Gender differences in thyroid cancer: a critical review

[Gender medicine: endocrine and neuroendocrine diseases : Implications for surgery and perioperative management]

Gender medicine is also becoming increasingly more important in the field of surgery of endocrine and neuroendocrine diseases. Gender differences in the incidence, symptoms and disease progression are common to all (neuro)endocrine diseases. Understanding these special features, which include socioeconomic aspects as well as different anatomical and biological factors, is essential for the selection of optimal diagnostics and treatment but in some cases further scientific research is required. To date, there is a paucity of gender-specific recommendations in established guideline recommendations. There is an enormous potential in all areas of endocrine surgery to take advantage of differences between men and women in the diagnostics, surgical treatment and perioperative management. Individualized approaches could lead to improved surgical outcomes, reduced perioperative complications and improved follow-up.

Spatiotemporal distribution of mediastinal neoplasms: A comprehensive multi-center study

OBJECTIVES

Mediastinal neoplasms are typical but uncommon thoracic diseases with increasing incidence and unfavorable prognoses. A comprehensive understanding of their spatiotemporal distribution is essential for accurate diagnosis and timely treatment. However, previous studies are limited in scale and data coverage. Therefore, this study aims to elucidate the distribution of mediastinal lesions, offering valuable insights into this disease.

MATERIALS AND METHODS

This multi-center, hospital-based observational study included 20 nationwide institutions. A retrospective search of electronic medical records from January 1st, 2009, to December 31st, 2020, was conducted, collecting sociodemographic data, computed tomography images, and pathologic diagnoses. Analysis focused on age, sex, time, location, and geographical region. Comparative assessments were made with global data from a multi-center database.

RESULTS

Among 7,765 cases, thymomas (30.7%), benign mediastinal cysts (23.4%), and neurogenic tumors (10.0%) were predominant. Distribution varied across mediastinal compartments, with thymomas (39.6%), benign cysts (28.1%), and neurogenic tumors (51.9%) most prevalent in the prevascular, visceral, and paravertebral mediastinum, respectively. Age-specific variations were notable, with germ cell tumors prominent in patients under 18 and aged 18-29, while thymomas were more common in patients over 30. The composition of mediastinal lesions across different regions of China remained relatively consistent, but it differs from that of the global population.

CONCLUSION

This study revealed significant heterogeneity in the spatiotemporal distribution of mediastinal neoplasms. These findings provide useful demographic data when considering the differential diagnosis of mediastinal lesions, and would be beneficial for tailoring disease prevention and control strategies.

Association between oil spill clean-up work and thyroid cancer: Nine years of follow-up after the Hebei Spirit oil spill accident

In 2007, an unprecedented oil spill occurred in Taean, Korea. Although crude oil contains chemicals that could increase thyroid cancer risk, few studies have examined the long-term effects of oil exposure during clean-up and thyroid cancer incidence. We investigated the long-term thyroid cancer incidence among participants involved in clean-up work. 1798 participants engaged in at least two surveys since the baseline was tracked from 2008 to 2018. Participants reported the days they participated in oil clean-up works and cancer diagnoses. Cox proportional hazard models were used to estimate the hazard ratios between clean-up work duration and thyroid cancer. Over the 9-year follow-up, 30 thyroid cancer cases were diagnosed. A positive association was observed between clean-up duration and thyroid cancer risk. This effect was more pronounced among residents living <50 m from traffic roads. Our results indicate that crude oil clean-up work participation may increase the thyroid cancer risk.

Natural History and Prognostic Model of Untreated Papillary Thyroid Cancer: A SEER Database Analysis

PURPOSE

This investigation leveraged the SEER database to delve into the progression patterns of PTC when left untreated. Furthermore, it aimed to devise and authenticate a nomogram for prognosis prediction for such patients.

METHODS

We extracted data from the SEER database, focusing on PTC-diagnosed individuals from 2004-2020. To discern disease progression intervals, median survival times across stages were gauged, and the disease progression time was estimated by subtracting the median survival time of a more severe stage from its preceding stage. Prognostic determinants in the training set were pinpointed using both univariate and multivariate Cox regression. Using these determinants, a prognostic nomogram was crafted.

RESULTS

In untreated PTC patients, those in stages I and II had a favorable prognosis, with 10-year overall survival rates of 86.34% and 66.03%, respectively. Patients in stages III and IV had a relatively poorer prognosis. The median survival time of stage III, stage IVA, stage IVB and stage IVC patients was 108months, 43 months, 20 months and 8 months, respectively. The deduced progression intervals from stages III-IVC were 65, 23, and 12 months. In the training set, age, tumor stage, gender, and marital status were identified as independent risk factors influencing the prognosis of untreated PTC, and a nomogram was constructed using these variables.

CONCLUSION

In the absence of treatment intervention, early-stage PTC progressed slowly with an overall favorable prognosis. However, in mid to advanced-stage PTC, as tumor stage increased, disease progression accelerated, and prognosis gradually worsened. Age, tumor stage, marital status, and gender were independent risk factors influencing the prognosis of untreated PTC, and the nomogram based on these factors demonstrated good prognostic capability.

Male gender as a poor prognostic factor in medullary thyroid carcinoma: behavior or biological difference?

BACKGROUND

Due to the low incidence and heterogeneous behavior of medullary thyroid carcinoma (MTC), its prognostic factors are still not well stablished. While several large studies have investigated the impact of gender in differentiated thyroid cancer (DTC), its role in MTC outcomes remains controversial. We aim to identify MTC prognostic features, specially focusing on the role of gender.

METHODS

The present study is a retrospective analysis of 76 patients diagnosed with MTC between 1984 and 2018 at a Portuguese Comprehensive Cancer Center.

RESULTS

Patients presented a median age at diagnosis of 49 years and multiple endocrine neoplasia type 2 (MEN2) was identified in 27.6% of them, with those individuals being significantly younger (P<0.001). Most cases were diagnosed as stage IV disease (46.9%), except for the subgroup detected through presymptomatic genetic screening (55.6% at stage I). The 5- and 10-year survival rates were 87.6% and 75.6%, respectively. Univariate analysis identified male gender (P=0.010), age ≥45 years (P=0.007), presence of distant metastasis at diagnosis (P<0.01), capsule invasion (P=0.004), extrathyroidal invasion (P=0.003) and absence of biochemical cure after surgery (P=0.042) as having a negative impact on prognosis. On multivariate analysis, male gender (P=0.046) remained an independent predictor of mortality, as well as an older age (P<0.001) and the presence of distant metastases (P=0.012).

