China and the University of Pisa. Of the 87 trials, 32 were Phase I and 55 were Phase II, mostly exploring combination therapies involving immune checkpoint inhibitors.

CONCLUSION

The study's dual approach verifies the swift advancement of thyroid cancer immunotherapy from diverse perspectives. Immune checkpoint inhibitors have become the preferred regimen for advanced MTC and ATC in late therapeutic lines. However, since ICB plays a pivotal role in ATC, current clinical trial data show that ATC patients account for more and the curative effect is more accurate. Anticipated future developments are inclined toward combination regimens integrating immunotherapy with chemotherapy or targeted therapies. Emerging approaches, such as bispecific antibodies, cytokine-based therapies, and adoptive cell therapies like CAR-T and TCR-T, are exhibiting considerable potential. Upcoming research is expected to concentrate on refining the tumor immune milieu and discovering novel biomarkers germane to immunotherapeutic interventions.

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.

The two-year prognosis of multinodular goiter following radiofrequency ablation: based on all nodule burdens

OBJECTIVE

Few studies used all nodule burdens to specify the prognosis of multinodular goiter (MNG) following radiofrequency ablation (RFA), so this study addresses this question for MNG after completely ablating dominant nodules.

METHODS

The RFA indications for MNG included a total of 2-5 benign nodules with over 50% normal tissue on ultrasound, 1-3 well-defined benign dominant nodules on cytology, largest diameter ≥20 mm and/or with clinical complaints, and patient refusal or unable of surgery. A retrospective study of 185 MNG patients with completely ablated dominant nodules in a single-session RFA was conducted. The efficacy and complications were evaluated at 1, 6, 12 months and yearly thereafter. Based on retreatment risks, progressive disease (PD), stable disease (SD) and complete relief (CR) were introduced to assess all nodule load changes. PD was clarified as having new/non-target nodules newly appeared to ACR TI-RADS≥4, or new/enlarged non-target nodules ≥1 cm.

RESULTS

The initial ablation ratios of target nodules were 100% at one month. During a mean 22.38±13.75 months (range, 12-60 months), the VRR of ablated nodules was 98.25% at 24 months without regrowth. Cosmetic and symptomatic scores decreased to 1 and 0, respectively, after 48 months. 9.7% of patients (18/185) had PD and the retreatment rate was 2.2% (4/185). The complication rate was 2.7% (5/185).

CONCLUSIONS

RFA provides cosmetic and symptomatic relief for an average of two years. RFA is an useful minimally invasive treatment modality for selected MNG patients.

Interaction between Genetic Risks and Socioeconomic Factors on Thyroid Cancer: Evidence from 0.5 Million UK Biobank Participants

BACKGROUND

There is a research gap between genetic predisposition, socioeconomic factors, and their interactions on thyroid tumorigenesis.

METHODS

Individual and genetic data were obtained from UK Biobank. Logistic regression models were used to evaluate the association between genetic risk, socioeconomic factors, and thyroid cancer (TCa). A stratified analysis was conducted to estimate their joint effects. A two-sample Mendelian randomization (MR) analysis was further used to examine the potential causality.

RESULTS

A total of 502,394 participants were included in this study. Three index loci (rs4449583, rs7726159, and rs7725218) of telomerase reverse transcriptase (TERT) were found to be significantly related to incident TCa. Association analyses showed that high genetic risk, low household income, and high education level were independent risk factors, while unemployment and frequent social connection were suggestive risk factors for TCa. Interaction analyses showed that in participants with low genetic risk, low household income was significantly associated with TCa (odds ratio [OR] = 1.56, 95% confidence interval [CI]: 1.00-2.46). In participants with high genetic risk, those with a high education level (OR = 1.32, 95%CI: 1.06-1.65) and frequent social connection (OR = 1.36, 95%CI: 1.02-1.81) had a significantly increased risk of TCa. However, no causal relationship was observed in the MR analysis.

CONCLUSION

Interactions exist between genetic risk, household income, education level, and social connection and thyroid cancer.

Per- and polyfluoroalkyl substances and the associated thyroid cancer risk: A case-control study in China

The role of perfluoroalkyl and polyfluoroalkyl substances (PFAS) as thyroid carcinogens is unclear. Therefore, we intended to identify associations between each PFAS congener and their mixture with thyroid cancer risk. This case-control study of thyroid cancer was conducted in Shijiazhuang, Hebei Province, China. Three hundred participants were recruited from January to May 2022 and were matched according to sex and age. Twelve PFAS were assessed using ultra-high-performance liquid chromatography-tandem mass spectrometry. Associations between PFAS congeners and thyroid cancer risk were considered under conditional logistic regression analysis and a restricted cubic spline model. Mixture effects were also assessed with quantile g-computation and a Bayesian kernel machine regression model. Compared to the first tertile, third tertile PFOA, PFNA, PFHxS, PFDA, and PFUnDA concentrations were associated with lower thyroid cancer risk (ORPFOA: 0.32, 95% confidence interval (CI): 0.15-0.69; ORPFNA: 0.18, 95% CI: 0.07-0.46; ORPFHxS: 0.37, 95% CI: 0.15-0.92; ORPFDA: 0.07, 95% CI: 0.02-0.23; ORPFUnDA: 0.12, 95% CI: 0.05-0.30) after adjusting for confounding factors. PFNA, PFDA, and PFUnDA had a negative dose-response relationship with thyroid cancer risk. Mixture analysis also showed that thyroid cancer risk is negatively associated with the overall mixture and carboxylates. In the overall mixture, PFOS and PFDA contributed most to positive and negative changes in thyroid cancer risk, respectively. However, PFOS, PFNA, PFDA, and PFUnDA were of equally high importance. This study is the first to confirm the effects of the PFAS mixture on thyroid cancer, and further large-scale prospective studies are still warranted to test these inverse associations.

