Increased incidence of well-differentiated thyroid cancer associated with Hashimoto thyroiditis and the role of the PI3k/Akt pathway

The value of preoperative PET-CT in papillary thyroid cancer

OBJECTIVE

To evaluate the clinical usefulness of preoperative positron emission tomography-computed tomography (PET-CT) in primary papillary thyroid cancer (PTC).

METHODS

Preoperative PET-CT scans of patients with biopsy-confirmed PTC who were undergoing thyroidectomy were examined and the maximum standardized uptake value (SUV max) of 2-deoxy-2-((18)F)fluoro-D-glucose ((18)F-FDG) was calculated. Demographic and clinical data were obtained from medical records. Tumour tissue was pathologically classified according to World Health Organization guidelines. Univariate and multivariate analyses were performed to determined the demographic, clinical and pathological factors affecting PET positivity and SUV max.

RESULTS

The study included 194 patients. Multivariate analysis indicated that patients were significantly more likely to be PET positive if they were female, had larger tumours (>1 cm), coexisting pathology (nodular hyperplasia or Hashimoto's thyroiditis) or nonfollicular variant PTC. SUV max <2.0 indicated possible follicular variant PTC.

CONCLUSIONS

PET-positive results were unrelated to extrathyroidal extension and lymph node metastasis. PET positivity was related to larger tumour size and implied coexisting pathology. PET negativity or low SUV max suggested possible follicular variant PTC.

Clinical Review: Hashimoto's thyroiditis and papillary thyroid carcinoma: is there a correlation?

CONTEXT

The link between Hashimoto's thyroiditis (HT) and papillary thyroid cancer (PTC) has long been a topic of controversy. There are conflicting reports; some suggest that these two are positively correlated, whereas other studies report no relationship.

EVIDENCE ACQUISITION

We performed a systematic literature review of original studies that investigated the correlation between HT and PTC. The two main search engines used to identify articles were OVID Medline and PubMed. The included studies were categorized into a fine-needle aspiration biopsy (FNAB) group and an archival thyroidectomy specimen group.

EVIDENCE SYNTHESIS

There is no clear evidence to support the correlation between HT and PTC. Population-based FNAB studies report no linkage, whereas many of the studies of thyroidectomy specimens report a positive relationship. The average prevalence rate of PTC in patients with HT was 1.20% in 8 FNA studies of 18 023 specimens and 27.56% in 8 archival thyroidectomy studies of 9 884 specimens. The relative risk ratio of finding evidence of PTC in HT specimens ranged from .39 to 1.00 in the FNA group (average RR = .69) in contrast to 1.15 to 4.16 from the archival thyroidectomy studies (average RR = 1.59). In addition, there are many studies in the literature that propose a genetic link between HT and PTC involving the PI3K/Akt pathway and RET/PTC gene rearrangements.

CONCLUSION

Although limited by the lack of definitive pathology, population-based FNA studies did not find a statistically significant correlation between HT and PTC. Thyroidectomy studies, which reported a statistically significant positive correlation, are subject to selection bias. More prospective studies with longer follow-up are needed to further elucidate this relationship.

The nuclear factor kappa-B signaling pathway as a therapeutic target against thyroid cancers

BACKGROUND

The nuclear factor kappa-B (NF-κB) proteins, a family of transcription factors found virtually in all cells, are known to play crucial roles in the growth of a number of human malignancies. The ability of NF-κB to target a large number of genes that regulate cell proliferation, differentiation, survival, and apoptosis, provides clues toward its deregulation during the process of tumorigenesis, metastatic progression, and therapeutic resistance of tumors.

SUMMARY

In addition to the signaling pathways known to be involved in thyroid tumorigenesis, such as the mitogen-activated protein kinase and janus kinase cascades, studies implicate the NF-κB pathway in the development of both less aggressive thyroid cancers, papillary and follicular adenocarcinomas, and progression to aggressive thyroid cancers, such as anaplastic adenocarcinomas. A constitutively activated NF-κB pathway also closely links Hashimoto's thyroiditis with increased incidence of thyroid cancers. The NF-κB pathway is becoming one of the major targets for drug development, and a number of compounds have been developed to inhibit this pathway at different levels in cancer cells. Some of these targets have shown promising outcomes in both in vitro and in vivo investigations and a handful of them have shown efficacy in the clinical setting.

CONCLUSIONS

This review discusses the recent findings that demonstrate that the inhibition of NF-κB, alone or with other signaling pathway inhibitors may be of significant therapeutic benefits against aggressive thyroid cancers.

Some clinical aspects in chronic autoimmune thyroiditis associated with thyroid differentiated cancer

BACKGROUND

The coexistence of Hashimoto's thyroiditis (HT) with differentiated thyroid cancer (DTC) was reported with a heterogeneous incidence. The wide distribution of this association may be related to differences in the level of morphological examination, autoimmunity used criteria, patient selection, surgical indication, genetic background, geographical and environmental factors.Some consider the coexistence of these two entities a coincidental one, others suspecting a causative link between these conditions.

METHODS

This retrospective paper included 216 patients with HT, issued from an iodine-replete area. 21 cases of nodular HT were investigated by means of: thyroid functional tests (TFT), immunological determinations, thyroid ultrasonography (US) and cytological analysis.ALL CASES WERE OPERATED BECAUSE OF DIFFERENT REASONS: compressive symptoms and signs, suspicious sonographic features and certain cytological smears (malignant, indeterminate and non-diagnostic).

RESULTS

The morphologic investigation revealed 9 patients with DTC and 12 cases with benign thyroid disease (BTD).None of the US analyzed characteristics provided sufficient accuracy for the diagnosis of DTC in cases with HT. The preoperative cytological examination by means of fine-needle-aspiration biopsy (FNAB) showed a better sensitivity and specificity vs. US criteria.

CONCLUSION

The coexistence of HT with DTC represents a clinical reality with yet unknown significance. The difficulty of diagnosis imposes the corroboration of different types of investigations. The best diagnostic accuracy seems to be offered by thyroid US and thyroid cytological investigation.

Coexistence of papillary thyroid cancer with Hashimoto thyroiditis

Aims

Conflicting data have been reported with regard to Hashimoto thyroiditis (HT) and risk of malignancy. The aim of this study was to evaluate coexistence of papillary thyroid cancer (PTC) with HT.

Patients and methods

This is a retrospective cohort study in which HT was diagnosed in 452 (F/M ratio = 405:47, median age 53.5 ± 12.1 years) of 7,545 patients qualified for thyroidectomy throughout the years 2002 to 2010. Pathological reports were reviewed to identify prevalence of PTC in HT vs. non-HT patients.

Results

PTC was diagnosed in 106 of 452 (23.5 %) HT patients vs. 530 of 7,093 (7.5 %) non-HT patients (p < 0.001). Metastases to level VI lymph nodes were observed in 81 of 106 (76.4 %) patients with PTC in HT vs. 121 of 530 (22.8 %) patients with PTC in non-HT disease (p < 0.001).

