Maternal health, in-utero, and perinatal exposures and risk of thyroid cancer in offspring: a Nordic population-based nested case-control study

Thyroid cancer trends in China and its comparative analysis with G20 countries: Projections for 2020-2040

Background

Thyroid cancer, a leading type of endocrine cancer, accounts for 3-4% of all cancer diagnoses. This study aims to analyse and compare thyroid cancer patterns in China and the Group twenty (G20) countries, and predict these trend for the upcoming two decades.

Methods

This observational longitudinal study utilised data from the Global Burden of Disease (GBD) study 2019. We used metrics including incidence, mortality, mortality-incidence ratio (MIR), age-standardised rate (ASR) and average annual percent change (AAPC) to examine thyroid cancer trends. Joinpoint regression analysis was used to identify periods manifesting notable changes. The association between sociodemographic index (SDI) and AAPC were investigated. The autoregressive integrated moving average (ARIMA) model was used to predict thyroid cancer trends from 2020 to 2040.

Results

From 1990 to 2019, thyroid cancer incidence cases in China increased by 289.6%, with a higher AAPC of age-standardised incidence rate (ASIR) in men. Contrastingly, the G20 demonstrated a smaller increase, particularly among women over 50. Despite the overall age-standardised mortality rate (ASMR) was higher in the G20, the increase in mortality was less pronounced than in China. Age-standardised incidence rate increased across all age groups and genders, with a notable rise among men aged 15-49. ASMR decreased in specific age groups and genders, especially among women. Conversely, the ASMR significantly increased in group aged over 70. The MIR exhibited a declining trend, but this decrease was less noticeable in men and the group aged over 70. Joinpoint analysis pinpointed significant shifts in overall ASIR and ASMR, with the most pronounced increase in ASIR during 2003-2011 in China and 2003-2010 in the G20. Predictions suggested a continual ASIR uptrend, especially in the 50-69 age group, coupled with a predicted ASMR downturn among the elderly by 2040. Moreover, the proportion of thyroid cancer deaths attributable to high body mass index (BMI) escalated, with significant increase in Saudi Arabia and a rise to 7.4% in China in 2019.

Conclusions

Thyroid cancer cases in incidence and mortality are escalating in both China and the G20. The increasing trend may be attributed to factors beyond overdiagnosis, including environmental and genetic factors. These findings emphasise the necessity for augmenting prevention, control, and treatment strategies. They also highlight the significance of international collaboration in addressing the global challenge posed by thyroid cancer.

Geographic disparities in trends of thyroid cancer incidence and mortality from 1990 to 2019 and a projection to 2030 across income-classified countries and territories

Background

The rising incidence of thyroid cancer (TC) has generated growing concern globally; yet there are no studies examining whether this incidence was followed by a rise in related mortality. We aimed to comprehensively quantify current trends and future projections of TC incidence and mortality, and to explore the association between the TC burden and socioeconomic inequality in different income strata.

Methods

We obtained incidence and mortality data on TC and population from the 2019 Global Burden of Disease (GBD) study and the United Nations' World Population Prospects 2022. We applied an age-period-cohort (APC) model to estimate the overall annual percentage change (net drift) and age, period, and cohort effects from 1990 to 2019, and also constructed a Bayesian APC model to predict the TC burden through 2030.

Results

Over a third of global TC cases belonged to the high-income group. From 1990 to 2019, net drifts of TC incidence were >0 in all income groups, while a modest reduction (net drift <0) in mortality was observed in most income groups, except for the lower-middle-income group. Unfavourable age, period, and cohort effects were most notable in Vietnam, China, and Korea. The age-standardised incidence rate (ASIR) is predicted to increase whereas the age-standardized mortality rate (ASMR) is expected to decrease globally between 2020 and 2030, with geographic heterogeneity being detected across income groups. We observed a positive correlation between ASIR and universal health coverage index and health worker density, but a negative one between ASMR and the two indicators, primarily in upper-middle-income and high-income countries.

Conclusions

Opposite patterns in incidence and mortality of TC raise concerns about overdiagnosis, particularly in upper-middle-income and high-income countries. Discrepancies in the distribution of health service accessibility, including diagnostic techniques and therapeutic care, should be addressed by narrowing health inequalities in the TC burden across countries.

