Time trends for thyroid cancer in northwestern Spain: true rise in the incidence of micro and larger forms of papillary thyroid carcinoma

Iodine intake as a risk factor for thyroid cancer: a comprehensive review of animal and human studies

Thyroid cancer (TC) is the most common endocrine malignancy and in most countries, incidence rates are increasing. Although differences in population iodine intake are a determinant of benign thyroid disorders, the role of iodine intake in TC remains uncertain. We review the evidence linking iodine intake and TC from animal studies, ecological studies of iodine intake and differentiated and undifferentiated TC, iodine intake and mortality from TC and occult TC at autopsy, as well as the case–control and cohort studies of TC and intake of seafood and milk products. We perform a new meta-analysis of pooled measures of effect from case–control studies of total iodine intake and TC. Finally, we examine the post-Chernobyl studies linking iodine status and risk of TC after radiation exposure. The available evidence suggests iodine deficiency is a risk factor for TC, particularly for follicular TC and possibly, for anaplastic TC. This conclusion is based on: a) consistent data showing an increase in TC (mainly follicular) in iodine deficient animals; b) a plausible mechanism (chronic TSH stimulation induced by iodine deficiency); c) consistent data from before and after studies of iodine prophylaxis showing a decrease in follicular TC and anaplastic TC; d) the indirect association between changes in iodine intake and TC mortality in the decade from 2000 to 2010; e) the autopsy studies of occult TC showing higher microcarcinoma rates with lower iodine intakes; and f) the case control studies suggesting lower risk of TC with higher total iodine intakes.

Prevalence of Cancer in Patients with Thyroid Nodules in the Island of Cyprus: Predictive Value of Ultrasound Features and Thyroid Autoimmune Status

BACKGROUND

The purpose of this study was to determine the prevalence of thyroid carcinoma in patients who underwent ultrasound-guided fine needle aspiration biopsy (USgFNA) of thyroid nodules in the island of Cyprus. Ultrasound features as well as the presence of autoimmune thyroid disease were evaluated as risk factors for malignancy.

METHODS

322 consecutively examined patients (272 females/50 males, age 13-81) underwent USgFNA of thyroid nodules in a referral endocrine clinic between July 2007 and July 2009. The ultrasonographic characteristics examined were: echogenicity, margin irregularity, composition, calcifications, presence of increased vasculature and nodule size. The presence or absence of autoimmune thyroid disease was recorded.

RESULTS

From the 548 nodules examined, 74 (13.6%) were classified as THY3, 4 or 5. 75 patients (123 nodules) underwent surgical resection. 46 patients (64 nodules) proved to have thyroid carcinoma by histology. There was a significant correlation of suspicious/malignant cytology with solid composition, hypoechogenicity, irregular margins and the presence of calcifications. A significant association was also noted between the presence of positive antithyroglobulin antibodies (p < 0.05) and Graves' disease (p = 0.01) with suspicious/malignant cytology.

CONCLUSION

The overall prevalence of thyroid cancer was 14.3%. Ultrasound characteristics were highly predictive of thyroid malignancy. Thyroid autoimmunity should be considered as a risk factor.

[Thyroid carcinoma: epidemiological, clinical and therapeutic profiles, about 102 cases]

Les carcinomes thyroïdiens sont des tumeurs malignes assez rares, représentant 1% des cancers. Ils sont généralement de bon pronostic, et présentent des aspects cliniques et évolutifs variés selon leur origine histologique. Notre travail est une étude rétrospective portant sur 102 cas de carcinomes de la thyroïde, colligés sur un nombre total de 811 gestes chirurgicaux thyroïdiens, au service d'oto-rhino-laryngologie et de chirurgie cervico-faciale de l'hôpital militaire Avicenne de Marrakech, sur une période de 8 ans, allant de janvier 2006 à décembre 2013. Les carcinomes thyroïdiens atteignent le sujet jeune avant l’âge de 50 ans, en particulier le sexe féminin. La tendance dans les pays en voie de développement, comme dans le monde entier est en croissance continue, ceci peut être expliqué par l'amélioration des outils d'imagerie et des moyens diagnostiques cytologiques et anatomo-pathologiques.

A descriptive study of the characteristics of differentiated thyroid cancer in Catalonia during the period 1998-2012. The CECaT registry

INTRODUCTION

The consortium for the study of thyroid cancer (CECaT), including 20 hospitals and one research institute, was recently created in Catalonia (Spain). One of the first initiatives of the group was to perform a descriptive analysis of the characteristics of patients with differentiated thyroid carcinoma (DTC).

PATIENTS AND METHODS

The cohort included 1,855 patients from 11 hospitals treated over a period of 15 years (1998-2012).

RESULTS

In this series, 1.470 (79.2%) patients were women. Mean age was 47.7 (15.7) years old. Age was significantly higher in male than in female patients, 49.3 (15) versus 47.3 (15.8); p=0.02. Papillary thyroid carcinoma accounted for 88.9% of cases. Mean tumor size was 21.5 (16) mm, and was significantly lower in females than in males, 20.1 (14.5) mm and 26.6 (20.3) mm respectively (p<0.001). After a follow-up period of 5.5 (3.7) years, information was available for 1,355 patient, of whom 1065 (78.6%) were free of disease, 239 (17.6%) had no tumor persistence, and 51 (3.8) % had died. The risk of persistent or recurrent disease was significantly associated to older age at diagnosis, male gender, larger tumor size, lymph node metastases at surgery, no signs of thyroiditis in the remaining thyroid tissue, and presence of vascular and/or extraglandular invasion.

CONCLUSIONS

Patient characteristics analyzed are similar to those reported in other parts of the world.

[Clinical guideline for management of patients with low risk differentiated thyroid carcinoma]

Incidence of thyroid cancer is increasing in Spain and worldwide. Overall thyroid cancer survival is very high, and stratification systems to reliably identify patients with worse prognosis have been developed. However, marked differences exist between the different specialists in clinical management of low-risk patients with thyroid carcinoma. Almost half of all papillary thyroid carcinomas are microcarcinomas, and 90% are tumors < 2 cm that have a particularly good prognosis. However, they are usually treated more aggressively than needed, despite the lack of adequate scientific support. Surgery remains the gold standard treatment for these tumors. However, lobectomy may be adequate in most patients, without the need for total thyroidectomy. Similarly, prophylactic lymph node dissection of the central compartment is not required in most cases. This more conservative approach prevents postoperative complications such as hypoparathyroidism or recurrent laryngeal nerve injury. Postoperative radioiodine remnant ablation and strict suppression of serum thyrotropin, although effective for the more aggressive forms of thyroid cancer, have not been shown to be beneficial for the treatment of low risk patients, and may impair their quality of life. This guideline provides recommendations from the task force on thyroid cancer of the Spanish Society of Endocrinology and Nutrition for adequate management of patients with low-risk thyroid cancer.

[Comparison of differentiated thyroid carcinoma staging systems in a Spanish population]

BACKGROUND AND OBJECTIVE

Differentiated thyroid carcinoma staging is increasingly important due to the current trends to a less intensive therapy in low-risk patients. The TNM system is most widely used, but other systems based on follow-up of several patient cohorts have been developed. When these systems have been applied to other populations, results have been discordant. Our study evaluates the suitability of several differentiated thyroid carcinoma staging systems in a Spanish population.

MATERIAL AND METHOD

729 patients with differentiated thyroid carcinoma and staging data available were enrolled. Mean follow-up time was 10.8 years. The TNM, EORTC, AMES, Clinical class, MACIS, Ohio, NTCTCS, and Spanish systems were applied to all histological types. The Kaplan-Meier survival curves for each system were analyzed, and compared using the proportion of explained variation (PEV).

RESULTS

The demographic and clinical characteristics of our population were similar to those of other Spanish and international cohorts reported. The best systems were NTCTCS, with 74.7% PEV, and TNM (68.3%), followed by the Ohio, MACIS, EORTC, and AMES systems with minimal differences between them, while the least adequate were the Spanish (55.2%) and Clinical class (47.1%) systems.