Oxidative stress mediates the associations between phthalate exposures and thyroid cancer/benign nodule risk

Epidemiological studies have suggested that phthalate exposures are associated with increased risks of thyroid cancer and benign nodule, while the underlying mechanisms are largely unknown. Here, we explored the mediation effects of oxidative stress (OS) biomarkers in the associations between phthalate exposures and the risks of thyroid cancer and benign nodule. Urine samples collected from 143 thyroid cancer, 136 nodule patients, and 141 healthy controls were analyzed for 8 phthalate metabolites and 3 OS biomarkers [8-hydroxy-2-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal-mercapturic acid (HNE-MA), and 8-iso-prostaglandin F_2α (8-isoPGF_2α)]. Multivariable linear or logistic regression models were used to explore the associations of OS biomarkers with phthalate metabolite concentrations and the risks of thyroid cancer and nodule. The mediation role of OS biomarkers was also investigated. Urinary monoethyl phthalate (MEP), monomethyl phthalate (MMP), mono (2-ethyl-5-oxohexyl) phthalate (MEOHP), mono (2-ethylhexyl) phthalate (MEHP), and mono (2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) were positively associated with at least 2 OS biomarkers (all P-values<0.01), and part of these positive associations varied in different subgroups. All 3 OS biomarkers were positively associated with the risks of thyroid nodule and cancer (P-values<0.001). The mediation analysis showed that OS biomarkers significantly mediated the associations between urinary MEHOP concentration and nodule, as well as between urinary MMP, MEHP, and MEHHP concentrations and cancer and nodule, with the estimated proportions of mediation ranging from 15.8% to 85.6%. Our results suggest that OS is a potential mediating mechanism through which phthalate exposures induce thyroid carcinogenesis and nodular formation.

Thyroid Nodules and Obesity

A widely discussed topic in the pathophysiology of thyroid nodules is the role of obesity, a state that leads to increased systemic inflammatory markers. Leptin plays a vital role in forming thyroid nodules and cancer through several mechanisms. Together with chronic inflammation, there is an augmentation in the secretion of tumor necrosis factor (TNF) and the cytokine interleukin 6 (IL-6), which contributed to cancer development, progression and metastasis. In addition, leptin exerts a modulatory action in the growth, proliferation and invasion of thyroid carcinoma cell lines via activating various signal pathways, such as Janus kinase/signal transducer and activator of transcription, mitogen-activated protein kinase (MAPK) and/or phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt). Through several proposed mechanisms, aberrant endogenous estrogen levels have been suggested to play a vital role in the development of both benign and malignant nodules. Metabolic syndrome triggers the development of thyroid nodules by stimulating thyroid proliferation and angiogenesis due to hyperinsulinemia, hyperglycemia and dyslipidemia. Insulin resistance influences the distribution and structure of the thyroid blood vessels. Insulin growth factor 1 (IGF-1) and insulin affect the regulation of the expression of thyroid genes and the proliferation and differentiation of thyroid cells. TSH can promote the differentiation of pre-adipocytes to mature adipocytes but also, in the presence of insulin, TSH possesses mitogenic properties. This review aims to summarize the underlying mechanisms explaining the role of obesity in the pathophysiology of thyroid nodules and discuss potential clinical implications.

Preoperative evaluation of thyroid nodules - Diagnosis and management strategies

Thyroid cancer is the most common endocrine malignancy, with increasing incidence over the past few decades. Fine needle aspiration (FNA) biopsy is the gold standard for preoperative diagnosis of thyroid malignancies. Nevertheless, this method renders indeterminate results in up to 30% of the cases. Therefore, these patients are often referred to unnecessary surgery to establish the diagnosis. To improve the accuracy of preoperative diagnosis, several other ways, such as ultrasonography, elastography, immunohistochemical analysis, genetic testing, and core needle biopsy, have been developed and can be used either in association with or as an alternative to FNA. This review aims to evaluate all these diagnostic tools to determine the most appropriate way of managing thyroid nodules and subsequently improve the selection of cases referred to surgery.

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.

Selenium and thyroid diseases

Selenium, a non-metallic element, is a micronutrient essential for the biosynthesis of selenoproteins containing selenocysteine. In adults, the thyroid contains the highest amount of selenium per gram of tissue. Most known selenoproteins, such as glutathione peroxidase, are expressed in the thyroid and are involved in thyroid hormone metabolism, redox state regulation, and maintenance of cellular homeostasis. Some clinical studies have shown that lack of selenium will increase the prevalence of several kinds of thyroid diseases. Selenium treatment in patients with Graves' orbitopathy has been shown to delay disease progression and improve the quality of life. Selenium supplementation in Hashimoto's thyroiditis was associated with the decreased levels of anti-thyroid peroxidase antibody and improved thyroid ultrasound structure. In thyroid cancer, various selenium supplements have shown variable anticancer activity. However, published results remain the conflicting and more clinical evidence is still needed to determine the clinical significance of selenium. This article reviews the strong association between selenium and thyroid disease and provides new ideas for the clinical management of selenium in thyroid disease.

Association Between Genetic Risk, Adherence to Healthy Lifestyle Behavior, and Thyroid Cancer Risk

Importance

Genetic and lifestyle factors are related to thyroid cancer (TC). Whether a healthy lifestyle is associated with TC and could attenuate the influence of genetic variants in TC remains equivocal.

Objectives

To examine the associations between genetics and healthy lifestyle with incident TC and whether adherence to a healthy lifestyle modifies the association between genetic variants and TC.

Design, Setting, and Participants

A prospective cohort study using UK Biobank data recruited 502 505 participants aged 40 to 69 years between March 13, 2006, and October 1, 2010. A total of 307 803 participants of European descent were recruited at baseline, and 264 956 participants were available for the present study. Data analysis was conducted from November 1, 2021, to April 22, 2022.

Exposures

Lifestyle behaviors were determined by diet index, physical activity, weight, smoking, and alcohol consumption. Lifestyle was categorized as unfavorable (scores 0-1), intermediate (score 2), and favorable (scores 3-5). The polygenic risk score (PRS) was derived from a meta-genome-wide association study using 3 cohorts and categorized as low, intermediate, and high.

Main Outcomes and Measures

Thyroid cancer was defined using the International Classification of Diseases, Ninth Revision (code 193), International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (code C73), and self-report (code 1065).

Results

Of 264 956 participants, 137 665 were women (52%). The median age was 57 (IQR, 49-62) years. During a median follow-up of 11.1 (IQR, 10.33-11.75) years (2 885 046 person-years), 423 incident TCs were ascertained (14.66 per 100 000 person-years). Higher PRSs were associated with TC (hazard ratio [HR], 2.25; 95% CI, 1.91-2.64; P = 8.65 × 10-23). An unfavorable lifestyle was also associated with a higher risk of TC (HR, 1.93; 95% CI, 1.50-2.49; P < .001). When stratified by PRS, unfavorable lifestyle was associated with TC in the higher PRS group (favorable vs unfavorable HR, 0.52; 95% CI, 0.37-0.73; P < .001). Furthermore, participants with both a high PRS and unfavorable lifestyle had the highest risk of TC (HR, 4.89; 95% CI, 3.03-7.91; P < .001).

Conclusions and Relevance

In this prospective cohort study, genetic and lifestyle factors were independently associated with incident TC, which suggests that a healthier lifestyle may attenuate the deleterious influence of genetics on the risk of TC in individuals of European descent.