Maternal Health, Pregnancy and Offspring Factors, and Maternal Thyroid Cancer Risk: A Nordic Population-Based Registry Study

Thyroid cancer incidence is higher in women than men, especially during the reproductive years, for reasons that remain poorly understood. Using population-based registry data from 4 Nordic countries through 2015, we examined associations of perinatal characteristics with risk of maternal thyroid cancer. Cases were women diagnosed with thyroid cancer ≥2 years after last birth (n = 7,425, 83% papillary). Cases were matched to controls (n = 67,903) by mother's birth year, country, and county of residence. Odds ratios (ORs) were estimated using conditional logistic regression models adjusting for parity. Older age at first pregnancy, postpartum hemorrhage (OR = 1.18, 95% (confidence interval) CI: 1.08, 1.29), and benign thyroid conditions (ORs ranging from 1.64 for hypothyroidism to 10.35 for thyroid neoplasms) were associated with increased thyroid cancer risk, as were higher offspring birth weight (per 1-kg increase, OR = 1.17, 95% CI: 1.12, 1.22) and higher likelihood of offspring being large for gestational age (OR = 1.26, 95% CI: 1.11, 1.43). Unmarried/noncohabiting status (OR = 0.91, 95% CI: 0.84, 0.98), maternal smoking (OR = 0.75, 95% CI: 0.67, 0.84), and preterm birth (OR = 0.90, 95% CI: 0.83, 0.98) were associated with reduced risk. Several factors (e.g., older age at first pregnancy, maternal smoking, goiter, benign neoplasms, postpartum hemorrhage, hyperemesis gravidarum, and neonatal jaundice) were associated with advanced thyroid cancer. These findings suggest that some perinatal exposures may influence maternal thyroid cancer risk.

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.

Long noncoding RNA SNHG6 promotes papillary thyroid cancer cells proliferation via regulating miR-186/CDK6 axis

Background

Papillary thyroid cancer (PTC) is a common endocrine malignancy, and its incidence rate has been increasing in recent years. Long noncoding RNAs (lncRNAs) participate in cell biological processes through a variety of regulatory ways, and play an essential role in tumor development.

Methods

This study explored the expression of lncRNA small nucleolar RNA host gene 6 (SNHG6) in PTC by bioinformatics analysis, and quantitative real-time PCR (qRT-PCR). Cell counting kit-8 (CCK-8) assay, colony formation assay, and 5-ethynyl-2'-deoxyuridine (EdU) assay were used to study the effect of SNHG6 on the proliferation of PTC cells. Luciferase reporter gene assay and western blot were used to study the mechanism.

Results

SNHG6 was highly expressed in PTC tissue samples and cell lines. In vitro, overexpression of SNHG6 promoted the proliferation of PTC cells, while silencing SNHG6 inhibited the proliferation of PTC cells. miR-186 is the downstream target of SNHG6. SNHG6 regulates the proliferation of PTC cells through miR-186. In addition, CDK6 is the target gene of miR-186, which can inhibit the expression of CDK6 protein. SNHG6 can promote the expression of CDK6 by regulating miR-186.

Conclusions

SNHG6 is highly expressed in PTC and can promote the proliferation of PTC cells by regulating the miR-186/CDK6 axis, which is expected to become a potential therapeutic target for PTC.

Thyroid cancer incidence trends by histology in 25 countries: a population-based study

BACKGROUND

The incidence of thyroid cancer has increased in different populations worldwide in the past 30 years. We present here an overview of international trends of thyroid cancer incidence by major histological subtypes.

METHODS

We did a population-based study with data for thyroid cancer incidence collected by the International Agency for Research on Cancer (IARC) for the period 1998-2012. Data were extracted from the Cancer Incidence in Five Continents plus compendium. We selected data for 25 countries that had a population of more than 2 million individuals covered by cancer registration (87 registries in total). Further criteria were that the selected registration areas had to have a proportion of unspecified thyroid cancer of less than 10% and analyses were restricted to individuals aged 20-84 years. We calculated age-specific incidence rates and age-standardised rates per 100 000 person-years for individuals aged 20 to 84 years, and assessed trends by country, sex, and major histological subtype (papillary, follicular, medullary, or anaplastic) based on absolute changes in age-standardised incidence rates between 1998-2002 and 2008-12.