CONCLUSION

The NTCTCS staging system was found to be better than TNM in our population but, because of its simplicity and greater dissemination, the TNM appears to be recommended for staging of patients with differentiated thyroid carcinoma.

The Frequency and Clinical Implications of the BRAF(V600E) Mutation in Papillary Thyroid Cancer Patients in Korea Over the Past Two Decades

BACKGROUND

Over the past several decades, there has been a rapid worldwide increase in the prevalence of papillary thyroid cancer (PTC) as well as a number of changes in the clinicopathological characteristics of this disease. BRAF(V600E), which is a mutation of the proto-oncogene BRAF, has become the most frequent genetic mutation associated with PTC, particularly in Korea. Thus, the present study investigated whether the prevalence of the BRAF(V600E) mutation has increased over the past two decades in the Korean population and whether various PTC-related clinicopathological characteristics have changed.

METHODS

The present study included 2,624 patients who underwent a thyroidectomy for PTC during two preselected periods; 1995 to 2003 and 2009 to 2012. The BRAF(V600E) mutation status of each patient was confirmed using the polymerase chain reaction-restriction fragment length polymorphism method or by the direct sequencing of DNA.

RESULTS

The prevalence of the BRAF(V600E) mutation in Korean PTC patients increased from 62.2% to 73.7% (P=0.001) over the last two decades. Additionally, there was a greater degree of extrathyroidal extension (ETE) and lymph node metastasis in 2009 to 2012 patients with the BRAF(V600E) mutation and a higher frequency of thyroiditis and follicular variant-PTC in 2009 to 2012 patients with wild-type BRAF. However, only the frequency of ETE was significantly higher in 1995 to 2003 patients with the BRAF(V600E) mutation (P=0.047). Long-term recurrence rates during a 10-year median follow-up did not differ based on BRAF(V600E) mutation status.

CONCLUSION

The BRAF(V600E) mutation rate in Korean PTC patients has been persistently high (approximately 70%) over the past two decades and continues to increase. The present findings demonstrate that BRAF(V600E)-positive PTC was associated with more aggressive clinicopathological features, especially in patients who were recently diagnosed, suggesting that BRAF(V600E) mutation status may be a useful prognostic factor for PTC in patients recently diagnosed with this disease.

Time trends and age-period-cohort analyses on incidence rates of thyroid cancer in Shanghai and Hong Kong

Background

Increasing incidence rates of thyroid cancer have been noted worldwide, while the underlying reasons remain unclear.

Methods

Using data from population-based cancer registries, we examined the time trends of thyroid cancer incidence in two largest cities in China, Shanghai and Hong Kong, during the periods 1973–2009 and 1983–2011, respectively. We further performed age-period-cohort analyses to address the possible underlying reasons for the observed temporal trends.

Results

We observed continuous increases in the incidence rates of thyroid cancer in Shanghai and Hong Kong, since the 1980s, in addition to higher incidence rates in the 1970s in both sexes in Shanghai. The age-standardized incidence rate of thyroid cancer increased by 3.1% [95% confidence interval (CI): 1.0%, 5.1%] and 3.8% (95% CI: 1.9%, 5.7%) per year on average, respectively, in Shanghai men and women during the period 1973–2009, while it increased by 2.2% (95% CI: 1.5%, 2.8%) and 2.7% (1.6%, 3.8%) per year on average, respectively, in Hong Kong men and women during the period 1983–2011. We observed global changes in trends across all age groups in similar ways, in addition to varied trends across different generations (birth cohorts).

Conclusions

The increased incidence rates of thyroid cancer in these two Chinese populations during recent decades may be contributable to a combination of the introduction of more sensitive diagnostic techniques and the increasing prevalence of environmental exposures in the populations.

Increasing thyroid cancer rate and the extent of thyroid surgery in Korea

BACKGROUND

It is evident that the rate of thyroid cancer is increasing throughout the world. One reason is increased detection of preclinical small cancers. However, it is not clear whether the increase in thyroid cancer rate is reducing the extent of thyroid surgeries. The purpose of this study was to evaluate the thyroid cancer rate and analyze recent changes in the extent of thyroid cancer surgeries in Korea.

METHODS

An observational study was conducted using data from Korea's Health Insurance Review and Assessment Service (HIRAS) for thyroidectomy with/without neck dissection, with 228,051 registered patients between 2007 and 2011. Data were categorized by the extent of surgery: unilateral thyroidectomy without neck dissection (UT), bilateral thyroidectomy or radical thyroidectomy without neck dissection (TT), any thyroidectomy with unilateral selective neck dissection (SND), any thyroidectomy with unilateral modified radical neck dissection (MRND), any thyroidectomy with unilateral radical neck dissection (RND), and any thyroidectomy with bilateral neck dissection (BND). Annual rate difference for each surgery was analyzed with a linear by linear association.

RESULTS

The absolute numbers of total thyroid surgeries (UT+TT+SND+MRND+RND+BND) were increased from 28539 to 61481. The proportion of patients who underwent only thyroidectomy without neck dissection (UT+TT) decreased from 67.30% to 60.50%, whereas the proportion of patients who underwent neck dissection (SND+MRND+RND+BND) increased from 32.70% to 39.50% during the 5-year study period.

CONCLUSION

Despite the increase in rate of thyroid cancer due to earlier detection, increased rate of neck dissection was noted.

Incidence rate of thyroid cancer in Neuquén (2001-2012)

During the past decades, an increasing incidence of thyroid cancer (TC) has been reported worldwide. In Argentina there is no national cancer registry, and its incidence has therefore not been established. The aim of our study was to determine the incidence of TC in the province of Neuquén and to compare it to that reported in the literature. The medical records of 229 patients admitted over a period of 12 years (2001 to 2012) were used for data analysis. Tumor size, age, sex, and histological type were evaluated. The study period was divided into four three-year periods, and differences in each of these features were analyzed. We found an incidence of 4.72/100,000 inhabitants/year, and almost all patients had papillary TC. TC was five times more common in females as compared to males (7.78 and 1.55 respectively). Mean tumor size was 22.2 ± 1.1 mm. Tumor size was significantly greater in men (31.8 ± 3.7 mm) than in women (20.4 ± 1.0 mm). When grouped by three-year periods, a higher number of cases was found in the last one (47, 49, 49 and 84 respectively). As regards tumor distribution by size, there was a significant decrease in mean tumor size in the fourth period and an increase in the proportion of tumors <10mm. We report an increase in TC incidence in the Argentinean province of Neuquén which is similar to the overall increase reported in the international literature.

The influence of the environment on the development of thyroid tumors: a new appraisal

Most epidemiological studies concerning differentiated thyroid cancers (DTC) indicate an increasing incidence over the last two decades. This increase might be partially explained by the better access to health services worldwide, but clinicopathological analyses do not fully support this hypothesis, indicating that there are carcinogenetic factors behind this noticeable increasing incidence. Although we have undoubtedly understood the biology and molecular pathways underlying thyroid carcinogenesis in a better way, we have made very little progresses in identifying a risk profile for DTC, and our knowledge of risk factors is very similar to what we knew 30-40 years ago. In addition to ionizing radiation exposure, the most documented and established risk factor for DTC, we also investigated the role of other factors, including eating habits, tobacco smoking, living in a volcanic area, xenobiotics, and viruses, which could be involved in thyroid carcinogenesis, thus, contributing to the increase in DTC incidence rates observed.

Evolution of differentiated thyroid cancer: a decade of thyroidectomies in a single institution

BACKGROUND

Numerous studies have shown an increase in the incidence of thyroid cancer (TC) in recent years.

OBJECTIVES

In this paper, we reviewed the incidence of TC in a series of patients undergoing thyroid surgery at a single institution over a 10-year period.

PATIENTS AND METHODS

The cohorts were divided into two periods (2001-2005 and 2006-2010) with the purpose of comparing various clinicopathologic variables.