Conclusions

HT was associated with a threefold increase of PTC prevalence as compared to other non-HT thyroid diseases, and the spread of PTC to level VI lymph nodes was four times more frequent in HT than in non-HT patients.

Blood neutrophil-to-lymphocyte ratio correlates with tumor size in patients with differentiated thyroid cancer

BACKGROUND AND OBJECTIVES

Inflammation has been implicated in the initiation and progression of thyroid cancer. Neutrophil-to-lymphocyte ratio (NLR) is a simple index of systemic inflammatory response, and has been shown to be a prognostic indicator in some types of cancer. The aim of this study was to examine the relationship between NLR and clinicopathological features in patients with differentiated thyroid cancer.

METHODS

Total white blood cell and differential counts of 159 patients with differentiated thyroid cancer were compared to those of 318 age- and sex-matched controls undergoing thyroidectomy for benign thyroid nodules. Clinicopathological variables, stratified by NLR tertiles, were analyzed.

RESULTS

There was no difference in NLR between patients having benign and malignant thyroid nodules (P = 0.293). Cancer patients in the higher NLR tertile had significantly larger tumor size (P = 0.004). Higher NLR was observed in patients with high American Thyroid Association (ATA) risk of recurrence.

CONCLUSIONS

High preoperative NLR was associated with increased tumor size and high ATA risk of recurrence in patients with differentiated thyroid cancer.

Health disparities in endocrine disorders: biological, clinical, and nonclinical factors--an Endocrine Society scientific statement

OBJECTIVE

The aim was to provide a scholarly review of the published literature on biological, clinical, and nonclinical contributors to race/ethnic and sex disparities in endocrine disorders and to identify current gaps in knowledge as a focus for future research needs. PARTICIPANTS IN DEVELOPMENT OF SCIENTIFIC STATEMENT: The Endocrine Society's Scientific Statement Task Force (SSTF) selected the leader of the statement development group (S.H.G.). She selected an eight-member writing group with expertise in endocrinology and health disparities, which was approved by the Society. All discussions regarding the scientific statement content occurred via teleconference or written correspondence. No funding was provided to any expert or peer reviewer, and all participants volunteered their time to prepare this Scientific Statement.

EVIDENCE

The primary sources of data on global disease prevalence are from the World Health Organization. A comprehensive literature search of PubMed identified U.S. population-based studies. Search strategies combining Medical Subject Headings terms and keyword terms and phrases defined two concepts: 1) racial, ethnic, and sex differences including specific populations; and 2) the specific endocrine disorder or condition. The search identified systematic reviews, meta-analyses, large cohort and population-based studies, and original studies focusing on the prevalence and determinants of disparities in endocrine disorders. consensus process: The writing group focused on population differences in the highly prevalent endocrine diseases of type 2 diabetes mellitus and related conditions (prediabetes and diabetic complications), gestational diabetes, metabolic syndrome with a focus on obesity and dyslipidemia, thyroid disorders, osteoporosis, and vitamin D deficiency. Authors reviewed and synthesized evidence in their areas of expertise. The final statement incorporated responses to several levels of review: 1) comments of the SSTF and the Advocacy and Public Outreach Core Committee; and 2) suggestions offered by the Council and members of The Endocrine Society.

CONCLUSIONS

Several themes emerged in the statement, including a need for basic science, population-based, translational and health services studies to explore underlying mechanisms contributing to endocrine health disparities. Compared to non-Hispanic whites, non-Hispanic blacks have worse outcomes and higher mortality from certain disorders despite having a lower (e.g. macrovascular complications of diabetes mellitus and osteoporotic fractures) or similar (e.g. thyroid cancer) incidence of these disorders. Obesity is an important contributor to diabetes risk in minority populations and to sex disparities in thyroid cancer, suggesting that population interventions targeting weight loss may favorably impact a number of endocrine disorders. There are important implications regarding the definition of obesity in different race/ethnic groups, including potential underestimation of disease risk in Asian-Americans and overestimation in non-Hispanic black women. Ethnic-specific cut-points for central obesity should be determined so that clinicians can adequately assess metabolic risk. There is little evidence that genetic differences contribute significantly to race/ethnic disparities in the endocrine disorders examined. Multilevel interventions have reduced disparities in diabetes care, and these successes can be modeled to design similar interventions for other endocrine diseases.

Sociodemographic Predictors of Survival in Differentiated Thyroid Cancer: Results from the SEER Database

Background. Differentiated thyroid carcinoma (DTC) is prognosticated upon a combination of tumor characteristics, such as histology and stage, and patient age. DTC is also notable for having a strong female predominance. Using a nationwide database with long follow-up times, we explored the interplay between tumor biology and patient characteristics in predicting mortality. Methods. The Surveillance, Epidemiology, and End Results (SEER) registry data 1973–2005 was examined for patients with DTC as their only known malignancy. Cox multivariate analyses were used to generate mortality hazard ratios to evaluate the effects of age, gender, ethnicity, and marital status. Results. We identified 55,995 patients with DTC as their only malignancy. Consistent with the existing literature, the tumors are primarily diagnosed in women (77.5%), and predominantly affect Caucasians (78.3%). Female gender had a protective effect resulting in a 37% decrease in mortality. Age at diagnosis predicted mortality over age 40. Black ethnicity was associated with a 51% increase in mortality compared to Caucasians. Conclusion. Multiple demographic factors predict mortality in patients with DTC after adjusting for tumor characteristics, and they appear to have complex interactions. Recognizing the importance of these factors may enable clinicians to better tailor therapy.

Role of chronic lymphocytic thyroiditis in central node metastasis of papillary thyroid carcinoma

OBJECTIVE

(1) To investigate the role of chronic lymphocytic thyroiditis (CLT) in central node metastasis of papillary thyroid carcinoma (PTC) and (2) to evaluate the presence of chronic lymphocytic thyroiditis according to PTC-specific molecular markers.

STUDY DESIGN

Historical cohort study.

SETTING

Academic medical center.

SUBJECTS AND METHODS

All patients who underwent total thyroidectomy with central neck dissection for PTC at Oregon Health & Science University between 2005 and 2010 were screened for the presence of CLT and reviewed for clinical prognostic factors. Patients with inadequate central neck dissections were excluded. Molecular markers for PTC were analyzed on archived tumor samples.

RESULTS

A total of 139 patients met selection criteria. The rate of CLT was 43.8%. The rate of central node positivity was 63%. Presence of CLT was associated with a significantly lower proportion of central node metastases (49% vs 74%, P = .003) and angiolymphatic invasion (31% vs 15%, P = .03). There was no significant difference in mean age, tumor size, and extracapsular extension. Molecular genotyping did not reveal a significant difference in the types of mutations found in both groups.

