Estrogen and its role in thyroid cancer

ETV5 overexpression contributes to tumor growth and progression of thyroid cancer through PIK3CA

AIMS

Thyroid cancer is a common endocrine malignancy and sex hormone plays an important role in it. We have previously shown that activation of estrogen receptor (ER) α promotes thyroid cancer cell proliferation and invasion. Here, we attempted to investigate the role of ETS variant 5 (ETV5) on estrogen drived thyroid malignancy.

MAIN METHODS

Ten patients with follicular thyroid cancer were enrolled in this study. Cell proliferation and migration ability were analyzed by CCK-8 assay and cell migration assay, respectively. Chromatin immunoprecipitation-PCR and luciferase assay were conducted to analyze the relationship of ETV5 and PIK3CA.

KEY FINDINGS

ETV5 is highly expressed in thyroid tissues from patients with follicular thyroid cancer as well as in FTC133 cells. 17b-estradiol or overexpression of ERα induced an increase in ETV5 protein level in FTC133 cells. Knockdown of ETV5 inhibited FTC133 cell proliferation, migration, and epithelial-mesenchymal transition, while 17b-estradiol could not correct this effect. Additionally, the level of PIK3CA was markedly decreased in ETV5 knockdown cells and had a positive correlation with ETV5 in thyroid cancer patients. Chromatin immunoprecipitation-PCR analysis and luciferase assay confirmed that ETV5 directly targeted PIK3CA and that ETV5 was bound to the promoter region of PIK3CA. In addition, PIK3CA overexpression abrogated ETV5-induced cell growth, migration and epithelial-mesenchymal transition.

SIGNIFICANCE

ETV5 enhanced cell proliferation, migration, and epithelial-mesenchymal transition through the PIK3CA signaling pathway, indicating that ETV5 may be a therapeutic target in thyroid cancer.

Adolescents with thyroid nodules: retrospective analysis of factors predicting malignancy

Thyroid nodules are less common in children than in adults. However, pediatric thyroid nodules have a higher rate of malignancy compared to those in adults, and increased risk of metastasis and recurrence. In the present study, we analyzed the clinical features as well as laboratory and thyroid ultrasound (US) findings of children and adolescents with thyroid nodules to identify predictive factors of thyroid cancer. We retrospectively analyzed 275 patients with thyroid nodules under 18 years of age who visited Severance Children's Hospital between January 2005 and May 2017. Among them, 141 patients who underwent ultrasonography-guided fine needle aspiration biopsy (FNAB), and four patients without FNAB who underwent surgical resection, were included in this study. The remaining 125 patients without FNAB and five patients with follow-up loss after FNAB were excluded. Clinical, laboratory, and US data were evaluated in 145 patients to establish the potential predictive factors of thyroid cancer. Thyroid malignancies were observed in 101 patients. Grade 2 goiters were seen more often in benign nodule group. Hypoechoic nodules, nodules with microcalcifications, abnormal lymph nodes, and irregular margins were findings significantly associated with thyroid cancer. The findings of hypoechoic nodule, nodule with microcalcifications, and abnormal lymph nodes showed statistical significance in predicting thyroid cancer.Conclusion: Hypoechoic nodules, nodules with microcalcifications, and abnormal lymph nodes are predictive factors for thyroid cancer in children. Therefore, further diagnostic evaluations, including FNAB, should be considered in patients with such findings.What is Known:• Thyroid nodules are less common in children than in adults, but pediatric thyroid nodules have a higher rate of malignancy, and also have increased risk of metastasis and recurrence.• Research on ways to predict thyroid cancer have mostly been accomplished in adult patients, and the application of risk stratification system has not been fully satisfactory in children, which requires further studies in pediatric thyroid nodules.What is New:• Hypoechoic nodules, nodules with microcalcifications, and abnormal lymph nodes are predictive factors for thyroid cancer in Korean children.

Nutritional status and follicular-derived thyroid cancer: An update

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

Association of Changes in Metabolic Syndrome Status With the Incidence of Thyroid Nodules: A Prospective Study in Chinese Adults

Although several cross-sectional studies have shown an association of metabolic syndrome (MetS) with nodular thyroid disease, related prospective studies are scarce. This study investigated the association of MetS with thyroid nodule (TN) incidence in Chinese adults, and explored whether the development of or recovery from MetS is associated with changes in the risk of developing TNs. A total of 4,749 Chinese aged 18-65 years were involved in this 6-year prospective study. The association of MetS with TN prevalence was examined. TN-free individuals at baseline (n = 3,133) were further examined. TN incidence rates in groups with different MetS statuses (MetS-free, MetS-developed, MetS-recovery and MetS-chronic) were analyzed. Of all participants, 18.21 and 31.65% had MetS and TNs, respectively. MetS patients had a higher TN prevalence than the non-MetS group (31.08 vs. 19.81% in males, p < 0.01; 59.52 vs. 39.59% in females, p < 0.01). Sex, age and MetS were independent risk factors for TNs. At a median follow up of 5.94 years, the MetS-chronic group (4.37/100 person-years) had a higher risk of TNs (adjusted incidence rate ratio [IRR] = 1.288 [95% CI 1.014-1.636]) compared with the MetS-free group (2.72/100 person-years) in the whole cohort. In males, the MetS-chronic group (3.76/100 person-years) had a higher risk of TNs (adjusted IRR = 1.367 [95% CI 1.017-1.835]) compared with the MetS-free group (2.31/100 person-years). In females, the risk of TNs was significantly higher in the MetS-chronic (6.44/100 person-years) and MetS-developed (6.31/100 person-years) groups compared with the MetS-free group (3.23/100 person-years).

Thyroid Stimulating Hormone (TSH) Is Associated With General and Abdominal Obesity: A Cohort Study in School-Aged Girls During Puberty in East China

Objectives: Although the association between thyroid stimulating hormone (TSH) and obesity in children has been investigated in several cross-sectional studies, no study evaluated this association among girls during puberty, which were in a key period closely related to the fluctuations of thyroid hormones and development of obesity. Therefore, we conducted a cohort study to investigate the association of general and abdominal obesity with TSH in girls during puberty. Setting and participants: A cohort study of 481 school-aged girls during puberty was conducted in four regions in east China, with a baseline survey in 2017 and a follow-up survey in 2019. Outcome measures: Anthropometric indexes including height, weight and waist circumference (WC) were measured, and body mass index (BMI) was then calculated. Blood samples were collected to determine TSH and free thyroxine (FT4). Results: Of the 474 girls at baseline survey, the prevalences of BMI-based general obesity and WC-based abdominal obesity were 19.8% (94/474) and 21.7% (103/474), respectively. Compared with normal weight girls, the median serum TSH level was significantly higher in general obese girls (P = 0.037), but not in central obese girls (P = 0.173). Multiple logistic regression models indicated that those in the highest tertile of serum TSH level had a significantly higher risk of BMI-based overweight/obesity (OR = 1.83, 95% CI 1.01 to 3.32) compared with the lowest tertile. Analyses from 435 girls prospectively followed-up for 2 years revealed that those with general or central obesity also had higher follow-up TSH level (P = 0.004 and P = 0.008, respectively). The TSH level for girls with general obesity at baseline but normal weight at follow-up was 0.45 mU/L (95% CI 0.11 to 0.79) higher than those with normal weight at baseline and follow-up. Conclusions: TSH was positively associated with both general and abdominal obesity among girls during puberty.