RESULTS

A total of 1,263 patients were included. A significant increase in the number of malignancies was shown in the second period, namely 90 cases in 2001-2005 (15.2% of all interventions) compared to 163 cases in 2006-2010 (24.3%) (p < 0.001). These differences were attributed to an increase in papillary thyroid carcinoma (PTC), as there were 66 PTC cases in the first period (11.13% of thyroidectomies performed) compared to 129 cases in the second period (19.25%). There were no clinicohistological differences among PTC cases in these two periods.

CONCLUSIONS

Over the last decade, there has been an increase in the incidence of TC in patients undergoing thyroid surgery. This increase is exclusively due to increases in PTC. Our study verifies the existence of this trend in our geographical area, similar to that noted in other parts of the world.

Benign and malignant nodular thyroid disease in acromegaly. Is a routine thyroid ultrasound evaluation advisable?

Data on the prevalence of benign and malignant nodular thyroid disease in patients with acromegaly is a matter of debate. In the last decade an increasing incidence of thyroid cancer has been reported. The aim of this study was to evaluate the prevalence of goiter, thyroid nodules and thyroid cancer in a large series of patients with acromegaly with a cross-sectional study with a control group. Six Spanish university hospitals participated. One hundred and twenty three patients (50% men; mean age 59±13 years; disease duration 6.7±7.2 years) and 50 controls (51% males, mean age 58±15 years) were studied. All participants underwent thyroid ultrasound and fine needle aspiration. Cytological analysis was performed in suspicious nodules between 0.5 and 1.0 cm and in all nodules greater than 1.0 cm. Goiter was more frequently found in patients than in controls (24.9 vs. 8.3%, respectively; p<0.001). Nodular thyroid disease as well as nodules greater than 1 cm were also more prevalent in acromegalic patients (64.6%, vs. 28.6%, p<0.05 and 53.3 vs. 28.6%, respectively; p<0.05), and all underwent fine needle aspiration. Suspicious cytology was detected in 4 patients and in none of the controls. After thyroidectomy, papillary thyroid carcinoma was confirmed in two cases (3.3% of patients with thyroid nodules), representing 1.6% of the entire group of patients with acromegaly (2.4% including a case with previously diagnosed papillary thyroid carcinoma). These data indicated that thyroid nodular disease and cancer are increased in acromegaly, thus justifying its routine ultrasound screening.

Current management of papillary thyroid microcarcinoma in Canada

Introduction

The detection of papillary thyroid microcarcinoma (PTMC) is on the rise and its optimal management remains controversial. Our aim was to determine the current self-reported management of PTMC amongst Canadian otolaryngologist-head and neck surgeons (OHNS) and endocrinologists and to identify factors influencing their management decisions.

Methods

A nine item web-based questionnaire was distributed to Canadian OHNS and endocrinologists. The three main domains were demographics, current management of PTMC scenarios, and factors influencing the decisions.

Results

One hundred and thirteen OHNS and endocrinologists completed the survey. Respondents were closely divided between recommending hemithyroidectomy (47%) or total thyroidectomy (43%) for a newly diagnosed PTMC in a low risk patient. Observation was the preferred method for managing PTMC detected incidentally after hemithyroidectomy (76%). Respondents chose more aggressive treatment for male patients compared to female patients. A positive history of thyroid cancer or previous radiation exposure was the most important factor influencing the management of PTMC.

Conclusion

The current practices of Canadian OHNS and endocrinologist largely coincide with available guidelines. The slight variation in practice might be explained by the opposing evidence supporting different management options. Given the dramatic increase in the incidence of PTMC we suggest future guidelines address the management of PTMC independently.

Conventional papillary thyroid carcinoma: effects of cystic changes visible on ultrasonography on disease prognosis

Purpose

To investigate the characteristics of papillary thyroid carcinoma (PTC) with cystic changes visible on ultrasonography (US).

Methods

This study included 553 PTCs in 553 patients between January 2003 and August 2004. One radiologist with 10 years of experience in thyroid imaging retrospectively reviewed the preoperative US images. Two different groups were formed according to two different reference points (group 1, 25%; group 2, 50%) of the cystic component. Patients between the groups were compared according to their clinicopathologic characteristics. Disease-free survival (DFS) was estimated. Cox’s multivariate proportional hazards regression model was used to identify the effect of variable factors on the recurrence risk.

Results

Fifty-six patients (10.1%) were confirmed to have tumor recurrence within the follow-up period. Thirty-five patients had regional metastasis, one had distant metastasis, eight had multiple site metastases, and 12 had biochemical recurrence. PTC patients with a ≤ 50% or PTC patients with a ≤ 25% cystic component did not have a statistically significant longer DFS than those with a >50% (hazard ratio [HR], 1.118; 95% confidence interval [CI], 0.255 to 4.910; P=0.883) or those with a >25% cystic component (HR, 0.569; 95% CI, 0.164 to 1.976; P=0.375), respectively. Moreover, independent predictors of recurrence were pathologic size, male gender, and lymph node metastasis, not a >50% or >25% cystic component.

Conclusion

The proportion of the cystic component in PTCs did not affect DFS.

A Review on Ultrasound-Based Thyroid Cancer Tissue Characterization and Automated Classification

In this paper, we review the different studies that developed Computer Aided Diagnostic (CAD) for automated classification of thyroid cancer into benign and malignant types. Specifically, we discuss the different types of features that are used to study and analyze the differences between benign and malignant thyroid nodules. These features can be broadly categorized into (a) the sonographic features from the ultrasound images, and (b) the non-clinical features extracted from the ultrasound images using statistical and data mining techniques. We also present a brief description of the commonly used classifiers in ultrasound based CAD systems. We then review the studies that used features based on the ultrasound images for thyroid nodule classification and highlight the limitations of such studies. We also discuss and review the techniques used in studies that used the non-clinical features for thyroid nodule classification and report the classification accuracies obtained in these studies.

Increased prevalence of chronic lymphocytic thyroiditis in Korean patients with papillary thyroid cancer

Background

In recent years, some reports have suggested that papillary thyroid cancers are more frequently associated with lymphocytic thyroiditis or Hashimoto's thyroiditis. This study investigated a potential increase in the prevalence of chronic lymphocytic thyroiditis among papillary thyroid cancer patients.

Materials and Methods

We used national epidemiological survey data on thyroid cancer patients diagnosed in 1999, 2005, and 2008. A retrospective medical record survey was conducted by representative sampling of a national cancer incidence database. The analysis included 5,378 papillary thyroid cancer patients aged 20–79 years. We calculated the age-standardized prevalence and age-adjusted prevalence ratios using a binomial regression model with a log link for the prevalence of chronic lymphocytic thyroiditis among papillary thyroid cancer patients by sex for each year.

Results

The prevalence of chronic lymphocytic thyroiditis among papillary thyroid cancer patients was 4.0% and 12.8% for men and women in 1999, 6.5% and 24.6% in 2005, and 10.7% and 27.6% in 2008, respectively. Between 1999 and 2008, the age-standardized prevalence of chronic lymphocytic thyroiditis increased 4.1-fold in male patients and 2.0-fold in female patients with papillary thyroid cancer. The prevalence of other thyroid diseases, however, did not increase in either gender.

Conclusions

Among Korean papillary thyroid cancer patients, the prevalence of chronic lymphocytic thyroiditis increased between 1999 and 2008, whereas the prevalence of other thyroid disorders did not change.

Continued rapid increase in thyroid cancer incidence in california: trends by patient, tumor, and neighborhood characteristics

BACKGROUND

Thyroid cancer incidence is increasing worldwide. Incorporating 22 years of incidence data through 2009, we extend examination of these trends among a wide array of subgroups defined by patient (age, sex, race/ethnicity, and nativity), tumor (tumor size and stage), and neighborhood (socioeconomic status and residence in ethnic enclaves) characteristics, to identify possible reasons for this increase.

METHODS

Thyroid cancer incidence data on 10,940 men and 35,147 women were obtained from the California Cancer Registry for 1988-2009. Population data were obtained from the 1990 and 2000 U.S. Census. Incidence rates and 95% confidence intervals (CI) were calculated and incidence trends were evaluated using Joinpoint regression to evaluate the timing and magnitude of change [annual percentage change (APC) and rate ratios].