CONCLUSION

The data indicate a lower incidence of central compartment lymph node metastasis in those with CLT in this patient population, suggesting a potential protective role in tumor spread. The equal distribution of tumor mutations between the carcinomas with and without evidence of CLT argues against a mutation-specific antigen as the immunologic stimulus. Further research is needed to characterize the role of autoimmunity in thyroid cancer.

Riedel's thyroiditis - a case report with genes' expression studies

Background

Genetic background of Riedel's thyroiditis remains unknown. Herein, we describe our results of studies on genes expression levels in Riedel's thyroiditis.

Case report and genetic findings

We report the case of 48-year old woman with Riedel's thyroiditis who has presented unusual course of disease with non-specific cervical discomfort, though as with no pain and/or no compression symptoms. After surgery, thyroid specimens were quantitatively evaluated, regarding PIK3CA, PIK3CD, PIK3CG, Tg, TGFB1, THRB, COL1, CDKN1C, CDH3 and CACNA2D2 genes expression levels, by real-time PCR in the ABI PRISM^® 7500 Sequence Detection System. Out of 10 above genes, in 2 cases the expression was higher than in respective Controls of unchanged thyroid tissue. In the remaining 8 cases, expression in question became comparable or lower as in Controls.

Discussion

The association between increased expression levels of PIK3CA and CDH3 genes and Riedel's thyroiditis is not well-defined. However, the increased expression of PIK3CA and CDH3 genes in our case report and in previous studies of other authors on various malignancies may suggest possible molecular relation between Riedel's thyroiditis and certain neoplastic processes, the relation of which requires further genetic evaluation. It is to be stressed that gene expression studies in Riedel's thyroiditis are difficult to perform, mainly due to fibrosis, resulting in scarce thyroid specimens and - in consequence - small amount of genetic material.

Total thyroidectomy for benign thyroid diseases

OBJECTIVE

To review the indications for total thyroidectomy as the preferred option in certain benign diseases of the thyroid in order to prevent recurrence or future reoperations.

METHODS

A retrospective study of patients with benign thyroid diseases, carried out from January 1997 to December 2009, analyzing the data relating to age, surgical treatment and postoperative evolution.

RESULTS

The mean age was 51.8 years (21/77), with the highest incidence in the fifth and sixth decades of life, with 34 (51.5%) patients. The most common preoperative diagnosis was nontoxic multinodular goiter, of which seven were also intrathoracic, followed by autoimmune thyroiditis; recurrent goiter occurred in 11 cases. Multinodular goiter was found in 37 (56.1%) patients, autoimmune thyroiditis in 22 (33.3%), follicular adenoma isolated in five (7.6%), Hurthle cell adenoma in two (3.0%). Sixteen patients (24.2%) had more than one histopathological diagnosis. Permanent injury of the recurrent nerve was observed in one patient (1.5%). There was no case of permanent hypoparathyroidism. There was no operative mortality.

CONCLUSION

Total thyroidectomy is an operation that can be safely performed, with low incidence of permanent complications, which allows one to broaden its indications in various benign thyroid diseases, thus avoiding future recurrences and reoperations.

Shear wave elastography in the diagnosis of thyroid nodules: feasibility in the case of coexistent chronic autoimmune Hashimoto's thyroiditis

OBJECTIVE

ShearWave™ Elastography (SWE) is real-time, quantitative and user-independent technique, recently introduced in the diagnostic work-up of thyroid nodules. Hashimoto's thyroiditis (HT), characterized by variable degrees of lymphocytic infiltration and fibrosis, might affect shear wave propagation. The aim of this study was to assess the feasibility of SWE in cytologically benign thyroid nodules within both Hashimoto's and nonautoimmune thyroid glands. The effect of autoimmunity on the gland stiffness was also evaluated.

DESIGN

longitudinal study in a single centre.

PATIENTS

SWE was performed in 75 patients with a benign thyroid nodule at cytology: 33 with Hashimoto's thyroiditis (HT group) and 42 with uni- or multi-nodular goitre, negative for thyroid autoimmunity (non-HT group).

RESULTS

The elasticity index (EI) of the extra-nodular tissue was greater, though not statistically significant, in the HT than in the non-HT group (24·0 ± 10·5 kPa vs 20·8 ± 10·4 kPa; P = 0·206). However, the EI of extra-nodular tissue was related to the TPOAb titre in the HT group (P = 0·02) and was significantly higher in patients with HT receiving L-thyroxine than in the euthyroid subjects (P = 0·02). The EI of thyroid nodules was similar in HT and non-HT groups. In both groups, the stiffness of nodules was significantly higher than that of the embedding tissue.

CONCLUSIONS

Our data indicate that SWE correctly defines the elasticity of thyroid nodules independently from the coexistence of autoimmune thyroiditis, always being able to differentiate nodular tissue from the surrounding parenchyma. In HT, the stiffness of extra-nodular tissue increases in relation to both the thyroid antibody titre and the degree of impairment of thyroid function.

An elevated level of TSH might be predictive of differentiated thyroid cancer

Suppression therapy of thyreostimulin (TSH) using thyroid hormones improves survival of subjects operated for differentiated thyroid cancer. The TSH level might be different depending on the type of nodule. The objective of this study was to compare retrospectively the TSH level between two groups of subjects who underwent total thyroidectomy for a nodule, matched on sex, ethnicity, age and biological method of TSH measurement, one whose final histology was benign and one malignant. There was no significant difference between the two groups in terms of age, sex, family history of thyroid disease or thyroid autoimmunity. The subjects, whose final histology was malignant, had a mean TSH level significantly higher than subjects with benign disease (1.55 mU/l versus 0.96 mU/l, P=0.003). Cancer risk was greater when the TSH was in the upper tertile of normal range. There was no correlation between the risk of thyroid cancer and age, sex, family history of thyroid disease, or menopausal status. The relative risk of having thyroid carcinoma was higher when the margins of nodules were blurred or in the presence of microcalcifications. These data confirm a trend toward baseline values of TSH higher in subjects with a thyroid-differentiated cancer. However, we could not define a preoperative threshold that would reliably determine the malignant or benign nature of the nodule.

Clinical relationship between Hashimoto's thyroiditis and papillary thyroid cancer

BACKGROUND

The relationship between Hashimoto's thyroiditis (HT) and papillary thyroid cancer (PTC) with regard to their co-occurrence and the effect of concurrent HT on the prognosis of PTC has been debated. The aim of the present study is to determine a clinical relationship between these two disease entities and to evaluate the correlation between concurrent HT and various clinicopathological parameters.

MATERIAL AND METHODS

Demographic and histopathological data were collected from 675 patients undergoing thyroid surgery from 2000 to 2005, and 303 patients who received initial treatment for thyroid disease at our institution and whose medical records were accessible for review were enrolled in this study. Of these participants, 269 with histologically confirmed PTC were analysed according to the presence or absence of concurrent HT.

