6: Thyroid nodules and thyroid cancer

Will metformin use lead to a decreased risk of thyroid cancer? A systematic review and meta-analyses

BACKGROUND

It has been reported that metformin use may reduce the risk of thyroid cancer, but existing studies have generated inconsistent results. The purpose of this study was to investigate such association between metformin use and the risk of thyroid cancer.

METHODS

Studies of metformin use for the risk of thyroid cancer were searched in Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure, China Biomedical Database, Wanfang Data, and Chinese Scientific Journals Database (VIP) from the establishment date to December 2022. Newcastle-Ottawa scale is adopted for assessing the methodological quality of included studies, and the inter-study heterogeneity was assessed by using the I-squared statistic. Combined odds ratios (ORs) with the corresponding 95% confidence intervals (CIs) were calculated through either fixed-effects or random-effects model according to the heterogeneity. Besides, subgroup analyses, sensitivity analyses and test for publication bias were conducted.

RESULTS

Five studies involving 1,713,528 participants were enrolled in the qualitative and quantitative synthesis. The result of the meta-analyses showed that metformin use was associated with a statistically significant lower risk of thyroid cancer (pooled OR = 0.68, 95% CI = 0.50-0.91, P = 0.011). Moreover, in the subgroup analysis, we found that the use of metformin may also aid in the prevention of thyroid cancer in Eastern population (pooled OR = 0.55, 95% CI = 0.35-0.88, P = 0.012) rather than Western population (pooled OR = 0.89, 95% CI = 0.52-1.54, P = 0.685). Sensitivity analysis suggested the results of this meta-analyses were relatively stable. No publication bias was detected.

CONCLUSION

Metformin use is beneficial for reducing the risk of thyroid cancer. For further investigation, more well-designed studies are still needed to elucidate the association between metformin use and the risk of thyroid cancer.

Normalized TSH strategy can improve the initial assessment of thyroid nodules

BACKGROUND

Serum thyrotropin (TSH) has been recommended for the initial assessment of patients with thyroid nodules to exclude functional thyroid nodules (FTN). However, the sensitivity of TSH is very low. The increased level of thyroid peroxidase antibody (TPOAb) is considered to be one of the reasons.

OBJECTIVE

To investigate whether normalized TSH (nTSH) can improve diagnostic efficiency by removing TPOAb interference in the first evaluation of thyroid nodules compared with traditional TSH strategy.

METHODS

Thyroid nodules were retrospectively analysed in 90 patients with FTN and 1038 patients with non-functioning thyroid nodules (non-FTN). The regression coefficient (β) of TPOAb affecting the TSH levels was assessed in patients with thyroid nodules, and then, the nTSH level was calculated based on the following formula: nTSH = TSH-β*TPOAb. We used nTSH levels to initially evaluate the thyroid nodules instead of the traditional TSH values and finally compared the results of the two strategies.

RESULTS

The sensitivity, specificity, accuracy, positive prediction rate (PPV) and negative prediction rate (NPV) of nTSH for accessing FTN were 50.00%, 87.70%, 84.67%, 26.01% and 95.29%, respectively, which were better than the values of 48.90%, 78.70%, 76.33%, 16.60% and 94.67% associated with TSH, respectively (p < 0.001).

CONCLUSION

Serum TPOAb testing is recommended for the first assessment of thyroid nodules. Normalized TSH levels can improve assessment efficiency compared to traditional TSH assessment, increase the specificity and reduce an unnecessary 99mTc-TS test.