RESULTS

The incidence of papillary thyroid cancer continues to increase in both men (APC, 5.4; 95% CI, 4.5-6.3 for 1998-2009) and women (APC, 3.8; 95% CI, 3.4-4.2 for 1998-2001 and APC, 6.3; 95% CI, 5.7-6.9 for 2001-2009). Increasing incidence was observed in all subgroups examined.

CONCLUSIONS

Although some variation in the magnitude or temporality of the increase in thyroid cancer incidence exists across subgroups, the patterns (i) suggest that changes in diagnostic technology alone do not account for the observed trends and (ii) point to the importance of modifiable behavioral, lifestyle, or environmental factors in understanding this epidemic.

IMPACT

Given the dramatic and continued increase in thyroid cancer incidence rates, studies addressing the causes of these trends are critical. Cancer Epidemiol Biomarkers Prev; 23(6); 1067-79. ©2014 AACR.

Long-term prognosis of differentiated thyroid cancer with lung metastasis in Korea and its prognostic factors

BACKGROUND

Distant metastasis, generally to lung and bone, is rare in differentiated thyroid carcinoma (DTC) and the prognosis is still elusive. We investigated long-term outcomes of lung metastasis in DTC patients and its prognostic factors.

METHODS

A retrospective review was performed of 4572 patients who underwent surgery for DTC from 1962 to 2009 at Seoul National University Hospital. Among them, 164 patients were identified with lung metastasis and 152 patients were enrolled in the final analysis. Poor prognosis was defined as progressive disease or death.

RESULTS

Of these 152 patients, 10- and 20-year survival rates were 85.0% and 71.0%, respectively. No evidence of disease, stable disease, progressive disease, and death was identified in 22.4%, 28.3%, 35.5%, and 13.8%, respectively, after 11 years of median follow-up (range 2-41 years). Older age at diagnosis (≥45 years), primary tumor size ≥2 cm, follicular thyroid cancer, metastasis diagnosed after initial evaluation or (131)I remnant ablation (late metastasis), multiple metastases other than lung, (131)I nonavidity, and the presence of macronodules (≥1 cm) were more frequent in poor prognoses. Cox proportional hazard ratio for progression-free survival showed that (131)I nonavidity was the only independent predictive factor for poor prognosis.

CONCLUSIONS

The prognosis of lung metastasis from DTC in Korea within this study was favorable. (131)I nonavidity, observed more frequently in late metastasis, was the only independent factor predicting poor prognosis.

Papillary thyroid microcarcinoma: how to diagnose and manage this epidemic?

The incidence of papillary thyroid microcarcinoma (PTmC) has been increasing everywhere due to the improvement of imaging and morphological diagnoses and probably also due to environmental alterations. Despite this, the mortality caused by thyroid cancer has not increased, reflecting the low clinical aggressiveness of most papillary thyroid carcinomas (PTCs) and the quality of the available treatment. The criteria used to classify PTmC remain questionable, making the clinical risk evaluation of these lesions very difficult. There is no solid basis for establishing the most appropriate tumor size (currently <10 mm) to distinguish PTmC from PTC. Moreover, PTmCs encompass all sorts of PTC histotypes, thus turning the whole group of PTmC genetically and biologically heterogeneous. In this review, we address the 2 most interesting issues from a practical standpoint: Are there any specific morphological or molecular features distinguishing PTmC from PTC? Is it possible to predict the clinical behavior of PTmC in fine needle aspiration biopsy and in surgical specimens, using morphological and/or molecular markers?

Changes in the clinicopathological characteristics and outcomes of thyroid cancer in Korea over the past four decades

BACKGROUND

Thyroid cancer has increased globally, with a prominent increase in small, papillary thyroid cancers (PTC). The Korean population has a high iodine intake, high prevalence of BRAF V600E mutations, and family histories of thyroid cancer. We examined the clinicopathological characteristics and outcomes of thyroid cancers in Korean patients over four decades.

METHODS

The medical records of 4500 thyroid cancer patients, between 1962 and 2009 at a single center, including 3147 PTC patients, were reviewed.

RESULTS

The mean age of the patients was 46.8±13.2 years; women accounted for 82.9% of the patients, and the median follow-up duration was 4.8 years (mean 7.0±5.8 years, range 1-43 years). The number of patients visiting the clinic increased from 411 during 1962-1990 to 2900 during 2000-2009. Age at diagnosis increased from 39.6±12.9 to 48.6±12.4 years. The male to female ratio increased from 1:6 to 1:4.5. The proportion of small (<1 cm) tumors increased from 6.1% to 43.1%, and the proportion of cancers with lymph node (LN) involvement or extrathyroidal extension (ETE) decreased from 76.4% to 44.4% and from 65.5% to 54.8% respectively. Although there were decreases in the proportion of LN involvement and ETE, these decreasing rates were not proportional to the expected rates based on the decreased proportion of large tumors. The overall recurrence and mortality rates were 13.3% and 1.4%. The five-year recurrence rate significantly decreased (from 11% to 5.9%), and the five-year mortality also improved (from 1.5% to 0.2%).

CONCLUSIONS

The incidence of thyroid cancer has rapidly increased, with a decrease in tumors of large size, LN involvement, and ETE, although the decreasing rates of LN involvement and ETE were not as prominent as decreasing rates of large size tumors. The mortality and recurrence rates have also decreased. Future long-term follow-up of patients diagnosed in the most recent decade is needed to confirm the prognostic characteristics of Korean PTC patients.

Worldwide increasing incidence of thyroid cancer: update on epidemiology and risk factors

Background. In the last decades, thyroid cancer incidence has continuously and sharply increased all over the world. This review analyzes the possible reasons of this increase. Summary. Many experts believe that the increased incidence of thyroid cancer is apparent, because of the increased detection of small cancers in the preclinical stage. However, a true increase is also possible, as suggested by the observation that large tumors have also increased and gender differences and birth cohort effects are present. Moreover, thyroid cancer mortality, in spite of earlier diagnosis and better treatment, has not decreased but is rather increasing. Therefore, some environmental carcinogens in the industrialized lifestyle may have specifically affected the thyroid. Among potential carcinogens, the increased exposure to medical radiations is the most likely risk factor. Other factors specific for the thyroid like increased iodine intake and increased prevalence of chronic autoimmune thyroiditis cannot be excluded, while other factors like the increasing prevalence of obesity are not specific for the thyroid. Conclusions. The increased incidence of thyroid cancer is most likely due to a combination of an apparent increase due to more sensitive diagnostic procedures and of a true increase, a possible consequence of increased population exposure to radiation and to other still unrecognized carcinogens.

Preoperative ultrasonographic features of papillary thyroid carcinoma predict biological behavior

BACKGROUND

Although ultrasound (US) features of papillary thyroid carcinoma (PTC) are well established, little is known regarding biological behavior according US features. We investigated whether there was a difference in biological behavior between PTCs that did and did not meet malignant US criteria.

PATIENTS AND METHODS

We retrospectively reviewed clinical records and histological and US findings of the index tumors in 488 patients who underwent surgery for PTC. Benign-looking PTC (B-PTC) was defined as showing none of the accepted US criteria for malignancy. Malignant-looking PTCs (M-PTCs) and B-PTCs were compared in terms of patients' age, sex, tumor size, histological subtype, multifocality, lymph node (LN) metastasis, extrathyroidal extension, stage, recurrence, and distant metastasis.

RESULTS

B-PTCs accounted for 74 (15%) of all 488 PTCs. Mean tumor size was not significantly different between the groups, with 1.10 cm for M-PTC and 1.11 cm for B-PTC (P = .947). Univariate and multivariate analysis indicated that M-PTC more frequently had LN metastasis, extrathyroidal extension, and a higher stage than B-PTC (all P < .05). The results were significant in tumors ≥1.0 cm, whereas there were no significant differences in tumors <1 cm. As the number of malignant US features increased, multifocality, extrathyroidal extension, LN metastasis, and a higher stage were more likely.