Cribriform-Morular Variant of Papillary Thyroid Carcinoma Shows High Ki-67 Labeling Indices, despite Its Excellent Prognosis

OBJECTIVE

This study aimed to demonstrate that the cribriform-morular variant (CMV) of papillary thyroid carcinoma (PTC) has high Ki-67 labeling indices, despite its excellent prognosis.

METHODS

We examined 21 CMV-PTCs and 5 conventional PTCs (C-PTCs) resected at Kuma Hospital between 2008 and 2018. All of the patients with CMV-PTC were women. Their ages ranged from 17 to 35 years, with a mean of 25.2 years. An immunohistochemical study using β-catenin, estrogen receptor (ER), and Ki-67 was performed. For apoptotic analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling staining was performed.

RESULTS

All CMV-PTCs were encapsulated with thick fibrous connective tissue. Eleven and one CMV-PTCs exhibited capsular invasion and extrathyroidal invasion, respectively. Two patients showed regional nodal metastasis. The Ki-67 labeling index ranged from 4.8 to 36.4% (mean 15.2%). Apoptotic cells were counted, which showed 2-52 positive cells (mean 12.6) per 10 high-power fields. The Ki-67 labeling index was positively correlated with the apoptotic cell count (r = 0.48, p = 0.030). Ki-67 labeling indices of CMV-PTCs were significantly higher than those of C-PTCs (p = 0.0027). Ages and tumor sizes did not have significant correlations with Ki-67 labeling indices or apoptotic cell counts.

CONCLUSION

This study is the first to demonstrate disproportionally high Ki-67 labeling indexes in a large number of CMV-PTC cases, despite the fact that these cases had favorable prognoses. The favorable prognosis of CMV-PTC may be attributable to encapsulation and nuclear ER expression.

Thyroid Cancer: The Quest for Genetic Susceptibility Involving DNA Repair Genes

The incidence of thyroid cancer (TC), particularly well-differentiated forms (DTC), has been rising and remains the highest among endocrine malignancies. Although ionizing radiation (IR) is well established on DTC aetiology, other environmental and genetic factors may also be involved. DNA repair single nucleotide polymorphisms (SNPs) could be among the former, helping in explaining the high incidence. To further clarify the role of DNA repair SNPs in DTC susceptibility, we analyzed 36 SNPs in 27 DNA repair genes in a population of 106 DTCs and corresponding controls with the aim of interpreting joint data from previously studied isolated SNPs in DNA repair genes. Significant associations with DTC susceptibility were observed for XRCC3 rs861539, XPC rs2228001, CCNH rs2230641, MSH6 rs1042821 and ERCC5 rs2227869 and for a haplotype block on chromosome 5q. From 595 SNP-SNP combinations tested and 114 showing relevance, 15 significant SNP combinations (p < 0.01) were detected on paired SNP analysis, most of which involving CCNH rs2230641 and mismatch repair variants. Overall, a gene-dosage effect between the number of risk genotypes and DTC predisposition was observed. In spite of the volume of data presented, new studies are sought to provide an interpretability of the role of SNPs in DNA repair genes and their combinations in DTC susceptibility.

Hemithyroidectomy for benign euthyroid asymmetric nodular goitre

BACKGROUND

There is no consensus on the optimal surgery extent for patients with benign euthyroid asymmetric nodular goitre (AMNG).

METHODS

We reviewed medical literature using the PubMed engine to address the following issues: definition and prevalence, rationale for hemithyroidectomy, long-term outcomes, follow-up, revision surgery and image-guided thermal ablation of contralateral benign thyroid nodules following hemithyroidectomy for AMNG.

RESULTS

In total, 102 articles were found in MEDLINE using a keyword search strategy; subsequently, we selected 36 articles with clinical pertinence.

CONCLUSIONS

AMNG is a common clinical and surgical problem. Depending on the extent of the disease and individual surgeon preferences, either unilateral or bilateral thyroidectomy can be performed. Hemithyroidecomy can be considered for some patients with AMNG and the low risk of recurrent disease as a safer alternative to total thyroidectomy but it requires life-long follow-up, is associated with a higher recurrence risk and a need for revision thyroidectomy in selected subjects.

Phytoestrogens: Dietary Intake, Bioavailability, and Protective Mechanisms against Colorectal Neoproliferative Lesions

Phytoestrogens are natural substances that have been extensively studied for their beneficial effect on human health. Herein, we analyzed the data of the literature on the role of phytoestrogens in the prevention of colorectal neoproliferative lesions (CNL). Both in vitro and in vivo studies suggest that the beneficial effects of phytoestrogens on CNL mainly depend on their ability to bind estrogen receptor beta (ERβ) in the intestinal mucosa and counter ER-alpha (ERα) activity. Epidemiological data demonstrate a correlation between the low prevalence of CNL in Eastern populations and the consumption of soy products (phytoestrogen-enriched diet). However, both observational and interventional studies have produced inconclusive results. In our opinion, these discrepancies depend on an inadequate evaluation of phytoestrogen intake (dietary questionnaires were not aimed at establishing phytoestrogen intake) and absorption (depending mainly on the intestinal microbiota of the analyzed subjects). For this reason, in the present review, we performed an overview of phytoestrogen dietary intake and metabolism to offer the reader the opportunity for a better interpretation of the literature. Future prospective trials focusing on the protective effect of phytoestrogens against CNL should take into account both their dietary intake and absorption, considering the effective role of the intestinal microbiota.

Role of estrogen and its receptors mediated-autophagy in cell fate and human diseases

Studies have shown that morbidity of several diseases varies between males and females. This difference likely arises due to sex-related hormones. Estrogen, a primary female sex steroid hormone, plays a critical role in mediating many of the physiological functions like growth, differentiation, metabolism, and cell death. Recently, it has been demonstrated that estrogen mediates autophagy through its receptors (ERs) namely ERα, ERβ, and G-protein coupled estrogen receptor (GPER). However, the specific role of estrogen and its receptors mediated-autophagy in cell fate and human diseases such as cancers, cardiovascular disease and nervous system disease remains unclear. In this review, we comprehensively summarize the complex role of estrogen and its receptors-mediated autophagy in different cell lines and human diseases. In addition, we further discuss the key signaling molecules governing the role of ERs in autophagy. This review will serve as the basis for a proposed model of autophagy constituting a new frontier in estrogen-related human diseases. Here, we discuss the dual role of ERα in classical and non-classical autophagy through B-cell lymphoma 2 (BCL2)-associated athanogene 3 (BAG3). Next, we review the role of ERβ in pro-survival pathways through the promotion of autophagy under stress conditions. We further discuss activation of GPER via estrogen often mediates autophagy or mitophagy suppression, respectively. In summary, we believe that understanding the relationship between estrogen and its receptors mediated-autophagy on cell fate and human diseases will provide insightful knowledge for future therapeutic implications.