Association between Obesity Indexes and Thyroid Cancer Risk in Korean Women: Nested Case-Control Study

Objective: This study aimed to identify the association between various obesity indexes, including waist circumference (WC), waist−hip ratio (WHR), waist−height ratio (WHTR), and BMI, and their combinations with body mass index (BMI) and thyroid cancer risk. Methods: Of the 65,639 participants who completed a follow-up survey of the Health Examinee Study (HEXA), a prospective cohort of the Korean Genome and Epidemiology Study, 412 female incident thyroid cancer cases, and 1648 birth year- and enrollment year-matched female controls were included. Multiple conditional logistic regression was used to estimate the association between obesity indexes and thyroid cancer risk. Results: The risk of developing thyroid cancer was increased by 1.37-fold (95% confidence interval (CI) = 1.03−1.81) higher in the obese BMI group (≥25.0 Kg/m2) compared to that in the normal BMI group (<23.0 Kg/m2). Obesity in terms of WC (≥85.0 cm) and WHTR (≥0.5) was associated with an increased risk of thyroid cancer (OR 1.55, 95% CI = 1.16−2.07; OR 1.37, 95% CI = 1.07−1.75, respectively). However, increased WHR levels did not show any significant association. Women with both obese levels of BMI (≥25.0 Kg/m2) and other obesity indexes (WC ≥ 85.0 cm, WHR ≥ 0.85, or WHTR ≥ 0.5) showed an increased risk of thyroid cancer with OR of 1.63 (95% CI = 1.14−2.31), 1.49 (95% CI = 1.05−2.12), and 1.42 (95% CI = 1.04−1.94), compared to those with normal levels of BMI and each obesity index. Conclusion: These results provide evidence of the contribution of both total and central adiposity across the lifespan of thyroid cancer incidence. Risk factor modifications must be considered to explain the current thyroid cancer epidemic.

Thyroid Cancer and Psoriasis: A Nested Case-Control Study

Previous researchers have suggested an elevated risk of thyroid cancer (TC) in patients with psoriasis with mixed results. The current study evaluated the relationship of psoriasis with the risk of TC in an adult population. The data from the Korean National Health Insurance Service—Health Screening Cohort ≥ 40 years old were analyzed. In total, 6822 patients with TC were equalized with 27,288 control participants using overlap weighting adjustment based on the propensity score. The history of psoriasis was compared between the TC and control groups using multivariable logistic regression analysis. Secondary analyses were conducted according to age, sex, income, region of residence, systolic blood pressure, diastolic blood pressure, fasting blood glucose, total cholesterol, obesity, smoking, alcohol consumption, the Charlson Comorbidity Index scores, hypothyroidism, goiter, thyrotoxicosis, and thyroiditis. The history of psoriasis was not different in patients with TC (overlap-weighted odds ratio (OR) = 1.02, 95% confidence intervals (CI) = 0.85−1.22). The <55-year-old group showed a high rate of TC associated with psoriasis (overlap-weighted OR = 1.69, 95% CI = 1.22−2.36, p = 0.002). The population without hypothyroidism demonstrated an increased rate of TC related to psoriasis (overlap-weighted OR = 1.29, 95% CI = 1.06−1.57, p = 0.012). The patients with hypothyroidism showed a low rate of TC for psoriasis (overlap-weighted OR = 0.59, 95% CI = 0.37−0.96, p = 0.034). None of the other subgroups showed an association between psoriasis and TC. Psoriasis was not related to the risk of TC in the overall adult population. Young adults and populations without hypothyroidism indicated an elevated rate of TC for psoriasis.

Thyroid Diseases and Thyroid Asymptomatic Dysfunction in People Living With HIV

Thyroid diseases (TDs) and thyroid asymptomatic dysfunctions (TADs) are correlated with Human Immunodeficiency virus (HIV) infection and Acquired ImmunoDeficiency Syndrome (AIDS) as well as many endocrine dysfunctions and dysregulation of hormonal axes. To date, available studies on People Living With HIV (PLWH) affected by thyroid diseases and asymptomatic dysfunctions are few and rather controversial. The purpose of the present non-systematic literature review is to recap the current knowledge on the main features of thyroid dysfunctions and disorders in PLWH. Large cohort studies are needed for a better comprehension of the impact, evolution and treatment of thyroid pathologies in the HIV-infected population.

Relationship between Serum Levels of Selenium and Thyroid Cancer: A Systematic Review and Meta-Analysis

Thyroid cancer is one of the most malignant tumors and a serious threat to human health. Selenium (Se) is an essential trace element that is critical for thyroid function. Since the relationship between Se and thyroid cancer remains unclear, a meta-analysis was performed to clarify the relationship. A total of five databases (PubMed, Web of Science, Scopus, Embase and Cochrane library) were searched for case-control studies and cohort studies on serum levels of Se and thyroid cancer published up to 13 July 2022. Seven articles consisting of 10 case-control studies and comprised of 2,205 subjects met the inclusion criteria for meta-analysis. From the 10 selected studies, pooled analysis indicated that thyroid cancer patients had lower serum levels of Se than healthy controls [standardized mean difference = -1.25, 95% confidence interval = (-2.07, -0.44), P = 0.003]. Our meta-analysis supports a significant relationship between serum levels of Se and thyroid cancer.

Seaweed and Iodine Intakes and SLC5A5 rs77277498 in Relation to Thyroid Cancer

BACKGRUOUND

This study aims to elucidate the associations among dietary seaweed (gim and miyeok/dashima) and iodine intakes, the rs77277498 polymorphism of the SLC5A5 gene codifying the sodium/iodine symporter, and thyroid cancer risk in a Korean population.

METHODS

We conducted a case-control study of 117 thyroid cancer cases and 173 controls who participated in the Cancer Screenee Cohort between 2002 and 2014 at the National Cancer Center, Korea. The amount of seaweed and iodine consumption (g/day) was estimated using the residual energy adjustment method. We calculated odds ratios (ORs) and their 95% confidence intervals (CIs) using a multivariable logistic regression model for the separate and combined effect of dietary iodine-based intake and SLC5A5 polymorphism (rs77277498, C>G) on thyroid cancer.

RESULTS

Dietary gim and iodine intakes were inversely associated with thyroid cancer, with ORs of 0.50 (95% CI, 0.30 to 0.83) and 0.57 (95% CI, 0.35 to 0.95), respectively, whereas the associations for dietary miyeok/dashima and total seaweed intakes were not significant. However, compared with individuals carrying the C/C genotype of the rs77277498 polymorphism with a low intake of all dietary factors, those carrying the G allele with a high intake had a lower risk of thyroid cancer, with ORs of 0.25 (95% CI, 0.10 to 0.56), 0.31 (95% CI, 0.12 to 0.77), 0.26 (95% CI, 0.10 to 0.62), and 0.30 (95% CI, 0.12 to 0.73) for the consumption of gim, miyeok/dashima, total seaweed, and iodine, respectively.