CONCLUSION

PTCs that did not meet malignant US criteria had better prognostic indicators than PTCs that met US criteria. Therefore, US features at the time of diagnosis can serve as a useful tool for predicting biological behavior in PTC.

Descriptive epidemiology of human thyroid cancer: experience from a regional registry and the "volcanic factor"

Thyroid cancer (TC), the most common endocrine tumor, has steadily increased worldwide due to the increase of the papillary histotype. The reasons for this spread have not been established. In addition to more sensitive thyroid nodule screening, the effect of environmental factors cannot be excluded. Because high incidences of TC were found in volcanic areas (Hawaii and Iceland), a volcanic environment may play a role in the pathogenesis of TC. In January 2002, the Regional Register for TC was instituted in Sicily. With a population of approximately five million inhabitants with similar genetic and lifestyle features, the coexistence in Sicily of rural, urban, industrial, moderate-to-low iodine intake, and volcanic areas provides a conducive setting for assessing the environmental influences on the etiology of TC. In Sicily, between 2002 and 2004, 1,950 new cases of TC were identified, with an age-standardized rate (world) ASR(w) = 17.8/10(5) in females and 3.7/10(5) in males and a high female/male ratio (4.3:1.0). The incidence of TC was heterogeneous within Sicily. There were 2.3 times more cases in the Catania province (where most of the inhabitants live in the volcanic area of Mt. Etna): ASR(w) = 31.7/10(5) in females and 6.4/10(5) in males vs. 14.1 in females and 3.0 in males in the rest of Sicily. Multivariate analysis documented that residents in the volcanic area of Mt. Etna had a higher risk of TC, compared to the residents in urban, industrial, and iodine deficient areas of Sicily. An abnormally high concentration of several chemicals was found in the drinking water of the Mt. Etna aquifer, which provides water to most of the residents in the Catania province. Our data suggest that environmental carcinogen(s) of volcanic origin may promote papillary TC. Additional analyses, including cancer biological and molecular features, will allow a better understanding of risk factors and etiopathogenetic mechanisms.

Intra- and postoperative complications in 137 cases of giant thyroid gland tumor

The intra- and postoperative complications resulting from surgery for giant thyroid gland tumors (diameter greater than 10 cm) present serious challenges to patient recovery. Although there are a number of methods, all have limitations. In this study, we present our experience with several complications of surgical treatment of giant thyroid gland tumors to increase the awareness and aid the prevention of these complications. A total of 137 consecutive patients who underwent surgical treatment in Henan Tumor Hospital were retrospectively analyzed. Statistics pertaining to the patients' clinical factors were gathered. We found that the most common surgical complications were recurrent laryngeal nerve (RLN) injury and symptomatic hypoparathyroidism. Other complications included incision site infections, bleeding, infection and chyle fistula, the incidence of which increased significantly with increasing extent of surgery from group I (near-total thyroidectomy) to group V (total thyroidectomy plus lateral neck dissection). Low complication rates may be achieved with more accurate knowledge of the surgical anatomy, skilled surgical treatment and experience. More extensive surgery results in a greater number of complications.

Serum oncofetal fibronectin (onfFN) mRNA in differentiated thyroid carcinoma (DTC): large overlap between disease-free and metastatic patients

AIM

This study assessed if onfFN mRNA in the peripheral blood of patients with DTC can identify individuals with metastatic disease.

METHODS

Comparison of onfFN mRNA was made among 3 groups: disease-free, lymph node metastasis, and distant metastasis using real-time RT-PCR on 5 ml blood samples from each DTC patient.

RESULTS

Fifty-one patients were included: 30 (59%) were disease-free; 7 (13.7%) had lymph node metastasis; and 14 (27.5%) had distant metastasis. OnfFN mRNA levels in the 3 groups were significantly different (P=0.001) but with a large overlap and the expression being highest in the disease-free group. Subgroup analysis of the metastatic groups did not show any effect of age, cell type, and serum TSH, Tg, and antiTg on onfFN mRNA. The within-run and between-run root mean square coefficients of variations were <2%.

CONCLUSION

OnfFN mRNA in patients with DTC cannot identify those with metastatic disease.

Factors influencing the outcome of patients with incidental papillary thyroid microcarcinoma

Objective. To analyze some factors that could influence the outcome of patients with PTMC. Material and Methods. This is a longitudinal observational study. All patients diagnosed and treated for papillary thyroid microcarcinoma at the University Hospital of Vigo, between January 1994 and December 2003, were included in the present study. Demographic characteristics, tumour characteristics, TNM stage, rate of recurrence, and treatment with ¹³¹I were the study variables. Results. Ninety-one patients (75 females) with an average age of 47.7 ± 13.4 years, range 19–81, were studied. Initial tumour staging was T1 in 90 patients and T4a in 1 case. Initial lymph node involvement was present in 4 cases (4.4%). We only found one case with distant metastases at diagnosis. Postsurgical evaluation of thyroid specimens revealed that 28 (30.7%) tumours were multifocal. The average size of the tumour was 0.44 ± 0.25 cm, range 0.1–1. Univariate analysis reveals a statistically significant association between tumour multifocality and postsurgical ¹³¹I therapy with the recurrence rate. In the multivariate analysis only multifocality (P = 0.037, HR 5.7) was a significant risk factor for the recurrence rate. Conclusions. Our results indicate that tumour multifocality is an independent predictor of relapse but neither the tumour size nor postsurgical ¹³¹I therapy.

Time trend in tumour size and characteristics of anaplastic thyroid carcinoma

OBJECTIVE

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancies. Nevertheless, there have been reports that some patients experience long-term survival and those in whom ATCs of small size are often detected. We evaluated the time trend of characteristics of ATC such as size and association with coexistent differentiated thyroid carcinoma (DTC). We also found the characteristics of patients showing long-term survival.

DESIGN AND PATIENTS

This is a retrospective observational cohort study from the two major tertiary referral hospitals in Seoul, Korea. Ninety-five patients who had been diagnosed with ATC from 1995 to 2010 were included. We classified them into three groups according to the time of initial diagnosis: group 1 (1995-1999), group 2 (2000-2004) and group 3 (2005-2010).

RESULTS

The mean tumour size decreased significantly according to groups; 6·2, 5·5 and 4·0 cm in group 1, 2 and 3, respectively (P = 0·02). The frequency of cases with coexistent DTC increased; 10·3%, 35·1% and 48·3% in group 1, 2 and 3, respectively (P = 0·02). Fifteen of 95 patients survived more than 24 months, and among them, 13 are still alive who underwent curative surgery. Among 15 long-term survivors, nine patients with ATC arising from DTC had ATC tumour portion less than 1 cm. Another five patients with ATC without coexistent DTC had relatively small-sized tumours (1·0-4·0 cm).

CONCLUSION

The tumour size of ATC decreased, and cases with coexistent DTC increased over the last two decades. We found that patients with ATC showing long-term survival are those who had atypical presentations such as anaplastic transformation in early stage of DTC or small size of tumours without coexistent DTC.

Increasing incidence of thyroid cancer in Great Britain, 1976-2005: age-period-cohort analysis

Increases in the incidence of thyroid cancer have been previously reported. The purpose of the present study was to examine temporal trends in the incidence of primary thyroid cancer diagnosed in 0-49 year olds in parts of Great Britain during 1976-2005. Data on 4,337 cases of thyroid cancer were obtained from regional cancer registries. Age-standardized incidence rates (ASRs) were calculated. Negative binomial regression was used to examine effects of age, sex, drift (linear trend), non-linear period and non-linear cohort. The best fitting negative binomial regression model included age (P < 0.001), sex (P < 0.001) and drift (P < 0.001). Non-linear period (P = 0.648) and non-linear cohort (P = 0.788) were not statistically significant. For males aged 0-14, the ASR increased from 0.2 per million persons per year in 1976-1986 to 0.6 in 1997-2005. For males aged 15-29 and 30-49 the ASRs increased from 1.9 to 3.3 and from 7.4 to 12.7, respectively. For females aged 0-14, the corresponding ASR increased from 0.3 to 0.5. For females aged 15-29 and 30-49 the ASRs increased from 6.9 to 12.4 and from 21.2 to 42.3, respectively. For all age groups, there has been a linear increase in incidence of thyroid cancer, which has led to a doubling of the number of cases diagnosed over a twenty year span. The reasons for this increase are not well understood, but it is consistent with findings from other countries.