CONCLUSIONS

Male gender independently predicted worse survival in MTC patients even after adjusting for age and disease stage. The few older studies on the topic pointed to a behavioral explanation regarding medical care seeking patterns by men, but our study and newer genetic and basic-science oriented publications raise the possibility of a true biological difference between genders in the tumorigenesis of MTC that should me further investigated.

Exploring the oral-gut microbiota during thyroid cancer: Factors affecting the thyroid functions and cancer development

Thyroid cancer (TC) is categorized into papillary, follicular, medullary, and anaplastic. The TC is increasing in several countries, including China, the United States, the United Kingdom, Canada, France, Australia, Germany, Japan, Spain, and Italy. Thus, this review comprehensively covers the factors that affect thyroid gland function, TC types, risk factors, and symptoms. Lifestyle factors (such as nutrient consumption and smoking) and pollutants (such as chemicals and heavy metals) increased the thyroid-stimulating hormone (TSH) levels which are directly related to TC prevalence. The conventional and recent TC treatments are also highlighted. The role of the oral and gut microbiota as well as the application of probiotics on TC are also discussed. The variations in the composition of oral and gut microbes influence the thyroid function indirectly through alteration in metabolites (such as short-chain fatty acids) that are eminent for cellular energy metabolism. Maintenance of healthy gut and oral microbiota can help in regulating thyroid function by regulating iodine uptake. Oral or gut microbial dysbiosis can be considered as an early diagnosis factor or TC marker. High TSH during TC can increase the oral microbial diversity while disrupting the high ratio of Firmicutes and Bacteroidetes in the gut. Supplementation of probiotics as an adjuvant in TC treatment is beneficial. However, needs more extensive research to explore the direct effect of probiotics on thyroid function.

Sexual disparity and the risk of second primary thyroid cancer: a paradox

BACKGROUND

Despite extensive research on sex differences in primary thyroid cancer, there is a lack of data on the role of sex in the risk of developing second primary thyroid cancer (SPTC). We aimed to investigate the risk of SPTC development according to patient sex, with an emphasis concerning previous malignancy location as well as age.

METHODS

Cancer survivors diagnosed with SPTC were identified from the Surveillance, Epidemiology, and End Results (SEER) database. The SEER*Stat software package obtained standardized incidence ratios (SIR) and absolute excess risks of subsequent thyroid cancer development.

RESULTS

Data for 9,730 (62.3%) females and 5,890 (37.7%) males were extracted for a total of 15,620 SPTC individuals. Asian/Pacific Islanders had the highest incidence of SPTC [SIR =2.67, 95% confidence interval (CI): 2.49-2.86]. The risk of SPTC was higher in males (SIR =2.01, 95% CI: 1.94-2.08) than when compared to females (SIR =1.83, 95% CI: 1.79-1.88; P<0.001). Head and neck tumors had significantly higher SIRs for SPTC development in males when compared to females.

CONCLUSIONS

Survivors of primary malignancies have an increased risk SPTC, especially males. Our work suggests that oncologists and endocrinologists may consider the need for increased surveillance of both male and female patients given their increased risk of SPTC.

Risk Factors Associated With Reoperative Surgery for Thyroid Malignancies: A Retrospective Cohort Study

OBJECTIVE

To examine various factors associated with an increased risk of reoperation for persistent or recurrent malignant thyroid cancers.

STUDY DESIGN

Retrospective cohort study.

SETTING

Tertiary academic hospital centers.

METHODS

Patients undergoing surgery for thyroid cancer at 2 tertiary academic institutions from 2006 to 2020 were included. Those who underwent a reoperative procedure were compared with patients only requiring 1 procedure. The Pearson chi-square and independent t test were used to compare group data accordingly. Furthermore, a binomial logistic regression was performed, while machine learning models were used to construct a predictive algorithm.

RESULTS

This study included 2266 patients with surgically managed thyroid malignancy, of which 54 (2.4%) necessitated reoperations. Those requiring a second surgical procedure were more likely to be male (40.7% vs 20.9%, P < .001), undergo bilateral (24.1% vs 3.3%, P < .001) and lateral (16.7% vs 1.8%, P < .001) neck dissections, and have a greater number of metastatic lymph nodes (mean, 9.1 vs 3.5; P < .001) and a larger tumor size (mean, 3.0 vs 2.0 cm; P < .001). According to the binomial logistic regression model, lateral neck dissection, greater number of metastatic lymph nodes, and larger tumor size significantly increased the odds of necessitating a second procedure by 7.8 (95% CI, 2.523-24.083), 1.1 (95% CI, 1.032-1.152), and 1.3 (95% CI, 1.064-1.559), respectively. Last, machine learning models could not significantly predict the occurrence of reoperation.

CONCLUSION

This study identified patient- and cancer-related characteristics associated with an increased risk of requiring reoperation for thyroid malignancies.

Recent Changes in the Incidence of Thyroid Cancer in Korea between 2005 and 2018: Analysis of Korean National Data

BACKGRUOUND

In this study, we evaluated the recent changes in the standardized, age-specific, stage-specific incidence rates (IRs) of thyroid cancer in Korea and compared them with the incidence data reported by the Surveillance, Epidemiology, and End Results Program.

METHODS

The analysis was conducted using the incidence data (2005 to 2018) from the Statistics Korea and Korea Central Cancer Registry.

RESULTS

The age-standardized IR (SIR) of thyroid cancer increased from 24.09 per 100,000 in 2005 to 74.83 in 2012 (annual percent change [APC], 14.5). From 2012 to 2015, the SIR decreased to 42.52 (APC, -17.9) and then remained stable until 2018 (APC, 2.1). This trend was similar in both men and women. Regarding age-specific IRs, the IRs for ages of 30 years and older showed a trend similar to that of the SIR; however, for ages below 30 years, no significant reduction was observed from the vertex of IR in 2015. Regarding stage-specific IRs, the increase was more prominent in those with regional disease (APC, 17.4) than in those with localized disease until 2012; then, the IR decreased until 2015 (APC, -16.1). The average APC from 2005 to 2018 increased in men, those under the age of 30 years, and those with regional disease.

CONCLUSION

The SIR in Korea peaked in 2012 and decreased until 2015 and then remained stable until 2018. However, in young individuals under the age of 30 years, the IR did not significantly decrease but tended to increase again. In terms of stage-specific IRs, the sharpest increase was seen among those with regional disease.

