Expression of estrogen and androgen receptors in differentiated thyroid cancer: an additional criterion to assess the patient's risk

Androgen receptor signalling in non-prostatic malignancies: challenges and opportunities

The androgen receptor (AR) signalling pathway has been intensively studied in the context of prostate cancer, where androgen deprivation therapy is part of the standard of care for metastatic disease. By contrast, fewer studies have investigated the impact and translational potential of targeting AR in other cancer types where it is also expressed and functional. In this Review, we discuss the current understanding of AR in non-prostatic cancer types and summarize ongoing AR-directed clinical trials. While different androgen levels contribute to sexual dimorphism in cancer, targeting the AR system could benefit both sexes and help overcome resistance to targeted therapies. However, a bimodal function of AR signalling, which suppresses stromal changes associated with the early stages of cancer development, also needs to be considered. Future research is necessary to scrutinize cellular and molecular mechanisms of action of AR in cancer cells and the tumour microenvironment, to develop selective modulators of AR activity, and to identify patients with non-prostatic cancer who might benefit from targeting this pathway. AR-directed manipulation of host immune cells may offer a promising therapeutic approach for many types of cancers.

A review of complex hormone regulation in thyroid cancer: novel insights beyond the hypothalamus-pituitary-thyroid axis

Like the ovaries and prostate, the thyroid exhibits characteristic hormone secretion and regulation. Thyroid cancer (TC), especially differentiated thyroid carcinoma, has typical sex-specific and age-specific hormone-driven clinical features. Previous research has primarily focused on the effects of thyroid stimulating hormone, thyroid hormones, and estrogens on the onset and progression of TC, while the roles of growth hormone (GH), androgens, and glucocorticoids have largely been overlooked. Similarly, few studies have investigated the interactions between hormones and hormone systems. In fact, numerous studies of patients with acromegaly have shown that serum levels of GH and insulin-like growth factor-1 (IGF-1) may be associated with the onset and progression of TC, although the influences of age, sex, and other risk factors, such as obesity and stress, remain unclear. Sex hormones, the GH/IGF axis, and glucocorticoids are likely involved in the onset and progression of TC by regulating the tumor microenvironment and metabolism. The aim of this review was to clarify the roles of hormones and hormone systems in TC, especially papillary thyroid carcinoma, as references for further investigations.

Serum sex hormones correlate with pathological features of papillary thyroid cancer

PURPOSE

Sex hormones are thought to be responsible for the unique gender differences in papillary thyroid cancer(PTC). Most previous studies on these have focused on the expression of estrogen receptors, or have been limited to animal studies. The aim of our study was to explore the relationship between serum sex hormones and the pathological features of PTC in the clinical setting, as further evidence of the role of sex hormones in PTC.

METHODS

Retrospective data analysis of patients who underwent thyroid surgery at the Department of Thyroid Surgery, Nanjing Drum Tower Hospital from January 2022 to September 2022 Correlation between serum sex hormone and pathological features was analyzed in male patients and in menopausal female patients. Serum sex hormones include luteinizing hormone(LH), follicle stimulating hormone(FSH), estradiol(E2), total testosterone(TT), progesterone(P), and prolactin(PRL). Tumor pathological characteristics include the number and size of tumor, presence of extrathyroidal extension(ETE), presence of lymph node metastasis(LNM).

RESULTS

Preoperative serum E2 in male patients was positively correlated with tumor size in PTC, LH was negatively correlated with LNM, while TT and P were negatively correlated with ETE. Similar findings were not observed in menopausal female patients.

CONCLUSION

We observed that serum sex hormones correlate with the pathological features of PTC in male patients, for the first time in a clinical study. High serum estrogens may be a risk factor for PTC, while androgens are the opposite. This somewhat corroborates previous research and provides new variables for future PTC prediction models.

Sex-Specific Expression of Histone Lysine Demethylases (KDMs) in Thyroid Cancer

BACKGROUND

The incidence of thyroid cancer in women is 3-4-fold higher than in men. To characterize sex-specific molecular alterations in thyroid cancer, we examined the expression of sex-biased genes in normal thyroids and thyroid tumors.

METHODS

Ingenuity pathways analysis was used to define sex-biased gene networks using data from the Cancer Genome Atlas (TCGA). Confirmatory studies were performed through the analysis of histone lysine demethylases (KDMs) expression by real-time PCR and immunostaining.

RESULTS

In normal thyroids, 44 sex-biased genes were comparatively upregulated in male and 28 in female patients. The expressions of 37/72 (51%) sex-biased genes were affected in cancer tissues compared with normal thyroids. Gene network analyses revealed sex-specific patterns in the expressions of KDM5C, KDM5D, and KDM6A. In confirmatory studies, KDM5D mRNA and protein were detected only in males, whereas KDM5C and KDM6A were detected in samples from male and female patients. Nuclear staining with anti-KDMs was found in normal thyroids, but a loss of nuclear expression with a concomitant gain of cytoplasmic staining was observed in cancer tissues.

CONCLUSIONS

Normal thyroids have a sex-specific molecular signature, and the development of thyroid cancer is associated with a differential expression of sex-biased genes. The sex-specific expression of KDMs, coupled with cancer-related alterations in their intracellular localization, may contribute to mechanisms underlying sex differences in thyroid tumorigenesis.

Investigation of genetic sex-specific molecular profile in well-differentiated thyroid cancer: Is there a difference between females and males?

BACKGROUND

Although more common in females, thyroid cancer is deemed to be more aggressive in males. The reasons for sex disparities in thyroid cancer are not well understood. We hypothesised that differences in molecular mutations between females and males contribute to this phenomenon.

METHODS

Retrospective multicentre multinational study of thyroid nodules that underwent preoperative molecular profiling between 2015 and 2022. The clinical characteristics and mutational profiles of tumours in female and male patients were compared. Collected data included demographics, cytology results, surgical pathology, and molecular alterations.

RESULTS

A total of 738 patients were included of which 571 (77.4%) were females. The extrathyroidal extension was more common in malignancies in males (chi-squared, p = 0.028). The rate of point mutations and gene fusions were similar in both sex groups (p > 0.05 for all mutations). Patients with nodules with BRAFV600E mutations were significantly younger than BRAF wild-type nodule patients (t-test, p = 0.0001). Conversely, patients with TERT promoter mutations were significantly older than patients with wild-type TERT (t-test, p < 0.0001). For patients harbouring both BRAFV600E and TERT mutations, the difference in age at presentation was significantly different in females (t-test, p = 0.009) but not in males (t-test, p = 0.433). Among females, patients with BRAFV600E and TERT mutations were significantly older than their wild-type or single-mutation counterpart (t-test, p = 0.003).

CONCLUSION

The absolute rate of molecular mutations was similar in females and males. We found that extrathyroidal extension was more common in males. Moreover, BRAFV600E and TERT mutations occur at a younger age in males than in females. These two findings are factors that may explain the tendency of more aggressive disease in males.

Androgen Receptor Activation Induces Senescence in Thyroid Cancer Cells

Thyroid cancer (TC) is the most common endocrine malignancy, with an approximately three-fold higher incidence in women. TCGA data indicate that androgen receptor (AR) RNA is significantly downregulated in PTC. In this study, AR-expressing 8505C (anaplastic TC) (84E7) and K1 (papillary TC) cells experienced an 80% decrease in proliferation over 6 days of exposure to physiological levels of 5α-dihydrotestosterone (DHT). In 84E7, continuous AR activation resulted in G1 growth arrest, accompanied by a flattened, vacuolized cell morphology, with enlargement of the cell and the nuclear area, which is indicative of senescence; this was substantiated by an increase in senescence-associated β-galactosidase activity, total RNA and protein content, and reactive oxygen species. Additionally, the expression of tumor suppressor proteins p16, p21, and p27 was significantly increased. A non-inflammatory senescence-associated secretory profile was induced, significantly decreasing inflammatory cytokines and chemokines such as IL-6, IL-8, TNF, RANTES, and MCP-1; this is consistent with the lower incidence of thyroid inflammation and cancer in men. Migration increased six-fold, which is consistent with the clinical observation of increased lymph node metastasis in men. Proteolytic invasion potential was not significantly altered, which is consistent with unchanged MMP/TIMP expression. Our studies provide evidence that the induction of senescence is a novel function of AR activation in thyroid cancer cells, and may underlie the protective role of AR activation in the decreased incidence of TC in men.