FINDINGS

Papillary thyroid cancer was the main contributor to overall thyroid cancer in all the studied countries, and was the only histological subtype that increased systematically in all countries, although with large variability between countries. In women, the age-standardised incidence rate of papillary thyroid cancer during 2008-12 ranged from 4·3-5·3 cases per 100 000 person-years in the Netherlands, the UK, and Denmark, to 143·3 cases per 100 000 women in South Korea. For men during the same period, the age-standardised incidence rates of papillary thyroid cancer per 100 000 person-years ranged from 1·2 cases per 100 000 in Thailand to 30·7 cases per 100 000 in South Korea. In many countries in Asia, the increase in papillary thyroid cancer rates in women was particularly pronounced after the year 2000; rates stabilised since around 2009 in the USA, Austria, Croatia, Germany, Slovenia, Spain, Lithuania, and Bulgaria. Temporal trends for follicular and medullary thyroid cancer did not show consistent patterns across countries, but slight decreases were seen for anaplastic thyroid cancer in 21 of 25 countries between 1998-2002, and 2008-12. In 2008-12, age-standardised rates for the follicular subtype ranged between 0·5 and 2·5 cases per 100 000 women (and between 0·3 and 1·5 per 100 000 men), while those for the medullary subtype were always less than 1 case per 100 000 women or men, and for anaplastic thyroid cancer less than 0·2 cases per 100 000 women or men.

INTERPRETATION

In the period from 1998 to 2012, the rapid increases in thyroid cancer incidence were observed only for papillary thyroid cancer, the subtype more likely to be found in a subclinical form and therefore detected by intense scrutiny of the thyroid gland.

FUNDING

French Institut National du Cancer, Italian Association for Cancer Research, Italian Ministry of Health.

Best Achievements in Clinical Thyroidology in 2020

This review highlights the most interesting research in thyroidology conducted in 2020. The publications of interest discussed below dealt with the following topics: thyroid dysfunction, risk of thyroid cancer, molecular diagnostics and new therapeutics for thyroid cancer, and thyroid disease in the coronavirus disease 2019 pandemic era.

Seasonal Changes of Thyroid Function Parameters in Women of Reproductive Age Between 2012 and 2018: A Retrospective, Observational, Single-Center Study

BACKGROUND

Thyroid function can be influenced by external stimuli such as light and temperature. However, it is currently unknown whether there is seasonal variation of thyroid function in women of reproductive age. Adequate thyroid function in reproductive-aged women is necessary for optimal fetal-maternal outcomes. Therefore, this study aims to evaluate the seasonal changes in levels of thyrotropin (TSH), free triiodothyronine (FT₃), free thyroxine (FT₄), and TSH index (TSHI) in women of reproductive age.

METHODS

A large retrospective study was conducted that included women aged 20-49 years who visited our outpatient or checkup center between 2012 and 2018. Thyroid function was measured using the automated immunochemiluminescent assay kit. Subjects with overt thyroid dysfunction, pregnancy, thyroid disease, cancer, and severe infectious or psychological disease were excluded. Seasonal differences of thyroid function were analyzed using the Kruskal-Wallis test or the analysis of means with transformed ranks. Spearman's correlation was performed to evaluate the association between thyroid function parameters and age. A subset of 181 subjects was included in the longitudinal analyses. Differences in thyroid function between summer and winter were analyzed using the Wilcoxon signed-rank test.

RESULTS

A total of 48,990 women with a median age of 39 years were included. The prevalence of subclinical hypothyroidism was lower in summer but higher in winter (5.6% vs. 7.0%, p < 0.05). The TSH, FT₃, and FT₄ levels and TSHI reached a peak in winter, while they declined to trough in summer. The TSH concentrations (r = 0.044, p < 0.001) and TSHI (r = 0.025, p < 0.001) were positively correlated with age, whereas FT₃ (r = -0.073, p < 0.001) and FT₄ (r = -0.059, p < 0.001) were negatively correlated with age. The associations of thyroid parameters with age were similar between subjects with positive thyroid peroxidase antibody (TPOAb) and those with negative TPOAb. In the matched longitudinal analysis of 181 subjects, no differences were detected in the thyroid parameters between summer and winter.

CONCLUSIONS

This retrospective single-center study showed that thyroid hormone levels and central sensitivity to thyroid hormones are influenced by age and seasonal fluctuations among women of reproductive age, while their impact on reproductive health remains to be elucidated in future studies.