Burden of thyroid cancer in North Africa and Middle East 1990–2019

Background

Thyroid cancer is the leading cause of mortality and morbidity among cancers of the endocrine system. We aimed to describe the trends of thyroid cancer burden in North Africa and Middle East for 1990–2019.

Methods

Data on burden of thyroid cancer in North Africa and Middle East from 1990 to 2019 were obtained from the Global Burden of Disease (GBD) Study 2019. Decomposition analysis was used to estimate the effects of population growth, aging, and change in incident numbers on overall change of thyroid cancer incidence. Also, we used the comparative risk assessment framework of GBD to determine the burden of thyroid cancer attributable to a high body mass index (BMI).

Results

In 2019, the age-standardized incidence rate (ASIR) and age-standardized mortality rate (ASMR) of thyroid cancer were 3.5 (2.9–4) and 0.5 (0.5–0.7) per 100,000, respectively. The highest age-standardized incidence, deaths, and disability-adjusted life year (DALY) rate were in Lebanon, Afghanistan, and United Arab Emirates, respectively. The ASIR of thyroid cancer in region was about 2.5 times higher among women, which had a positive association with increasing age. In 2019, the age-standardized deaths attributable to a high BMI was 16.7% of all deaths due to thyroid cancer. In 1990–2019, the overall change in thyroid cancer incident cases was a 396% increase which was mostly driven by the increase in disease-specific incidence rate (256.8%).

Conclusions

Women, the elderly above about 60 years old, and countries with a higher sociodemographic index showed higher incidence rates of thyroid cancer. Regarding our findings, it is recommended to establish preventive plans by modification in life style like weight reduction programs.

Thyroid Nodule Shape Independently Predicts Risk of Malignancy

CONTEXT

Predictive models of thyroid nodule cancer risk are presently based upon nodule composition, echogenicity, margins, and the presence of microcalcifications. Nodule shape has shown promise to be an additive factor helping determine the need for nodule biopsy.

OBJECTIVE

We sought to determine if calculation of a nodule's spherical shape independently associates with cancer risk.

METHODS

This prospective cohort study, conducted at a single large academic healthcare system in the United States, included patients with 1 or 2 clinically relevant thyroid nodules (predominantly solid and over 1 cm) presenting for diagnostic evaluation. Thyroid ultrasound, cytological evaluation with fine-needle biopsy, and/or histopathological examination on occasion of thyroid surgery were performed. We calculated the nodule's long to short ratio (spherical shape), and its association with tissue proven benign or malignant endpoints.

RESULTS

The long to short nodule ratio was significantly lower in malignant compared to benign nodules indicating greater risk of malignancy in more spherical nodules (1.63 ± 0.38 for malignant nodules vs 1.74 ± 0.47 for benign, P < 0.0001). The risk of malignancy continually increased as the long to short ratio approached a purely spherical ratio of 1.0 (ratio > 2.00, 14.6% cancer; ratio 1.51-2.00, 19.7%; ratio 1.00-1.50, 25.5%, P < 0.0001). In multiple regression analysis, younger age, male sex, and nodule's spherical shape were each independently associated with cancer risk.

CONCLUSION

The more a thyroid nodule is spherically shaped, as indicated by a long to short ratio approaching 1.0, the greater its risk of malignancy. This was independent of age, sex, and nodule size. Incorporating a nodule's sphericity in the risk stratification systems may improve individualized clinical decision making.

Age-related risk for second breast cancer and gynecological malignant neoplasms after differentiated thyroid cancer

PURPOSE

In this study, we aimed to investigate the age-related risk of second breast cancer (SBC) and second gynecological malignant neoplasms (SGMNs) in female differentiated thyroid cancer (DTC) survivors by utilizing the Surveillance, Epidemiology, and End Results (SEER) database.

METHODS

A total number of 55,622 female DTC patients were identified between 1975 and 2016, including 2168 patients who developed SBC and SGMNs. The Fine and Gray model was used to calculate the cumulative incidence and sub-distribution hazards ratios (SHR). Poisson regression analysis was employed to calculate the relative risk (RR) and standardized incidence ratio (SIR). Kaplan-Meier survival and log-rank test analyses were also performed.

RESULTS

The overall 40-year cumulative incidence of SBC and SGMNs was 18.9%. Their incidence in the adolescent and young adults (AYA) group increased slowly in the first 30 years, but then was rapidly elevated in the last decade. It increased gradually in the middle-aged adults group and in the first 25 years in the older adults group, but it scarcely increased thereafter. Both the middle-aged adults (adjusted SHR, 2.09; RR, 1.76) and the older adults (adjusted SHR, 1.32; RR, 1.58) groups had higher risks of developing combined SBC and SGMNs than the AYA group. The risks increased mainly in the early latency period. The three groups also had higher SIRs than the US general population. Besides, the best survival after SBC and SGMNs was observed in the AYA group.

CONCLUSIONS

Age was an independent risk factor for SBC and SGMNs incidences among female DTC survivors.

The prevalence and associated predictors for Bethesda III-VI for reporting thyroid cytopathology in Royal Commission Hospital, Kingdom of Saudi Arabia

BACKGROUND

Thyroid cancer is increasing globally and is currently the most prevalent endocrine malignancy. Recent data show an increase in the incidence of thyroid cancer in the Kingdom of Saudi Arabia (KSA). Thyroid ultrasound and fine-needle aspiration cytology (FNAC) are the cornerstones in managing thyroid nodules. We conducted this study to evaluate the prevalence and the associated predictors for thyroid nodule Bethesda III-VI in eastern KSA.

METHODS

A retrospective study was conducted between January 2015 and 31 August 2021. The participants were recruited patients who received a thyroid ultrasound and ultrasound-guided thyroid FNAC, using the thyroid imaging reporting and data system (TI-RADS) and the Bethesda Classification, respectively.