CONCLUSION

In summary, our results supported the evidence of the protective effects of dietary gim and iodine intake against thyroid cancer risk, and this association can be strengthened by SLC5A5 rs77277498 genotypes.

The Effect of Gout on Thyroid Cancer Incidence: A Nested Case-Control Study Using a National Health Screening Cohort

In this study, we investigated the risk of thyroid cancer in patients with gout. Participants ≥40 years old in the Korean National Health Insurance Service−Health Screening Cohort were investigated. A total of 5844 patients with thyroid cancer were paired with 23,376 comparison participants (no history of thyroid cancer) to build the nested case−control study. A previous history of gout was collected from both the thyroid cancer and comparison participants. The relationship of thyroid cancer with a prior history of gout was analyzed using a conditional logistic regression model. The rate of gout was higher in the patients with thyroid cancer than in the comparison group. In the total study population, the relationship of thyroid cancer with a prior history of gout was not statistically evident. A previous history of gout was related to an increased risk of gout in the <60 years old, normal weight, abnormal blood pressure, and CCI score = 0 groups. The occurrence of thyroid cancer was not associated with a prior history of gout in the general adult population. However, a prior history of gout was related to an elevated risk of thyroid cancer in middle-aged and healthy populations without comorbidities.

Ferroptosis-Related APOE, BCL3 and ALOX5AP Gene Polymorphisms are Associated with the Risk of Thyroid Cancer

Purpose

This study aimed to evaluate the association between polymorphisms in the ferroptosis-related genes apolipoprotein E (APOE), BCL3 transcription coactivator (BCL3) and arachidonate 5-lipoxygenase activating protein (ALOX5AP) and the risk of thyroid cancer.

Methods

Six single nucleotide polymorphisms (SNPs) of APOE (rs429358 and rs7412), BCL3 (rs34698726 and rs8100239) and ALOX5AP (rs4076128 and rs4073259) were genotyped in 520 papillary thyroid carcinoma cases and 520 healthy controls using the MassARRAY platform.

Results

The rs429358-TC, rs34698726-TA/TT, and rs8100239-AT/AA genotypes exhibited an elevated risk of thyroid cancer (p_rs429358 = 0.002, p_rs34698726 = 0.007, p_rs8100239 = 0.002), while rs7412-CT/TT and rs4076128-GA/GG were found to be protective genotypes against the risk of disease (p_rs7412 = 0.0003, p_rs4076128 = 0.0001). Genetic model analysis showed that APOE-rs429358 was correlated with an increased risk of disease under dominant and log-additive models (p_dominant = 0.0004, p_log-additive = 0.0006). BCL3-s34698726 and rs8100239 were associated with an elevated risk of disease under all three genetic models (p < 0.05). In contrast, APOE-rs7412 was related to a decreased risk of thyroid cancer under dominant and log-additive models (p_dominant = 0.0001, p_log-additive = 0.0001). Moreover, ALOX5AP-rs4076128 was also correlated with a reduced risk of disease under all three genetic models (p < 0.05).

Conclusion

The results help us better understand how genetic polymorphisms in ferroptosis-related genes are relevant to thyroid cancer susceptibility.

Thyroid Cancer Diagnostics Related to Occupational and Environmental Risk Factors: An Integrated Risk Assessment Approach

There are still many questions remaining about the etiopathogenesis of thyroid cancer, the most common type of endocrine neoplasia. Numerous occupational and environmental exposures have been shown to represent important risk factors that increase its incidence. Updated information about thyroid cancer diagnostics related to occupational and environmental risk factors is reviewed here, considering an integrated risk assessment approach; new data concerning thyroid cancer etiology and pathogenesis mechanisms, diagnostic biomarkers and methodologies, and risk factors involved in its pathogenesis are presented. A special emphasis is dedicated to specific occupational risk factors and to the association between environmental risk agents and thyroid cancer development. The occupational environment is taken into consideration, i.e., the current workplace and previous jobs, as well as data regarding risk factors, e.g., age, gender, family history, lifestyle, use of chemicals, or radiation exposure outside the workplace. Finally, an integrative approach is presented, underlying the need for an accurate Risk Assessment Matrix based on a systematic questionnaire. We propose a complex experimental design that contains different inclusion and exclusion criteria for patient groups, detailed working protocols for achieving coherent and sustainable, well-defined research stages from sample collection to the identification of biomarkers, with correlations between specific oncometabolites integrated into the Risk Assessment Matrix.

Insufficient iodine nutrition may affect the thyroid cancer incidence in China

Epidemiological studies have focused on the effects of iodine intake on the risk of thyroid cancer. However, their relationship is still obscure. The objective of the present study was to examine the association in the Chinese population. A new ecological study which combined the Data of Annual Report of Cancer, the Survey of Iodine Deficiency Disorders (IDD) surveillance and the Water Iodine Survey was conducted to analyse the relationship between iodine intake and the thyroid cancer incidence in China. In total, 281 counties were included. Thyroid cancer incidence was negatively correlated with the consumption rate of qualified iodised salt (CRQIS) and positively correlated with goiter prevalence (GP) of children aged 8-10 years, residents' annual income and coastal status. Areas with a low CRQIS and areas with a high GP had a relatively high incidence of thyroid cancer. Regression models showed that a low CRQIS and a high GP in children aged 8-10 years (both reflecting iodine deficiency status) play a substantial role in thyroid cancer incidence in both males and females. Additionally, living in coastal areas and having a high annual income may also increase the risk of thyroid cancer. These findings suggest that mild iodine deficiency may contribute to the exceptionally high incidence of thyroid cancer in some areas in China. Maintaining appropriate iodine nutrition not only helps to eliminate IDD but also may help to reduce the occurrence of thyroid cancer.

Advanced thyroid carcinomas: neural network analysis of ultrasonographic characteristics

BACKGROUND

Ultrasound is the first-line imaging modality for detection and classification of thyroid nodules. Certain characteristics observable by ultrasound have recently been identified that may indicate malignancy. This retrospective cohort study was conducted to test the hypothesis that advanced thyroid carcinomas show distinctive clinical and sonographic characteristics. Using a neural network model as proof of concept, nine clinical/sonographic features served as input.