Vitamin D Status in Patients before Thyroidectomy

Thyroid neoplasms (tumors) are the most common pathology of the endocrine system that requires surgery, and in most cases changes are benign. The surgical treatment of thyroid neoplasms consists in total, subtotal, or one lobe excision. Our study aimed to assess the concentration of vitamin D and its metabolites in patients before thyroidectomy. The study included 167 patients with thyroid pathology. Before the thyroidectomy procedure calcidiol (25-OHD), calcitriol (1,25-(OH)₂D), and vitamin D binding protein (VDBP), as well as basic biochemical parameters, were measured using an enzyme-linked immunosorbent assay kit. Data analysis showed that the cohort of patients has a significant 25-OHD deficiency and proper concentration of 1,25-(OH)₂D. Before the surgery, more than 80% of patients have extreme vitamin D deficiency (<10 ng/mL), and only 4% of the study group has proper 25-OHD concentration. Patients undergoing thyroidectomy are exposed to many complications, including calcium reduction. Our research has shown that patients prior to surgery have a marked vitamin D deficiency, an indicator that may affect their subsequent convalescence and prognosis. The results suggest that determination of vitamin D levels prior to thyroidectomy may be useful for potential consideration of supplementation when vitamin D deficiency is marked and needs to be incorporated into the good clinical management of these patients.

Insufficient iodine nutrition may affect the thyroid cancer incidence in China

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

Alternative splicing events implicated in carcinogenesis and prognosis of thyroid gland cancer

Alternative splicing (AS), a critical post-transcriptional regulatory mechanism, expands gene expression patterns, thereby leading to increased protein diversity. Indeed, more than 95% of human genes undergo alternative splicing events (ASEs). In this study, we drew an all-around AS profile of thyroid cancer cells based on RNA-seq data. In total, there were 45,150 AS in 10,446 thyroid cancer cell genes derived from 506 patients, suggesting that ASEs is a common process in TC. Moreover, 1819 AS signatures were found to be significantly associated with the overall survival (OS) of TC patients. Kaplan–Meier survival analyses suggested that seven types of ASEs were associated with poor prognosis of TC (P < 0.05). Among them, exon skipping (ES) was the most common, with alternate promoter (AP) and alternate terminator (AT) coming second and third, respectively. Our results indicated that acceptor sites (AA) (AUC: 0.937), alternate donor sites (AD) (AUC: 0.965), AT (AUC: 0.964), ES (AUC: 0.999), mutually exclusive exons (ME) (AUC: 0.999), and retained intron (RI) (AUC: 0.837) exhibited an AUC greater than 0.6. In addition, age and risk score (All) were risk factors for TC patients. We also evaluated whether TC-ASEs are regulated by various splicing factors (SFs). We found that the expression of 90 SFs was associated with 469 ASEs and OS of TC patients. Our findings provide an insight into the role of spliceosomes in TC, which may offer novel perspectives in tumor research.

Standardisation of thyroid cytology terminology and practice: are modifications necessary?-a narrative review

Universally accepted guidelines for diagnosis and management of any disease are desirable. Standardization of thyroid cytology reporting is aimed at guiding and improving clinical decision-making and management. However, socio-economic, and local factors and differences in disease prevalence and patterns require modification to suit local settings. 'One size fit all' approach is not possible for any disease diagnosis or management. The same concept is applicable in diagnosis and management of thyroid nodules. An additional special issue is the well-known high inter and intra-observer variability in the histological and cytological diagnosis of thyroid neoplasms. Despite this, thyroid cytology has a very significant influence in the management of thyroid diseases. An approach based on common principals with appropriate modifications that suits countries or continents is desirable and sustainable. The principals of TBSRTC have served as a framework for similar tiered classifications for reporting thyroid cytopathology. This article discusses globally available professional guidelines based on a common framework with appropriate modifications, with the universal aim of risk stratification of thyroid nodules.