RESULT

Three hundred and ten patients who underwent thyroid FNAC were enrolled in the study. The median (interquartile, IQR) age was 47.0 (20.0) years, and 266 (85.8%) of them were females. The median (IQR) body mass index was 30.2 (7.6) kg/m². Out of these participants, 64.8% were euthyroid, 27.4% had hypothyroidism and 7.7% had hyperthyroidism. The ACR TI-RADS-3, 4 and 5 were 51.3%, 46.1% and 2.6%, respectively. The Bethesda outcome of thyroid FNAC I-VI was 5.2%, 63.9%, 15.5%, 5.8%, 3.5% and 6.1%, respectively. The risk for malignancy (Bethesda III-VI) was documented in 31.0% and atypia of undetermined significance was most prevalent (15.5%). A higher ACR TI-RADS score was associated with a higher risk of malignancy: ACR TI-RADS-3 (20.8%), ACR TI-RADS-4 (39.2%) and ACR TI-RADS-5 (87.5%). In a multivariate analysis, only the ACR TI-RADS score was significantly associated with the outcome of thyroid FNAC: ACR TI-RADS-4 [OR = 2.59 (95% CI = 1.54-4.36)] and ACR TI-RADS-5 [OR = 29.03 (95% CI = 3.44-245.07)].

CONCLUSION

There was a high prevalence of Bethesda III-VI and atypia of undetermined significance was most prevalent. A thyroid ultrasound report for TI-RADS was significantly associated with the outcome of thyroid FNAC and is a reliable tool in the absence of molecular testing for thyroid cancer.

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.

Improving the prediction of persistent and recurrent differentiated thyroid cancer using the American Thyroid Association 2015 risk stratification system

PURPOSE

The 2015 American Thyroid Association risk stratification system (ATA RSS) is used in patients with differentiated thyroid carcinoma (DTC) to assess their risk of persistent/recurrent disease. Our aims were to validate the 2015 ATA RSS in a registry of DTC patients and to examine whether the addition of factors not included in it, such as pre-radioactive iodine therapy stimulated thyroglobulin (pre-RAI sTg), gender, and age could increase its predictive ability.

METHODS

We studied 403 patients with DTC, treated at a tertiary center from 1990 to 2018 and subjected to total thyroidectomy. All patients had received RAI therapy, except those with low-risk papillary microcarcinoma.

RESULTS

Of our patients, 81.9% were women and 91.1% had papillary thyroid carcinoma. After a median follow-up of 5.0 years, 53 cases of persistent and 21 cases of recurrent disease were recorded. The proportion of variance explained (PVE) regarding the outcome (presence or absence of recurrent/persistent disease) using the 2015 ATA RSS alone was 18.3% (persistence) and 16.9% (recurrence), increasing to 74.4% and 52.0%, respectively, when pre-RAI sTg was added to the logistic regression model. Gender and age were not associated with the disease outcome. In ROC analysis, pre-RAI sTg had a high predictive value for persistent (AUC 0.983, 95% CI 0.962-1.000) and recurrent disease (AUC 0.856, 95% CI 0.715-0.997). The optimal cut-offs and sensitivity, specificity, and positive and negative predictive value for pre-RAI sTg were the following: for persistence 12.75 ng/ml, 100%, 90.5%, 64%, and 100%, and for recurrence 8.05 ng/ml, 77.8%, 85.5%, 36.8%, and 97%.

CONCLUSIONS

The 2015 ATA RSS displayed moderate performance in predicting recurrent/persistent disease in patients with DTC, which improved with the inclusion of pre-RAI sTg values; pre-RAI sTg was an independent predictor of the disease outcome, with high negative prognostic value.

Analysis of the Association between Female Medical History and Thyroid Cancer in Women: A Cross-Sectional Study Using KoGES HEXA Data

The purpose of this study was to evaluate the association between female medical history and thyroid cancer. Methods: Data from the Korean Genome and Epidemiology Study were collected from 2004 to 2016. Among a total of 1303 participants with thyroid cancer and 106,602 control (non-thyroid cancer) participants, the odds ratios (ORs) with 95% confidence intervals (CIs) of hysterectomy, oophorectomy, use of oral contraceptives, and number of children were evaluated. Results: The adjusted OR of hysterectomy for thyroid cancer was 1.73 (95% CI = 1.48-2.01, p < 0.001) in the minimally adjusted model. The adjusted ORs for thyroid cancer were 1.89 (95% CI = 1.06-3.37, p = 0.031), 0.89 (95% CI = 0.83-0.94, p < 0.001), and 0.85 (95% CI = 0.73-0.99, p = 0.040) for bilateral oophorectomy, number of children, and use of oral contraceptives, respectively, in the fully adjusted model. In the subgroup analysis, the adjusted ORs of bilateral oophorectomy were significant in the younger age (OR = 3.62, 95% CI = 1.45-9.03, p = 0.006), while the number of children was significant in the older age (OR = 0.86, 95% CI = 0.80-0.93, p < 0.001). Conclusions: The ORs of hysterectomy and bilateral oophorectomy were significantly higher in the thyroid cancer group in the younger age group. The adjusted ORs of the number of children were significantly low in the older age group.

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.

The intratumor microbiome predicts prognosis across gender and subtypes in papillary thyroid carcinoma

While the intratumor microbiome has become increasingly implicated in cancer development, the microbial landscape of papillary thyroid carcinoma (PTC) is essentially uninvestigated. PTC is characterized by varied prognosis between gender and cancer subtype, but the cause for gender and subtype-based dissimilarities is unclear. Women are more frequently diagnosed with PTC, while men suffer more advanced-staged PTC. In addition, tall cell variants are more aggressive than classical and follicular variants of PTC. We hypothesized that intratumor microbiome composition distinctly alters the immune landscape and predicts clinical outcome between PTC subtypes and between patient genders. Raw whole-transcriptome RNA-sequencing, Level 3 normalized mRNA expression read counts, and DNA methylation 450 k sequencing data for untreated, nonirradiated tumor, and adjacent normal tissue were downloaded from the Genomic Data Commons (GDC) legacy archive for 563 thyroid carcinoma patients. Microbe counts were extracted using Pathoscope 2.0 software. We correlated microbe abundance to clinical variables and immune-associated gene expression. Gene-set enrichment, mutation, and methylation analyses were conducted to correlate microbe abundance to characterize microbes' roles. Overall, PTC tumor tissue significantly lacked microbes that are populated in adjacent normal tissue, which suggests presence of microbes may be critical in controlling immune cell expression and regulating immune and cancer pathways to mitigate cancer growth. In contrast, we also found that microbes distinctly abundant in tall cell and male patient cohorts were also correlated with higher mutation expression and methylation of tumor suppressors. Microbe dysbiosis in specific PTC types may explain observable differences in PTC progression and pathogenesis. These microbes provide a basis for developing specialized prebiotic and probiotic treatments for varied PTC tumors.