METHODS

All 96 study enrollees had histologically confirmed thyroid carcinomas, categorized (n = 32, each) as follows: group 1, advanced carcinoma (ADV) marked by local invasion or distant metastasis; group 2, non-advanced papillary carcinoma (PTC); or group 3, non-advanced follicular carcinoma (FTC). Preoperative ultrasound profiles were obtained via standardized protocols. The neural network had nine input neurons and one hidden layer.

RESULTS

Mean age and the number of male patients in group 1 were significantly higher compared with groups 2 (p = 0.005) or 3 (p <  0.001). On ultrasound, tumors of larger volume and irregular shape were observed significantly more often in group 1 compared with groups 2 (p <  0.001) or 3 (p ≤ 0.01). Network accuracy in discriminating advanced vs. non-advanced tumors was 84.4% (95% confidence interval [CI]: 75.5-91), with positive and negative predictive values of 87.1% (95% CI: 70.2-96.4) and 92.3% (95% CI: 83.0-97.5), respectively.

CONCLUSIONS

Our study has shown some evidence that advanced thyroid tumors demonstrate distinctive clinical and sonographic characteristics. Further prospective investigations with larger numbers of patients and multicenter design should be carried out to show whether a neural network incorporating these features may be an asset, helping to classify malignancies of the thyroid gland.

Reproductive and menstrual factors for papillary thyroid cancer risk: A case-control study in Chinese women

BACKGROUND

Thyroid cancer (TC) is threefold more common in women than men. Reproductive and menstrual factors may be related to the onset of papillary thyroid cancer (PTC). This study aims to determine the association of reproductive and menstrual factors with PTC in Chinese females.

METHODS

A total of 335 histologically confirmed cases of PTC were recruited in this case-control study. The controls were matched for age with a deviation of ± 2 years, which conducted from September 2016 to February 2019. Logistic regression models were applied to identify the association of reproductive and menstrual factors with PTC.

RESULTS

After adjustment by some variables, early menarche age (OR ≤ 13 years vs. > 13years = 2.40, 95 % CI 1.12-5.13) and shorter lifetime breastfeeding (OR <6 months vs. ≥ 6 months = 1.99, 95 % CI 1.11-3.55) significantly increased the risk of PTC, whereas younger age at first pregnancy had a protective effect against PTC (OR ≤ 24years vs. > 24 years = 0.66, 95 % CI 0.44-0.98). There was a positive correlation between premenopausal and PTC in the lower age group (OR _{premenopausal vs. Menopause by natural} =2.34, 95 %CI 1.03-5.28).

CONCLUSIONS

Early menarche age, abortion, shorter breastfeeding duration and premenopausal may be related to the occurrence of PTC. Early age at first pregnancy and larger number of full-time pregnancies were possible to decrease the risk of PTC.

Effect of Cigarette Smoking on Thyroid Cancer: Meta-Analysis

BACKGROUND

Although smoking is generally carcinogenic, its effect on thyroid cancers is still subject to controversy. The purpose of this study was to summarize the role of smoking in relation to thyroid cancer occurrence.

METHODS

We performed a meta-analysis of 24 eligible studies: 21 case-control studies and three prospective cohort studies. The summary odds ratio (OR) and 95% confidence interval (CI) of all studies were acquired based on random effect model. Further subgroup analyses were conducted according to gender, histological type of thyroid cancer, and smoking status of patients for the case-control studies.

RESULTS

The summary effect size indicated a negative association of smoking for thyroid cancer (OR, 0.798; 95% CI, 0.681 to 0.935). From the subgroup analyses for the case-control studies, reduced risk of thyroid cancer was observed in both men (OR, 0.734; 95% CI, 0.553 to 0.974) and women (OR, 0.792; 95% CI, 0.700 to 0.897). The protective effect of smoking was observed in studies in which thyroid cancer was limited to differentiated thyroid cancers (DTCs) (OR, 0.798; 95% CI, 0.706 to 0.902).

CONCLUSION

Our results suggests that smoking may have a protective effect on thyroid cancer, especially on DTCs. Further studies with larger sample sizes should be conducted in elucidating the dose and time dependent effect of smoking on thyroid cancer with specific focus on the types of thyroid cancers.

Evaluation of the relationship between previous statin use and thyroid cancer using Korean National Health Insurance Service-Health Screening Cohort data

The association of thyroid cancer with statin use is controversial. This study aimed to investigate the association of previous statin use with thyroid cancer in the ≥ 40-year-old population in the Korean National Health Insurance Service-Health Screening Cohort. The 5501 patients in the thyroid cancer group were matched with the 22,004 patients in the non-thyroid cancer group for age, sex, income, and region of residence. Previous statin use during the 2 years before the diagnosis of thyroid cancer was examined. The odds ratios (ORs) with 95% confidence intervals (CIs) of previous statin use for thyroid cancer were estimated using conditional logistic regression analyses. Additionally, subgroup analyses were conducted. The thyroid cancer group showed more days of previous statin use than the non-thyroid cancer group (72.3, standard deviation [SD] = 181.2 days vs. 64.3, SD = 174.4 days, P = 0.003). Although the odds of previous statin use for thyroid cancer were high in the crude model (OR = 1.10, 95% CI 1.04–1.17, P = 0.002), they were low in the fully adjusted model (OR = 0.89, 95% CI 0.82–0.95, P = 0.001). According to age and sex subgroups, the younger (< 60 years old) male group showed lower odds for thyroid cancer according to previous statin use (adjusted OR = 0.70, 95% CI 0.55–0.88, P = 0.003), but this finding was not observed in other subgroups of older men or in any groups of women. Thyroid cancer was negatively associated with statin use in the previous 2 years in the adjusted model.

Thyroid cancer and its associated factors: A population-based case-control study

Considering the rising incidence and mortality of thyroid cancer (TC) worldwide, the aim of our study was to determine the risk factors for TC in a province with the highest incidence of TC in the country located at the South of Iran. A population-based case-control study was performed on 708 participants (361 new cases and 347 controls). The case participants were selected from the Iranian National Cancer Registry database. Frequency matched for gender and age, and the control participants were selected randomly from the neighborhood of the cases. Based on the results of multiple logistic regression analysis, benign thyroid diseases (eg, hyperthyroidism OR_yes/no = 14.06, 95% CI: 5.13-38.51), family history of TC (OR_yes/no = 3.54, 95% CI: 1.51-8.26), radiation exposure of the head (OR_yes/no = 1.92, 95% CI: 1.03-3.60), family history of thyroid diseases (OR_yes/no = 1.76, 95% CI: 1.19-2.62) and family history of other types of cancer (OR_yes/no = 1.67, 95% CI: 1.01-2.74), significantly increased the risk of developing TC. On the other hand, high blood pressure (OR_yes/no = 0.35, 95% CI: 0.19-0.64), higher education (OR_{college/illiterate} = 0.54, 95% CI: 0.30-0.96), consumption of unsaturated fat (OR_{unsaturated/saturated} = 0.59, 95% CI: 0.39-0.87) and being married (OR_{married/single} = 0.60, 95% CI 0.37-0.98) were found to be protective factors. Some community-based interventions, for example, reduction in radiation exposure and screening members of families with underlying thyroid diseases may help in preventing or early diagnosis of TC. More studies on the health effects of local herbs are highly recommended.