Systems Biology Approaches to Investigate Genetic and Epigenetic Molecular Progression Mechanisms for Identifying Gene Expression Signatures in Papillary Thyroid Cancer

Thyroid cancer is the most common endocrine cancer. Particularly, papillary thyroid cancer (PTC) accounts for the highest proportion of thyroid cancer. Up to now, there are few researches discussing the pathogenesis and progression mechanisms of PTC from the viewpoint of systems biology approaches. In this study, first we constructed the candidate genetic and epigenetic network (GEN) consisting of candidate protein–protein interaction network (PPIN) and candidate gene regulatory network (GRN) by big database mining. Secondly, system identification and system order detection methods were applied to prune candidate GEN via next-generation sequencing (NGS) and DNA methylation profiles to obtain the real GEN. After that, we extracted core GENs from real GENs by the principal network projection (PNP) method. To investigate the pathogenic and progression mechanisms in each stage of PTC, core GEN was denoted in respect of KEGG pathways. Finally, by comparing two successive core signaling pathways of PTC, we not only shed light on the causes of PTC progression, but also identified essential biomarkers with specific gene expression signature. Moreover, based on the identified gene expression signature, we suggested potential candidate drugs to prevent the progression of PTC with querying Connectivity Map (CMap).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Relation between hysterectomy, oophorectomy and the risk of incident differentiated thyroid cancer: The E3N cohort

BACKGROUND

Thyroid cancers are threefold more frequent in women than in men. A role of reproductive or hormonal factors has been suggested but with contradictory results. We investigated potential associations between history of hysterectomy, with or without oophorectomy, and history of benign gynaecological disease (uterine fibroids, endometriosis) and the incidence of differentiated thyroid cancer, in a large French prospective cohort.

METHODS

A total of 89 340 women from the E3N cohort were followed up between 1990 and 2012. Gynaecological diseases treated by surgery were self-reported. Thyroid cancers were validated by histological reports. Time-dependent covariates included smoking status, BMI and history of benign thyroid disease. Cox proportional hazard models with age as timescale were used to estimate Hazard Ratios (HR) and 95% confidence intervals (CI).

RESULTS

A total of 412 cases of thyroid cancer were diagnosed during follow-up. A history of hysterectomy was associated with an increased risk of differentiated thyroid cancer (adjusted HR=2.05; 95%CI: 1.65-2.55). The association was not altered after further adjustment for reproductive factors. Endometriosis, uterine polyps, ovarian cysts and oophorectomy without hysterectomy were not associated with the risk of thyroid cancer. A history of fibroids was also significantly related to the risk of thyroid cancer over the follow-up period (adjusted HR=1.91; 95%CI: 1.50-2.44) and the increased risk persisted after adjustment for history of hysterectomy.

CONCLUSIONS

Women who had either a history of fibroids or hysterectomy had an increased risk of differentiated thyroid cancer. These findings suggest shared biological mechanisms between fibroids and thyroid cancer, which deserve to be further dissected.

PES1 promotes the occurrence and development of papillary thyroid cancer by upregulating the ERα/ERβ protein ratio

PES1, a BRCT domain-containing protein, has been shown to play a role in modulating the balance and ratio between ERα and ERβ protein, which is involved in the occurrence and development of breast and ovarian cancer. However, its role in connection with the balance and ratio between ERα and ERβ protein in papillary thyroid cancer (PTC) remains unclear. Here, we found that ERα and ERβ were co-expressed in human PTC tissues and cells. ERα promoted and ERβ inhibited the proliferation, invasion and migration of PTC cells. PES1 modulated the balance between ERα and ERβ by elevating the ERα protein level and simultaneously reducing the ERβ protein level, then upregulating the ERα/ERβ protein ratio and promoting the proliferation, invasion and migration of PTC cells. In PTC tissues, PES1 protein level was positively correlated with the ERα protein level and negatively correlated with the ERβ protein level. The PES1 and ERα protein levels were gradually increased and the ERβ protein level was decreased by degree in the occurrence and development of PTC. Increased PES1 and ERα protein levels and decreased ERβ protein level were correlated with the aggressive behaviors of PTC patients such as large tumor size, extrathyroidal extension (ETE), lymph node metastasis (LNM), high BRAFV600E expression and high TNM stage. It is suggested that PES1 promotes the occurrence and development of PTC by elevating the ERα protein level and reducing the ERβ protein level, and then upregulating the ERα/ERβ protein ratio.

The Emerging Role of Estrogens in Thyroid Redox Homeostasis and Carcinogenesis

Reactive oxygen species (ROS) are the most critical class of free radicals or reactive metabolites produced by all living organisms. ROS regulate several cellular functions through redox-dependent mechanisms, including proliferation, differentiation, hormone synthesis, and stress defense response. However, ROS overproduction or lack of appropriate detoxification is harmful to cells and can be linked to the development of several diseases, such as cancer. Oxidative damage in cellular components, especially in DNA, can promote the malignant transformation that has already been described in thyroid tissue. In thyrocyte physiology, NADPH oxidase enzymes produce large amounts of ROS that are necessary for hormone biosynthesis and might contribute to the high spontaneous mutation rate found in this tissue. Thyroid cancer is the most common endocrine malignancy, and its incidence is significantly higher in women than in men. Several lines of evidence suggest the sex hormone estrogen as a risk factor for thyroid cancer development. Estrogen in turn, besides being a potent growth factor for both normal and tumor thyroid cells, regulates different mechanisms of ROS generation. Our group demonstrated that the thyroid gland of adult female rats exhibits higher hydrogen peroxide (H₂O₂) production and lower enzymatic antioxidant defense in comparison with male glands. In this review, we discuss the possible involvement of thyroid redox homeostasis and estrogen in the development of thyroid carcinogenesis.

Thyroid nodule recurrence following lobo-isthmectomy: incidence, patient's characteristics, and risk factors

PURPOSE

This study was aimed at assessing the incidence and timing of thyroid nodules recurrence, defined as appearance of new benign or malignant nodules in contralateral lobe in patients with benign thyroid nodules or thyroid microcarcinoma treated with lobo-isthmectomy. Patient's characteristics and risk factors associated with this phenomenon were also investigated.

METHODS

A retrospective study was performed by evaluating 413 patients undergoing lobo-isthmectomy with a minimum follow-up of 1 year. Clinical characteristics, surgical interventions and complications, histological diagnosis, and thyroid function at last follow-up were collected.

RESULTS

Single or multiple thyroid nodule recurrence equally occurred in 80 patients (23%) with a median time to relapse of ~ 5 years (range 0.3-34.5 years) after lobo-isthmectomy. Recurrence was significantly associated with younger age (< 46 years) and number of pregnancies in women. Development of hypothyroidism was not rare either (~ 10%) and appeared in 3-19 months; a preoperative TSH level > 2.43 mIU/L was associated with the need of l-thyroxin replacement therapy after surgery. The most frequent surgical complication was transient hypoparathyroidism (4.6%), while the rate of permanent hypoparathyroidism significantly increased in patients submitted to completion thyroidectomy (5.3%).

CONCLUSIONS

Thyroid nodules recurrence following lobo-isthmectomy is not a rare event and occurs within 5 years after surgery, more frequently in younger patients with family history of nodular goiter and in women with multiple pregnancies. Pre-surgical TSH levels may predict the development of post-surgical hypothyroidism, possibly improving the management of patients addressed to surgery.

Cancer risk in Chinese diabetes patients: a retrospective cohort study based on management data

The excess risk of cancer observed in patients with type 2 diabetes (T2DM) may have been influenced by detection bias. The aim of this study was to examine the real association by evaluating time-varying site-specific cancer risks in newly diagnosed T2DM patients. A total of 51,324 registered cancer-free individuals newly diagnosed with T2DM between 2004 and 2014 were linked with the Shanghai Cancer Registry and the Vital Statistics through September 2015. A total of 2920 primary, invasive cancer cases were identified during 325,354 person-years period. Within 1 year following diabetes onset, participants with T2DM had higher risks of total, lung and rectal cancer in men and total, liver, pancreas, thyroid, breast and uteri cancer in women. Thereafter the incidence for overall cancer decreased and then increased along with follow-up time, with the upward trend varying by cancer, suggesting potential detection bias. After the initial 1-year period, standardized incidence ratios (SIR) and 95% CIs for overall cancer were 0.80 (95% CI 0.76-0.85) in men and 0.93 (95% CI 0.88-0.99) in women, but a higher risk of breast and thyroid cancers were observed in women, with SIR and 95% CI being 1.13 (1.01, 1.28) and 1.37 (1.11, 1.63), respectively. Our results suggest that T2DM patients are at higher risk of certain cancers; this risk particularly increases shortly after diabetes diagnosis, which is likely to be due to detection bias caused by increased ascertainment. Prevention of female breast and thyroid cancers should be paid attention in Chinese individuals with T2DM.