RESULTS

Of 269 patients with PTC, 21.6% (58/269) had concurrent HT, whereas only 5.9% (2/34) had concurrent HT with another diagnosis (p = 0.031, odds ratio = 4.4; 95% CI, 1.02-18.90). Younger age at presentation and a greater female preponderance were noted in patients with HT compared with those without HT (p = 0.008 and p = 0.009, respectively). Although it was not statistically significant, PTC with HT patients tented to have smaller tumour size (1.6 ± 1.0 cm vs. 1.8 ± 1.5 cm), lower incidence of lymph node metastasis at presentation (12.2% vs. 29.9%), unifocal disease (84.5% vs. 78.7%), and early-stage disease. Additionally, PTC with HT patients exhibited better prognosis, viewed in recurrence and mortality, during the 62-month mean follow-up period.

DISCUSSION

HT was definitely associated with PTC as was chronic inflammation with cancer in other locations. Interestingly, however, the coexistence of HT in PTC cases introduced favourable clinical outcomes compared with those of PTC without HT.

Autoimmune thyroid disease: a risk factor for thyroid cancer

OBJECTIVE

To examine the relationship between clinical markers of autoimmune thyroid disease and the risk of thyroid cancer in patients with thyroid nodules.

METHODS

A retrospective cohort analysis was performed in a single clinical practice. In 2,500 consecutive patients, fine-needle aspiration biopsy (FNAB) was performed on all 3,658 ultrasonography-positive thyroid nodules that were ≥ 1.0 cm in diameter or ≥ 0.5 cm in diameter with ultrasound features suspicious for thyroid cancer. Serum concentrations of thyroglobulin antibodies (TgAb), thyroid peroxidase antibodies, and thyroid-stimulating hormone were measured before FNAB. Diagnosis of thyroid cancer was based on pathologic analysis of thyroidectomy tissue. Associations of thyroid cancer with the independent variables were determined by multivariate logistic regression analysis and reported as the adjusted odds ratio (OR) with the 95% confidence interval (CI).

RESULTS

There were 202 patients with malignant thyroid nodules, 51 patients with microscopic unsuspected thyroid cancer distal to the nodule under investigation (found at thyroidectomy), and 2,247 patients with benign thyroid nodules. To evaluate the association of clinical markers for autoimmune thyroid disease with thyroid cancer, we included all 253 patients with thyroid cancer in the malignant cohort. Thyroid cancer was associated with elevated levels of TgAb (OR = 1.57; CI = 1.11 to 2.23) and age <55 years (OR = 2.01; CI = 1.45 to 2.78), and a strong trend was demonstrated for association with male sex (OR = 1.45; CI = 0.99 to 2.12). Thyroid cancer was not associated with elevated levels of thyroid peroxidase antibodies.

CONCLUSION

In patients who have thyroid nodules with indications for FNAB, elevated levels of TgAb are associated with thyroid cancer.

Hashimoto thyroiditis is more frequent than expected when diagnosed by cytology which uncovers a pre-clinical state

Background

Our Thyroid-Multidisciplinary Clinic is a large referral site for thyroid diseases. Thyroid biopsies are mainly performed for thyroid cancer screening. Yet, Hashimoto thyroiditis (HT) is being too frequently diagnosed. The prevalence of HT is reported as 0.3-1.2% or twice the prevalence of type 1 diabetes. However, the prevalence of HT confirmed by cytology is still uncertain. To evaluate different aspects of thyroid physiopathology including prevalence of Hashimoto's, a database of clinical features, ultrasound images and cytology results of patients referred for FNA of thyroid nodules was prospectively developed.

Methods

We retrospectively studied 811 consecutive patients for whom ultrasound guided thyroid FNA biopsies were performed at our clinic over 2.5 year period (Mar/2006-Sep/2008).

Results

The analysis of our database revealed that from 761 patients, 102 (13.4%) had HT, from whom 56 (7.4%) were euthyroid or had sub-clinical (non-hypothyroid) disease, and 46 (6%) were clinically hypothyroid.

Conclusions

This is the first study to show such a high prevalence of HT diagnosed by ultrasound-guided FNA. More strikingly, the prevalence of euthyroid HT, appears to be >5% similar to that of type 2 diabetes. Based on our results, there might be a need to follow up on cytological Hashimoto's to monitor for thyroid failure, especially in high risk states, like pregnancy. The potential risk for thyroid cancer in patients with biopsy-proven inflammation of thyroid epithelium remains to be established prospectively. However, it may explain the increased risk for thyroid cancer observed in patients with elevated but within normal TSH.

Profile of Hashimoto's Thyroiditis in Sri Lankans: Is There an Increased Risk of Ancillary Pathologies in Hashimoto's Thyroiditis?

Hashimoto's thyroiditis has been reported to be associated with many neoplastic and nonneoplastic thyroid pathologies. This retrospective study aims to determine the demographic profile of Hashimoto's thyroiditis in Sri Lankans, document ancillary pathologies in Hashimoto's thyroiditis, and determine whether there is an increased risk of occurrence of malignancies, benign neoplasms, and nonneoplastic benign lesions in Hashimoto's thyroiditis by comparing with thyroids showing multinodular goiters, follicular adenomas, and colloid nodules. The mean age of Hashimoto's thyroiditis is 43.3 years with the majority in the 41 to 60 year age group and a female to male ratio of 10.3 : 1. This study revealed a statistically significant increase of thyroid malignancies in association with Hashimoto's thyroiditis. The association of Papillary carcinoma, Non-Hodgkin's lymphoma, and Hurthle cell adenoma with Hashimoto's thyroiditis was statistically significant.

Cyclooxygenase-2 expression and its association with thyroid lesions

Cyclooxygenase (COX), also known as prostaglandin H synthase, catalyses the formation of prostaglandins from arachidonic acid. It can be expressed in response to various stimuli, such as hormones, mitogens, cytokines, other inflammatory mediators and growth factors. The product of COX-2 activity has been implicated in carcinogenesis by promoting angiogenesis, inhibiting apoptosis, increasing cell invasion and stimulating cell proliferation. It has also been proved that the regular intake of non-steroidal anti-inflammatory drugs (NSAIDs) decreases the risk of developing colon and breast cancers. Thus, it speaks for an important role of COX-2 in growth processes of various types of neoplasms. The connection between COX-2 activity and carcinogenesis has also been examined in human thyroid neoplasms. COX-2 overexpression has been reported in thyroid cancers and also in inflammatory conditions. In consequence there is significant interest whether COX-2 could be of importance as a molecular marker of malignancy in the case of thyroid carcinoma.

The association between thyroid carcinoma and Hashimoto's thyroiditis: the ultrasonographic and histopathologic characteristics of malignant nodules

BACKGROUND

Some but not all reports, particularly those of a retrospective nature, have noted an increased risk of carcinoma in thyroid nodules in patients with Hashimoto's thyroiditis (HT). Thyroid cancer (TC) in patients with HT, however, have been reported to have a better prognosis. In the presence of HT, the ultrasonography (US) appearance of the thyroid gland might vary greatly, making it more difficult to differentiate between benign and malignant nodules. The aim of this study was to determine if there is an association between TC and HT and to determine if the US and histopathologic characteristics of malignant nodules in patients with and without HT are similar.