Serous BMP8A has Clinical Significance in the Ultrasonic Diagnosis of Thyroid Cancer and Promotes Thyroid Cancer Cell Progression

OBJECTIVE

This study aims to discover a potential cytokine biomarker for early diagnosis of thyroid cancer.

METHODS

We employed data mining of The Cancer Genome Atlas (TCGA) and experimentally elucidated its mechanistic contributions. The differential expression genes (DEGs) between thyroid cancer and health population were analyzed with TCGA online bioinformatic tools. The relative expression of Bone Morphogenetic Protein 8A (BMP8A) was determined by real-time PCR in ultrasonic diagnosed thyroid cancer both in vivo and in vitro. The serous BMP8A content was quantified with an ELISA kit. Protein levels of BMP8A, OCLN, ZEB1, EZH2 and β-Actin were analyzed by Western blot. Cell viability was measured by the MTT assay, and anchorage-independent growth was measured by the soft agar colony formation assay. Cell migrative and invasive capacities were interrogated with transwell chamber assays.

RESULTS

We identified aberrantly high expression of BMP8A in thyroid cancer, which was associated with unfavorable prognosis and tumor progression. The serous BMP8A was also significantly up-regulated in thyroid cancer patients. Ectopic over-expression of BMP8A remarkably stimulated cell viability and anchorage-independent growth. Meanwhile, the migrative and invasive capacities were greatly increased in response to BMP8A over-expression. Mechanistically, we characterized the positive correlation between BMP8A and TCF7L1, and forced expression of TCF7L1 induced BMP8A expression in TPC-1 cells.

CONCLUSION

In summary, we have identified a novel biomarker for early diagnosis in addition to Ultrasound for thyroid cancer, which is subjected to TCF7L1 regulation.

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.

Obesity is positively related and tobacco smoking and alcohol consumption are negatively related to an increased risk of thyroid cancer

The purpose of this study was to evaluate the relationships of smoking, alcohol consumption, and obesity with thyroid cancer in Korean residents. The Korean National Health Insurance Service-Health Screening Cohort includes individuals ≥ 40 years who were assessed from 2002 to 2013. In total, 4977 thyroid cancer participants were matched with respect to age, sex, income, and region of residence with 19,908 controls at a ratio of 1:4. Crude and adjusted (for the Charlson comorbidity index, smoking status, frequency of alcohol consumption, and obesity) odds ratios (ORs) were analyzed using conditional logistic regression analyses. Additionally, 95% confidence intervals (CIs) were calculated. The adjusted OR of smoking for thyroid cancer was 0.62 (95% CI 0.54–0.72, P < 0.001), and that of alcohol consumption was 0.83 (95% CI 0.75–0.92, P < 0.001). The adjusted ORs of the BMI categories were 1.13 (95% CI 1.05–1.22, P = 0.002) for obese I, and 1.24 (95% CI 1.04–1.47, P = 0.014) for obese II. The ORs of smoking and alcohol consumption were lower, and those of overweight and obesity were higher in thyroid cancer patients than in individuals in the control group.

Association between Family Histories of Thyroid Cancer and Thyroid Cancer Incidence: A Cross-Sectional Study Using the Korean Genome and Epidemiology Study Data

This study assessed the association between thyroid cancer and family history. This cross-sectional study used epidemiological data from the Korean Genome and Epidemiology Study from 2001 to 2013. Among 211,708 participants, 988 were in the thyroid cancer group and 199,588 were in the control group. Trained interviewers questioned the participants to obtain their thyroid cancer history and age at onset. The participants were examined according to their age, sex, monthly household income, obesity, smoking, alcohol consumption, and past medical history. The adjusted odds ratios (95% confidence intervals) for the family histories of fathers, mothers, and siblings were 6.59 (2.05–21.21), 4.76 (2.59–8.74), and 9.53 (6.92–13.11), respectively, and were significant. The results for the subgroup analyses according to sex were consistent. The rate of family histories of thyroid cancer for fathers and siblings were not different according to the thyroid cancer onset, while that of mothers were higher in participants with a younger age at onset (<50 years old group, 11/523 [2.1%], p = 0.007). This study demonstrated that thyroid cancer incidence was associated with thyroid cancer family history. This supports regular examination of individuals with a family history of thyroid cancer to prevent disease progression and ensure early management.

Risk Factors for Thyroid Cancer: What Do We Know So Far?

Thyroid cancer (TC) is the most common endocrine cancer today. The rising incidence of the differentiated papillary type cannot be entirely explained by early and meticulous diagnosis, since a proportion of large tumors has also been reported. In this review, we present the results of numerous investigations focused on possible factors causing increased TC incidence, such as chromosomal and genetic alterations, iodine intake, TSH level, autoimmune thyroid disease, gender, estrogen, obesity, lifestyle changes, and environmental pollutants. Up to now, only childhood exposure to ionizing radiation has been fully recognized as a risk factor. There is also a possibility that yet undiscovered carcinogens, especially during intrauterine life or early childhood, might be responsible for increased TC incidence as well as epigenetic changes. Therefore, more studies are necessary in order to further investigate the potential risk factors for TC and their mechanisms of action.

Epidemiologic, Clinical, Ultrasonographic, and Cytological Features of Thyroid Nodules in Predicting Malignancy Risk: A Retrospective Study of 442 French Afro-Caribbean Patients

OBJECTIVE

To evaluate epidemiologic, clinical, cytological, and ultrasonographic features of thyroid nodules in a sample French Afro-Caribbean population to determine if the standard criteria for predicting malignancy risk are applicable to this specific ethnic population. Methods and Design. This retrospectively designed study consisted of 442 patients who had consulted with the Endocrinology Department in Martinique (French overseas department) between 2007 and 2011. Of the 442 patients, 641 ultrasound-guided fine-needle aspirations (US-FNA) were performed by two experienced endocrinologists, and 212 patients underwent surgery. The geographical situation, age, gender of the patient, clinical and ultrasonographic features, TSH level, and US-FNA results were considered and cross-referenced with their pathology results.