Sleep duration and the risk of cancer: a systematic review and meta-analysis including dose-response relationship

Background

The effect of sleep duration on cancer risk remains controversial. We aimed to quantify the available evidence on this relationship using categorical and dose–response meta-analyses.

Methods

Population-based cohort studies and case-control studies with at least three categories of sleep duration were identified by searching PubMed, EMBASE, and the Cochrane Library database up to July 2017.

Results

Sixty-five studies from 25 articles were included, involving 1,550,524 participants and 86,201 cancer cases. The categorical meta-analysis revealed that neither short nor long sleep duration was associated with increased cancer risk (short: odds ratio [OR] = 1.01, 95% confidence intervals [CI] = 0.97–1.05; long: OR = 1.02, 95% CI = 0.97–1.07). Subgroup analysis revealed that short sleep duration was associated with cancer risk among Asians (OR = 1.36; 95% CI: 1.02–1.80) and long sleep duration significantly increased the risk of colorectal cancer (OR = 1.21; 95% CI: 1.08–1.34). The dose–response meta-analysis showed no significant relationship between sleep duration and cancer risk. When treated as two linear piecewise functions with a cut point of 7 h, similar nonsignificant associations were found (per 1-h reduction: OR = 1.02, 95% CI = 0.98–1.07; per 1-h increment: OR = 1.003, 95% CI = 0.97–1.03).

Conclusion

Categorical meta-analysis indicated that short sleep duration increased cancer risk in Asians and long sleep duration increased the risk of colorectal cancer, but these findings were not consistent in the dose–response meta-analysis. Long-term randomized controlled trials and well-designed prospective studies are needed to establish causality and to elucidate the mechanism underlying the association between sleep duration and cancer risk.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-5025-y) contains supplementary material, which is available to authorized users.

FKBP51 promotes migration and invasion of papillary thyroid carcinoma through NF-κB-dependent epithelial-to-mesenchymal transition

FK506-binding protein 51 (FKBP51) is a member of the immunophilin family, with relevant roles in multiple signaling pathways, tumorigenesis and chemoresistance. However, the function of FKBP51 in papillary thyroid carcinoma (PTC) remains largely unknown. In the present study, increased FKBP51 expression was detected in PTC tissues as compared with adjacent normal tissues, and the expression level was associated with clinical tumor, node and metastasis stage. Using FKBP51-overexpressing K1 cells and FKBP51-knockdown TPC-1 cells, both human PTC cell lines, it was identified that FKBP51 promoted the migration and invasion of PTC, without affecting cell proliferation. Further investigation revealed that FKBP51 activated the NF-κB pathway and epithelial-to-mesenchymal transition (EMT) genes, and EMT was suppressed when NF-κB was inhibited. It was also assessed whether FKBP51 promoted the formation of cytoskeleton to promote migration and invasion of PTC using a tubulin tracker; however, no evidence of such an effect was observed. These results suggested that FKBP51 promotes migration and invasion through NF-κB-dependent EMT.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

The Role of Polybrominated Diphenyl Ethers in Thyroid Carcinogenesis: Is It a Weak Hypothesis or a Hidden Reality? From Facts to New Perspectives

In the last decades, the incidence of thyroid cancer has increased faster than that of any other malignant tumor type. The cause of thyroid cancer is likely multifactorial and a variety of both exogenous and endogenous has been identified as potential risk factors. Polybrominated diphenyl ethers (PBDEs), used since the 1970s as flame retardants, are still widespread and persistent pollutants today, although their production was definitely phased out in the western countries several years ago. Polybrominated diphenyl ethers are known endocrine disruptors, and the endocrine system is their primary target. Whereas animal studies have ascertained the ability of PBDEs to affect the normal functionality of the thyroid, evidence in humans remains inconclusive, and only a few epidemiological studies investigated the association between exposure to PBDEs and thyroid cancer. However, a number of clues suggest that a prolonged exposure to these chemicals might act a trigger of the most common malignancy of the endocrine system, whereas further studies with an advanced design are suggested.

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.

Nutritional and Environmental Factors in Thyroid Carcinogenesis

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

Role of the Mechanisms of Detection in the Increased Risk of Thyroid Cancer: A Retrospective Cohort Study in an HMO in Buenos Aires

Background

Two hypotheses attempt to explain the increase of thyroid cancer (TC) incidence: overdetection by excessive diagnostic scrutiny and a true increase in new cases brought about by environmental factors. Changes in the mechanism of detection and the risk of incidentally diagnosed TC could result in an increase of TC incidence.

Methods

Retrospective cohort study. We identified incident cases of TC from the pathological reports of patients in a HMO and review of clinical records. The results were analyzed in two periods: 2003-2007 and 2008-2012. Incidence rates expressed per 100,000 person-years (with 95% CI) and relative risk of incidence rates of incidental and nonincidental TC were estimated.

Results

The relative risk of incidentally detecting a thyroid cancer in 2008-2012 compared to 2003-2007 was 6.06 (95%CI 1.84-20.04). Clinical evaluations detected 31 (75.6%) cancers in the period 2003-2007 and 70 (51.8%) cancers in the period 2008-2012 (p<0.007). Although tumor median size was significantly lower in the period 2008-2012 (10 vs. 14 mm, p<0.03), tumors greater than 40 mm (4.3%) were only present in 2008-2012. The female/male ratio decreased between analyzed periods from 8 (3-21) to 4 (3-7).

Conclusions

Our findings partially support the hypothesis of increased incidence due to overdetection but do not explain the changes in the increase of larger tumors and decrease in the female/male ratio, which could be secondary to the influence of unidentified environmental factors.

Review of the possible association between thyroid and breast carcinoma

Background

Thyroid and breast cancer are two of the malignant diseases with highest incidence in females. Based on clinical experience, breast and thyroid cancer often occur metachronously or synchronously. Therefore, thyroid and breast cancer might share some common etiological factors. The relationship between these diseases has attracted substantial attention, and because these two glands are both regulated by the hypothalamic-pituitary axis, such a relationship is not surprising. A study of this relationship will be useful for obtaining a better understanding of the mechanism by which these two malignancies co-occur.

Main body

This study reviewed the progress in research on the roles of iodine intake, folate metabolism, obesity, gonadal hormones, and thyroid hormone in thyroid and breast cancer. These studies evaluating the etiological roles of these factors in linking breast and thyroid cancer might also improve our understanding and identify new therapeutic approaches, such as sodium/iodide symporter-mediated radioiodine therapy and thyroid-stimulating hormone receptor antagonists, for breast cancer. In addition, some specific treatments for each cancer, such as radiotherapy for breast cancer or radioactive iodine therapy for thyroid cancer, might be risk factors for secondary malignances, including breast and thyroid cancer.

Conclusions

Studies of the precise relationship between the co-occurrence of breast and thyroid cancer will certainly improve our understanding of the biological behaviors of these two malignancies and direct evidence-based clinical practice.

Clinic-pathologic Features and Prognostic Analysis of Thyroid Cancer in the Older Adult: A SEER Based Study

Purpose: Age at diagnosis has been identified as a major determinant of thyroid cancer-specific survival. But the cut-off value for age was controversial. The interaction among gender, age and histologic subtypes needed to be answered.