The co-occurrence of both breast- and differentiated thyroid cancer: incidence, association and clinical implications for daily practice

Background

Breast cancer (BC) and differentiated thyroid cancer (TC) are two common cancer types with the highest incidence in women. BC and TC can develop synchronous or metachronous and the occurrence of both is higher than expected by chance. This study aimed to examine the association between BC and TC in the Netherlands.

Methods

This is a retrospective cohort study during the period of 1989–2020 retrieved from the Netherlands Cancer Registry (NCR). Patients diagnosed with BC-TC and BC alone as control group and TC-BC and TC alone as control group were included. The primary outcome was the standardized incidence ratio (SIR) of BC-TC and TC-BC. Secondary outcomes included data on the demographics, type of malignancy, treatment and overall survival (OS).

Results

The incidence of TC among 318.002 women with BC (BC-TC) was 0.1% (423 patients) (SIR = 1.86 (95% CI: 1.40–2.32)) and the incidence of BC among 12,370 patients with TC (TC-BC) was 2.9% (355 patients) (SIR = 1.46 (95% CI: 1.09–1.83)). BC-TC patients were younger compared to the BC alone group at BC diagnosis (55 vs 60 years, p < 0.001). The age-adjusted odds ratio to develop TC was not significantly increased for patients who received chemotherapy and radiotherapy. Most TC cases were synchronous tumors after BC diagnosis (19%) with a TNM stage 1. Only 6% of the BC tumors after TC occurred synchronous with a TNM stage 1 in most cases. The OS of all groups was the most favorable in patients with both BC and TC compared to BC- and TC alone.

Conclusion and relevance

The SIR of TC after BC diagnosis and BC after TC diagnosis was higher than predicted based on the rates of the general population. TC and BC as second primary tumors were diagnosed in an early stage and did not affect overall survival. Therefore, Dutch women who have been treated for BC or TC require no special surveillance for their thyroid- and breast gland.

Hormonal Crosstalk Between Thyroid and Breast Cancer

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

The Isoforms of Estrogen Receptor Alpha and Beta in Thyroid Cancer

The incidence of thyroid cancer was predominant in women, indicating that the sex hormone may have a role in thyroid cancer development. Generally, the sex hormone exerts its function by binding to the correspondent nuclear receptors. Therefore, aberrant of these receptors may be involved in the development of thyroid cancer. Estrogen receptor alpha (ERα) and beta (ERβ), two main estrogen receptors, have been reported to have an important role in the pathogenesis of thyroid cancer. When the ERα and ERβ genes undergo the alternative RNA splicing, some ERα and ERβ isoforms with incomplete functional domains may be formed. To date, several isoforms of ERα and ERβ have been identified. However, their expression and roles in thyroid cancer are far from clear. In this review, we summarized the expressions and roles of ERα and ERβ isoforms in thyroid cancer, aiming to provide the perspective of modulating the alternative RNA splicing of ERα and ERβ against thyroid cancer.

Sex Differences in Differentiated Thyroid Cancer

Background: Sex dimorphism strongly impacts tumor biology, with most cancers having a male predominance. Uniquely, thyroid cancer (TC) is the only nonreproductive cancer with striking female predominance with three- to four-fold higher incidence among females, although males generally have more aggressive disease. The molecular basis for this observation is not known, and current approaches in treatment and surveillance are not sex specific. Summary: Although TC has overall good prognosis, 6-20% of patients develop regional or distant metastasis, one third of whom are not responsive to conventional treatment approaches and suffer a 10-year survival rate of only 10%. More efficacious treatment strategies are needed for these aggressive TCs, as tyrosine kinase inhibitors and immunotherapy have major toxicities without demonstrable overall survival benefit. Emerging evidence indicates a role of sex hormones, genetics, and the immune system in modulation of both risk for TC and its progression in a sex-specific manner. Conclusion: Greater understanding of the molecular mechanisms underlying sex differences in TC pathogenesis could provide insights into the development of sex-specific, targeted, and effective strategies for prevention, diagnosis, and management. This review summarizes emerging evidence for the importance of sex in the pathogenesis, progression, and response to treatment in differentiated TC with emphasis on the role of sex hormones, genetics, and the immune system.

Cribriform-morular variant of papillary thyroid carcinoma with poorly differentiated features: report of a case and review of the literature

Introduction

Cribrifrom-morular variant of papillary thyroid carcinoma (CMVPTC) is an uncommon thyroid neoplasm that occurs predominantly in women and is sometime associated with familial adenomatous polyposis (FAP). Some of these tumors may undergo dedifferentiation to poorly differentiated thyroid carcinoma (PDTC). We describe a rare case of this carcinoma in a women without a history of FAP.

Case presentation

A 49-year-old woman with a history of breast carcinoma presented with a thyroid mass. A CMVPTC was diagnosed after excision. There was no history of FAP. Histological examination showed classical features of CMVPTC in most areas, but about 20% of the carcinoma showed features of a poorly differentiated carcinoma with a solid pattern of growth, increase mitotic activity and a high Ki-67 proliferative index (25%). Immunohistochemical stains were positive for nuclear and cytoplasmic beta catenin staining. These special studies supported the diagnosis.

Conclusion

CMVPTC with dedifferentiation to PDTC is a rare carcinoma with only 4 previous documented cases in the literature. This aggressive variant of thyroid carcinoma is more common in females, as is CMVPTC, and is often associated with an aggressive biological course. The cases usually express nuclear beta catenin and estrogen, progesterone and androgen receptors have been reported in some cases. Some cases may have somatic alterations of the APC gene and TERT promoter mutations. These carcinomas may metastasize to lung, bones and lymph nodes. Because of its aggressive behavior, patient with this diagnosis should be treated aggressively to control disease spread and mortality from the carcinoma.

Insufficient iodine nutrition may affect the thyroid cancer incidence in China

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

Can We Predict Differentiated Thyroid Cancer Behavior? Role of Genetic and Molecular Markers

Thyroid cancer is ranked in ninth place among all the newly diagnosed cancer cases in 2020. Differentiated thyroid cancer behavior can vary from indolent to extremely aggressive. Currently, predictions of cancer prognosis are mainly based on clinicopathological features, which are direct consequences of cell and tissue microenvironment alterations. These alterations include genetic changes, cell cycle disorders, estrogen receptor expression abnormalities, enhanced epithelial-mesenchymal transition, extracellular matrix degradation, increased hypoxia, and consecutive neovascularization. All these processes are represented by specific genetic and molecular markers, which can further predict thyroid cancer development, progression, and prognosis. In conclusion, evaluation of cancer genetic and molecular patterns, in addition to clinicopathological features, can contribute to the identification of patients with a potentially worse prognosis. It is essential since it plays a crucial role in decision-making regarding initial surgery, postoperative treatment, and follow-up. To date, there is a large diversity in methodologies used in different studies, frequently leading to contradictory results. To evaluate the true significance of predictive markers, more comparable studies should be conducted.