Global, regional, and national burden and quality of care index (QCI) of thyroid cancer: A systematic analysis of the Global Burden of Disease Study 1990-2017

BACKGROUND

Thyroid cancer (TC) is the most prevalent malignancy of the endocrine system. Over the past decades, TC incidence rates have been increasing. TC quality of care (QOC) has yet to be well understood. We aimed to assess the quality of TC care and its disparities.

METHODS

We retrieved primary epidemiologic indices from the Global Burden of Disease (GBD) 1990-2017 database. We calculated four secondary indices of mortality to incidence ratio, disability-adjusted life years (DALYs) to prevalence ratio, prevalence to incidence ratio, and years of life lost (YLLs) to years lived with disability (YLD) ratio and summarized them by the principal component analysis (PCA) to produce one unique index presented as the quality of care index (QCI) ranged between 0 and 100, to compare different scales. The gender disparity ratio (GDR), defined as the QCI for females divided by QCI for males, was applied to show gender inequity.

RESULTS

In 2017, there were 255,489 new TC incident cases (95% uncertainty interval [UI]: 245,709-272,470) globally, which resulted in 41,235 deaths (39,911-44,139). The estimated global QCI was 84.39. The highest QCI was observed in the European region (93.84), with Italy having the highest score (99.77). Conversely, the lowest QCI was seen in the African region (55.09), where the Central African Republic scored the lowest (13.64). The highest and lowest socio-demographic index (SDI) regions scored 97.27 and 53.85, respectively. Globally, gender disparity was higher after the age of 40 years and in favor of better care in women.

CONCLUSION

TC QOC is better among those countries of higher socioeconomic status, possibly due to better healthcare access and early detection in these regions. Overall, the quality of TC care was higher in women and younger adults. Countries could adopt the introduced index of QOC to investigate the quality of provided care for different diseases and conditions.

On the identification of thyroid nodules using semi-supervised deep learning

Detecting malign cases from thyroid nodule examinations is crucial in healthcare particularly to improve the early detection of such cases. However, malign thyroid nodules can be extremely rare and is hard to find using the traditional rule based or expert-based methods. For this reason, the solutions backed by Machine Learning (ML) algorithms are key to improve the detection rates of such rare cases. In this paper, we investigate the application of ML in the healthcare domain for the detection of rare thyroid nodules. The utilized dataset is collected from 636 distinct patients in 99 unique days in Turkey. In addition to the texture feature data of the Ultrasound (US), we have also included the scores of different assessment methods created by different health institutions (e.g., Korean, American and European thyroid societies) as additional features. For detection of extremely rare malign cases, we use auto-encoder based neural network model. Through numerical results, it is shown that the auto-encoder based model can result in an average Recall score of 0.98 and a Sensitivity score of 1.00 for detecting malign and non-malign cases from the healthcare dataset outperforming the traditional classification algorithms that are trained after Synthetic Minority Oversampling Technique (SMOTE) oversampling.

Secular Trends in the Epidemiologic Patterns of Thyroid Cancer in China Over Three Decades: An Updated Systematic Analysis of Global Burden of Disease Study 2019 Data

BACKGROUND

Thyroid cancer is the most common malignant endocrine disease worldwide. The changing epidemiologic pattern of thyroid cancer at the national level in China has remained unknown over the last three decades.

METHODS

Following the general analytical strategy used in the Global Burden of Disease Study (GBD) 2019, the age- and sex-specific incidence, mortality, and prevalence rates of thyroid cancer in China were analyzed. Trends in the incidence, mortality, prevalence, and disability-adjusted life years (DALYs) due to thyroid cancer from 1990 to 2019 were assessed by joinpoint regression analysis. Age, period, and cohort effects on incidence were estimated by an age-period-cohort model.

RESULTS

From 1990 to 2019, the age-standardized prevalence and incidence rates significantly increased in both males and females, and the age-standardized mortality rate decreased in females but increased in males. Moreover, the increments in all the age-standardized measures of thyroid cancer in China were higher in males than in females. The age effect showed that those aged 40-44 years had the highest relative risk (RR) among females, and the RR increased with age among males. The incidence increased with time and began to substantially increase in 2009. The cohort effect showed that the incidence decreased in successive birth cohorts.

CONCLUSIONS

The burden of thyroid cancer in China showed unexpected patterns that varied by sex, age, and year. Notably, males had higher average annual percentage changes in thyroid cancer incidence and mortality rates than females. More attention should be given to improving the thyroid cancer burden in males in China.

Analysis of Race and Gender Disparities in Incidence-Based Mortality in Patients Diagnosed with Thyroid Cancer from 2000 to 2016

Background

Well-differentiated thyroid cancer has better outcomes compared to undifferentiated/anaplastic thyroid cancer. The incidence of well-differentiated thyroid cancer is known to be more in women whereas it is approximately the same in both genders for anaplastic thyroid cancer. The variability of incidence-based mortality across gender in the context of race has not been studied. This study analyzes the rates of incidence-based mortality from the years 2000 to 2016 amongst both the genders in four racial groups.

Methods

The Surveillance, Epidemiology, and End Results (SEER) database was utilized to conduct a nation-wide analysis for the years 2000 to 2016. Incidence-based mortality for all stages of well-differentiated and undifferentiated thyroid cancer was queried and the results were grouped by race (Caucasian/White, African American/Black, American Indian/Alaskan Native and Asian/Pacific Islander) and gender. All stages and ages were included in the analysis. Two sample t-test was used to determine statistically significant difference between various subgroups.

Results

Incidence-based mortality rates (per 100,000) for well-differentiated and undifferentiated thyroid cancer for all races and both the genders were calculated. The incidence-based mortality rates for both genders are approximately the same despite a 2–3:1 difference in incidence. Anaplastic thyroid cancer has a higher mortality rate in Caucasian and Asian/Pacific Islander women compared to men despite an equal ratio in incidence. As expected, the mortality rates of anaplastic thyroid cancer were significantly higher compared to well-differentiated cancer across all races and genders. Also, Asian/Pacific Islander women have a higher rate of mortality compared to both the genders of Caucasian and African American races.

Conclusion

Incidence-based mortality for anaplastic thyroid cancer is higher in women in all races whereas there is no difference in mortality between men and women for well-differentiated thyroid cancer. This is divergent from the incidence ratios noted in these malignancies. In the context of increasing incidence of thyroid cancer for the past few decades, this data suggests that additional resources may be devoted to decreasing the disparity of mortality in this gender.