Methods: We identified 59,892 thyroid cancer (TC) patients from the Surveillance, Epidemiology, and End Results (SEER) database. We divided the patients into the following three groups according to age: 20-44 years (young), 45-64 years (middle-aged), and ≥ 65 years (elderly). Logistic regression model was used to identify factors relating to prognosis in elderly patients. Multivariable Cox regression model identified potential prognostic factors. All statistical tests were two-sided.

Results: Elderly patients had significantly worse prognosis than the other two groups, P=0.001. Elderly patients had higher proportion of male gender, advanced tumor grade, follicular subtype and advanced tumor stage. There was no survival difference for elderly patients to receive lobectomy and total thyroidectomy, P=0.852. Cox proportional hazards regression model showed that gender, marital status, histology, tumor grade, tumor size, TNM stage, surgery and radiotherapy were all independent prognostic factors in the multivariable analysis. Male patients with TC had worse prognosis than their female counterparts in differentiated tumor but not in undifferentiated tumor. There were more patients of larger tumor, advanced TNM stage and histologic subtypes in male patients.

Conclusions: In conclusion, there were a series of factors contributing to the poor prognosis in elderly patients including clinic-pathologic factors and therapy selection. There was no survival difference for elderly patients to receive lobectomy and total thyroidectomy.

Rare Clinical Entity: Metastatic malignant struma ovarii diagnosed during pregnancy - Lessons for management

Background

Malignant struma ovarii is an ovarian teratoma containing at least 50% thyroid tissue which has the potential to metastasize and produce thyroid hormone. Given its rarity, management strategies are not well-established. We report a case of metastatic malignant struma ovarii discovered during pregnancy with lessons for evaluation and management.

Case presentation

A 30-year-old woman who was two months pregnant was discovered to have struma ovarii with over half of the struma comprised of papillary thyroid cancer. Following tumor resection, delivery, and thyroidectomy, she underwent evaluation with stimulated thyroglobulin testing and diagnostic staging sodium iodide-131 scan (I-131), which revealed the presence of skeletal metastases. Following administration of 320 mCi I-131, post-therapy scan also showed miliary pulmonary metastases with improved ability to localize the bony and pulmonary metastases with concurrent SPECT/CT imaging. A second dosimetry-guided I-131 therapy resulted in complete resolution of pulmonary metastases; however, small foci of residual bone disease persisted. Post-therapy scans demonstrated additional findings not shown on diagnostic I-131 scans obtained prior to both her initial and second I-131 therapy.

Conclusions

SPECT/CT provides accurate anatomic correlation and localization of metastatic foci and can serve as a baseline study to assess interval response to treatment. Post-therapy scans should always be obtained when I-131 treatment is administered, as additional findings may be revealed versus low dose I-131 activity diagnostic scans. This patient had a high metastatic burden that would not have been discovered in a timely fashion with the conservative approach advocated by others. Thyroidectomy followed by a diagnostic staging radioiodine scan and a stimulated thyroglobulin level should be considered in patients with malignant struma ovarii for guiding therapeutic I-131 administration as metastatic risk is difficult to predict based on histopathologic examination.

Development and validation of an individualized diagnostic signature in thyroid cancer

New molecular signatures are needed to improve the diagnosis of thyroid cancer (TC) and avoid unnecessary surgeries. In this study, we aimed to develop a robust and individualized diagnostic signature in TC. Gene expression profiles of tumor and nontumor samples were from 13 microarray datasets of Gene Expression Omnibus (GEO) database and one RNA‐sequencing dataset of The Cancer Genome Atlas (TCGA). A total of 1246 samples were divided into a training set (N = 435), a test set (N = 247), and one independent validation set (N = 564). In the training set, 115 most frequent differentially expressed genes (DEGs) among the included datasets were used to construct 6555 gene pairs, and 19 significant pairs were detected to further construct the diagnostic signature by a penalized generalized linear model. The signature showed a good diagnostic ability for TC in the training set (area under receiver operating characteristic curve (AUC) = 0.976), test set (AUC = 0.960), and TCGA dataset (AUC = 0.979). Subgroup analyses showed consistent results when considering the type of nontumor samples and microarray platforms. When compared with two existing molecular signatures in the diagnosis of thyroid nodules, the signature (AUC = 0.933) also showed a higher diagnostic ability (AUC = 0.886 for a 7‐gene signature and AUC = 0.892 for a 10‐gene signature). In conclusion, our study developed and validated an individualized diagnostic signature in TC. Large‐scale prospective studies were needed to further validate its diagnostic ability.

Findings of Thyroid Ultrasound Examination Within 3 Years After the Fukushima Nuclear Power Plant Accident: The Fukushima Health Management Survey

CONTEXT

Childhood thyroid cancer is of great concern after the Fukushima nuclear power plant accident. Baseline analytical data on thyroid ultrasound examination (TUE) in children are important for future studies.

OBJECTIVE

We analyzed the age and sex distribution of findings from the TUEs of children and adolescents in the Fukushima Health Management Survey (FHMS).

DESIGN, SETTING, AND PARTICIPANTS

From October 2011 through March 2014, 294,905 participants aged 18 years or younger at the time of the earthquake voluntarily had TUEs in the first round of the FHMS. A secondary confirmatory examination was performed in 2032 subjects. Age- and sex-dependent prevalence and size of thyroid cysts, nodules, and cancers were analyzed.

MAIN OUTCOME MEASURES

Age, sex, and size distribution of findings were analyzed.

RESULTS

Thyroid cysts, nodules, and cytologically suspected cancers were detected in 68,009, 1415, and 38 male subjects and in 73,014, 2455, and 74 female subjects, respectively. There was an age-dependent increase in the detection rate of thyroid nodules and cancer, but that of cysts reached a peak at 11 to 12 years. Sex affected the prevalence of thyroid nodules and cancers after the onset of puberty, but only a small difference was exhibited in that of cysts.

CONCLUSIONS

The thyroid cancer detection rate in Fukushima was clarified, and the proportion of individuals with thyroid nodules and cysts varied substantially by age. The results of this study will contribute to future epidemiological research on nodular thyroid diseases in children and adolescents.

Mismatch repair single nucleotide polymorphisms and thyroid cancer susceptibility

Thyroid cancer (TC) is the most common endocrine malignancy and its incidence continues to rise worldwide. Ionizing radiation exposure is the best established etiological factor. Heritability is high; however, despite valuable contribution from recent genome-wide association studies, the current understanding of genetic susceptibility to TC remains limited. Several studies suggest that altered function or expression of the DNA mismatch repair (MMR) system may contribute to TC pathogenesis. Therefore, the present study aimed to evaluate the potential role of a panel of MMR single nucleotide polymorphisms (SNPs) on the individual susceptibility to well-differentiated TC (DTC). A case-control study was performed involving 106 DTC patients and 212 age- and gender-matched controls, who were all Caucasian Portuguese. Six SNPs present in distinct MMR genes (MLH1 rs1799977, MSH3 rs26279, MSH4 rs5745325, PMS1 rs5742933, MLH3 rs175080 and MSH6 rs1042821) were genotyped through TaqMan^® assays and genotype-associated risk estimates were calculated. An increased risk was observed in MSH6 rs1042821 variant homozygotes [adjusted odds ratio (OR)=3.42, 95% CI: 1.04-11.24, P=0.04, under the co-dominant model; adjusted OR=3.84, 95% CI: 1.18-12.44, P=0.03, under the recessive model]. The association was especially evident for the follicular histotype and female sex. The association was also apparent when MSH6 was analysed in combination with other MMR SNPs such as MSH3 rs26279. Interestingly, two other SNP combinations, both containing the MSH6 heterozygous genotype, were associated with a risk reduction, suggesting a protective effect for these genotype combinations. These data support the idea that MMR SNPs such as MSH6 rs1042821, alone or in combination, may contribute to DTC susceptibility. This is coherent with the limited evidence available. Nevertheless, further studies are needed to validate these findings and to establish the usefulness of these SNPs as genetic susceptibility biomarkers for DTC so that, in the near future, cancer prevention policies may be optimized under a personalized medicine perspective.