Decreased expression of TNFRSF12A in thyroid gland cancer predicts poor prognosis: A study based on TCGA data

Thyroid cancer (TC) is the most well-known endocrine neoplasia as well as a common malignant tumor in the head and neck. Our study was designed to assess the prognostic meaningful of TNFRSF12A expression in TC dependent on data acquired from TCGA and so as to increase further knowledge into the biological pathways involved in TC pathogenesis related TNFRSF12A.Information on gene expression and comparing clinical data were identified and downloaded from TCGA. Gene set enrichment analysis (GSEA) created an arranged list of all genes indicated by their connection with TNFRSF12A expression.Our study cohort included 370 (73.1%) female and 136 (26.9%) male patients. The scatter plot and paired plot showed the difference of TNFRSF12A expression between normal and tumor samples (P < .01). The univariate analysis suggested that TNFRSF12A-low associated essentially with age (HR: 1.15; 95%CI: 1.08-1.22; P < .01), stage (HR: 2.79; 95%CI: 1.43-5.46; I vs IV; P = .003) and tumor stage (HR: 2.39; 95%CI: 1.08-5.30; P = .031). The GSEA results show that type II diabetes mellitus, pantothenate and CoA biosynthesis, adipocytokine signaling pathway, PPAR signaling pathway, mTOR signaling pathway, insulin signaling pathway, are enriched in TNFRSF12A low expression phenotype.TNFRSF12A expression may be a potential useful prognostic molecular biomarker of bad survival in thyroid cancer, in addition, PPAR signaling pathway, insulin signaling pathway, mTOR signaling pathway may be the key pathway controlled by TNFRSF12A in thyroid cancer. Further experimental ought to be performed to demonstrate the biologic effect of TNFRSF12A.

Papillary Thyroid Cancer: Genetic Alterations and Molecular Biomarker Investigations

Papillary thyroid cancer (PTC) is the most prevalent form of malignancy among all cancers of the thyroid. It is also one of the few cancers with a rapidly increasing incidence. PTC is usually contained within the thyroid gland and generally biologically indolent. Prognosis of the cancer is excellent, with less than 2% mortality at 5 years. However, more than 25% of patients with PTC developed a recurrence during a long term follow-up. The present article provides an updated condensed overview of PTC, which focuses mainly on the molecular alterations involved and recent biomarker investigations.

Poly r(C) binding protein (PCBP) 1 expression is regulated by the E3 ligase UBE4A in thyroid carcinoma

Thyroid cancer patients with high miR-490-3p inhibit translation of PCBP1 mRNA, whereas in patients with low miR-490-3p PCBP1 mRNA expression is high; however, the resultant protein is targeted for degradation through the proteasome. The objective of the present study was to evaluate the molecular mechanism that regulates post-translation degradation of poly r(C) binding protein (PCBP) 1 expression in thyroid cancer cells. Mass spectrometric analysis of PCBP1 immunoprecipitates from MG-132 treated TPC1 cells revealed a list of ubiquitin ligases associated with PCBP1. RNAi-mediated silencing of the candidate ubiquitin ligases revealed that knockdown of the ubiquitin ligase UBE4A stabilized PCBP1 in TPC1 cells. Concurrent overexpression of the candidate ubiquitin ligases in the normal thyroid epithelial cell line Nthy-ori 3-1 confirmed that ubiquitin conjugation factor E4 A (UBE4A) is the ubiquitin ligase that is degrading PCBP1. Coimmunoprecipitation of HA-tagged PCBP1 in TPC1 cells cotransfected with FLAG-UBE4A revealed robust polyubiquitinated smear of PCBP1, thus confirming UBE4A as the ubiquitin ligase of PCBP1. UBE4A expression mimicked PCBP1 mRNA expression in thyroid cancer patients and was inversely correlated to PCBP1 protein expression. Low UBE4A expression level was associated with a better prognosis in thyroid cancer patients. Our data reveal a post-translational regulatory mechanism of regulating PCBP1 expression in thyroid cancer cells.