Androgen Activity Is Associated With PD-L1 Downregulation in Thyroid Cancer

Thyroid cancer is the most prevalent endocrine malignancy in the United States with greater than 53,000 new cases in 2020. There is a significant gender disparity in disease incidence as well, with women developing thyroid cancer three times more often than men; however, the underlying cause of this disparity is poorly understood. Using RNA-sequencing, we profiled the immune landscape of papillary thyroid cancer (PTC) and identified a significant inverse correlation between androgen receptor (AR) levels and the immune checkpoint molecule PD-L1. The expression of PD-L1 was then measured in an androgen responsive-thyroid cancer cell line. Dihydrotestosterone (DHT) treatment resulted in significant reduction in surface PD-L1 expression in a time and dose-dependent manner. To determine if androgen-mediated PD-L1 downregulation was AR-dependent, we treated cells with flutamide, a selective AR antagonist, and prior to DHT treatment to pharmacologically inhibit AR-induced signaling. This resulted in a > 90% restoration of cell surface PD-L1 expression, suggesting a potential role for AR activity in PD-L1 regulation. Investigation into the AR binding sites showed AR activation impacts NF-kB signaling by increasing IkBα and by possibly preventing NF-kB translocation into the nucleus, reducing PD-L1 promoter activation. This study provides evidence of sex-hormone mediated regulation of immune checkpoint molecules in vitro with potential ramification for immunotherapies.

Androgen receptor activation decreases proliferation in thyroid cancer cells

The American Cancer Society predicted more than 52 000 new cases of thyroid cancer in 2020, making it the most prevalent endocrine malignancy. Due to the approximately threefold higher incidence of thyroid cancer in women, we hypothesize that androgens and/or androgen receptors play a protective role and that thyroid cancer in men represents an escape from androgen-mediated cell regulation. The analysis of androgen receptor (AR) expression in patient tissue samples identified a 2.7-fold reduction in AR expression (p < 0.005) in papillary thyroid cancer compared with matched, normal tissue. An in vitro cell model was developed by stably transfecting AR into 8505C undifferentiated thyroid cancer cells (resulting in clone 84E7). The addition of DHT to the clone 84E7 resulted in AR translocation into the nucleus and a 70% reduction in proliferation, with a shift in the cell cycle toward G1 arrest. RNASeq analysis revealed significant changes in mRNA levels associated with proliferation, cell cycle, and cell cycle regulation. Furthermore, androgen significantly decreased the levels of the G1-associated cell cycle progression proteins cdc25a CDK6 CDK4 and CDK2 as well as increased the levels of the cell cycle inhibitors, p27 and p21. The data strongly suggest that DHT induces a G1 arrest in androgen-responsive thyroid cancer cells. Together, these data support our hypothesis that AR/androgen may play a protective, antiproliferative role and are consistent with younger men having a lower incidence of thyroid cancer than women.

Association Between the Presence of Female-Specific Tumors and Aggressive Clinicopathological Features in Papillary Thyroid Cancer: A Retrospective Analysis of 9,822 Cases

Objective

To investigate the association between the presence of female-specific tumors and aggressive clinicopathological features in papillary thyroid cancer (PTC).

Methods

This study retrospectively analyzed 9,822 female cases between June 2008 and December 2017. Odds ratios and corresponding 95% confidence intervals were calculated. Findings were stratified by age and body mass index (BMI) in different models.

Results

1443/9822 (14.7%) patients with PTC had a female-specific tumor. Presence of a benign breast mass was an independent risk factor for a primary PTC lesion > 1 cm in diameter (adjusted OR = 1.446, 95% CI 1.136–1.840, P = 0.003), but a protective factor against extrathyroidal extension of PTC (adjusted OR = 0.650, 95%CI 0.500–0.845, P = 0.001). Presence of a benign uterine mass was an independent risk factor for multifocal PTC (adjusted OR = 1.305, 95%CI 1.113–1.531, P = 0.001). Analyses stratified by age and BMI revealed the presence of a benign breast mass was an independent risk factor for a primary PTC lesion > 1 cm in diameter in patients aged <36 years (adjusted OR = 1.711, 95% CI 1.063–2.754, P = 0.027), and a protective factor against extrathyroidal extension of PTC in patients aged ≥36 - <42 years (OR adjusted = 0.533, 95% CI 0.302–0.941, P = 0.030) or with a BMI ≥ 23.4 kg/m² (BMI ≥ 23.4 to < 25.7 kg/m², adjusted OR = 0.441, 95% CI 0.246–0.792, P = 0.006; BMI ≥25.7 kg/m², adjusted OR = 0.558, 95% CI 0.315–0.998, P₂ = 0.045). Presence of a benign uterine mass was an independent risk factor for multifocal PTC in patients aged ≥49 years (adjusted OR = 1.397, 95% CI 1.088–1.793, P = 0.009) or with a BMI <21.5 kg/m² (OR adjusted = 1.745, 95% CI 1.214–2.509, P = 0.003).

Conclusion

The presence of a benign breast mass was an independent risk factor for a primary PTC lesion > 1 cm in diameter and a protective factor against extrathyroidal extension of PTC, while the presence of a benign uterine mass was an independent risk factor for multifocal PTC. Data from this study may help surgeons propose more personalized treatment plans when encountering patients with PTC and female-specific benign tumors.

Expression of Estrogen and Progesterone Receptors in Papillary Thyroid Carcinoma in Korea

Purpose

The aim of this study was to examine the rate of expression of estrogen receptor α (ERα) and β1 (ERβ1), progesterone receptor (PR), and rate of overexpression of epidermal growth factor receptor (EGFR) in a relatively large cohort of patients with papillary thyroid carcinoma (PTC). We also aimed to examine whether each receptor influenced clinicopathological characteristics and prognosis of PTC.

Materials and Methods

We made a microarray of paraffin-embedded PTC surgical tissues from 436 patients. We compared the results of the immunohistochemical staining for each hormone receptor with clinicopathological characteristics.

Results

The positive expression rate of hormonal receptors was 40.4% for ERα, 83.7% for ERβ1, and 71.3% for PR in patients with PTC. Overexpression of EGFR was shown in 19.3% of patients with PTC. The age was lower (44.6±12.1 years vs. 47.1±12.5 years, p=0.040) and tumor smaller (0.96±0.69 cm vs. 1.13±0.82 cm, p=0.020) in the ERα positive group, which also showed higher PR positivity (80.7% vs. 65.0%, p < 0.001) and overexpression of EGFR (27.3% vs. 13.8%, p < 0.001). However, neither the positivity of hormone receptors nor overexpression of EGFR affected the recurrence of PTC.

Conclusion

In conclusion, most (94.6%) patients with PTC were found to exhibit positive expression for ERs or PR. We also found that neither the positive expression of hormone receptors nor overexpression of EGFR were associated with the recurrence of PTC.

Estrogen Receptor Beta: The Promising Biomarker and Potential Target in Metastases

The discovery of the Estrogen Receptor Beta (ERβ) in 1996 opened new perspectives in the diagnostics and therapy of different types of cancer. Here, we present a review of the present research knowledge about its role in endocrine-related cancers: breast, prostate, and thyroid, and colorectal cancers. We also discuss the reasons for the controversy of its role in carcinogenesis and why it is still not in use as a biomarker in clinical practice. Given that the diagnostics and therapy would benefit from the introduction of new biomarkers, we suggest ways to overcome the contradictions in elucidating the role of ERβ.