Gender in Endocrine Diseases: Role of Sex Gonadal Hormones

Gender- and sex- related differences represent a new frontier towards patient-tailored medicine, taking into account that theoretically every medical specialty can be influenced by both of them. Sex hormones define the differences between males and females, and the different endocrine environment promoted by estrogens, progesterone, testosterone, and their precursors might influence both human physiology and pathophysiology. With the term Gender we refer, instead, to behaviors, roles, expectations, and activities carried out by the individual in society. In other words, "gender" refers to a sociocultural sphere of the individual, whereas "sex" only defines the biological sex. In the last decade, increasing attention has been paid to understand the influence that gender can have on both the human physiology and pathogenesis of diseases. Even the clinical response to therapy may be influenced by sex hormones and gender, but further research is needed to investigate and clarify how they can affect the human pathophysiology. The path to a tailored medicine in which every patient is able to receive early diagnosis, risk assessments, and optimal treatments cannot exclude the importance of gender. In this review, we have focused our attention on the involvement of sex hormones and gender on different endocrine diseases.

Association between chronic exposure to different water iodine and thyroid cancer: A retrospective study from 1995 to 2014

The controversy that iodine intake may increase the risk of thyroid cancer has heightened over the past twenty years. In this retrospective study, we mainly analyzed the association between water iodine and thyroid cancer and discussed the possible cause of the increase in thyroid cancer. This study was supported by three hospitals in areas with different water iodine concentration. 5574 patients with thyroid disease were recruited, of which 1429 patients had been diagnosed with thyroid cancer. These samples collectively were used to analyze the relationship of incidence and prevalence associated with water iodine. In addition, the ratio of maximum tumor diameter was analyzed. By analyzing the proportion of patients with thyroid cancer in thyroid diseases, we found a decrease in the proportion of thyroid cancer with increasing water iodine (P<0.0001). In addition, there was no significant correlation between the median water iodine and the prevalence of thyroid cancer, including papillary thyroid cancer (P>0.05). Meanwhile, the 5years' cumulative incidence of thyroid cancer increased with years (P<0.01). Comparing Cao county and Shan county, which are areas with high water iodine, to adequate iodine area such as in Mudan district, an increasing incidence is observed in 2010-2014 in Mudan district. Again, we observed a significant increase in the proportion of thyroid cancer with tumor size <1cm (P<0.01). Therefore, we concluded that cause(s) of increase in thyroid cancer may be ascribed to the sensitive diagnostic techniques and the improvement of living condition, but not water iodine.

Carcinogenic risk and Bisphenol A exposure: A focus on molecular aspects in endoderm derived glands

Epidemiological and experimental evidence associates the exposure to Bisphenol A with the increase of cancer risk in several organs, including prostate. BPA targets different pathways involved in carcinogenicity including the Nuclear Receptors (i.e. estrogen and androgen receptors), stress regulated proteins and, finally, epigenetic changes. Here, we analyse BPA-dependent carcinogenesis in endoderm-derived glands, thyroid, liver, pancreas and prostate focusing on cell signalling, DNA damage repair pathways and epigenetic modifications. Mainly, we gather molecular data evidencing harmful effects at doses relevant for human risk (low-doses). Since few molecular data are available, above all for the pancreas, we analysed transcriptomic data generated in our laboratory to suggest possible mechanisms of BPA carcinogenicity in endoderm-derived glands, discussing the role of nuclear receptors and stress/NF-kB pathways. We evidence that an in vitro toxicogenomic approach might suggest mechanisms of toxicity applicable to cells having the same developmental origin. Although we cannot draw firm conclusions, published data summarized in this review suggest that exposure to BPA, primarily during the developmental stages, represents a risk for carcinogenesis of endoderm-derived glands.

Estrogen receptor subtype expression and regulation is altered in papillary thyroid cancer after menopause

BACKGROUND

Estrogen receptors can regulate growth in papillary thyroid cancer and may affect prognosis after menopause. This study examines changes of estrogen receptor subtype ratio expression in papillary thyroid cancer cell lines derived from pre- and postmenopausal women.

METHODS

Cells were harvested from papillary thyroid cancer and non-papillary thyroid cancer thyroid tissue (control) from pre- (n = 9) and postmenopausal women (n = 11). Protein expression of estrogen receptor α, estrogen receptor β, and phosphorylated extracellular signal-regulated kinase and protein kinase B were analyzed. Matrix metalloproteinase-2 activity was determined as a measure of tumor invasiveness. Mitochondrial retrograde signaling was altered with ethidium bromide to determine its effect on estrogen receptor α protein expression.

RESULTS

Estrogen receptor α expression was increased in postmenopausal papillary thyroid cancer cells compared with controls but was unchanged in premenopausal papillary thyroid cancer. Estrogen receptor β expression did not change in either group. Increased matrix metalloproteinase-2 activity was observed only in postmenopausal papillary thyroid cancer. Premenopausal papillary thyroid cancer cells demonstrated increased extracellular signal-regulated kinase and unchanged protein kinase B activation. Conversely, postmenopausal papillary thyroid cancer cells had decreased extracellular signal-regulated kinase and increased protein kinase B activation. Ethidium bromide treatment resulted in increased estrogen receptor α protein expression only in premenopausal papillary thyroid cancer cells.

CONCLUSION

Increased estrogen receptor α expression may be involved in papillary thyroid cancer aggressiveness after menopause. This process may be regulated by differential activation of intracellular pathways and differing sensitivities to mitochondrial signaling regulation.

Study on the status of thyroid function and thyroid nodules in chinese breast cancer patients

We performed a study to investigate the status of thyroid nodules and thyroid functions in Chinese breast cancer women. The clinical data of female patients with breast cancer or benign breast diseases and normal populace were evaluated. The thyroxine(T4) level in initially diagnosed breast cancer patients were significantly higher than those in benign breast diseases patients (7.68±1.51 vs 7.29±1.52ug/dl, p<0.001), while the TSH levels were slightly lower than in benign breast diseases patients(3.23±4.59 vs 3.60±6.74uIU/ml, p=0.302). The overall incidence of hypothyroidism in initially diagnosed breast cancer and benign breast diseases patients were 28.65% and 32.74%(p=0.195). During chemotherapy, the T4(7.08±1.69ug/dl), fT3(2.87±0.48pg/ml) and fT4(0.83±0.15ng/dl) levels were significantly lower than in initially diagnosed breast cancer patients(7.68±1.51ug/dl, 3.07±0.50pg/ml, 0.88±0.20ng/dl, p<0.05). The incidence of thyroid nodules in initially diagnosed breast cancer patients, benign breast diseases patients and healthy population were 56.17%, 43.64%, 34.49%(p<0.001). The incidence of TI-RADS≥4 TN in initially diagnosed breast cancer patients and benign breast diseases patients were significantly higher than in normal population(7.27% vs 9.45% vs 2.87%, p<0.001). The incidence of TI-RADS≥4 thyroid nodules in breast cancer patients receiving chemotherapy was significantly higher than in initially diagnosed breast cancer patients(11.71% vs 7.27%, p<0.05). These data indicate that the incidence of thyroid disease in breast disease patients is higher than in normal population in China, and the breast diseases, especially breast cancer, might be related to the high incidence of thyroid nodules.