Gender Differential Transcriptome in Gastric and Thyroid Cancers

Cancer has an important and considerable gender differential susceptibility confirmed by several epidemiological studies. Gastric (GC) and thyroid cancer (TC) are examples of malignancies with a higher incidence in males and females, respectively. Beyond environmental predisposing factors, it is expected that gender-specific gene deregulation contributes to this differential incidence. We performed a detailed characterization of the transcriptomic differences between genders in normal and tumor tissues from stomach and thyroid using Genotype-Tissue Expression (GTEx) and The Cancer Genome Atlas (TCGA) data. We found hundreds of sex-biased genes (SBGs). Most of the SBGs shared by normal and tumor belong to sexual chromosomes, while the normal and tumor-specific tend to be found in the autosomes. Expression of several cancer-associated genes is also found to differ between sexes in both types of tissue. Thousands of differentially expressed genes (DEGs) between paired tumor-normal tissues were identified in GC and TC. For both cancers, in the most susceptible gender, the DEGs were mostly under-expressed in the tumor tissue, with an enrichment for tumor-suppressor genes (TSGs). Moreover, we found gene networks preferentially associated to males in GC and to females in TC and correlated with cancer histological subtypes. Our results shed light on the molecular differences and commonalities between genders and provide novel insights in the differential risk underlying these cancers.

Angiotensin-converting enzyme inhibitor and angiotensin II type 1 receptor blocker: Potential agents to reduce post-surgical scar formation in humans

Studies on the effectiveness and mechanisms of reducing scar formation by interfering with the renin-angiotensin-aldosterone-system (RAAS) have been demonstrated in animals, but not in humans due to the lack of clinical support. Our aim was to investigate whether angiotensin-converting enzyme inhibitor (ACEI) and angiotensin II type 1 receptor blocker (ARB) could inhibit scar formation in humans. Thus, an observational and hypothesis-generating study using a designed questionnaire was carried out. A total of 347 patients with postoperative scars secondary to thyroid tumours were enrolled. They were divided into four groups: ACEI group, ARB group, other antihypertensive drugs control group and blank control group according to the administration of antihypertensive drugs. The width of scar was measured, and the Scar Cosmesis Assessment and Rating (SCAR) Scale was filled out. Results showed that patients of ACEI group (mean scar width 1.60 mm) and ARB group (mean scar width 1.57 mm) formed smaller scars than those of other antihypertensive drugs control group (mean scar width 2.09 mm) and blank control group (mean scar width 2.0 mm). Oral administration of ACEI and ARB may be associated with better post-surgical scar formation in humans. These two kinds of antihypertensive drugs may be active components of anti-scar medicine.

Thyroid Carcinoma: Do We Need to Treat Men and Women Differently?

BACKGROUND

For differentiated thyroid carcinoma, gender-specific differences exist in regard to incidence, age at onset, tumor stage, and recurrence, but causative factors remain to be elucidated. Possible and likely contributors are genetic and hormonal differences. While some of these factors are known to be differently distributed between the sexes, like, for example, BRAF-mutation and estrogen levels, their role in thyroid cancer initiation or promotion awaits further investigation.

SUMMARY

Apart from generally accepted risk factors for differentiated thyroid carcinoma, an apparent gender disparity of thyroid cancer with a general female predominance, an age-dependent difference in growth acceleration during the reproductive years, and a peak at the time of entering menopause have been demonstrated. Hormonal status and hormonal receptor mediation seem to be most likely to contribute to the differences in thyroid cancer phenotypes of males and females. However, specific cause-and-effect pathways have not yet been determined.

KEY MESSAGES

Female gender is overrepresented in the incidence of differentiated thyroid carcinoma, as it is in the more favorable tumor stages. Besides the assumption of gender-specific differences in general health awareness and behavior, hormonal age-dependent and gender-specific factors appear to be contributory. In the advanced stage of thyroid cancer, males are overrepresented. Therefore, the real cause of gender differences in thyroid cancer is likely due to a mixed effect. Present knowledge does not favor different treatment modalities of thyroid carcinoma according to gender.

Lenvatinib and sorafenib for differentiated thyroid cancer after radioactive iodine: a systematic review and economic evaluation

BACKGROUND

Thyroid cancer is a rare cancer, accounting for only 1% of all malignancies in England and Wales. Differentiated thyroid cancer (DTC) accounts for ≈94% of all thyroid cancers. Patients with DTC often require treatment with radioactive iodine. Treatment for DTC that is refractory to radioactive iodine [radioactive iodine-refractory DTC (RR-DTC)] is often limited to best supportive care (BSC).

OBJECTIVES

We aimed to assess the clinical effectiveness and cost-effectiveness of lenvatinib (Lenvima®; Eisai Ltd, Hertfordshire, UK) and sorafenib (Nexar®; Bayer HealthCare, Leverkusen, Germany) for the treatment of patients with RR-DTC.

DATA SOURCES

EMBASE, MEDLINE, PubMed, The Cochrane Library and EconLit were searched (date range 1999 to 10 January 2017; searched on 10 January 2017). The bibliographies of retrieved citations were also examined.

REVIEW METHODS

We searched for randomised controlled trials (RCTs), systematic reviews, prospective observational studies and economic evaluations of lenvatinib or sorafenib. In the absence of relevant economic evaluations, we constructed a de novo economic model to compare the cost-effectiveness of lenvatinib and sorafenib with that of BSC.

RESULTS

Two RCTs were identified: SELECT (Study of [E7080] LEnvatinib in 131I-refractory differentiated Cancer of the Thyroid) and DECISION (StuDy of sorafEnib in loCally advanced or metastatIc patientS with radioactive Iodine-refractory thyrOid caNcer). Lenvatinib and sorafenib were both reported to improve median progression-free survival (PFS) compared with placebo: 18.3 months (lenvatinib) vs. 3.6 months (placebo) and 10.8 months (sorafenib) vs. 5.8 months (placebo). Patient crossover was high (≥ 75%) in both trials, confounding estimates of overall survival (OS). Using OS data adjusted for crossover, trial authors reported a statistically significant improvement in OS for patients treated with lenvatinib compared with those given placebo (SELECT) but not for patients treated with sorafenib compared with those given placebo (DECISION). Both lenvatinib and sorafenib increased the incidence of adverse events (AEs), and dose reductions were required (for > 60% of patients). The results from nine prospective observational studies and 13 systematic reviews of lenvatinib or sorafenib were broadly comparable to those from the RCTs. Health-related quality-of-life (HRQoL) data were collected only in DECISION. We considered the feasibility of comparing lenvatinib with sorafenib via an indirect comparison but concluded that this would not be appropriate because of differences in trial and participant characteristics, risk profiles of the participants in the placebo arms and because the proportional hazard assumption was violated for five of the six survival outcomes available from the trials. In the base-case economic analysis, using list prices only, the cost-effectiveness comparison of lenvatinib versus BSC yields an incremental cost-effectiveness ratio (ICER) per quality-adjusted life-year (QALY) gained of £65,872, and the comparison of sorafenib versus BSC yields an ICER of £85,644 per QALY gained. The deterministic sensitivity analyses show that none of the variations lowered the base-case ICERs to < £50,000 per QALY gained.