Incidental thyroid cancer found during surgery for head and neck squamous cell carcinoma

OBJECTIVE

To quantify the incidence of occult thyroid cancer encountered during neck dissection in patients with head and neck squamous cell carcinoma (HNSCC), to discuss the management of these patients, and to assess the need for further treatment of the incidentally discovered thyroid cancer.

STUDY DESIGN

Case series with chart review.

SETTING

University-based tertiary care hospital.

METHODS

The authors retrospectively reviewed 2538 neck dissections performed at their institution over a 15-year period. Twenty-nine patients had an incidental pathologic finding of thyroid cancer at surgery. The authors reviewed demographics, diagnoses, histopathology, initial and subsequent management, and outcome.

RESULTS

Well-differentiated thyroid cancer (WDC) was found in every case in this cohort. Fifteen patients died during the period of the study (2.4-year follow-up), with 14 patients still alive (4.3-year follow-up). Seven patients, all of whom are still alive, received further treatment for their thyroid cancer: 2 with completion thyroidectomy, 2 with I-131 ablation, and 3 with both. There was no clinical evidence of recurrence of thyroid cancer in any of the patients who died, and none died as a result of thyroid cancer. In addition, none of the patients still alive have biopsy-proven evidence of thyroid cancer recurrence.

CONCLUSION

None of the patients in this cohort died as a result of their thyroid disease, and none of the patients had evidence of recurrence of their WDC during the follow-up period. The results suggest that further management of occult WDC discovered in patients receiving neck dissections for HNSCC is not necessary.

Simultaneous medullary and differentiated thyroid cancer: a population-level analysis of an increasingly common entity

BACKGROUND

Simultaneous medullary thyroid carcinoma (MTC) and differentiated thyroid carcinoma (DTC) is a rare entity. This is the first population-level analysis of the characteristics and outcomes of simultaneous MTC/DTC.

METHODS

In the Surveillance, Epidemiology, and End Results (SEER) database (1988-2008), patients with simultaneous MTC/DTC were retrospectively compared with those with MTC alone using χ(2), ANOVA, log-rank tests, Cox multivariate regression, and Kaplan-Meier analyses.

RESULTS

A total of 162 patients had simultaneous MTC/DTC; 1,699 had MTC alone. MTC was diagnosed first in 67.9 % of simultaneous MTC/DTC cases. Simultaneous MTC/DTC increased from 2.7 % of all MTCs in 1988-1997 to 12.3 % in 2003-2008. Compared with MTC alone, simultaneous MTC/DTC had smaller mean MTC tumor size (2.9 vs. 2.2 cm; p = 0.005) and lower rates of MTC extrathyroidal extension (25.4 vs. 16.8 %; p = 0.015) and distant metastases (15.7 vs. 9.3 %; p = 0.032). Patients diagnosed with DTC first had smaller mean MTC tumor sizes (p = 0.01), whereas patients diagnosed with MTC first had tumor sizes similar to those of MTC alone. Compared with MTC alone, patients with simultaneous MTC/DTC were more likely to receive thyroidectomy (84.7 vs. 93.2 %; p = 0.003) and radioisotopes (4.4 vs. 25 %; p < 0.001). On Kaplan-Meier analysis, disease-specific survival rates were higher for simultaneous MTC/DTC than for MTC alone (10-year survival rates 87 vs. 81 %; p = 0.056).

CONCLUSIONS

Simultaneous MTC/DTC is diagnosed earlier in tumor development than MTC alone, with a trend toward better prognosis. This entity likely represents a primary tumor with an incidental pathologic finding of a second malignancy. Each malignancy should be treated according to its respective stage and current guidelines.

Disparities in the initial presentation of differentiated thyroid cancer in a large public hospital and adjoining university teaching hospital

BACKGROUND

Healthcare disparities associated with insurance and socioeconomic status have been well characterized for several malignancies, such as lung cancer. To assess whether there are healthcare disparities in thyroid cancer, this study evaluated the stage on initial presentation of patients with differentiated thyroid cancer (DTC) in a public versus university teaching hospital.

METHODS

A retrospective chart review was performed to identify patients with a new diagnosis of DTC from January 1, 2007, to January 1, 2010, in a large public and adjoining university teaching hospital at a single academic medical center. Medical records were reviewed for demographics, pathology, and American Joint Committee on Cancer tumor-node-metastasis stage at initial presentation.

RESULTS

There were 49 cases of well-DTC (96% papillary and 4% Hürthle) in the public hospital and 370 cases (95% papillary, 2% Hürthle, and 3% follicular) in the university teaching hospital. Median age (years) at presentation was 50 in the public versus 48 in the university teaching hospital (p=0.39). Ninety-six percent of public hospital patients were from ethnic minorities compared with 16% of university teaching hospital patients (p<0.0001). Only 1 (2%) public hospital patient had private insurance compared with 85% of university teaching hospital patients. Tumor status (p=0.002) and stage (p=0.03) were more advanced and extrathyroidal extension (p=0.02) was more prevalent among public hospital patients compared with university teaching hospital patients. In a multivariable analysis, public hospital, male gender, increasing age, advanced tumor status, and the presence of lymphovascular invasion were the best predictors of more advanced disease stage. Public hospital patients were 3.4 times more likely to present with advanced DTC than university teaching hospital patients of the same age, gender, tumor status, and lymphovascular invasion status (95% confidence interval 1.29-8.95).

CONCLUSIONS

In a public hospital, where the patient population is defined primarily by insurance status, patients were more likely to present with advanced-stage DTC than patients presenting to an adjacent university teaching hospital. These results suggest a disparity in the stage on initial presentation of DTC, possibly resulting in a delayed diagnosis of cancer.

Increasing incidence of thyroid cancer in Shanghai, China, 1983-2007

Increasing incidence of thyroid cancer has been observed in some countries such as the United States, United Kingdom, France, and so on. Joinpoint regression was used to analyze the incidence of thyroid cancer in Shanghai, China, from 1983 to 2007. The results showed that there were 2 distinct slopes: in men, representing a significant annual percentage change (APC) of 2.6% from 1983 to 2000 (P < .001) followed by a sharp APC of 14.4% (P < .001), and in women, representing a significant APC of 4.9% from 1983 to 2003 (P < .001) followed by a sharp APC of 19.9% (P = .001). The sharp increase in thyroid cancer occurred 5 and 8 years after the iodine supplementation by salt, for men and women, respectively, suggesting that either the developed screening techniques or iodine supplementation might have contributed to the rapid increase in the incidence of thyroid cancer. The burden of thyroid cancer cases is expected to be substantial, based on predictions through 2020.

[Incidental differentiated thyroid carcinoma is less prevalent in Graves' disease than in multinodular goiter]

OBJECTIVE

Risk factors for differentiated thyroid carcinoma (DTC) are poorly understood, but serum TSH levels, thyroid nodularity, and presence of autoimmunity are well-recognized factors that modulate DTC prevalence. TSH stimulates proliferation of both normal and neoplastic follicular cells. Consequently, thyroid-stimulating immunoglobulins (TSI), because of its TSH-like action, should induce DTC progression in patients with Graves' disease (GD). The study objective was to compare the prevalence of incidental DTC in patients undergoing thyroidectomy for benign thyroid disease.

METHODS

The pathology reports of 372 patients with preoperative diagnosis of euthyroid multinodular goiter (EMG) or hyperthyroidism were reviewed. Scintigraphy results and serum TSI levels were used to diagnosed either GD or hyperactive MG (HMG) to hyperthyroid subjects. Prevalence of DTC in each category was calculated using a Chi-square test.