Thyroid Papillary Microtumor: Validation of the (Updated) Porto Proposal Assessing Sex Hormone Receptor Expression and Mutational BRAF Gene Status

Given the high incidence and excellent prognosis of many papillary thyroid microcarcinomas, the Porto proposal uses the designation papillary microtumor (PMT) for papillary microcarcinomas (PMCs) without risk factors to minimize overtreatment and patients' stress. To validate Porto proposal criteria, we examined a series of 190 PMC series, also studying sex hormone receptors and BRAF mutation. Our updated Porto proposal (uPp) reclassifies as PMT incidental PMCs found at thyroidectomy lacking the following criteria: (a) detected under the age of 19 years; (b) with multiple tumors measuring >1 cm adding up all diameters; and (c) with aggressive morphologic features (extrathyroidal extension, angioinvasion, tall, and/or hobnail cells). PMCs not fulfilling uPp criteria were considered "true" PMCs. A total of 102 PMCs were subclassified as PMT, 88 as PMC, with no age or sex differences between subgroups. Total thyroidectomy and iodine-131 therapy were significantly more common in PMC. After a median follow-up of 9.6 years, lymph node metastases, distant metastases, and mortality were only found in the PMC subgroup. No subgroup differences were found in calcifications or desmoplasia. Expression of estrogen receptor-α and estrogen receptor-β, progesterone receptor, and androgen receptor was higher in PMC than in nontumorous thyroid tissue. BRAF mutations were detected in 44.7% of PMC, with no differences between subgroups. In surgical specimens, the uPp is a safe pathology tool to identify those PMC with extremely low malignant potential. This terminology could reduce psychological stress associated with cancer diagnosis, avoid overtreatment, and be incorporated into daily pathologic practice.

Circular RNA DOCK1 downregulates microRNA-124 to induce the growth of human thyroid cancer cell lines

BACKGROUND

Both circular RNA DOCK1 (circDOCK1) and microRNA-124 (miR-124) are implicated in carcinogenesis, but functional association between these two molecules remains uncharacterized. Here, we aimed to ascertain the role of circDOCK1-miR-124 node in thyroid cancer cells.

METHODS

circDOCK1 in thyroid cancer specimens from 25 patients was quantified by qRT-PCR. FTC-133 and TPC-1 cells were enforced to overproduce circDOCK1 and miR-124 which were confirmed by qRT-PCR. The alteration in viability, migration and invasion was monitored. Cellular lysis was subjected to Western blot for detecting cyclin D1, p53, matrix metallopeptidase 9 (MMP-9), and vimentin. The phosphorylation of JAK1, STAT3, and AMPK was determined by Western blot.

RESULTS

Results from qRT-PCR showed circDOCK1 was enriched in thyroid carcinoma tissues. circDOCK1 fortified the viability of FTC-133 and TPC-1 cells, as well as their activities to migrate and invade. circDOCK1 increased cyclin D1 and decreased p53, and meanwhile induced the accumulation of MMP-9 and vimentin. miR-124 conferred a reverse effect on the abovementioned alteration. Besides, miR-124 blockaded the phosphorylation of JAK1, STAT3, and AMPK which was induced by circDOCK1.

CONCLUSION

circDOCK1 contributed to thyroid carcinogenesis through inhibition of miR-124 in thyroid cancer cells with dampening signaling transduction of JAK/STAT/AMPK in virtue of miR-124 downregulation.

Uterine Fibroids Increase the Risk of Thyroid Cancer

Objectives: The formation of uterine fibroids (UF) is potentially linked to the development of thyroid cancer through a common factor: female sex hormones. Methods: We conducted a nationwide population-based cohort study to determine whether Taiwanese women with UF have an increased risk of thyroid cancer. The data of both the UF and control groups were derived from the National Health Insurance Research Database (NHIRD) of Taiwan. Groups were matched by the year of UF diagnosis, age, income, urbanization level, occupation, and comorbidities. A Cox proportional hazard regression model was used to compare the incidence of thyroid cancer between the UF and control groups. In addition, the model was used to determine the hazard ratio of thyroid cancer in the UF group in comparison with the control group. Results: Women with UF had a statistically significantly increased risk of thyroid cancer compared with controls (adjusted hazard ratio (aHR): 1.64, 95% confidence interval (CI): 1.26–2.13). Stratified analyses showed that women with UF who had a significantly increased risk of thyroid cancer were more likely to be middle aged, have middle and higher income levels, and a medium follow-up period (1–5 years) of UF. No other UF patient characteristics and comorbidities showed association with the risk of thyroid cancer. In addition, UF patients had a significantly increased risk of thyroid cancer regardless of whether or not they underwent myomectomy. Conclusions: The results suggest that women with UF have an increased risk of subsequent thyroid cancer. Further research is needed to explore whether surveillance strategies for the early detection of thyroid cancer using ultrasonography should be implemented among patients with UF.

Distribution and Prognostic Significance of Estrogen Receptor α (ERα), Estrogen Receptor β (ERβ), and Human Epidermal Growth Factor Receptor 2 (HER-2) in Thyroid Carcinoma

Purpose

The primary aim of this study was to determine the incidence of estrogen receptor α (ERα), estrogen receptor β (ERβ), and human epidermal growth factor receptor 2 (HER-2) expression in various subtypes of thyroid carcinoma (TC) of follicular origin and the secondary aim was to correlate the expression with various clinicopathologic prognostic factors.

Methods

Immunohistochemistry analysis was performed on archival paraffin-embedded tissue sections (1991–2016). ERα, ERβ, and HER-2 expressions were correlated with clinicopathologic prognostic factors, disease recurrence, and overall survival (OS).

Results

A total of 264 TC patients were included in the study. Incidences of ERα, ERβ, and HER-2 were 8.1 vs 16.3 vs 13.9% (p=0.15), 26.6 vs 11.5 vs 36.1% (p=0.002), and 12.9 vs 2.9 vs 0% (p=0.003) in papillary thyroid carcinoma (PTC), follicular thyroid carcinoma (FTC), and poorly differentiated thyroid carcinoma (PDTC), respectively. Overall ERα had significant correlation with distant metastases (0.038) and in case of PDTC with multicentricity (p=0.037). ERβ had significant correlation with lymph node metastases (p=0.023) in FTC. HER-2 correlated with tumor size (p=0.027) only on univariate analysis. OS did not correlate with expression of any receptor.

Conclusion

ERα, ERβ, and HER-2 have differential expression and prognostic implications in different TC subtypes.

Aberrant Expression of Androgen Receptor Associated with High Cancer Risk and Extrathyroidal Extension in Papillary Thyroid Carcinoma

Male gender is a risk factor for mortality in patients with papillary thyroid carcinoma (PTC). This study investigated the impact of androgen receptor (AR) gene expression on the clinical features and progression of PTC. The levels of AR mRNA and protein in frozen, formalin-fixed, paraffin-embedded tissue samples from PTC and adjacent normal thyroid tissue were assessed by quantitative real-time polymerase chain reaction and immunohistochemical staining, respectively, and the relationships between AR expression and clinical features were analyzed. The thyroid cancer cell lines, BCPAP and TPC-1, were used to evaluate the effects of AR on the regulation of cell migration, and key epithelial-mesenchymal transition (EMT) markers. AR mRNA expression was significantly higher in normal thyroid tissue from men than women. The sex difference in AR mRNA expression diminished during PTC tumorigenesis, as AR mRNA expression levels were lower in PTC than normal thyroid tissues from both men and women. AR mRNA expression was significantly decreased in PTC patients with higher risk and in those with extrathyroidal extension. Overexpression of AR in BCPAP cells decreased cell migration and repressed the EMT process by down-regulating mRNA expression of N-cadherin, Snail1, Snail2, Vimentin, and TWIST1 and up-regulating E-cadherin gene expression. These results suggest that suppression of the androgen-AR axis may lead to aggressive tumor behavior in patients with PTC.

Phytoestrogens and Thyroid Cancer Risk: A Population-Based Case-Control Study in Connecticut

BACKGROUND

Very few previous studies have examined the relationship between thyroid cancer risk and intake of phytoestrogens (PE); furthermore, these studies have reached inconsistent results.