METHODS

Six hundred thirteen patients who underwent total thyroidectomy between 2005 and 2008 for nodular goiter were included in this study. The preoperative US characteristics and postoperative histopathologic features in patients with and without HT were compared. The diagnosis of HT was based on histopathologic features.

RESULTS

Ninety-two patients had HT. The prevalence of TC in the HT patients was 45.7%. In contrast, it was 29% in patients without HT (p = 0.001). The prevalence of HT in the patients with TC was 21.8% and in patients without TC was 11.9% (p = 0.001). The rate of incidental TC, defined as TC identified during surgery or following histopathologic examination of permanent sections despite preoperative benign cytology results, was higher in patients with HT (33.3%) than in those without (13.0%) HT (p = 0.004). The US characteristics of papillary thyroid carcinoma, which included number of nodules, echogenity, echoic texture, microcalcifications, macrocalcifications, halo sign, and regularity of margins, were similar in the group with HT compared with the group without HT. When the histopathologic characteristics of papillary thyroid carcinoma in patients with and without HT were compared, again there was no significant difference.

CONCLUSIONS

We suggest that there is an association between HT and TC, and HT may predispose to the development of TC. This indicates the need for close observation of neoplastic changes in patients with HT. Nevertheless, the presence of HT seems to have no effect on the US and histopathologic characteristics of malignant nodules in TC patients. This finding may indicate that evaluation of nodules and initial treatment of TC in these patients does not require different management.

Involvement of PTEN/Akt signaling in capsular invasive carcinomas developed in a rat two-stage thyroid carcinogenesis model after promotion with sulfadimethoxine

PURPOSE

Rat thyroid follicular cell carcinomas invading into the thyroid capsule are highly produced by promotion with sulfadimethoxine (SDM) in a rat two-stage thyroid carcinogenesis model. In this study, we investigated the participation of phosphoinositide 3-kinase (PI3K) signaling pathway that is associated with malignant phenotypes of many cancers on the development of SDM-induced capsular invasive carcinomas.

METHODS

Thyroid proliferative lesions developed 10 or 15 weeks after promotion with SDM in male F344 rats initiated with N-bis(2-hydroxypropyl)nitrosamine were immunohistochemically analyzed with regard to cellular distribution of phosphatase and tensin homolog (PTEN) and Akt isoforms, as well as their downstream molecules.

RESULTS

Increased expression of PI3K signaling molecules was evident in association with the development of lesion stages from the early focal hyperplasia to the late carcinomas. Capsular carcinomas, and the less frequent parenchymal carcinomas, exclusively expressed phosphorylated, inactive PTEN, and active Akt isoforms, as did their downstream molecules. Among the Akt isoforms, enhanced expression of Akt1 was more prominent than that of Akt2 in both capsular and parenchymal carcinomas.

CONCLUSIONS

Activation of the PI3K pathway through phosphorylation of PTEN promotes the high production of capsular carcinomas as well as the development of less frequent parenchymal carcinomas.

The tyrosine kinase receptor c-met, its cognate ligand HGF and the tyrosine kinase receptor trasducers STAT3, PI3K and RHO in thyroid nodules associated with Hashimoto's thyroiditis: an immunohistochemical characterization

Hepatocyte growth factor (HGF) exerts proliferative activities in thyrocytes upon binding to its tyrosine kinase receptor c-met and is also expressed in benign thyroid nodules as well as in Hashimoto's thyroiditis (HT). The simultaneous expression of HGF/c-met and three trasducers of tyrosine kinase receptors (STAT3, PI3K, RHO) in both the nodular and extranodular tissues were studied by immunohistochemistry in 50 benign thyroid nodules (NGs), 25 of which associated with HT. The ligand/tyrosine kinase receptor pair HGF/c-met and the two trasducers PI3K and RHO were expressed in NGs, regardless of association with HT, with a higher positive cases percentage in HT-associated NGs compared to not HT-associated NGs (25/25 or 100% vs 7/25 or 28%; P<0.001). HGF, PI3K and RHO expression was only stromal (fibroblasts and endothelial cells), in all 32 reactive NGs, while c-met localization was consistently epithelial (thyrocyes). Immunoreactions for HGF, c-met, PI3K and RHO were also apparent in the extra-nodular tissue of HT specimens, where HGF and PI3K were expressed not only in stromal cells but also in thyrocyes along with the c-met. Finally, a positive correlation was observed between the proportion of HGF, c-met, PI3K follicular cells and the grade of lymphoid aggregates in HT. In conclusion, HGF, c-met, PI3K are much more frequently and highly expressed in HT compared to NGs, and among all NGs in those present in the context of HT. A paracrine effect of HFG/c-met on nodule development, based on the prevalent stromal expression, may be suggested along with a major role of HGF/c-met and PI3K in HT. Finally, the expression of such molecules in HT may be regulated by lymphoid infiltrate.

Hashimoto's thyroiditis is not associated with increased risk of thyroid cancer in patients with thyroid nodules: a single-center prospective study

BACKGROUND

The risk of thyroid carcinoma in patients with thyroid nodules associated with Hashimoto's thyroiditis (HT) is a debatable issue. The studies defining the true risk of thyroid malignancy are scanty and mainly depend on retrospective series. To eliminate inherent bias of retrospective studies, this prospective study was carried out to evaluate the true malignancy rate of unselected thyroid nodules in patients with HT who underwent fine-needle aspiration cytology (FNAC).

METHODS

These prospective data were gathered on all patients newly diagnosed with thyroid nodules who were sent for FNAC between May 2006 and August 2009. All patients were evaluated for the presence of HT diagnosis by measuring thyroid autoantibodies. If a patient had at least one positive thyroid autoantibody, then the patient was defined as HT with thyroid nodules. There were 164 patients (147 women and 17 men) with thyroid nodules associated with HT (HT group). There were 551 patients (432 women and 119 men) with thyroid nodules without HT (control group). All patients underwent FNAC and ultrasonography (US).

RESULTS

The malignancy rate was 1.0% in HT group (2 out of 191 nodules) and 2.7% in the control group (19 out of 713 nodules), a not significant (p = 0.19) difference. In the two cytologically malignant nodules in HT group and 19 in the control group, papillary thyroid carcinoma was diagnosed after thyroidectomy and histopathological examination. US features of nodule echogenicity, structure, margin, and Doppler flow were similar between the two groups. US features of microcalcification and absence of peripheral halo were more prominent in the nodules of the control group (p = 0.002 and p < 0.001, respectively).

CONCLUSIONS

On the basis of cytopathological criteria, thyroid nodules in patients with HT are no more likely to be malignant than in those without HT. Many of the US features of benign thyroid nodules are similar in patients with and patients without HT.