RESULTS

EMG, GD, and HMG were diagnosed in 221, 125, and 26 patients. There were 58 DTCs, distributed as follows [n (%)]: EMG, 49 (22.2%); GD, 8 (6.4%), and HMG, 1 (3.8%). Difference in prevalence of incidental DTC between the groups was statistically significant (p<0.001). After adjustment for age, patients with EMG had a greater DTC prevalence than GD patients, with an OR of 4.17 (p<0.001). Tumor size (mm, mean ± SD) was 6.92 ± 11.26, 1.97 ± 1.85, and 9.0 for EMG, GD and HMG respectively (p=0.017).

CONCLUSIONS

Incidental DTC was less prevalent in GD as compared to EMG irrespective of age. This finding may suggest a predisposition to develop DTC in patients with thyroid nodular disease and/or a potential effect of autoimmunity to protect against development of neoplastic disease.

The molecular diagnosis and management of thyroid neoplasms

PURPOSE OF REVIEW

The molecular work-up of thyroid nodules on fine needle aspiration (FNA) cytology samples has given clinicians a new level of diagnostic information. We focus this review on the molecular techniques used in the diagnosis of thyroid cancer, especially BRAF, and the resulting management considerations that are raised.

RECENT FINDINGS

BRAF testing offers both diagnostic and prognostic information; it has been used along with the Bethesda Thyroid FNA Classification System to offer preoperative guidance in the management of thyroid nodules. Various authors have successfully utilized molecular panels on cytologic specimens including mutations and rearrangements such as RAS and RET/PTC. Preoperative mutation detection allows initial management decisions to be made with a greater clinical confidence.

SUMMARY

BRAF molecular testing holds promise as a possible diagnostic tool for indeterminate FNAs, and as a determinant for planning initial clinical management of thyroid nodules. Further developments in the molecular approach to thyroid cancer are expected to allow greater individualization of patient care.

Efficacy of dosimetric versus empiric prescribed activity of 131I for therapy of differentiated thyroid cancer

BACKGROUND

The optimal management of high-risk patients with differentiated thyroid cancer (DTC) consists of thyroidectomy followed by radioiodine ((131)I) therapy. The prescribed activity of (131)I can be determined using two approaches: 1) empiric prescribed activity of (131)I (E-Rx); and 2) dosimetry-based prescribed activity of (131)I (D-Rx).

AIM

The aim of the study was to compare the relative treatment efficacy and side effects of D-Rx vs. E-Rx.

METHODS

A retrospective analysis was performed of patients with distant metastases and/or locoregionally advanced radioiodine-avid DTC who were treated with either D-Rx or E-Rx. Response to treatment was based on RECIST (Response Evaluation Criteria in Solid Tumors) 1.1 criteria.

RESULTS

The study group consisted of 87 patients followed for 51 ± 35 months, of whom 43 were treated with D-Rx and 44 with E-Rx. Multivariate analysis, controlling for age, gender, and status of metastases revealed that the D-Rx group tended to be 70% less likely to progress (odds ratio, 0.29; 95% confidence interval, 0.087-1.02; P = 0.052) and more likely to obtain complete response (CR) compared to the E-Rx group (odds ratio, 8.2; 95% confidence interval, 1.2-53.5; P = 0.029). There was an association in the D-Rx group between the observed CR and percentage of maximum tolerable activity given as a first treatment of (131)I (P = 0.030). The advantage of D-Rx was specifically apparent in the locoregionally advanced group because CR was significantly higher in D-Rx vs. E-Rx in this group of patients (35.7 vs. 3.3%; P = 0.009). The rates of partial response, stable disease, and progression-free survival, as well as the frequency of side effects, were not significantly different between the two groups.

CONCLUSION

Higher efficacy of D-Rx with a similar safety profile compared to E-Rx supports the rationale for employing individually prescribed activity in high-risk patients with DTC.

Activation of tumor cell proliferation by thyroid hormone in a mouse model of follicular thyroid carcinoma

Thyroid cancers are the most common malignancy of the endocrine system in humans. To understand the molecular genetic events underlying thyroid carcinogenesis, we have generated a mouse model that spontaneously develops follicular thyroid carcinoma similar to human thyroid cancer (Thrb(PV/PV) mouse). This mutant mouse harbors a dominant-negative mutated thyroid hormone receptor β (denoted PV). The PV mutation was identified in a patient with resistance to thyroid hormone (TH). Thrb(PV/PV) mice exhibit highly elevated serum thyroid-stimulating hormone levels and increased TH. We have previously shown that thyroid-stimulating hormone is required, but not sufficient to induce metastatic follicular thyroid cancer in Thrb(PV/PV) mice. However, whether the elevated TH also contributes to the thyroid carcinogenesis of Thrb(PV/PV) mice was not elucidated. To understand the role of TH in thyroid carcinogenesis, we blocked the production of TH by treating Thrb(PV/PV) mice with propylthiouracil (Thrb(PV/PV)-PTU mice) and compared the development of thyroid cancer in Thrb(PV/PV)-PTU and untreated Thrb(PV/PV) mice. We found that thyroid tumor growth was reduced by ∼42% in Thrb(PV/PV)-PTU mice as compared with Thrb(PV/PV) mice. Analysis by bromodeoxyuridine-nuclear labeling showed decreased incorporation of bromodeoxyuridine in thyroid tumor cells of Thrb(PV/PV)-PTU mice, indicative of decreased tumor cell proliferation. However, cleaved-caspase 3 staining showed no apparent changes in apoptosis of tumor cells in Thrb(PV/PV)-PTU mice. Molecular studies identified a marked attenuation of the PI3K-AKT-β-catenin signaling pathway that led to decreased protein levels of cyclin D2, thereby decreasing tumor cell proliferation in Thrb(PV/PV)-PTU mice. Furthermore, matrix metalloproteinase-2, a downstream target of β-catenin and a key regulator during tumor invasion and metastasis, was also decreased. Thus, the present study uncovers a critical role of TH in promoting the thyroid carcinogenesis of Thrb(PV/PV) mice via membrane signaling events. Importantly, these findings suggest that anti-thyroid drugs could be considered as possible therapeutic agents of thyroid cancer.

Simultaneous medullary and papillary thyroid cancer: a novel entity?

BACKGROUND

The causes underlying the phenomenon of simultaneous medullary (MTC) and papillary thyroid cancer (PTC) are unclear.

METHODS

This study of 26 patients with simultaneous MTC and PTC aimed at clarifying clinical and histopathologic characteristics and trends of this unusual condition among MTC and PTC patients who were operated on at a tertiary referral center in Germany.

RESULTS

A total of 26 patients revealed simultaneous MTC and PTC, yielding the following rates: 2.6% (26 patients) among all 1019 PTC patients, 2.6% (6 patients) among all 235 hereditary MTC patients, 4.1% (20 patients) among all 492 sporadic MTC patients, and 3.6% (26 patients) among all 727 MTC patients. Simultaneous MTC and PTC were consistently smaller than nonsimultaneous MTC (6 vs. 13 mm for hereditary MTC, P = .16; 12 vs. 23 mm for sporadic MTC, P = .009; and 11 vs. 20 mm for any MTC, P = .008) and PTC (8 vs. 20 mm, P < .001). Simultaneous MTC and PTC increased among MTC and PTC patients over time: from 0% to 4.3% (PTC), from 0% to 4.6% (hereditary MTC), from 0% to 8.1% (sporadic MTC), and from 0% to 7.0% (any MTC). For sporadic MTC, these rates virtually doubled every 5 years. Of 6 patients with simultaneous hereditary MTC and PTC, 5 revealed late-onset REarranged during Transfection (RET) mutations (1 L790F carrier; 2 V804L and 2 S891A carriers).

CONCLUSIONS

Greater pathologic scrutiny, in addition to environmental changes, explains the surge of simultaneous MTC and PTC in Germany. More data are needed from additional geographic areas and populations to delineate individual contributions of these factors.