Current Advances in Thyroid Cancer Management. Are We Ready for the Epidemic Rise of Diagnoses?

A rising incidence of thyroid cancers (TCs) mainly small tumors, observed during recent years, lead to many controversies regarding treatment strategies. TCs represent a distinct molecular background and clinical outcome. Although in most cases TCs are characterized by a good prognosis, there are some aggressive forms, which do not respond to standard treatment. There are still some questions, which have to be resolved to avoid dangerous simplifications in the clinical management. In this article, we focused on the current advantages in preoperative molecular diagnostic tests and histopathological examination including noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). We discussed the controversies regarding the extent of thyroid surgery and adjuvant radioiodine therapy, as well as new treatment modalities for radioiodine-refractory differentiated thyroid cancer (RR-DTC). Considering medullary thyroid cancer (MTC), we analyzed a clinical management based on histopathology and RET (ret proto-oncogene) mutation genotype, disease follow-up with a special attention to serum calcitonin doubling time as an important prognostic marker, and targeted therapy applied in advanced MTC. In addition, we provided some data regarding anaplastic thyroid cancer (ATC), a highly lethal neoplasm, which lead to death in nearly 100% of patients due to the lack of effective treatment options.

Sex disparities in cancer incidence in Jiashan County, China, 1995-2014

PURPOSE

To describe the sex-specific incidence rates and the male-to-female incidence-rate ratios (IRRs) of different cancer types, and to explore the corresponding sex disparities in an area of Eastern China.

METHODS

We used data from the Cancer Registry in Jiashan County, and calculated the sex-specific age-standardized (2010 China standard population) incidence rates and the male-to-female IRRs for different cancer types during the period 1995-2014.

RESULTS

The age-standardized incidence rates of all cancers for the whole period 1995-2014 were 151.48 per 100,000 person-years for males and 83.75 per 100,000 person-years for females, and the corresponding male-to-female IRR was 1.81 (95% confidence interval: 1.77-1.85). Specifically, males presented higher incidences in most types of cancer with the exceptions of cancers of connective and other soft tissues, gallbladder (including extrahepatic bile ducts), and thyroid gland. In addition, the age-specific incidences of the ten most common cancers in males were higher than those in females in most age groups.

CONCLUSIONS

Our results reveal a male predominance in incidence for a majority of cancers in Jiashan County, Eastern China. Possible explanations for these sex disparities in cancer incidence may include lifestyle factors, particularly smoking.

Higher urinary bisphenol A concentration and excessive iodine intake are associated with nodular goiter and papillary thyroid carcinoma

In the present study, we investigated whether bisphenol A (BPA) levels and excessive iodine intake were associated with papillary thyroid carcinoma (PTC) and nodular goiter (NG). We determined total BPA concentrations (TBC) in paired serum and urine samples, and urinary iodine concentrations (UIC) in urine samples collected from PTC patients, NG patients, and healthy individuals, then compared BPA concentrations and UIC within and between each patient group. The results showed that there were no gender-specific differences in serum TBC and UIC in each group, and no differences across all patient groups. Urinary BPA concentrations (UBC) were higher in the NG and PTC groups compared with the control group. UBC showed gender-specific differences in the NG and PTC group. Furthermore, UIC were higher in the NG and PTC groups compared with the control group. Higher UBC and excessive iodine intake were risk factors for NG and PTC according to multivariate logistic regression analysis. There was a significant correlation between UBC and UIC in each group. These data suggested that higher UBC and excessive iodine intake are associated with NG and PTC. The metabolic and functional pathways between BPA and iodine are potentially linked to the pathogenesis and progression of NG and PTC.

Low dose of Bisphenol A enhance the susceptibility of thyroid carcinoma stimulated by DHPN and iodine excess in F344 rats

Thyroid carcinoma (TC) is the most common endocrine neoplasm. The risk of TC as a second primary malignancy (SPM) of breast cancer is significantly increased. Bisphenol A (BPA) is a widely contacted xenoestrogen and increases susceptibility to breast cancer through binding to estrogen receptor alpha (ERα). However, the effect of BPA on thyroid carcinogenesis has not been fully demonstrated. This present study aimed to characterize the effects of BPA on the development of TC using a Fischer 344 (F344) rat model. In this study, we established a TC model using female F344 rats pretreated with N-Bis (2-hydroxypropyl) nitrosamine (DHPN) at a single dose of 2800 mg/kg (the DA group) or without DHPN (the DN group), followed by stimulation with BPA at the level of 250 μg/kg (BPA250) or 1000 μg/kg (BPA1000) and a basic diet containing potassium iodine (KI, 1000 μg/L) for 64 weeks. We demonstrated that the incidence of TC in the BPA250 + KI of DA groups reached the highest at 50%, the incidence of thyroid hyperplasia lesions (including both tumors and focal hyperplasia lesions) in the BPA1000 + KI of DA groups reached 100% (P < 0.05). ERα protein and immunochemistry expression was upregulated in the BPA-exposed groups and the immunochemistry scores were positively correlated with PCNA. Thus, the present results indicate that BPA could enhance the susceptibility to TC stimulated by DHPN and iodine excess. ERα is probably involved in the proliferation effect of BPA. BPA or KI alone could not increase TC incidence.

The effect of Tributyltin on thyroid follicular cells of adult male albino rats and the possible protective role of green tea: a toxicological, histological and biochemical study

Introduction

Tributyltin is one of the important and wide-spread persistent organic contaminants that accumulate in the food chain. It is suspected to cause endocrine-disrupting effects in mammals, due in part to its possible transfer through marine food chains and to the consumption of contaminated seafood.

Aim of the work

Was to study the possible toxic effect of Tributyltin on thyroid follicular cells of adult male albino rats and to evaluate the possible protective role of green tea.

Material and methods

Forty-five adult male albino rats were included and randomly divided into 3 equal groups: a control group (Group I); Group II: received tributyltin chloride (TBT) dissolved in corn oil orally in a dose of 5 mg/kg for 30 days. Group III: received tributyltin chloride in the same dose with concomitant oral administration of green tea extract for 30 days. At the end of the experiment, the animals were sacrificed and blood samples were subjected to hormonal assay for T3, T4 and TSH levels. Malondialdehyde and reduced glutathione were assessed. The thyroid tissue was processed for histological and ultrastructure examination. The colloid area of thyroid follicles was evaluated morphometrically and statistically analyzed.

Results

A significant decrease in T3 and T4 levels and serum reduced glutathione in the group II when compared with the other groups. Furthermore, a significant increase in serum Malondialdehyde and TSH levels was recorded in group II treated group by comparison to the other two groups. Histopathological and ultrastructural changes of thyroid gland follicles were detected in tributyltin treated rats; the follicular cells appeared swollen and vacuolated. Epithelial stratification was noticed in some foci with excessive vacuolation of the colloid. Dilated rough endoplasmic reticulum filled with flocculent material and increased number of lysosomes were also detected together with variation in shape and size of the nuclei. A marked improvement in the histological features of thyroid follicles was noticed in group III.

Conclusion

Tributyltin induces oxidative stress in rats as well as anti-thyroid effect. The green tea extract is useful in combating tissue injury that is a result of tributyltin toxicity.