RESULTS

The overall malignancy rate on final histopathology was 9% (women only), 80% of which were papillary cancer, and 20% were follicular cancer. Occult micropapillary carcinoma represented 35% of the papillary cancer. There was no significant difference in age, nodule localization, number of nodules, or thyroid function test between benign and malignant nodules. Contrary to the literature, we found only 12% incidentaloma in our series, while more than half of the nodules were discovered on palpation or as a clinical symptom. Hypoechogenicity in solid pattern nodules and nodules between 2 and 3 cm in size revealed a high diagnostic value in detecting malignancy. The corresponding rate of malignancy on Bethesda system histopathologic examination was as follows: 0% in undiagnosed (I), 0% benign (II) (micropapillary), 5% (FLUS)/atypia (III), 9% follicular neoplasm (IV), 33% suspected malignancy (V), and no malignant cytology (VI). These results show a different Bethesda system predictive value for this French Afro-Caribbean population.

CONCLUSION

Studies evaluating ethnic cancer disparities among patients with thyroid cancer are limited and do not specifically focus on the French Afro-Caribbean population. Despite rare thyroid incidentaloma, 35% of the papillary cancer cases were micropapillary carcinoma, and the incidence and standardized mortality rate in Martinique are lower than in metropolitan France. The malignant risk distribution of thyroid FNA Bethesda classification in this sample population differs from the standard risk, and it is necessary to take that into account in the decision to operate by associating it with echographic malignancy criteria.

Total thyroidectomy versus thyroid lobectomy in the treatment of papillary carcinoma

Extent of thyroidectomy for papillary thyroid carcinoma is still matter of debate. Indeed, recently, international guidelines endorsed thyroid lobectomy as initial surgical approach for low risk, small medium-sized (T1-T2), N0 papillary thyroid carcinoma in absence of extrathyroidal extension. When dealing with a conservative surgery for oncologic disease is of utmost importance to exclude effectively more advanced disease, which could benefit from a more aggressive initial operation. However, in the setting of surgery for papillary thyroid carcinoma, despite an accurate preoperative work up could led to identify some suspicious characteristics as macroscopic evidence of multifocality or extrathyroidal extension, and/or evidence of lateral neck lymph node metastases, it is difficult to reliably assess the central neck nodal status both pre- and intra-operatively. Frozen section examination of the central neck nodes ipsilateral to the side of the tumor has been proposed in patients scheduled for thyroid lobectomy, in order to modulate the extension of both thyroidectomy and central neck dissection. Future molecular and genetic evidences are needed to establish high-risk patients with small papillary thyroid carcinoma in which thyroid lobectomy could be not and adequate surgical treatment.

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.

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

PURPOSE

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

Materials and Methods

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

RESULTS

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

CONCLUSION

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

Genetic variations in TAS2R3 and TAS2R4 bitterness receptors modify papillary carcinoma risk and thyroid function in Korean females

Type 2 taste receptors (T2Rs, TAS2Rs) mediate bitterness perception and are involved in diverse defence mechanisms in extraoral tissues. The thyrocyte-expressed T2Rs control thyroid hormone production, and this regulatory role may be associated with susceptibility to thyroid diseases. This study examined whether the variations in TAS2Rs modify the risk of papillary thyroid carcinoma (PTC) and whether such T2R-related PTC risk is associated with genetically modified thyroid function. We conducted a case-control study with 763 Korean females, including 250 PTC cases. Seventy-three single-nucleotide polymorphisms in 13 TAS2R genes and the pre-diagnosis levels of 4 thyroid-related functional markers [total triiodothyronine (TT3), free thyroxine, thyroid-stimulating hormone and thyroglobulin] were analysed. Individuals with TAS2R3/4 CC haplotype (rs2270009 and rs2234001) were at a lower risk for PTC than those with the remaining haplotypes (odds ratio = 0.59, 95% confidence interval: 0.36-0.97). Furthermore, TT3 levels were significantly reduced for TAS2R3/4 CC haplotype carriers compared with other haplotype carriers (p = 0.005). No other genetic variants exhibited critical associations with the PTC phenotype and biomarkers. In summary, genetic variations in T2R3/4 bitterness receptors may modify the PTC risk, and the genetically modified thyroid hormone level by those variations may be linked with the PTC-T2Rs association.

The Relationship Between Human Development Index and Its Components with Thyroid Cancer Incidence and Mortality: Using the Decomposition Approach

BACKGROUND

The link between age specific-rates of thyroid cancer (TC) and human development index (HDI) and also its components can be a new direction for planning by policy makers.

OBJECTIVES

This study aimed at identifying the relationship between TC rates by gender, and HDI and its components in different regions of the world.

METHODS

An ecological study was conducted; the data was obtained from the GLOBOCAN project in 2012. Inequality in TC estimates (age-specific incidence and mortality rates), according to the HDI and its components was calculated. Concentration index (CI) was used to estimate inequality and CI was decomposed to determine contribution of HDI and its components in inequality.

RESULTS

The inequality index (CI) was 0.29 (95% CI: 0.21 - 0.38) and -0.15 (95% CI: -0.23 - 0.06) for incidence and mortality of TC by HDI, respectively. The important contributors in inequality for incidence rates of TC were life expectancy at birth (0.30), mean years of schooling (0.26), and expected years of schooling (0.18). The important contributors in inequality of mortality rates were mean years of schooling (0.19), expected years of schooling (0.17), and urbanization (0.17).

CONCLUSIONS

According to the findings of this study, global inequalities exist in the TC incidence and mortality rates; incidence rates of TC are more concentrated in countries with high HDI, yet inequality index showed that deaths occurred more in disadvantaged countries.

Radiation and Second Primary Thyroid Cancer Following Index Head and Neck Cancer

OBJECTIVES/HYPOTHESIS

Radiation is thought to increase risk of developing second primary thyroid cancer (SPTC). This study estimated the rate of SPTC following index head and neck cancer (HNC) and determined whether radiation treatment among HNC survivors increased SPTC risk.

STUDY DESIGN

Retrospective data analysis.

METHOD

The Surveillance, Epidemiology, and End Results database (1975-2014) was queried for cases of index HNC (N = 127,563) that developed SPTC. Adjusted multivariable competing risk proportional hazards model tested risk of developing a SPTC following index HNC. Sensitivity analyses using proportional hazards models were also performed restricting data to patients who 1) received both radiation and chemotherapy and 2) radiation alone.

RESULTS

Only 0.2% of index HNC survivors (n = 229) developed SPTC, yielding a rate of 26.1 per 100,000 person-years. For every increasing year of age at diagnosis, patients were 3% less likely to develop an SPTC (adjusted hazard ratio [aHR] = 0.97, 95% CI: 0.96-0.98). Males were also less likely to develop an SPTC (aHR = 0.73, 95% CI: 0.55-0.96). Radiation (aHR = 0.92, 95% CI: 0.68-1.25), surgery (aHR = 0.79, 95% CI: 0.56-1.11), and chemotherapy (aHR = 1.13, 95% CI: 0.76-1.69) were not significantly associated with developing SPTC. The sensitivity models also did not find an association between treatment and risk of SPTC.