ACTH-secreting medullary thyroid cancer: a case series

Medullary thyroid cancer (MTC) is a rare neuroendocrine tumour that originates from the parafollicular cells of the thyroid gland. The most common presentation of MTC is with a single nodule; however, by the time of diagnosis, most have spread to the surrounding cervical lymph nodes. Cushing’s syndrome is a rare complication of MTC and is due to ectopic adrenocorticotrophic hormone (ACTH) secretion by tumour cells. Cushing’s syndrome presents a challenging diagnostic and management issue in patients with MTC. Tyrosine kinase inhibitors (TKI) previously used for the management of metastatic MTC have become an important therapeutic option for the management of ectopic ACTH in metastatic MTC. The article describes three cases of ectopic ACTH secretion in MTC and addresses the significant diagnostic and management challenges related to Cushing’s syndrome in metastatic MTC.

[Analysis of predictors of malignancy of nodular goiters: about 500 cases]

Les nodules thyroïdiens sont très fréquents et moins de 10% d'entre eux sont malin. Ils posent un véritable problème diagnostique et thérapeutique surtout par rapport à leur nature bénigne ou maligne. L’étude de certains facteurs cliniques et paracliniques de présomption de malignité permet de bien codifier la stratégie thérapeutique. Le but de ce travail est d’étudier les facteurs prédictifs de malignité des goitres nodulaires et comparer nos résultats à ceux de la littérature. Il s'agit d'une étude rétrospective à propos de 500 cas de goitres nodulaires opérés au service d'Oto-rhino-laryngologie (ORL) et Chirurgie cervico-faciale (CCF) de l'hôpital militaire Avicenne de Marrakech entre 2006 et 2012. Le pourcentage de cancers a été de 6,8%. L’âge moyen de nos patients était de 46 ans, avec une sex-ratio de 5 (F/H). A la palpation cervicale; le caractère dure du nodule a été constaté dans 94,4% des cas de cancer, avec des limites irrégulières dans 64,70% des cas de cancer. Trois nodules étaient fixes et ils étaient tous malins. Les adénopathies cervicales ont été constatées chez 8 malades dont 7 présentaient des cancers. A l’échographie, 61,8% des nodules malins présentaient un aspect hypoéchogène, avec des contours flous dans 88,24% des cas. La vascularisation intra nodulaire était présente dans 35,3% de ces cas des cancers avec des microcalcifications chez 55,9% d'entre eux. Le halo hypoéchogene périnodulaire était incomplet dans 73,5% des cas de cancer. Nos patients étaient en euthyroïdie dans 84,6% des cas. Les facteurs prédictifs de malignité d'un goitre nodulaire, étaient donc dans notre étude d'abord cliniques: l’âge supérieur à 60 ans, la consistance dure du nodule, sa fixité, son caractère irrégulier et mal limité à la palpation, ainsi que la présence d'adénopathie(s) cervicale(s) à l'examen; et échographiques: le caractère hypoéchogène, les limites floues, la présence de microcalcifications et la visualisation d'une vascularisation intranodulaire avec ou sans vascularisation périnodulaire. Bien que certains de ces facteurs soient fortement prédictifs de malignité, seule l'histologie définitive apporte le diagnostic de certitude. Le clinicien doit alors se baser sur un faisceau d'arguments pour adopter une conduite pratique en vue d'une prise en charge adéquate.

Acoustic radiation force impulse elastography for differentiation of benign and malignant thyroid nodules with concurrent Hashimoto's thyroiditis