Intake of Boron, Cadmium, and Molybdenum enhances rat thyroid cell transformation

Background

Epidemiologic data in volcanic areas suggest that environmental factors might be involved in the increase of thyroid cancer (TC) incidence. Recent reports indicate that several heavy metals and metalloids are increased in volcanic areas. This study aims to evaluate the combined effect of three of these elements Boron (B), Cadmium (Cd), and Molybdenum (Mo) - all increased in the volcanic area of Mt. Etna, in Italy - on thyroid tumorigenesis in the rat.

Methods

Female Wistar rats prone to develop thyroid tumors by low-iodine diet and methimazole treatment received ad libitum drinking water supplemented with B, Cd, and Mo at concentrations in the range found in the urine samples of residents of the volcanic area. At 5 and 10 months animals were euthanized, and their thyroid analysed. Statistical analysis was performed with a 2-way unpaired t-test.

Results

No toxic effect of the three elements on the growth of the animals was observed. A significant increase of histological features of transformation was observed in thyroid follicular cells of rats treated with B, Cd, and Mo compared with those of control group. These abnormalities were associated with decreased iodine content in the thyroid.

Conclusions

This study provides the evidence that slightly increased environmental concentrations of B, Cd, and Mo can accelerate the appearance of transformation marks in the thyroid gland of hypothyroid rats.

The association of cancer risks with pentachlorophenol exposure: Focusing on community population in the areas along certain section of Yangtze River in China

Pentachlorophenol (PCP) was used in large quantities, and mainly for killing the intermediate host snails of schistosome in China, thereby resulting in ubiquitous PCP residue in the environment. However, studies considering the carcinogenicity of PCP for humans mainly focused on occupational workers, and the actual carcinogenicity of PCP for general population is uncertain. To investigate the association between cancer risks and PCP exposure in a community population, an ecological study was conducted in three contaminated areas along the Yangtze River. Standardized rate ratio (SRR) was calculated to represent the risk of cancer incidence, by using incidence in the low PCP exposure category as the reference group. A total of 15,962 cancer records were collected, and 76 water samples and 213 urine samples in three areas were examined. Our findings suggested that compared with the low PCP group, the high PCP group had significantly excessive incidences of various cancers related to different organs including lymph (SRR = 19.44, 95% CI = 15.00-25.19), blood (SRR = 17.24, 95% CI = 12.92-23.01), nasopharynx (SRR = 3.97, 95% CI = 3.75-4.21), gallbladder (SRR = 3.46, 95% CI = 3.09-3.87), pancreas (SRR = 3.41, 95% CI = 3.07-3.79), respiratory system (SRR = 3.41, 95% CI = 3.27-3.57) and liver (SRR = 3.31, 95% CI = 3.09-3.56). Taken together, our present study provides evidence that general community population exposed to high level of PCP exhibits a broader spectrum of increased cancer risks as compared to occupational groups.

GPER/ERK&AKT/NF-κB pathway is involved in cadmium-induced proliferation, invasion and migration of GPER-positive thyroid cancer cells

The higher incidence of thyroid cancer in women during reproductive years compared with men and the increased risk associated with the therapeutic use of estrogen have strongly suggested that estrogen may be involved in the occurrence and development of thyroid cancer. Cadmium (Cd) is a potent metalloestrogen that disrupts the endocrine system by mimicking the effects of 17β-estradiol (E2). In the present study, we demonstrate that similar to E2 and G1, a specific agonist for G protein-coupled estrogen receptor (GPER), Cd induces the proliferation, invasion and migration of human WRO and FRO thyroid cancer cells that have endogenous GPER. Moreover, like E2 and G1, Cd leads to a rapid activation of ERK/AKT, and then nuclear translocation of NF-κB, increased expression of cyclin A and D1, and secretion of IL-8, all of which are significantly attenuated by GPER blockage or knock-down in both WRO and FRO cells. Furthermore, the Cd-induced proliferation, invasion and migration are suppressed either by specific inhibitors for GPER, ERK, AKT and NF-κB, or by knock-down of GPER. These results suggest that GPER/ERK&AKT/NF-κB signaling pathway is involved in the Cd-induced proliferation, invasion and migration of GPER-positive thyroid cancer cells.

Association between thyroid cancer and epidermal growth factor receptor mutation in female with nonsmall cell lung cancer

BACKGROUND

The aim of this study was to investigate the association between epidermal growth factor receptor (EGFR) mutation and thyroid cancer in female patients with nonsmall-cell lung cancer (NSCLC).

METHODS

In a retrospective study, we examined 835 female patients who were diagnosed with NSCLC and underwent an EGFR mutation test between June 2003 and August 2013. The associations of EGFR mutation with thyroid cancer and a family history of thyroid cancer were evaluated using logistic regression models.

RESULTS

EGFR mutation was found in 378 of 835 patients. In addition to adenocarcinoma (P < 0.001), EGFR mutations were positively associated with a personal history of thyroid cancer (5.8% versus 2.6%; P = 0.020), while showing a trend toward inverse association with a personal history of nonthyroid cancer (5.8% vs. 9.0%; P = 0.086). Likewise, the incidence of EGFR mutations was associated with a family history of thyroid cancer (2.9% vs. 0.9%; P = 0.028), while showing a trend toward inverse association with a family history of nonthyroid cancer (27.8% vs. 33.7%; P = 0.066). Multivariate logistic regression showed that the incidence of EGFR mutations was different in women with thyroid or nonthyroid cancer (P = 0.035) and in women with a family history of thyroid or nonthyroid cancer (P = 0.023).

CONCLUSIONS

Our data suggest that thyroid cancer and a family history of thyroid cancer are associated with EGFR-mutated NSCLC in female patients. The differences in the incidence of thyroid cancer and a family history of thyroid cancer by EGFR mutational status provide new insight into pathogenesis of this genetic change.

Female Reproductive Factors and Differentiated Thyroid Cancer

Differentiated thyroid cancer (DTC) is markedly more common in women than men, the highest female-to-male ratio being recorded during the reproductive period. This evidence has led to the suggestion that female hormonal and reproductive factors may account for the observed DTC gender disparity. This review focuses on current evidence on the risk of DTC in conjunction with major female reproductive factors, including the impact of pregnancy on DTC occurrence and progression/recurrence. Overall, studies exploring the link between the risk of DTC and menstrual and menopausal factors, oral contraceptives and/or hormone replacement therapy, showed these associations, if any, to be generally weak. Nonetheless, there is some evidence that higher levels of exposure to estrogens during reproductive years may confer an increased risk of DTC. As far as pregnancy is concerned, it is unclear whether a potential association between parity and risk of DTC actually exists, and whether it is enhanced in the short-term following delivery. A possible role for pregnancy-related factors in DTC progression has been recently suggested by some reports, the results of which are consistent with a worse outcome in the short-term of women diagnosed with DTC during gestation compared to non-pregnant control patients. Also, some progression of disease has been described in women with structural evidence of disease prior to pregnancy. However, there seems to be no impact from pregnancy in DTC-related death or overall survival. Several in vitro and animal studies have evaluated the influence of estrogens (E) and estrogen receptors (ERs) on thyroid cell proliferation. Presently available data are indicative of a role of E and ERs in thyroid cancer growth, although considerable discrepancies in respect to ER expression patterns in thyroid cancer tissues actually exist. Further studies providing more direct evidence on the possible role of E and of placental hormones and growth factors on thyroid growth may expand our knowledge on the mechanisms beyond the gender disparity of proliferative thyroid diseases.