CONCLUSIONS

Rate of developing SPTC following index HNC was very low, and previous exposure to radiation did not significantly increase risk in our study population. More studies are needed to understand the increasing incidence of thyroid cancer across the United States.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:1014-1020, 2019.

Cigarette smoking and thyroid cancer risk: a cohort study

Background

We evaluated the association between smoking status and thyroid cancer risk and whether this association is mediated by body mass index (BMI) and thyroid-stimulating hormone (TSH).

Methods

We performed a cohort study of 96,855 Korean adults who were followed annually or biennially for a median of 5.9 years.

Results

During 511,052.9 person-years of follow-up, 1,250 participants developed thyroid cancer. In men, we observed a dose-dependent inverse association between current smoking, pack-years, and thyroid cancer. After adjustment for confounders, adjusted hazard ratios (95% confidence intervals) for thyroid cancer comparing current and former smokers to never smokers were 0.58 (0.45–0.75) and 0.93 (0.73–1.18), respectively. After further adjustment for BMI and TSH as potential mediators, this association was slightly attenuated, but remained significant. For women, current smokers tended to have a lower risk of thyroid cancer, but this association did not reach statistical significance.

Conclusions

In this cohort study, current smoking was associated with a decreased risk of incident thyroid cancer in men but not in women and this association was observed even after adjusting for TSH and BMI levels as potential mediators. Further mechanistic studies are needed to elucidate the possible effect of smoking on the pathogenesis of thyroid cancer development.

Thyroid cancer among female workers in Korea, 2007-2015

Background

Prevalence of thyroid cancer has been increasing rapidly worldwide, especially among women. There has been a debate as to whether such an increase represents consequences of over-diagnosis or a true increase. To find the occupational risk of Korean female workers in different industry sectors, we analyzed the data of Korean female workers.

Methods

National Female Worker Cohort data that contain information on total female workers were used for our analysis of prevalence of thyroid cancer (C73 according to KCD-5, 6 code) derived from National Health Insurance data. By combining industrial codes from National Health Insurance Service and those from Korea Workers' Compensation and Welfare Service, the classification of industrial codes became to consist of the total of thirty three representing both non-office (NO) and office (O) categories. Both an internal comparison among female workers within the cohort and an external comparison to compare female workers with Korean general female population were carried out.

Results

Among 149,258 female workers, 2,641 cases of thyroid cancers were identified. Differences in prevalence of thyroid cancer between female workers (40.5%) and general Korean female population (32.6%) were observed; however, the differences in prevalence of thyroid cancer between NO workers and O workers were not apparent. An analysis involving workers in Financial and insurance activities sector revealed that, standardized prevalence rate (SPR) of both NO (2.96, 95% CI = 2.01-4.20) and O workers (3.68, 95% CI = 3.10-4.33) increased significantly and that an AOR (adjusted odds ratio) increased marginally (1.38, 95% CI = 0.97-1.96). Further, when stratified in respect to the duration of employment, an AOR of female workers having been employed for more than 8 years showed a significant increase (1.63, 95% CI = 1.07-2.49).

Conclusions

Female workers had a higher risk of thyroid cancer than general female population but the difference between NO workers and O workers was not found to be significant in most industrial sectors. Further studies using data with information regarding specific occupational exposures are needed.

Bethesda thyroid categories and family history of thyroid disease

OBJECTIVE

Thyroid cancer is the most common type of endocrine-related cancer worldwide. The aim of this article was to assess the relationship between thyroid diseases diagnosed by fine needle aspiration (FNA) and family history of thyroid disease.

DESIGN

The study was conducted in a tertiary high-volume thyroid cancer centre. Fine needle aspiration (FNA) of a thyroid nodule detected on neck ultrasound for any reason was performed in all included patients.

PATIENTS

A total of 10 709 patients were included in the study.

MEASUREMENTS

Correlation of cytological findings classified according to the Bethesda system and family history was calculated using Fisher's exact test.

RESULTS

There were 2580 (24.09%) patients with non-malignant thyroid diseases in the family and 198 (1.85%) patients who had a history of thyroid cancer in the family. A total of 2778 (25.94%) patients had positive family history of thyroid diseases, and 7931 (74.06%) patients had negative family history. In patients with papillary thyroid carcinoma in family history, the difference between those with benign (Bethesda 2) and malignant thyroid FNA diagnosis (Bethesda 6) was found to be statistically significant (P = .0432).

CONCLUSIONS

Family history plays a significant role in the development of thyroid cancer, and having first-degree relatives with not only medullary, but also papillary thyroid cancer strongly predicts the risk of developing the malignant thyroid disease. In contrast, benign thyroid disorders in family history do not lead to the development of thyroid cancer.

Interplay between Body Size Measures and Thyroid Cancer Aggressiveness: A Retrospective Analysis

Considering controversial data about the relationship between body size and prognosis of differentiated thyroid cancer (DTC), the current study aimed to assess the influence of body weight, body mass index (BMI), and body surface area (BSA) on DTC. We conducted a retrospective analysis of patients' records from the Thyroid Cancer Unit, assessing body size measures, clinical and laboratory prognostic factors, and disease evolution. 337 patients, aged 45.95 ± 13.04 years old, with BMI of 27.87 ± 5.13 kg/m² and BSA of 1.74 ± 0.18 m² were enrolled. After 9.5 ± 6.9 years of follow-up, 87.29% of patients were disease-free and 12.71% had persistent disease; no patient had deceased. Patients aged <45 years old with extrathyroidal invasion tumor had greater baseline body weight and BSA than those without extrathyroidal invasion (median 79.5 kg versus 67 kg and 1.85 m² versus 1.74 m²). Women with poorly differentiated tumor and patients aged ≥45 years old with distant metastasis presented greater weight loss during follow-up compared to patients without such characteristics (median -2 kg versus +1.5 kg and -3 kg versus +1 kg, respectively). The relationship between body size and DTC evolution was not observed. In conclusion, higher weight and BSA were associated with a greater chance of extrathyroidal tumor invasion in younger patients. Specific subgroups of patients with aggressive disease presented higher weight loss. Young patients with higher BSA should be carefully treated due to possible worse prognosis related to increased incidence of extrathyroid invasion. Findings related to tumor aggressiveness and weight loss in specific groups deserve further mechanistic studies.