The purpose of the study was to explore the diagnostic performance of acoustic radiation force impulse (ARFI) elastography in differential diagnosis between benign and malignant thyroid nodules in patients with coexistent Hashimoto's thyroiditis (HT). A total of 141 pathological proven nodules in 141 HT patients (7 males and 134 females, mean age 50.1 years, range 23-75 years) received conventional ultrasound (US), elasticity imaging (EI) and ARFI elastography, including virtual touch tissue imaging (VTI) and virtual touch tissue quantification (VTQ), before surgery. Shear wave velocity (SWV) and SWV ratio were measured for each nodule on VTQ. The US, EI and ARFI elastography features were compared between benign and malignant nodules in HT patients. Receiver operating characteristic curve (ROC) analyses and area under curve (AUC) were performed to assess the diagnostic performance. Pathologically, 70 nodules were benign and 71 nodules were malignant. Significant differences were found between benign and malignant nodules in HT patients for EI (EI score) and ARFI (VTI grade and SWV) (all P value <0.05). The AUCs for EI, VTI, SWV and SWV ratio were 0.68 [95% confidence interval (CI): 0.59-0.77], 0.90 (95% CI: 0.84-0.95), 0.77 (95%CI: 0.70-0.85) and 0.74 (95%CI: 0.66-0.82), respectively. The cut-off points were EI score ≥3, VTI grade ≥4, SWV ≥2.58 m/s and SWV ratio ≥1.03, respectively. In conclusion, ARFI elastography is useful for differentiation between benign and malignant thyroid nodules in HT patients. The diagnostic performance of ARFI elastography is better than EI.

Preliminary study on the diagnostic value of acoustic radiation force impulse technology for differentiating between benign and malignant thyroid nodules

OBJECTIVES

This study aimed to evaluate the diagnostic value of acoustic radiation force impulse (ARFI) elasticity imaging for differentiating between benign and malignant thyroid lesions.

METHODS

Hospitalized patients needing thyroid surgery were evaluated. After routine thyroid sonography, the patients underwent ARFI elasticity imaging. Virtual Touch tissue imaging (VTI) and Virtual Touch tissue quantification (VTQ; Siemens Medical Solutions, Mountain View, CA) were used to qualitatively and quantitatively analyze the elasticity and hardness of nodules. For statistical analysis, the Student t test, analysis of variance, and the χ(2) test were used to compare the elastic parameters.

RESULTS

Of the 98 thyroid nodules observed in 72 hospitalized patients, 56 were nodular goiters, 16 thyroid adenomas, 4 thyroiditis, and 22 thyroid malignancies, with mean VTQ values ± SD of 2.034 ± 0.484, 1.835 ± 0.364, 2.293 ± 0.787, and 3.941 ± 1.393 m/s, respectively. The elastic parameters of malignant nodules were significantly higher than those of benign nodules (P < .001) and the surrounding thyroid parenchyma (P < .001). There was no significant difference between the VTQ value of benign nodules and that of the surrounding normal thyroid parenchyma (P > .05). For differentiating between benign and malignant nodules, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accordance rate were 86.36%, 93.42%, 79.17%, 95.95%, and 91.84% based on the standard VTQ value (2.555m/s). In total, 77.6% (59 of 76) of the benign nodules showed softer and equal images in the VTI mode, and 77.3% (17 of 22) of the malignant nodules showed stiffer images (P < .001).

CONCLUSIONS

Acoustic radiation force impulse imaging has high sensitivity and specificity in evaluating benign and malignant thyroid nodules and therefore had good diagnostic value in clinical applications.

Metastatic phenotype is regulated by estrogen in thyroid cells

BACKGROUND

Over 200 million people worldwide are affected by thyroid proliferative diseases, including cancer, adenoma, and goiter, annually. The incidences of thyroid malignancies are three to four times higher in women, suggesting the possible involvement of estrogen. Based on this observed sex bias, we hypothesize that estrogen modulates the growth and metastatic propensity of thyroid cancer cells.

METHODS

In this study, two thyroid cell lines (Nthy-ori 3-1 and BCPAP) were evaluated for the presence of estrogen receptor (ER) by Western blot analysis and estrogen responsiveness by using a cell proliferation assay. In addition, the effect of estradiol (E(2)) on modulation of metastatic phenotype was determined by using in vitro adhesion, migration, and invasion assays.

RESULTS

Thyroid cells expressed a functionally active ER-alpha and ER-beta as evidenced by 50-150% enhancement of proliferation in the presence of E(2). E(2) also enhanced adhesion, migration, and invasion of thyroid cells in an in vitro experimental model system that, based on our results, is modulated by beta-catenin.