[Epidemiology of thyroid carcinoma over the world]

Thyroid cancer (TC) incidence, in France and over the world, has dramatically increased over the last two decades. The temporal and geographical incidence trends in France and in the world are analysed. The increased incidence of TC is actual, mainly due to an increase of papillary microcarcinomas. The spread of ultrasonographic and cytological procedures, the extensiveness of thyroidectomies lead to diagnostic advance, to a better preoperative selection of patients and to the discovery of occult microcarcinomas. Nevertheless, the impact of the risk factors of thyroid cancer on the increase of incidence is not excluded. These risk factors are analysed, especially environmental chemicals agents that disrupt thyroid function.

[Differentiated thyroid carcinoma: survival and prognostic factors]

BACKGROUND AND AIMS

Differentiated thyroid carcinoma (DTC) is the most common endocrine tumor. DTC has a good prognosis and survival rates higher than 85%. The aim of our study was to assess our current survival rate and to analyze prognostic factors.

PATIENTS AND METHODS

A retrospective analysis was conducted of 308 patients with DTC (93.5% with papillary tumors, 78.8% women). Mean age at diagnosis was 45.4±15.8years, and mean follow-up time was 8.9±6.8years. The whole group was treated and followed up using the same protocol at our hospital. The following data were collected: age at diagnosis, sex, histology, TNM stage, treatments, and date and cause of death. Survival probability was calculated using Kaplan-Meier analyses. Prognostic factors were analyzed using a univariate log rank test and a multivariate Cox regression analysis model.

RESULTS

Twenty-six patients died during follow-up, 15 of them (4.9%) from DTC. Thyroid carcinoma-related survival was 92.7% for the whole group. In multivariate analyses, the following parameters were associated to a significantly increased risk of death from DTC: presence of distant metastases, follicular histology, age at diagnosis older than 60years, and extrathyroid invasion.

DISCUSSION

Our survival rate is similar to that reported in literature. Assessment of prognostic factors related to an increased risk of death in our patient group, is essential to establish active therapeutic approaches in high risk patients.

Increasing incidence of differentiated thyroid cancer in South East England: 1987-2006

There has been a worldwide increase in the incidence of thyroid cancer (TC). Documenting these recent trends is of immense value to cancer control measures, monitoring policies, improving clinical outcomes, resource allocation and stimulating research. Hence this study aimed to analyse the changes in incidence, staging and morphologic types of TC in South East England (1987-2006) by means of a retrospective, descriptive epidemiological study using anonymized data obtained from the Thames Cancer Registry (TCR) of all patients registered with TC in the period 1987-2006. Ethical approval was obtained from the Kent Research Ethics Committee. 4,880 anonymized datasets using the ICD-10 code for thyroid cancer (C73) were analyzed using SPSS v.17. TC was commoner amongst females 3,560 (73%) than males 1,320 (27%) with a 2.7:1 ratio. Mean age at diagnosis was 53 years (Range 5-99) years. An increasing incidence trend was observed in early stage disease (p < 0.001), in young adults aged ≤ 49 years (p < 0.001) and in well-differentiated TC (papillary p < 0.001 and follicular p = 0.03). The results showed that TC is commoner in females than males in SE England with a 2.7:1 ratio. The results also indicate that TC incidence has increased in SE England over the 20 years studied, with the greatest increase occurring in early stage disease, in females, young adults and well-differentiated types (papillary and follicular). This may be due to widespread usage of ultrasound with detection of incidental nodules. Further studies are required to explain the trend.

[Comparative study of historical series of differentiated thyroid carcinoma in two tertiary hospitals in Spain versus North American series]

BACKGROUND AND OBJECTIVE

There is little national literature on descriptive series of patients with differentiated thyroid carcinoma (DTC) and long-term monitoring in Spain. The aim of our study was to describe the DTC series in two tertiary hospitals [Hospital Clínic de Barcelona (HC) and Hospital Germans Trias i Pujol (HGTiP)] and compare these series with those described in the National Cancer Data Base (NCDB) and the Mayo Clinic, the leading international series by number of patients and length of follow-up.

MATERIAL AND METHODS

We performed a retrospective review of the medical records of patients diagnosed with DTC in two tertiary hospitals in the Barcelona area. The results were compared with those published by the NCDB and the Mayo Clinic.

RESULTS

We reviewed 480 medical records of patients with DTC diagnosed between 1973 and 2006, with a mean follow-up of 16±8 years. No significant differences were observed in clinical characteristics, risk factors or the most frequent form of presentation between the joint HC/HGTiP group and the NCDB series. The most commonly used diagnostic methods were ultrasound and cytology in all series and the main type of surgery was total or nearly total thyroidectomy, with no differences between groups. Postoperative I-131 was administered more often in the HC/HGTiP series (83.9%) than in the NCDB series (55.1%) and in the Mayo Clinic (46%). In the HC/HGTiP group tumor recurrence was 9.3% and mortality 1.8%.

CONCLUSIONS

The HC and HGTiP series were comparable and the various diagnostic and therapeutic techniques used were similar. This study highlights historical trends in the use of imaging techniques, as well as differences with large American series in some procedures (such as laryngoscopy) and the use of radioiodine therapy.

Screening for thyroid disease: defining high-risk populations

The pros and cons of population screening for thyroid disease have been hotly debated over the past several decades. This article addresses the issue from the point of view of the potential benefit of screening, that is, disease detection. Earlier diagnoses of hypothyroidism, hyperthyroidism, thyroid nodules, thyroid cancer and so on, with implementation of the indicated diagnostic and therapeutic interventions, avoid the adverse consequences of unrecognized and untreated progressive disease. Arguments against screening and case-finding often focus on cost considerations. To achieve the greatest yield at the lowest cost, our emphasis is on vulnerable populations with associated risk factors, and special situations such as pregnancy.

Decreasing tumor size of thyroid cancer in Germany: institutional experience 1995-2009

OBJECTIVE

Decreasing tumor size in a population over time is widely interpreted as a measure of effectiveness of cancer screening programs. Nonetheless, thyroid cancer size is rarely analyzed as a function of time. This study aimed to explore secular trends of thyroid cancer diameter in Germany.

DESIGN

Retrospective analysis of 1644 thyroid cancer patients from a large referral center for thyroid cancer (1995-2009).

METHODS

Calculation of largest tumor diameters for each type of cancer as a function of time periods and birth cohorts.

RESULTS

Over the past 25 years, subdivided into 5-year periods by year of thyroidectomy (1985-1989; 1990-1994; 1995-1999; 2000-2004; 2005-2009), tumor diameters diminished from 25 to 16 mm (P=0.025) for medullary thyroid cancer and from 28 to 18 mm (P=0.017) for papillary thyroid cancer. This reduction was greater for hereditary medullary thyroid cancer (from 27 to 11 mm; P=0.088) than sporadic medullary thyroid cancer (from 23 to 19 mm; P=0.11). No decline was observed for follicular thyroid cancer (means of 45 to 42 mm; P=0.52). From the first (1921-1940) to the most recent birth cohort (1981-2000), tumor size fell from 22 to 10 mm (P<0.001) for medullary thyroid cancer, from 24 to 22 mm (P<0.001) for papillary thyroid cancer, and from 49 to 38 mm (P=0.011) for follicular thyroid cancer. The reduction of medullary thyroid cancers affected exclusively patients with hereditary disease (from 20 to 7 mm; P<0.001).

CONCLUSION

The consistency and robustness of these data signify powerful secular trends toward smaller papillary, follicular, and medullary thyroid cancers. The causes and consequences of these trends warrant further investigation.

Thyroid cancer epidemiology and prognostic variables

Thyroid cancer comprises a broad spectrum of diseases with variable prognoses. Although most patients with this disease have excellent overall survival, there are some who do not fare so well. With the worldwide increase in incidence, the need to identify which tumours pose the greatest risk to patients is more acute than ever. This paper will discuss this rising trend in incidence with an analysis of the possible reasons for the increase. In addition, the paper will explore the factors that portend a worse prognosis for the individual patient. Finally, the limitations of the current staging systems will be discussed, with particular emphasis on why they are not as informative in the management of patients with thyroid cancer.