METHODS

We analyzed data from a population-based case-control study in Connecticut from 2010 to 2011, including 387 histologically confirmed thyroid cancer cases and 433 population-based controls, with compound data available concerning specific PEs. Multivariate unconditional logistic regression models were used to estimate the associations between specific PEs and the risk of thyroid cancer, adjusting for potential confounders.

RESULTS

An elevated risk of thyroid cancer was associated with moderate to high levels of coumestrol intake [OR = 2.48, 95% confidence interval (CI), 1.39-4.43 for 40-80 μg/day; OR = 2.41, 95% CI, 1.32-4.40 for 80-130 μg/day; and OR = 2.38, 95% CI, 1.26-4.50 for >200 μg/day compared with <40 μg/day], and the main elevation in risk appeared among microcarcinomas (≤1 cm). A decreased risk of papillary macrocarcinomas (>1 cm; OR = 0.26, 95% CI, 0.08-0.85 for 1,860-3,110 μg/day compared with <760 μg/day) was associated with moderate genistein intake among women.

CONCLUSIONS

Our study suggests that high coumestrol intake increases the risk of thyroid cancer, especially microcarcinomas, whereas moderate amounts of genistein intake appear to be protective for females with thyroid macrocarcinomas.

IMPACT

The study highlights the importance of distinguishing between microcarcinomas and macrocarcinomas in future research on the etiology of thyroid cancer.

The androgen receptor expression and association with patient's survival in different cancers

To understand the androgen receptor (AR) in different human malignancies, we conducted a pan-cancer analysis of AR in different tumor tissues and association with patient survival and obtained AR expression data from The Cancer Genome Atlas. Pan-Cancer Analysis of AR indicated that 12 tumor types had decreased AR expression in the tumor, while glioblastoma multiforme has overexpressed AR. The survival analysis showed that high AR mRNA is associated with poor survival of stomach adenocarcinoma and low-grade glioma, but better survival of adrenocortical carcinoma, kidney renal clear cell carcinoma, acute myeloid leukemia, liver hepatocellular carcinoma, ovarian serous cystadenocarcinoma, and skin cutaneous melanoma based on AR mRNA, protein or AR-score. AR was associated with different clinical characteristics and AR correlated genes enriched in cancer-related pathways. These data indicate that AR signaling may be strongly associated with some cancer development and patients' survival, which is promising for potential treatment using antiandrogen therapies.

Mutational profile of papillary thyroid microcarcinoma with extensive lymph node metastasis

PURPOSE

Papillary thyroid microcarcinoma (PTMC) has excellent outcomes, but extensive lymph node (LN) metastasis can be associated with fatal outcomes. We evaluated the mutational profiles of primary tumors and their metastatic LNs of PTMCs with extensive lateral cervical LN metastases.

METHODS

Formalin-fixed, paraffin-embedded archival samples from 16 sets of normal thyroid tissue, the primary PTMC, and the largest metastatic LN were used for targeted sequencing.

RESULTS

A total of seven somatic variants were confirmed in the PTMCs compared to the normal tissue. The BRAF^V600E mutation was the most common and seen in 12 primary tumors (75%) and 11 metastatic LNs (69%). A nonsense mutation in AR and an in-frame deletion in ACVR2A were detected in one primary tumor and its metastatic LN (6%). Missense mutations in KMT2A, RAF1, and ROS1 were detected in one primary tumor (3%). A frameshift deletion mutation in JAK2 was detected in a metastatic LN (3%). In PTMCs without the BRAF mutation, an ALK and RET rearrangement (one PTMC and its metastatic LN, 6%) was detected. In one patient, the BRAF mutation was detected in the primary tumor, but only a RET rearrangement was detected in its metastatic LN. No mutations were detected in two patients.

CONCLUSION

The mutational frequency of PTMCs was really low, even in those with extensive LN metastasis. The mutational status of the primary tumor and its metastatic LNs were not significantly different, and this suggests a minor role for genetic alterations in the process of LN metastasis in PTMC.

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.

Regulation of sex hormone receptors in sexual dimorphism of human cancers

Gender differences in the incidences of cancers have been found in almost all human cancers. However, the mechanisms that underlie gender disparities in most human cancer types have been under-investigated. Here, we provide a comprehensive overview of potential mechanisms underlying sexual dimorphism of each cancer regarding sex hormone signaling. Fully addressing the mechanisms of sexual dimorphism in human cancers will greatly benefit current development of precision medicine. Our discussions of potential mechanisms underlying sexual dimorphism in each cancer will be instructive for future cancer research on gender disparities.

Estrogen receptor β upregulated by lncRNA-H19 to promote cancer stem-like properties in papillary thyroid carcinoma

Estrogen receptor β (ERβ) plays critical roles in thyroid cancer progression. However, its role in thyroid cancer stem cell maintenance remains elusive. Here, we report that ERβ is overexpressed in papillary thyroid cancer stem cells (PTCSCs), whereas ablation of ERβ decreases stemness-related factors expression, diminishes ALDH⁺ cell populations, and suppresses sphere formation ability and tumor growth. Screening estrogen-responsive lncRNAs in PTC spheroid cells, we find that lncRNA-H19 is highly expressed in PTCSCs and PTC tissue specimens, which is correlated with poor overall survival. Mechanistically, estradiol (E2) significantly promotes H19 transcription via ERβ and elevates H19 expression. Silencing of H19 inhibits E2-induced sphere formation ability. Furthermore, H19 acting as a competitive endogenous RNA sequesters miRNA-3126-5p to reciprocally release ERβ expression. ERβ depletion reverses H19-induced stem-like properties upon E2 treatment. Appropriately, ERβ is upregulated in PTC tissue specimens. Notably, aspirin attenuates E2-induced cancer stem-like traits through decreasing both H19 and ERβ expression. Collectively, our findings reveal that ERβ-H19 positive feedback loop has a compelling role in PTCSC maintenance under E2 treatment and provides a potential therapeutic targeting strategy for PTC.

Expression of hormone receptors in oropharyngeal squamous cell carcinoma

OBJECTIVES

Hormone receptors play an important role in many types of cancers. Alongside factors associated with human papillomavirus (HPV) infection, hormonal receptors may impact the tumorigenesis of oropharyngeal cancer.

MATERIALS AND METHODS

This study consists of 199 consecutive oropharyngeal squamous cell carcinoma (OPSCC) patients diagnosed and treated with a curative intent. We examined androgen (AR), estrogen (ER; both alpha and beta), and progesterone receptor (PR) expressions using immunohistochemistry comparing tumor and patient characteristics.

RESULTS

AR was expressed in 16%, PR in 27% and ER-beta in 63% of the tumors. HPV- and p16-positive tumors expressed more AR and less PR than their negative counterparts. High PR expression was associated with poor disease-specific and locoregional recurrence-free survival.

CONCLUSION

AR, PR, and ER-beta are expressed in OPSCC, and AR and PR expressions are associated with HPV and p16 status. Furthermore, PR appears to have prognostic significance. This may allow us to investigate the role of anti-hormone receptors in the treatment of OPSCC.