CONCLUSION

Our data provide evidence that the higher incidence of thyroid cancer in women is potentially attributed to the presence of a functional ER that participates in cellular processes contributing to enhanced mitogenic, migratory, and invasive properties of thyroid cells. These findings will enable and foster the possible development of antiestrogenic therapy targeting invasion and migration, thus affecting metastatic propensity.

Recombinant human thyroid-stimulating hormone (Thyrogen) in thyroid cancer follow up: experience at a single institution

BACKGROUND

Recombinant human thyroid-stimulating hormone (Thyrogen; Genzyme Corporation, Cambridge, MA, USA) (rhTSH)-stimulated serum thyroglobulin (Tg) (stim-Tg) and (131)I whole-body scanning (WBS) have been reported to allow follow up of patients with thyroid cancer without the symptoms of thyroxine withdrawal and with equivalent diagnostic information to that obtained after thyroxine withdrawal. The aim of the study was to report results of rhTSH use at the Alfred Hospital, Melbourne, from 1999 to 2006 and in particular to examine the significance of detectable serum Tg after rhTSH in relation to thyroid cancer staging and to compare the sensitivity of rhTSH-stimulated serum Tg to whole-body (131)I scanning (WBS) in the detection of residual and recurrent thyroid cancer.

METHODS

The study was a retrospective chart review.

RESULTS

In 90 patients, rhTSH was used for 96 diagnostic episodes and 18 doses of rhTSH were used to facilitate treatment with (131)I. In stages I and II cancer (n = 42), of three patients with stim-Tg 1-2 microg/L, none had identifiable disease, and the three patients who had stim-Tg >2 microg/L did not experience recurrent disease during follow up. In contrast, in stages III and IV cancer (n = 43) 2 of 5 with stim-Tg 1-2 microg/L had identifiable disease and 7 of 10 with stim-Tg >2 microg/L had identifiable disease. In Tg-positive, WBS-negative disease, further imaging identified persistent/recurrent disease.

CONCLUSION

rhTSH was effective and safe in the management of thyroid cancer follow up for diagnosis of persistent/recurrent cancer and to enable (131)I treatment. In no case did rhTSH-stimulated WBS identify the presence of disease not also identified by raised basal Tg or stim-Tg. Therefore, in low risk cancer WBS may be omitted.

Radioiodine therapy for differentiated thyroid carcinoma with thyroglobulin positive and radioactive iodine negative metastases

BACKGROUND

Differentiated thyroid carcinoma with thyroglobulin positive and radioactive iodine negative metastases has been observed in follow-up studies. The management of this condition remains controversial. Most studies support blind radioactive iodine treatment while others negate this approach.

OBJECTIVES

To assess the effects of radioiodine therapy for differentiated thyroid carcinoma with thyroglobulin positive and radioactive iodine negative metastases.

SEARCH STRATEGY

Studies were obtained from computerised searches of MEDLINE, EMBASE, The Cochrane Library, China National Infrastructure (CNKI) and paper collections of conferences held in Chinese.

SELECTION CRITERIA

Randomised controlled clinical trials and prospective controlled clinical trials.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data and interviewed authors of all potentially relevant studies by electronic mail to verify randomisation procedures. One author entered data into a data extraction form and the second one verified the results of this procedure.

MAIN RESULTS

Because of the absence of any suitable randomised or prospective controlled trial in this area, results currently cannot be presented.

AUTHORS' CONCLUSIONS

The currently available evidence is insufficient to reliably assess the potential of radioiodine treatment for differentiated thyroid carcinoma with thyroglobulin positive and radioactive iodine negative metastases.

[What are the alternative criteria for fine needle aspiration biopsy of a thyroid nodule?]

OBJECTIVES

To identify the clinical and paraclinical factors of thyroid nodule malignancy (in absence of ultrasound-guided fine needle aspiration biopsy data).