Role of NF-kappaB in thyroid cancer

Thyroid cancer is the most common neoplasia of the endocrine system and accounts for approximately 1% of all newly diagnosed cancer cases. Its incidence has rapidly grown over the past few decades. Although most thyroid carcinomas are of the well-differentiated papillary histology, and respond well to treatment with surgical resection followed by radioactive iodine ablation, tumors with more aggressive phenotype, such as follicular, poorly differentiated, anaplastic, and medullary cancers, lead to almost 1500 patient deaths annually. Therefore, understanding molecular mechanisms that regulate the biology of these carcinomas could be helpful to identify new molecules acting as novel targets for therapeutic intervention. NF-kappaB has been recently shown to play an important role in thyroid cancer for its ability to control the proliferative and the anti-apoptotic signaling pathways of thyroid neoplastic cells. Oncogenic proteins RET/PTC, RAS and BRAF, that are involved in many aspects of thyroid carcinogenesis, can induce NF-kappaB activation in papillary, follicular, and medullary thyroid carcinomas, while constitutive de-regulated NF-kappaB activity has been found in anaplastic thyroid carcinomas. A number of NF-kappaB inhibitors have been demonstrated to induce anti-proliferative effects and/or massive apoptosis, especially in combination with radio- or chemo-therapy. The results obtained suggest that targeting NF-kappaB could be a promising strategy for advanced thyroid cancer treatment.

The PI3K-Akt-mTOR pathway in initiation and progression of thyroid tumors

The phosphoinositide-3 (OH) kinase (PI3K) signaling cascade is involved in regulating glucose uptake and metabolism, growth, motility, and other essential functions for cell survival. Unregulated activation of this pathway commonly occurs in cancer through a variety of mechanisms, including genetic mutations of kinases and regulatory proteins, epigenetic alterations that alter gene expression and translation, and posttranslational modifications. In thyroid cancer, constitutive activation of PI3K signaling has been shown to play a role in the genetic predisposition for thyroid neoplasia in Cowden's syndrome, and is recognized to be frequently overactivated in sporadic forms of thyroid cancer including those with aggressive clinical behaviors. In this review, the key signaling molecules in the PI3K signaling cascade, the abnormalities known to occur in thyroid cancer, and the potential for therapeutic targeting of PI3K pathway members will be discussed.

[Usefulness of the immunohistochemical analysis of several molecular markers in the characterization of papillary thyroid carcinoma with initial lymph node metastasis]

INTRODUCTION AND OBJECTIVE

Regional lymph node metastases (LNM) are a common finding in papillary thyroid cancer (PTC). Approximately half of patients have LNM at diagnosis. The aim of this study was to analyze immunohistochemically the combined expression of different PTC-related molecules in order to identify cases with a tendency to show LNM.

PATIENTS AND METHODS

Thirty-five patients were included in the study. The patients were distributed in two groups. Group I included 19 patients with no histological evidence of LNM at diagnosis. Group II included 16 patients with histological evidence of cervical LNM. Samples were stained for RET/PTC, EGFR, p16(INk4a), p21(cip1), p27(kip1), BCL2, and pAKT.

RESULTS

Expression of p21(cip1), p27(kip1), p16(INk4a), Bcl-2, and pAKT showed no differences between the two groups. However, RET/PTC and EGFR expression showed significant differences: in both cases, staining was more frequent in patients with LNM. Simultaneous positivity of RET/PTC and EGFR was a discriminative marker in patients with LNM. Finally, the combination of RET/PTC negative, EGFR negative and p16(INk4a) negative was found in none of the patients with LNM but in nearly half of those in group I.

CONCLUSIONS

Immunohistochemical analysis of several molecular markers could be useful in the phenotypic characterization of PTC. Application of these markers could enhance diagnosis and improve the management of patients with thyroid cancer.

Sonography and fine-needle aspiration biopsy in the diagnosis of benign versus malignant nodules in patients with autoimmune thyroiditis

PURPOSE

To correlate sonographic (US) characteristics and results of fine-needle aspiration biopsy (FNAB) of thyroid nodules in autoimmune thyroiditis (AT) with surgical pathological findings.

METHOD

Forty AT patients with 40 nodular lesions were analyzed retrospectively. Five sonographic characteristics were recorded for each nodule: diameter, echogenicity, microcalcification, halo sign, and margin. Preoperative sonograms and FNAB results were compared with postoperative histopathological findings.

RESULT

Twenty-four of the 40 nodules were malignant, including 20 papillary carcinomas, 3 follicular carcinomas, and 1 medullary carcinoma. Of the 16 benign nodules, 8 were nodular hyperplasia, 6 lymphocytic thyroiditis, and 1 each follicular adenoma and Hürthle cell adenoma. The only US parameter that was significant in malignant vs. benign nodules was the presence of poorly defined margins. Based on preoperative cytology, 22 of the 23 malignant nodules were correctly diagnosed, and 10 of the 14 benign nodules were correctly identified. The positive predictive value was 78.6%, and the negative predictive value was 93.7%.

CONCLUSION

No single US parameter can predict thyroid malignancy in patients with AT. A combination of US and FNAB provides the most sensitive and specific approach available preoperatively.

Inhibitory effects of aminoguanidine on thyroid follicular carcinoma development in inflamed capsular regions of rats treated with sulfadimethoxine after N-bis(2-hydroxypropyl)nitrosamine-initiation

We have reported that thyroid capsular thickening with inflammation induced by an antithyroidal agent, sulfadimethoxine (SDM), might play a role in the development of invasive follicular carcinomas in rats initiated with N-bis(2-hydroxypropyl)nitrosamine (DHPN). Inducible nitric oxide synthase (iNOS) expressed in the inflamed capsular regions further appeared to be implicated in the tumor progression. In the present study, the effects of an iNOS inhibitor, aminoguanidine (AG), on thyroid carcinogenesis were examined. F344 male rats were treated with SDM in drinking water (0.1%) with or without concomitant dietary administration of AG (0.2%) for 4 and 10 weeks after subcutaneous injection of DHPN at 2800 mg/kg bodyweight. At week 4, thyroid capsular thickening with inflammation was observed and iNOS-positive foci were found in the inflamed regions. In addition, single-strand DNA-positive inflammatory cells were scattered among neighboring follicular cells, indicating some cellular damage, at least partly in association with iNOS induction. Concurrent dietary administration of AG with SDM treatment slightly decreased the number of single-strand DNA-positive cells but did not alter the incidence and multiplicity of iNOS-positive foci in the inflamed capsular regions at week 4. At week 10, however, invasive follicular carcinomas predominantly arose in the thickened capsule in the DHPN-SDM-treated rats, and AG administration decreased (P < 0.05) their multiplicity. The carcinoma cells were partly positive for iNOS. These results thus suggested that iNOS induction in both inflammatory and tumor cells might play pivotal roles in tumor progression in this DHPN-SDM rat model.