Reduced expression of oestrogen receptor-β is associated with tumour invasion and metastasis in oestrogen receptor-α-negative human papillary thyroid carcinoma

Oestrogens play an important role in the development and progression of papillary thyroid carcinoma (PTC) through oestrogen receptor (ER)-α and -β, which may exert different or even opposing actions in PTC. The roles of ERβ in ERα-negative PTC are still not clear. This study investigated the expression dynamics of ERβ1 (wild-type ERβ) and its clinical significance in female ERα-negative PTC patients. ERβ1 expression was detected in thyroid tissues of 136 female patients diagnosed with PTC. The relationships between ERβ1 expression and clinicopathological/biological factors were also analysed in female ERα-negative PTC patients. The total score for ERβ1 was significantly lower in female ERα-negative PTC patients with LNM or ETE when compared to those without LNM or ETE (Z = -2.923, P = 0.003 and Z = -3.441, P = 0.001). Accordingly, the total score for ERβ1 was significantly higher in ERα-negative PTC patients expressing E-cadherin compared to patients negative for E-cadherin expression (Z = -2.636, P = 0.008). The total score was lower in ERα-negative PTC patients positive for VEGF expression compared to those negative for VEGF expression (Z = -1.914, P = 0.056). This preliminary study indicates that reduced expression of ERβ1 in female ERα-negative PTC patients is associated with greater progression of the disease. This may provide insights into the underlying molecular mechanisms of ERβ1 and could help design targeted approaches for treating or even preventing this disease.

Review of Factors Related to the Thyroid Cancer Epidemic

Thyroid cancer is the most common endocrine cancer, of which the incidence has dramatically increased worldwide in the past few decades. The reasons for the observed rapid increase still are not fully understood, but evidence suggests that overdiagnosis, with the advancement in detection methods and screening policies, is not the sole driver of the substantial increase of the incidence. However, the effect of environmental/lifestyle factors remains speculative other than that of radiation exposure at a young age. This review tries to give a balanced view of debated factors leading to the thyroid cancer epidemic, to offer some alternatives in understanding the controversies, and to suggest potential directions in the search of modifiable risk factors to help reduce thyroid cancer.

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.

Androgen receptor CAG and GGN repeat length variation contributes more to the tumorigenesis of osteosarcoma

The androgen receptor (AR) is involved in the differentiation and growth of many cancers. We hypothesized that two microsatellite polymorphic variants, AR (CAG)n and (GGN)n repeats, were also associated with the development of Papillary thyroid cancer (PTC) and Osteosarcoma. In current study, we conducted two case-control studies in a Chinese population to investigate the possible relationship between these two AR repeat polymorphisms and the risk of PTC and Osteosarcoma. The AR CAG repeat length was significantly associated with both risk of PTC and Osteosarcoma. Subjects with shorter AR CAG repeats had a higher risk of developing PTC (OR = 1.47, 95% CI: 1.17–1.85, P = 0.001) and Osteosarcoma (OR = 1.53, 95% CI: 1.19–1.97, P = 9.2 × 10^–4). Specifically, shorter GGN repeats also contribute a significant increased risk of Osteosarcoma (OR = 1.35, 95% CI: 1.03–1.77, P = 0.030). Our results contribute to a better understanding of the complex hormone related mechanisms underlying PTC and Osteosarcoma.

AMERICAN ASSOCIATION OF CLINICAL ENDOCRINOLOGISTS AND AMERICAN COLLEGE OF ENDOCRINOLOGY DISEASE STATE CLINICAL REVIEW: THE INCREASING INCIDENCE OF THYROID CANCER

OBJECTIVE

(1) Describe current epidemiology of thyroid cancer in the United States; (2) evaluate hypothesized causes of the increased incidence of thyroid cancer; and (3) suggest next steps in research and clinical action.

METHODS

Analysis of data from Surveillance, Epidemiology and End Results System and the National Center for Vital Statistics. Literature review of published English-language articles through December 31, 2013.

RESULTS

The incidence of thyroid cancer has tripled over the past 30 years, whereas mortality is stable. The increase is mainly comprised of smaller tumors. These facts together suggest the major reason for the increased incidence is detection of subclinical, nonlethal disease. This has likely occurred through: health care system access, incidental detection on imaging, more frequent biopsy, greater volumes of and extent of surgery, and changes in pathology practices. Because larger-size tumors have increased in incidence also, it is possible that there is a concomitant true rise in thyroid cancer incidence. The only clearly identifiable contributor is radiation exposure, which has likely resulted in a few additional cases annually. The contribution of the following causes to the increasing incidence is unclear: iodine excess or insufficiency, diabetes and obesity, and molecular disruptions. The following mechanisms do not currently have strong evidence to support a link with the development of thyroid cancer: estrogen, dietary nitrate, and autoimmune thyroid disease.

CONCLUSION

Research should focus on illuminating which thyroid cancers need treatment. Patients should be advised of the benefits as well as harms that can occur with treatment of incidentally identified, small, asymptomatic thyroid cancers.

Impact of estrogen and progesterone receptor expression on the clinical and molecular features of papillary thyroid cancer

BACKGROUND

Thyroid cancer is highly prevalent in women during the fertile age, which suggests a possible impact of hormonal and reproductive factors.

METHODS

We studied the expression of estrogen receptor α (ERα or ESR1) and progesterone receptor (PR or PGR) in 182 female and male patients with papillary thyroid cancer and correlated it to clinical and molecular features.

RESULTS

ERα and PR expression was found in 66.5 and 75.8% of patients respectively and was significantly correlated with larger tumor size and with a non-incidental diagnosis. Moreover, a trend toward a higher prevalence of local metastases was observed in ER- and PR-expressing tumors, which possibly indicates a more aggressive behavior. Interestingly, the occurrence of the 'receptor conversion' phenomenon, which has already been reported to have a negative prognostic effect in breast cancer, was demonstrated for the first time in thyroid tumors. Indeed, almost all of the ERα-positive primary tumors analyzed had ERα-negative metastatic lymph nodes. At the genetic analyses, BRAF(V600E) mutation was detected in 23.2% of the tumors and had a higher prevalence in larger tumors and in those with a stronger ERα or PR staining.

CONCLUSIONS

The whole of the findings reported in the present study argue for an association between ERα and PR sex hormone receptor expression and a more aggressive presentation. Although no impact on outcome was found, the evaluation of ERα and PR receptor expression could add insights into the biological behavior of tumors and could modify the follow-up, particularly in fertile women affected with persistent disease.

ER-alpha and ER-beta expression in differentiated thyroid cancer: relation with tumor phenotype across the TNM staging and peri-tumor inflammation

Thyroid cancer may express estrogen receptors (ERs) and various grades of peri-tumor inflammation. The aim of the study was to evaluate the expression of ERs in relation to the TNM stage and peri-tumor inflammatory infiltrate in differentiated thyroid cancers. 127 patients (109 females, 18 males) with differentiated thyroid cancer (T1 = 91, T2 = 18, T3 = 11, T4 = 7) were evaluated. In tumors and in the correspondent extra-tumor parenchyma, ERs expression was evaluated by immunohistochemistry. In 114 tumors and correspondent peri-tumor tissues, the presence of inflammatory infiltration was also recorded. ER-alpha expression was higher in clinical than in incidental tumors of the T1 subgroup (p = 0.037), and was associated with capsular invasion in T2 tumors (p < 0.0001). ER-beta expression was negatively associated with vascular invasion in T1 (p = 0.005) and T2 tumors (p = 0.015). No significant relationship between ERs expression and tumor phenotype emerged in T3 and T4 subgroups. Tumors without inflammatory cell infiltrate showed a higher expression of both ER-alpha (p = 0.035) and ER-beta (p = 0.026) than the ones with inflammatory infiltrate. The relationship between tumor phenotype and ERs expression did not vary in the presence or absence of peri-tumor inflammatory infiltration. ER-alpha positivity and ER-beta negativity are associated with a more aggressive phenotype in both T1 and T2 thyroid cancers, suggesting that tumor biology may be more relevant than tumor size for cancer risk assessment. Inflammatory status is also associated with ERs expression, but not with tumor growth or phenotype.