PATIENTS AND METHODS

This retrospective study was conducted on a cohort of 282 patients admitted for management of a thyroid nodule disease. All patients had undergone surgery and the specimen had been analyzed anatomically and pathologically. Forty-four patients had malignant disease. Epidemiological, clinical, and paraclinical data, as well as the anatomical and pathological characteristics of the specimen were collected for each patient.

RESULTS

We showed that the epidemiological data (sex and age), the nodule's characteristics (consistency, irregularities of the edges and fixity to underlying structures, and size), the presence of adenopathies, signs of compression, and the presence of calcifications were the predictability criteria of malignant disease. However, the scintigraphic aspect, the echostructure, and the hormonal status were not significant.

CONCLUSION

This study underscores that a relevant clinical and paraclinical analysis remains highly contributive in the presurgical identification of factors predictive of malignancy of a thyroid nodule, notably in countries where technological tools are not always available.

Variable Background Active Contour Model for Computer-Aided Delineation of Nodules in Thyroid Ultrasound Images

This paper presents a computer-aided approach for nodule delineation in thyroid ultrasound (US) images. The developed algorithm is based on a novel active contour model, named variable background active contour (VBAC), and incorporates the advantages of the level set region-based active contour without edges (ACWE) model, offering noise robustness and the ability to delineate multiple nodules. Unlike the classic active contour models that are sensitive in the presence of intensity inhomogeneities, the proposed VBAC model considers information of variable background regions. VBAC has been evaluated on synthetic images, as well as on real thyroid US images. From the quantification of the results, two major impacts have been derived: 1) higher average accuracy in the delineation of hypoechoic thyroid nodules, which exceeds 91%; and 2) faster convergence when compared with the ACWE model.

Immunohistochemical Analysis of Survivin Expression in Thyroid Follicular Adenoma and Carcinoma

Survivin is one of the 8 members of human inhibitor of apoptosis , which is differentially expressed in cancerous/transformed cells versus normal differentiated tissues. This retrospective study of thyroid histologic samples aimed to assess the clinical usefulness of survivin immunostaining for discrimination between follicular adenoma and carcinoma of thyroid. Immunohistochemical staining for survivin was performed on 41 lesions from patients who had undergone surgery for either follicular adenoma or carcinoma of thyroid. Survivin expression was significantly (P < 0.005) higher in the cases that received a diagnosis of carcinoma in comparison with follicular adenomas cases. Odds ratio of follicular carcinoma for survivin expression was 21.375 (95% CI: 3.283 to 139.177). Our results showed potential value of survivin in discrimination between follicular thyroid adenoma and follicular thyroid carcinoma. We conclude that survivin is a potential candidate for further investigation in the proper histologic diagnosis of thyroid cancers.

Pilot Study Using SELDI-TOF−MS Based Proteomic Profile for the Identification of Diagnostic Biomarkers of Thyroid Proliferative Diseases

Biomarkers for thyroid cancer (TCa) lack specificity. To develop TCa specific biomarkers, SELDI-TOF-MS was used to examine the proteomic profile of biopsies obtained from papillary TCa along with adjacent normal tissue. Sixty-three potential biomarkers were categorized by univariate analysis into single biomarker candidates and segregated by multivariate analysis into normal and cancerous groups. Our studies demonstrate the sensitivity and reproducibility of this approach to detect biomarkers for TCa.