Increasing incidence of differentiated thyroid cancer in the United States, 1988-2005

BACKGROUND

Studies have reported an increasing incidence of thyroid cancer since 1980. One possible explanation for this trend is increased detection through more widespread and aggressive use of ultrasound and image-guided biopsy. Increases resulting from increased detection are most likely to involve small primary tumors rather than larger tumors, which often present as palpable thyroid masses. The objective of the current study was to investigate the trends in increasing incidence of differentiated (papillary and follicular) thyroid cancer by size, age, race, and sex.

METHODS

Cases of differentiated thyroid cancer (1988-2005) were analyzed using the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) dataset. Trends in incidence rates of papillary and follicular cancer, race, age, sex, primary tumor size (<1.0 cm, 1.0-2.9 cm, 3.0-3.9 cm, and >4 cm), and SEER stage (localized, regional, distant) were analyzed using joinpoint regression and reported as the annual percentage change (APC).

RESULTS

Incidence rates increased for all sizes of tumors. Among men and women of all ages, the highest rate of increase was for primary tumors <1.0 cm among men (1997-2005: APC, 9.9) and women (1988-2005: APC, 8.6). Trends were similar between whites and blacks. Significant increases also were observed for tumors > or =4 cm among men (1988-2005: APC, 3.7) and women (1988-2005: APC, 5.70) and for distant SEER stage disease among men (APC, 3.7) and women (APC, 2.3).

CONCLUSIONS

The incidence rates of differentiated thyroid cancers of all sizes increased between 1988 and 2005 in both men and women. The increased incidence across all tumor sizes suggested that increased diagnostic scrutiny is not the sole explanation. Other explanations, including environmental influences and molecular pathways, should be investigated.

Vitamin D receptor polymorphisms in differentiated thyroid carcinoma

BACKGROUND

Vitamin D receptor (VDR) expression has been shown to be upregulated in several tumors and is supposed to represent an important endogenous response to tumor progression. To investigate the role of the VDR gene and its influence on 25(OH)D(3) and 1,25(OH)(2)D(3) plasma levels in thyroid carcinoma, we analyzed four VDR polymorphisms in patients and healthy controls (HC).

METHODS

Patients with thyroid carcinoma (n = 172) (n = 132 for papillary and n = 40 for follicular) and HC (n = 321) were genotyped for the ApaI (rs7975232), TaqI (rs731236), BsmI (rs1544410), and FokI (rs10735810) polymorphisms within the VDR gene and correlated with 25(OH)D(3) and 1,25(OH)(2)D(3) plasma levels.

RESULTS

The genotypes AA of the ApaI (rs7975232) and FF of the FokI (rs10735810) polymorphisms were significantly less frequent (12.5% vs. 35.2% and 25% vs. 42.1%, respectively, both corrected p [p(c)] = 0.04) in patients with follicular thyroid cancer (FTC) than in HC. Additionally, the haplotypes, Ta (57.5% vs. 41.4%; p(c) = 0.0207), af (24.6% vs. 14.3%; p(c) = 0.0116), Tab (51.1% vs. 36.8%; p(c) = 0.0495), and Tabf (18.7% vs. 13.6%; p(c) = 0.0240) were more frequent, whereas the haplotypes AF (17.1% vs. 37.2%; p(c) = 0.0008), BF (11.4% vs. 31.9%; p(c) = 0.012), tF (7.9% vs. 25.5%; p(c) = 0.0016), and tABF (7.6% vs. 23%; p(c) = 0.0115) were less frequent in the FTC patients compared to HC. Neither genotype nor haplotype frequencies differed between patients with papillary thyroid cancer (PTC) and HC. Further, individuals with PTC and FTC had a significantly lower level of circulating 1,25(OH)(2)D(3) compared to controls. In contrast, no differences of the 25(OH)D(3) concentration between patients and HC were observed. VDR polymorphisms were not associated with 25(OH)D(3) and 1,25(OH)(2)D(3) plasma levels.

CONCLUSIONS

Lower circulating levels of 1,25(OH)(2)D(3) are observed in patients with differentiated thyroid carcinoma. Further, while the alleles AA and FF of the ApaI (rs7975232) and FokI (rs10735810) VDR polymorphisms and the haplotype tABF confer to protection from follicular carcinoma, the haplotype Tabf appeared to be associated with an increased FTC risk. Since this is the first report associating VDR polymorphisms with thyroid carcinoma, these findings need to be confirmed in studies with larger numbers of patients.

Serum hepatocyte growth factor is increased in Hashimoto's thyroiditis whether or not it is associated with nodular goiter as compared with healthy non-goitrous individuals

BACKGROUND

Some growth factors and cytokines are known to cooperate with TSH in thyroid nodular growth, but few data are available on their circulating levels in Hashimoto's thyroiditis (HT).

AIM

To evaluate in HT patients whether thyroid nodules are associated with variations in serum levels of hepatocyte growth factor (HGF) and interleukin-6 (IL-6).

SUBJECTS AND METHODS

Serum levels of HGF and IL-6 were measured by enzyme-linked immunosorbent assay in 176 euthyroid subjects, subdivided into 4 groups: A) HT patients with nodular goiter (no.=42); B) non-goitrous HT patients (no.=36); C) non-HT patients with nodular goiter (no.=48), and D) healthy subjects without thyroid disease (no.=50).

RESULTS

The highest concentrations of serumHGF were found in patients with nodular goiter, irrespective of the presence of associated HT (groups A and C). Nevertheless, in group A serum HGF levels were significantly higher than in group C (860.8+/-333.6 pg/ml vs 691.5+/-156 pg/ml, p<0.01). Moreover, though serum HGF levels in group B (578.3+/-217 pg/ml) were lower than in group A, they were significantly higher than in healthy controls (group D, 512.7+/-170.4 pg/ml, p<0.001). Serum IL-6 levels were similar in the two HT groups (A and B), and increased with respect to groups C and D.

CONCLUSIONS

Serum HGF is increased in HT, especially associated to thyroid nodules, as compared with healthy non-goitrous individuals.

Development and characterization of a novel in vivo model of carcinoid syndrome

PURPOSE

Carcinoid syndrome, characterized by flushing, diarrhea, and valvular heart disease, can occur following carcinoid tumor metastasis to the liver and systemic release of bioactive hormones into the systemic circulation. Treatment of this devastating disease is hampered by the lack of an in vivo model that recapitulates the clinical syndrome.

EXPERIMENTAL DESIGN

Here, we have injected BON cells, a novel human carcinoid cell line established in our laboratory, into the spleens of athymic nude mice to establish liver metastases.

RESULTS

The majority of mice injected intrasplenically with BON cells developed significant increases in plasma serotonin and urine 5-hydroxyindoleacetic acid, and several mice exhibited mesenteric fibrosis, diarrhea, and fibrotic cardiac valvular disease reminiscent of carcinoid syndrome by both echocardiographic and histopathologic evaluation. Mice pretreated with octreotide, a long-acting somatostatin analogue, or bevacizumab, a vascular endothelial growth factor inhibitor, developed fewer liver metastases and manifestations of carcinoid syndrome, including valvular heart disease.