The association of menstrual and reproductive factors with thyroid nodules in Chinese women older than 40 years of age

The purpose of the study was to explore the association of menstrual and reproductive factors with thyroid nodules in Chinese women older than 40 years of age. A questionnaire was completed by 6,571 women aged 40 years or older in a community-based epidemiological investigation of thyroid nodules conducted from June to November 2011 in Nanjing City. Thyroid nodules were measured by ultrasound. The Thyroid Imaging Reporting and Data System score was used to differentiate between benign and possibly malignant nodules. Menopausal age (>55 vs. <50 years: RR = 1.17, 95 % CI 1.00-1.34) and number of reproductive years (>40 vs. <35 years: RR = 1.12, 95 % CI 1.01-1.24) increased the risk of thyroid nodules, but were not associated with suspected malignant nodules. Women who experienced more pregnancies (≥5 vs. ≤1: RR = 2.09, 95 % CI 1.79-2.40) and abortions (≥3 vs. 0: RR = 1.61, 95 % CI 1.41-1.81) were prone to development of thyroid nodules, and more likely to form suspected malignant nodules (pregnancies, RR = 3.59, 95 % CI 1.60-7.20; abortions, RR = 2.36, 95 % CI 1.31-4.06). Furthermore, higher risks of thyroid nodules (RR = 1.36, 95 % CI 1.14-1.59) and suspected malignant nodules (RR = 2.80, 95 % CI 1.08-6.53) were observed in women who had undergone artificial compared with natural abortion. Periods of elevated estrogen and progesterone levels in women, such as pregnancy, were the key occasions for occurrence of both benign and suspiciously malignant thyroid nodules, while longer lifetime length of exposure to female sex hormones might promote the growth of thyroid nodules.

Loss of ERβ expression in papillary thyroid carcinoma is associated with recurrence in young female

OBJECTIVES

We investigated the expression of oestrogen receptors (ERs) in papillary thyroid cancers (PTCs) and evaluated their prognostic role.

METHODS

We enrolled 81 female patients who underwent thyroid surgery and had a confirmed diagnosis of PTC between 01 January 1995 and 31 December 1996. Data on clinicopathologic parameters were obtained from patients' medical records. Tissue paraffin blocks of these 81 patients were collected for immunohistochemistry for ERα and ERβ.

RESULTS

ERα expression was observed in only eight patients (9·9%). In contrast, ERβ expression was positive in 36 (44·4%) patients. Total thyroidectomy (84·4% vs 61·1%, P = 0·017) and cervical lymph node metastasis (62·2% vs 22·2%, P = 0·000) were more frequent in the ERβ-negative group than in the ERβ-positive group. Among younger female patients (<45 years), the ERβ-negative group showed a tendency towards more frequent recurrent or persistent disease than the ERβ-positive group (42·3% vs 13·6%, P = 0·029). In contrast, the ERα-positive group showed more recurrent or persistent disease than the ERα-negative group in older female patients (100% vs 24·1%, P = 0·024). In multivariate analysis, ERβ negativity, extrathyroidal invasion and radioactive iodine treatment were risk factors for recurrence in young female patients.

CONCLUSION

Loss of ERβ expression was associated with recurrence in young female PTC patients. This finding suggests that oestrogen might play a protective role in the progression of PTC via ERβ, especially in young female patients.

Estrogen and its role in thyroid cancer

Proliferative thyroid diseases are more prevalent in females than in males. Upon the onset of puberty, the incidence of thyroid cancer increases in females only and declines again after menopause. Estrogen is a potent growth factor both for benign and malignant thyroid cells that may explain the sex difference in the prevalence of thyroid nodules and thyroid cancer. It exerts its growth-promoting effect through a classical genomic and a non-genomic pathway, mediated via a membrane-bound estrogen receptor. This receptor is linked to the tyrosine kinase signaling pathways MAPK and PI3K. In papillary thyroid carcinomas, these pathways may be activated either by a chromosomal rearrangement of the tyrosine receptor kinase TRKA, by RET/PTC genes, or by a BRAF mutation and, in addition, in females they may be stimulated by high levels of estrogen. Furthermore, estrogen is involved in the regulation of angiogenesis and metastasis that are critical for the outcome of thyroid cancer. In contrast to other carcinomas, however, detailed knowledge on this regulation is still missing for thyroid cancer.

Crossover of the hypothalamic pituitary-adrenal/interrenal, -thyroid, and -gonadal axes in testicular development

Besides the well-known function of thyroid hormones (THs) for regulating metabolism, it has recently been discovered that THs are also involved in testicular development in mammalian and non-mammalian species. THs, in combination with follicle stimulating hormone, lead to androgen synthesis in Danio rerio, which results in the onset of spermatogenesis in the testis, potentially relating the hypothalamic-pituitary-thyroid (HPT) gland to the hypothalamic-pituitary-gonadal (HPG) axes. Furthermore, studies in non-mammalian species have suggested that by stimulating the thyroid-stimulating hormone (TSH), THs can be induced by corticotropin-releasing hormone. This suggests that the hypothalamic-pituitary-adrenal/interrenal gland (HPA) axis might influence the HPT axis. Additionally, it was shown that hormones pertaining to both HPT and HPA could also influence the HPG endocrine axis. For example, high levels of androgens were observed in the testis in Odonthestes bonariensis during a period of stress-induced sex-determination, which suggests that stress hormones influence the gonadal fate toward masculinization. Thus, this review highlights the hormonal interactions observed between the HPT, HPA, and HPG axes using a comparative approach in order to better understand how these endocrine systems could interact with each other to influence the development of testes.

Thyroid cancer after in vitro fertilization: a retrospective, non-consecutive case-series analysis

Although a firm association between fertility treatment and thyroid cancer has not been established, the widespread use of IVF, as a substantial reservoir of subclinical thyroid cancer disease and evidence suggesting an estrogen-dependent behavior may render thyroid cancer patients after IVF a distinct subpopulation of particular interest. Thus, a retrospective, non-consecutive case-series analysis of patients with history of thyroid cancer after in vitro fertilization was conducted. Twelve female patients with thyroid cancer who had previously undergone IVF treatment were identified within the cohort of thyroid cancer patients followed in our institution. All cases of thyroid cancer were papillary thyroid carcinoma (PTC) on histology and median tumor size (25th and 75th percentile) was 12 mm (7 and 17 mm). Thyroid cancer was diagnosed after a median of 4 years (2 and 6 years) from the last IVF cycle and at the time of diagnosis lymph node metastases were present in five patients (42%) and distant metastases where seen in four of them. Collectively, these data suggest that an aggressive pattern of PTC might be present in this distinct subpopulation. This preliminary observation may be explained, at least in part, by the delay in the diagnosis.

Differential expression patterns and clinical significance of estrogen receptor-α and β in papillary thyroid carcinoma

Background

The incidence of papillary thyroid cancer (PTC) is markedly higher in women than men during the reproductive years. In vitro studies have suggested that estrogen may play an important role in the development and progression of PTC through estrogen receptors (ERs). This study aimed to investigate the expression patterns of the two main ER subtypes, α and β1 (wild-type ERβ), in PTC tissue and their clinical significance.

Methods

Immunohistochemical staining of thyroid tissue sections was performed to detect ER expression in female patients with PTC (n = 89) and nodular thyroid goiter (NTG; n = 30) using the Elivision™ plus two-step system. The relationships between ER subtype expression and clinicopathological/biological factors were further analyzed.

Results

The positive percentage and expression levels of ERα were significantly higher in female PTC patients of reproductive age (18–45 years old; n = 50) than age-matched female NTG patients (n = 30), while ERβ1 exhibited the opposite pattern. There was no difference in ERα or ERβ1 expression between female PTC patients of reproductive age and those of advanced reproductive age (>45 years old; n = 39). In the female PTC patients of reproductive age, ERα expression level was positively correlated with that of Ki-67, while ERβ1 was negatively correlated with mutant P53. Furthermore, more patients with exclusively nuclear ERα expression had extrathyroidal extension (ETE) as compared with those with extranuclear ERα localization. VEGF expression was significantly decreased in female PTC patients of reproductive age with only nuclear ERβ1 expression when compared with those with extranuclear ERβ1 localization. In PTC patients of advanced reproductive age, neither ERα nor ERβ1 expression showed any correlation with that of Ki-67, mutant P53, VEGF, tumor size, TNM stage, ETE, or lymph node metastases.