3,3′-Diindolylmethane, a cruciferous vegetable derived synthetic anti-proliferative compound in thyroid disease

Considerable epidemiological evidence exists to link thyroid disease with differing patterns of dietary consumption, in particular, cruciferous vegetables. We have been studying the anti-thyroid cancer (TCa) activity of indole-3-carbinol (I3C) found in cruciferous vegetables and its acid catalyzed dimer, 3,3'-diindolylmethane (DIM). There are no studies as yet to elucidate the effect of these compounds on the altered proliferative patterns in goiter or thyroid neoplasia. In this study, we tested the anti-proliferative effects of I3C and DIM on four different thyroid cancer cell lines representative of papillary (B-CPAP and 8505-C) and follicular carcinoma of the thyroid (CGTH-W-1 and ML-1), and primary human goiter cells. Cell survival and IC50 values for I3C and DIM were calculated by the XTT assay and cell cycle distribution analysis was done by flow cytometry. DIM was found to be a better anti-proliferative agent than I3C in both papillary and follicular TCa resulting in a greater cytotoxic effect at a concentration over three fold lower than predicted by the molar ratio of DIM and I3C. The anti-proliferative activity of DIM in follicular TCa was mediated by a G1 arrest followed by induction of apoptosis. DIM also inhibited the growth of primary goiter cells by 70% compared to untreated controls. Contrary to traditional belief that cruciferous vegetables are "goitrogenic", DIM has anti-proliferative effects in glandular thyroid proliferative disease. Our preclinical studies provide a strong rationale for the clinical exploration of DIM as an adjuvant to surgery in thyroid proliferative disease.

Étude du contenu en ADN nucléaire dans les nodules thyroïdiens

Thyroid nodules are frequent and sometimes they pose a diagnostic and prognostic problem. DNA ploidy study and cell cycle analysis could be of value in the distinction between benign tumors and malignant tumors. Formalin-fixed and paraffin-embedded tissues from 69 patients with different benign and neoplastic lesions were investigated. Nuclear DNA content in thyroid cells was measured after Feulgen staining using SAMBA 200 image analysis system. A diploid DNA stemline was revealed in 75% of histologically proven benign thyroid tumors (15/20) and aneuploidy was found in 57.2% of malignant tumors (28/49). There is a significant correlation between aneuploidy and extra-thyroid extension (p=0.007) and bilateral and/or mediastinal lymph node metastasis (p=0.02). In the majority of benign tumors (19/20), the proliferation index was lower than 3% (< or =3%) however, this index value was higher than 3% (>3%) in more than 83% of malignant tumors (41/49) (p<0.001). The S phase fraction analysis revealed that the threshold of 14% divide the near whole of benign and malignant tumors (p<0.001). Our findings show that in follicular lesions, proliferation index and S phase fraction study appears interesting and helpful in the distinction between benign and malignant tumors, and aneuploidy seems more interesting in prognosis evaluation of these tumors.

Prevalence of differentiated thyroid cancer in 810 cases of surgically treated goiter in Yemen

BACKGROUND

In 1990, the World Health Organization (WHO) suggested that severe iodine deficiency exists in Yemen. Therefore, we looked at the prevalence of differentiated thyroid goiter in 810 cases consecutively treated by surgery for goiter.

METHODS

This was a retrospective study of 810 surgically operated cases of goiter over a 5-year period (1999-2003). All cases were evaluated on H&E stained sections from embedded, 10% buffered formalin fixed tissue blocks. Special stains and immunohistochemical analysis were done in Yemen and abroad. Most patients were older than 20 years of age and were from the high altitude areas (2000 to 2600 meters above sea level), where iodine deficiency disorders (IDD) are well documented.

RESULTS

In the 810 cases, 729 (90%) were females and the remaining 81 (10%) were males, with female-to-male ratio of 9:1. Differentiated thyroid cancer (DTC) was found in 170 (21%) cases, including 148 (86.4%) females and 22 (13.6%) males. Nearly 60% of the cases were in the age group of 21-40 years. Papillary carcinoma was the most common type of DTC (164 cases, 96.5%).

CONCLUSIONS

In a Yemeni population, which has a high prevalence of iodine deficiency, 21% of patients operated on for nodular goiter without pre-operative fine needle aspiration biopsy had thyroid cancer, mostly of the papillary type. In this study, males and elderly patients with goiter had a higher chance of having malignancy.