CONCLUSION

We have provided an important in vivo model to further delineate novel treatment modalities for carcinoid syndrome that will also be useful to elucidate the factors contributing to the sequelae of carcinoid disease (e.g., mesenteric fibrosis and valvular heart disease).

1513A>C polymorphism in the P2X7 receptor gene in patients with papillary thyroid cancer: correlation with histological variants and clinical parameters

INTRODUCTION

The modulation of the purinergic receptor P2X7 may be implicated in human carcinogenesis. The 1513A>C and 489C>T polymorphisms of P2X7R gene induce loss of function and gain of function, respectively.

AIM

The aim of the study was to assess the frequency of both 1513A>C and 489C>T polymorphisms in patients with papillary thyroid carcinoma (PTC) and to evaluate the possible association with clinical and histological features.

PATIENTS AND METHODS

P2X7R analysis was performed in lymphocytes from 121 PTC patients (100 women, 21 men; aged 43.4 +/- 13.6 yr), 100 matched healthy subjects, and 80 patients with nodular goiter.

RESULTS

The minor allele frequency for 1513A>C polymorphism in PTC patients with the classical variant was similar to controls (0.21 and 0.20, respectively), whereas it resulted in a significant increase in patients with the follicular variant (0.36; P = 0.01 vs. classical variant, and P = 0.005 vs. controls). In detail, 13.6% of patients with PTC follicular variant were homozygous for the 1513C allele, compared to 2.6% of patients with the classical variant and 2% of controls. Moreover, a positive relationship between 1513A>C polymorphism and either cancer diameter (Rho = 0.22; P = 0.02) or TNM stage (Rho = 0.38; P < 0.001) was found. No significant difference in the genotype frequency of 489C>T polymorphism between PTC patients and healthy controls was observed (0.42 and 0.47, respectively).

CONCLUSIONS

Our data show, for the first time, a strong association between 1513A>C polymorphism of P2X7R gene and the follicular variant of PTC. Further studies are needed to confirm the possible role of this polymorphism as a novel clinical marker of PTC follicular variant and its usefulness in selecting patients with different clinical outcome.

Endogenous thyrotropin and triiodothyronine concentrations in individuals with thyroid cancer

BACKGROUND

Thyroid hormone suppression therapy is associated with decreased recurrence rates and improved survival in patients with differentiated thyroid cancer. Recently higher baseline thyrotropin (TSH) levels have been found to be associated with a postoperative diagnosis of differentiated thyroid cancer. Our objective was to confirm whether preoperative TSH levels were higher in patients who were diagnosed with differentiated thyroid cancer after undergoing thyroidectomy, compared with patients who were found to have benign disease. We also sought to determine whether thyroid hormone levels were lower in the patients with malignancy.

METHODS

The study was a retrospective analysis of a prospective study. The study setting was the General Clinical Research Center of an Academic Medical Center. Participants were 50 euthyroid patients undergoing thyroidectomy. Thyroxine, triiodothyronine (T(3)), and TSH levels were documented in patients prior to their scheduled thyroidectomy. Following thyroidectomy, patients were divided into those with a histologic diagnosis of either differentiated thyroid cancer or benign disease. Preoperative thyroid profiles were correlated with patients' postoperative diagnoses.

RESULTS

All patients had a normal serum TSH concentration preoperatively. One-third of the group was diagnosed with thyroid cancer as a result of their thyroidectomy. These patients had a higher serum TSH level (mean = 1.50 mIU/L, CI 1.22-1.78 mIU/L) than patients with benign disease (mean = 1.01 mIU/mL, CI 0.84-1.18 mIU/L). There was a greater risk of having thyroid cancer in patients with TSH levels in the upper three quartiles of TSH values, compared with patients with TSH concentrations in the lowest quartile of TSH values (odd ratio = 8.7, CI 2.2-33.7). Patients with a thyroid cancer diagnosis also had lower T(3) concentrations measured by liquid chromatography tandem mass spectrometry (mean = 112.6 ng/dL, CI 103.8-121.4 ng/dL) than did patients with a benign diagnosis (mean 129.9 ng/dL, CI 121.4-138.4 ng/dL).

CONCLUSION

These data confirm that higher TSH concentrations, even within the normal range, are associated with a subsequent diagnosis of thyroid cancer in individuals with thyroid abnormalities. This further supports the hypothesis that TSH stimulates the growth or development of thyroid malignancy during its early or preclinical phase. We also show for the first time that patients with thyroid cancer also have lower T(3) levels than patients with benign disease.

TGF-beta promotes thyroid epithelial cell hyperplasia and fibrosis in IFN-gamma-deficient NOD.H-2h4 mice

IFN-gamma(-/-)NOD.H-2h4 mice given 0.05% NaI in their water develop severe thyroid epithelial cell (thyrocyte) hyperplasia and proliferation (TEC H/P) and fibrosis. Proliferating thyrocytes of IFN-gamma(-/-) mice with TEC H/P produce TGF-beta as demonstrated by immunohistochemical staining and in situ hybridization. Strong expression of activating phosphorylated Smad-2/3 and weak expression of inhibitory Smad-7 by proliferating thyrocytes correlate with the severity of TEC H/P. Splenocytes from IFN-gamma(-/-) mice with severe TEC H/P transfer severe TEC H/P to IFN-gamma(-/-)NOD.H-2h4.SCID mice. Mice given anti-TGF-beta had markedly reduced thyrocyte proliferation and decreased fibrosis compared with mouse Ig-treated controls, suggesting that TGF-beta plays an important role in development of TEC H/P induced by activated splenocytes. Moreover, transgenic IFN-gamma(-/-)NOD.H-2h4 mice expressing TGF-beta on thyrocytes all develop fibrosis and moderate to severe TEC H/P with accelerated kinetics, directly demonstrating a role for TGF-beta in severe TEC H/P and fibrosis.

Controversies in thyroid pathology: the diagnosis of follicular neoplasms

Thyroid nodules are common; almost 20% of the population has a palpable thyroid nodule and approximately 70% has a nodule detected by ultrasound. Thyroid cancer is the most frequent endocrine malignancy, and incidence rates have steadily increased over the last decades. Papillary carcinoma (PTC) is the most common malignant neoplasm of the thyroid; the diagnosis of this most frequent type (85-90%) has been increasing, possibly due to changing recognition of morphologic criteria. PTC is defined histologically as a malignant tumor showing evidence of follicular epithelial differentiation and characterized by distinctive nuclear features. However, there are borderline lesions that do not completely fulfill these criteria, making the diagnosis difficult. The use of immunohistochemical and molecular markers adds objective criteria to this confusing and controversial area of pathology. We review the differential diagnosis of well-differentiated follicular thyroid neoplasms and the ancillary techniques and molecular characteristics that have been proposed for application in the diagnosis of PTC.