Conclusions

The differential expression patterns of the two ER subtypes between PTC and NTG indicate that ERα may be a useful immunohistochemical marker for differential diagnosis of PTC. The associations of ER subtype expression with Ki-67, mutant P53, VEGF expression and ETE in female PTC patients of reproductive age suggest that estrogen-activated ERα may mediate stimulatory effects on PTC growth and progression whereas ERβ1 has some inhibitory actions.

Impact of pregnancy on prognosis of differentiated thyroid cancer: clinical and molecular features

OBJECTIVE

Differentiated thyroid cancer (DTC) commonly occurs in women of child-bearing age and represents the second most frequent tumor diagnosed during pregnancy only behind breast cancer. It is possible that associated physiological changes could favor tumor development and growth. However, few data are available about the outcome of DTC related to pregnancy, leading to conflicting results.

METHODS

Among the study population, 340 patients with DTC <45 years old were retrospectively studied. Patients were divided into three groups according to the time of tumor diagnosis in respect of pregnancy. Group 1, diagnosis of DTC at least 2 years after delivery; group 2, diagnosis during pregnancy or within the second year after delivery; and group 3, nulliparous patients at the time of diagnosis. We evaluated clinical outcome and immunohistochemical expression of estrogen receptor α (ERα), ERβ, progesterone receptor, and aromatase. We also analyzed the gene expression of NIS (SLC5A5) and the prevalence of BRAF(V600E) mutations.

RESULTS

Persistence/recurrence of disease was significantly higher in group 2 patients than control groups (P=0.023). No significant differences were observed in other clinical parameters. Furthermore, no differences among the groups were recorded about ER pattern, NIS expression, and BRAF mutations.

CONCLUSIONS

Persistence/recurrence of DTC is significantly higher in pregnant patients, suggesting that pregnancy could really exert a negative prognostic role in patients with DTC. The underlying mechanisms are not yet clarified and further studies are required. Our results suggest that a more careful follow-up is needed when diagnosis of DTC occurs during pregnancy or shortly after.

Androgen receptor expression: prognostic value in locally advanced squamous cell carcinoma of the head and neck

BACKGROUND AND PURPOSE

This study investigated the prognostic value of androgen receptor (AR) expression of tumor cells in patients treated with surgery and subsequent radio(chemo)therapy for locally advanced squamous cell carcinoma of the head and neck (SCCHN).

MATERIAL AND METHODS

The impact of AR and 11 additional factors on locoregional control (LRC), metastases-free survival (MFS), and overall survival (OS) was retrospectively studied in 163 patients with nonmetastatic stage III/IV SCCHN. Additional factors included age, gender, ECOG performance status, pre-radiotherapy (pre-RT) hemoglobin levels, tumor site, histologic grade, T category, N category, HPV status, extent of resection, and concurrent chemotherapy.

RESULTS

On multivariate analysis, improved LRC was significantly associated with pre-RT hemoglobin levels≥12 g/dl (risk ratio [RR] 2.22; 95% confidence interval [CI] 1.19–4.13; p=0.013), tumor site (RR 1.39; 95% CI 1.14–1.70; p=0.001), lower T category (RR 1.67; 95% CI 1.18–2.44; p=0.003), and lower N category (RR 4.18; 95% CI 1.90–10.55; p<0.001). Improved MFS was associated with AR expression (RR 2.21; 95% CI 1.01–5.41; p=0.048), better ECOG performance status (RR 3.19; 95% CI 1.50–7.14; p=0.003), lower T category (RR 2.24; 95% CI 1.47–3.65; p<0.001), and lower N category (RR 5.33; 95% CI 2.07–16.63; p<0.001). OS was positively associated with AR expression (RR 1.99; 95% CI 1.06–4.00; p=0.032), better ECOG performance status (RR 2.20; 95% CI 1.20–4.09; p=0.010), pre-RT hemoglobin levels≥12 g/dl (RR 2.13; 95% CI 1.19–3.82; p=0.012), lower T category (RR 1.81; 95% CI 1.30–2.62; p<0.001), and lower N category (RR 3.41; 95% CI: 1.65–7.80; p<0.001).

CONCLUSION

Tumor cell expression of AR was an independent prognostic factor for MFS and OS and should be considered in future prospective trials.

Obesity and thyroid cancer: epidemiologic associations and underlying mechanisms

The incidence of thyroid cancer has been rising over the past few decades along with a parallel increase in obesity. Observational studies have provided evidence for a potential association between the two. By contrast, clinical data for a link between type 2 diabetes mellitus, a condition strongly associated with obesity, and thyroid cancer are limited and largely not supportive of such an association. Obesity leads to hypoadiponectinemia, a pro-inflammatory state, and insulin resistance, which, in turn, leads to high circulating insulin and insulin-like growth factor-1 levels, thereby possibly increasing the risk for thyroid cancer. Thus, insulin resistance possibly plays a pivotal role in underlying the observed association between obesity and thyroid cancer, potentially leading to the development and/or progression of thyroid cancer, through its interconnections with other factors including insulin-like growth factor-1, adipocytokines/cytokines and thyroid-stimulating hormone. In this review, epidemiological and clinical evidence and potential mechanisms underlying the proposed association between obesity and thyroid cancer risk are reviewed. If the association between obesity and thyroid cancer demonstrated in observational studies proves to be causal, targeting obesity (and/or downstream mediators of risk) could be of importance in the prevention and management of thyroid cancer.

The cross-talk between estrogen receptor and peroxisome proliferator-activated receptor gamma in thyroid cancer

BACKGROUND

Estrogen receptor (ER) and peroxisome proliferator-activated receptor gamma (PPARγ) are associated with thyroid tumorigenesis and treatment. However, the interaction between them has not been studied.

METHODS

The impact of ER over-expression or down-expression by DNA/small interfering RNA (siRNA) transfection, ERα agonists, and the ERβ agonist diarylpropiolnitrile (DPN) on PPARγ expression/activity was examined in papillary thyroid carcinoma (PTC) and anaplastic thyroid carcinoma (ATC) cells. The effects of PPARγ modulation by rosiglitazone (RTZ), a PPARγ ligand, and of PPARγ siRNA on ER expression were determined. Cellular functions reflected by cell proliferation and migration were assayed. Apoptosis was analyzed by terminal deoxynucleotidyl transferase dUTP nick-end labeling, and apoptotic-related proteins were evaluated by Western blot analysis.

RESULTS

PPARγ protein and activity were reduced by the over-expression of either ERα or ERβ, whereas repression of ERα or ERβ increased PPARγ expression. The administration of RTZ counteracted the effects of ER and also reduced their expression, particularly in PTC cells. Moreover, knockdown of PPARγ increased ER expression and activity. Functionally, ERα activation offset the inhibitory effect of PPARγ on cellular functions, but ERβ activation aggregated it and induced apoptosis, particularly in PTC cells. Finally, the interaction between ERβ and PPARγ enhanced the expression of proapoptotic molecules, such as caspase-3 and apoptosis-inducing factor.

CONCLUSIONS

This study provides evidence supporting a cross-talk between ER and PPARγ. The reciprocal interaction between PPARγ and ERβ significantly inhibits the proliferation and migration of thyroid cancer cells, providing a new therapeutic strategy against thyroid cancer.