LIMITATIONS

We consider that it is not possible to compare the clinical effectiveness or cost-effectiveness of lenvatinib and sorafenib.

CONCLUSIONS

Compared with placebo/BSC, treatment with lenvatinib or sorafenib results in an improvement in PFS, objective tumour response rate and possibly OS, but dose modifications were required to treat AEs. Both treatments exhibit estimated ICERs of > £50,000 per QALY gained. Further research should include examination of the effects of lenvatinib, sorafenib and BSC (including HRQoL) for both symptomatic and asymptomatic patients, and the positioning of treatments in the treatment pathway.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42017055516.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Association of IRAK1 Gene Polymorphism rs3027898 With Papillary Cancer Restricted to the Thyroid Gland: A Pilot Study

BACKGROUND/AIM

The incidence of thyroid cancer has increased predominantly due to an increase in papillary thyroid cancer (PTC). Alteration of toll-like receptor function has been reported to play a crucial role in carcinogenesis. The aim of the present study was to investigate predisposition to PTC associated with genetic markers of toll-like receptor and interleukin-1 receptor pathways involving nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-ĸB) stimulation. Specifically, the study focused on the following genes: interleukin-1 receptor-associated kinase 1 (IRAK1, rs3027898), NF-ĸB inhibitor alpha (NFKBIA, rs696), NF-ĸB subunit 1 (NFKB1, rs28362491), and microRNA-146a (miR-146a, rs2910164).

PATIENTS AND METHODS

Forty-eight unrelated patients with papillary cancer restricted to the thyroid gland and 93 healthy volunteers were enrolled in the study.

RESULTS

A strong statistically significant difference was observed between patients with PTC and controls for IRAK1 rs3027898 variant. When the statistical analysis was replicated taking into account patient's sex, the rs3027898 A allele was revealed to be the risky variant in males.

CONCLUSION

Additional studies in larger groups of patients of various origins are needed to validate these preliminary findings.

The Pregnancy Pickle: Evolved Immune Compensation Due to Pregnancy Underlies Sex Differences in Human Diseases

We hypothesize that, ancestrally, sex-specific immune modulation evolved to facilitate survival of the pregnant person in the presence of an invasive placenta and an immunologically challenging pregnancy - an idea we term the 'pregnancy compensation hypothesis' (PCH). Further, we propose that sex differences in immune function are mediated, at least in part, by the evolution of gene content and dosage on the sex chromosomes, and are regulated by reproductive hormones. Finally, we propose that changes in reproductive ecology in industrialized environments exacerbate these evolved sex differences, resulting in the increasing risk of autoimmune disease observed in females, and a counteracting reduction in diseases such as cancer that can be combated by heightened immune surveillance. The PCH generates a series of expectations that can be tested empirically and that may help to identify the mechanisms underlying sex differences in modern human diseases.

Menstrual and reproductive factors in the risk of thyroid cancer in Japanese women: the Japan Public Health Center-Based Prospective Study

The aim of this study was to evaluate the associations between menstrual and reproductive factors and thyroid cancer risk among Japanese women. A total 54 776 women aged 40-69 years completed a self-administered questionnaire, which included menstrual and reproductive history. During 1990-2012, 187 newly diagnosed cases of thyroid cancer were identified. Hazard ratios (HRs) and 95% confidence intervals (CIs) for menstrual and reproductive factors and incidence of thyroid cancer were estimated using Cox proportional hazards regression. Postmenopausal women who had natural menopause were at reduced risk of thyroid cancer than premenopausal women in the age-area-adjusted model (HR: 0.62 per 1 year increase, 95% CI: 0.39-0.99), but this association was slightly attenuated and no longer statistically significant in the multivariable-adjusted model. On analysis by menopausal status, an inverse association between age at menarche and risk of thyroid cancer was observed for premenopausal women (HR: 0.83 per 1 year increase, 95% CI: 0.70-0.98, P trend=0.03), but not for postmenopausal women. The risk of thyroid cancer increased with surgical menopause compared with natural menopause (HR: 2.34, 95% CI: 1.43-3.84). Although increasing age at menopause and duration of fertility were associated with an increased risk of thyroid cancer, this association was not observed among postmenopausal women. This study confirmed that early age at menarche for premenopausal women and surgical menopause and late age at natural menopause for postmenopausal women were associated with the development of thyroid cancer. Our results support the hypothesis that exposure to estrogens increases the risk of thyroid cancer.

Impact of Gender and Age on the Prognosis of Differentiated Thyroid Carcinoma: a Retrospective Analysis Based on SEER

The incidence of thyroid cancer in females is significantly higher than that in males; however, females are more likely to have more favorable outcomes. We aimed to determine the characteristics of differentiated thyroid carcinoma (DTC) subtypes in males and females, and to compare their clinical behavior and survival. A total of 68,337 cases were recruited from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program. The disease-specific survival (DSS) of follicular variant papillary thyroid carcinoma (FVPTC) and follicular thyroid carcinoma (FTC) were similar to that of classical variant papillary thyroid carcinoma (CPTC) in male patients (FVPTC vs. CPTC, adjusted hazard ratio (aHR) = 0.947, P = 0.776; FTC vs. CPTC, aHR = 1.512, P = 0.104). In premenopausal female (< 55 years old), FVPTC had better DSS than CPTC (aHR = 0.321, P = 0.038) while FTC had worse DSS than CPTC (aHR = 3.272, P = 0.013); in postmenopausal female, FTC had poorer prognosis than CPTC (aHR = 2.145, P = 0.002), no statistical difference was found between CPTC and FVPTC (aHR = 0.724, P = 0.087). For patients younger than 55 years, women had significantly better DSS compared with men with CPTC (aHR = 0.376, P < 0.001) and FVPTC (aHR = 0.102, P < 0.001). However, no difference was observed in patients older than 55 years. Interestingly, outcomes of FTC were not affected by gender in patients of all ages. These results suggested that different clinical behaviors and outcomes of DTC subtypes should be considered in patients with different genders.

Racial disparities of differentiated thyroid carcinoma: clinical behavior, treatments, and long-term outcomes

BACKGROUND

The incidence of thyroid cancer in black Americans is significantly lower than that in white Americans, and the impact of race on the prognosis of thyroid cancer remains controversial. The purpose of this study was to determine the risk factors for survival in black and white patients and to compare the survival of differentiated thyroid carcinoma subtypes between these two races. We further investigated the association of lymph node and distant metastases with races.

METHODS

This is a retrospective analysis using data from the National Cancer Institute's Surveillance, Epidemiology, and End Results Program. A total of 70,346 cases were included in our study. Patients' demographics and cancer- and treatment-related characteristics were compared between the black and white Americans using chi-square and Fisher's exact tests. For multivariate analysis, Cox proportional hazards regression were used to assess the association between potential risk factors and the survival in black and white patients.

RESULT

Black Americans had a worse overall survival than white Americans (HR = 1.127, P = 0.002). While disease-specific survival (DSS) was comparable, the risk factors for DSS were different between white and black Americans. Black Americans had less lymph node metastasis of classical variant papillary thyroid carcinoma (CPTC, OR = 0.476, P < 0.001) and follicular variant papillary thyroid carcinoma (FVPTC, OR = 0.522, P < 0.001), but not follicular thyroid carcinoma (FTC). However, black Americans with FVPTC, but not CPTC or FTC, had a higher potential of distant metastasis (OR = 1.715, P = 0.026). Furthermore, only white patients with tumor > 2 cm and lymph node metastasis benefited from radioactive iodine.

CONCLUSIONS

The risk factors for DSS were significantly different in white and black patients. The impact of race should be considered in treatment strategy for thyroid cancer.

An Indian Tertiary Care Hospital Scenario of Papillary Carcinoma of Thyroid

INTRODUCTION

Thyroid carcinoma is the most common endocrine malignancy and its Papillary Histotype {Papillary Carcinoma of Thyroid (PTC)} is the most common type of Thyroid cancer. The clinicopathological features of PTC vary with geographical location.

AIM

To describe the clinicopathological profile of PTC in a Tertiary Care Hospital located in Chennai, Tamil Nadu, India.

MATERIALS AND METHODS

Data on age, sex, centricity of the tumour, presence of calcifications, infiltration, metastasis, associated non malignant conditions and frequency of histological subtypes of all cases of PTC diagnosed in Department of Pathology, Madras Medical College Chennai, Tamil Nadu, India between January 2007 and December 2011 were obtained from clinicopathological documents and analysed statistically.

RESULTS

Statistically significant correlations were found between age and sex, age and metastasis, sex and centricity, sex and metastasis, size of lesion and sex, size of lesion and age, size and presence of calcifications and presence of calcifications and metastasis.

CONCLUSION

Scenario of PTC in our tertiary care setup which warrants attention is male preponderance of multicentric lesions. Further, a high association with colloid nodular goitre, while low incidence of tall cell variant is notable clinico pathological scenarios in this study.

Impact of sex on the clinicopathological characteristics and prognosis of papillary thyroid cancer

SUMMARY

Papillary thyroid cancer (PTC) is the most common endocrine malignancy. Observed clinical and pathological differences between the sexes of PTC patients have been reported. There is currently no consensus regarding the impact of sex on PTC prognostication. We studied 566 PTC patients and observed that there was a higher PTC incidence in women, that PTC diagnosis was more challenging in women, and that men tended to present with larger cancers. However, once PTC is diagnosed, both sexes have a similar cancer prognosis, as evaluated using the MACIS (Metastasis, Age, Completeness of Resection, Invasion, Size) score. Our observations suggest that research efforts should be especially directed at improving the diagnostic yield of preoperative fine needle aspiration biopsy in women who present with nodular thyroid disease.

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.

Thyroid fine-needle aspiration biopsy and thyroid cancer diagnosis: a nationwide population-based study

BACKGROUND

Thyroid cancer is the most common endocrine gland malignancy and fine-needle aspiration biopsy is widely used for thyroid nodule evaluation. Repeated aspiration biopsies are needed due to plausible false-negative results. This study aimed to investigate the overall relationship between aspiration biopsy and thyroid cancer diagnosis, and to explore factors related to shorter diagnostic time.

METHODS

This nationwide retrospective cohort study retrieved data from the Longitudinal Health Insurance Database in Taiwan. Subjects without known thyroid malignancies and who received the first thyroid aspiration biopsy after 2004 were followed-up from 2004 to 2009 (n = 7700). Chi-square test, Kaplan-Meier survival analysis, and Cox proportional hazards model were used for data analysis.

RESULTS

Of 7700 newly-aspirated patients, 276 eventually developed thyroid cancer (malignancy rate 3.6%). Among the 276 patients with thyroid cancer, 61.6% underwent only one aspiration biopsy and 81.2% were found within the first year after the initial aspiration. Cox proportional hazards model revealed that aspiration frequency (HR 1.07, 95% CI 1.06-1.08), ultrasound frequency (HR 1.02, 95% CI 1.01-1.03), older age, male sex, and aspiration biopsies arranged by surgery, endocrinology or otolaryngology subspecialties were all associated with shorter time to thyroid cancer diagnosis.

CONCLUSIONS

About 17.4% of thyroid cancer cases received more than two aspiration biopsies and 18.8% were diagnosed one year after the first biopsy. Regular follow-up with repeated aspiration or ultrasound may be required for patients with clinically significant thyroid nodules.

Evaluation of thyroid incidentaloma

Thyroid nodules are an extremely common endocrine disorder with a generally accepted prevalence of around 4% to 7%. Incidental thyroid nodules are typically nonpalpable thyroid nodules found during radiographic evaluation for a non-thyroid-related issue (eg, computed tomographic scan, positron emission tomography scan, carotid duplex). Incidental thyroid nodules are contributing to but are not the sole reason for the rising incidence of thyroid cancer in the Unites States and other developed nations.