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Os nódulos de tireoide são frequentemente encontrados na prática clínica e, com o auxílio de ultrassonografia de alta resolução, podem ser identificados em 17 a 67% da população. A alta prevalência desses nódulos causa preocupação frequente aos pacientes e aos clínicos devido ao risco de malignidade, o que, por sua vez, leva a investigações laboratoriais de alto custo, invasivas e, eventualmente, a cirurgias desnecessárias. A punção aspirativa com agulha fina (PAAF) é o método diagnóstico pré-operatório mais preciso para identificação de um nódulo maligno de tireoide, mas não consegue excluir malignidade nos casos de citologia inadequada, nódulos com diagnóstico citológico de lesão folicular ou atipia de significado indeterminado e nas citologias sugestivas de neoplasia folicular. O objetivo deste estudo foi analisar as características clínicas, laboratoriais, ultrassonográficas e citológicas de uma população de pacientes com nódulos de tireoide submetidos a tireoidectomia e a relação entre estes achados e o risco de malignidade. Além disto, em relação aos nódulos malignos, verificar se o valor de TSH esteve associado a um estadiamento mais avançado da doença. Foram avaliados prontuários de 353 pacientes submetidos a tireoidectomia, acompanhados no Hospital das Clínicas da FMUSP de São Paulo, no período de fevereiro de 2002 a abril de 2010. O número total de nódulos nestes pacientes foi 392. As características clínicas e laboratoriais analisadas em cada paciente foram idade, sexo, valores séricos de TSH e T4 livre, presença de anticorpo anti-tireoperoxidase (anti- TPO) e anti-tireoglobulina (anti-TG). Foram avaliadas a presença de características ultrassonográficas sugestivas de benignidade (presença de halo periférico hipoecoico, aparência espongiforme, aspecto isoecóico ou hiperecoico) e de malignidade (nódulo sólido hipoecoico, contornos irregulares, presença de microcalcificações). Baseados nestas características, os nódulos foram classificados em benignos, indeterminados e suspeitos para malignidade. O diagnóstico citológico foi classificado em benigno, indeterminado, suspeito e maligno, e a análise combinada das características ultrassonográficas e citológicas também foi avaliada. Ao exame histopatológico, 200 nódulos eram malignos e 192 nódulos eram benignos. Os nossos resultados mostraram que sexo, idade, valores séricos de TSH e T4 livre e presença de anticorpo anti-TPO e anti-TG não estiveram associados a uma maior chance de malignidade. O valor de TSH sérico também não esteve associado a maior risco de recorrência ou estadiamento mais avançado nos pacientes com câncer Os nódulos maiores estiveram mais associados a benignidade quando avaliamos toda amostra. Na análise multivariada de toda amostra, após regressão logística, apenas a citologia maligna, hipoecogenicidade e presença de microcalcificações foram associados a malignidade. Já, a classificação ultrassonográfica que não se baseia em apenas uma característica mas em um conjunto de características, apresentou um alto valor preditivo de benignidade e foi útil na identificação de nódulos com citologia indeterminada. A classificação ultrassonográfica tem o potencial de reduzir o número de cirurgias para nódulos com citologia indeterminada / Thyroid nodules are often encountered in clinical practice, and with the use of high-resolution ultrasound may be identified in 17 to 67% of the population. The high prevalence of these nodules cause frequent concern to patients and clinicians due to the risk of malignancy, wich in turn leads on costly investigations, use of invasive diagnostic methods and sometimes unnecessary surgeries. Fine needle aspiration biopsy (FNAB) is the most accurate preoperative diagnostic method to identify a malignant thyroid nodule. However, FNAB cannot rule out malignancy in cases of inadequate cytology, follicular lesions, atypia of undetermined significance, and in cytology suggestive of follicular neoplasm. The aim of this study was to analyze clinical, laboratory, ultrasound and cytopathologic characteristics of a group of patients with thyroid nodules undergoing thyroidectomy and the relationship between serum levels of TSH and the risk of malignancy. In nodules found to be malignant in this cohort, we analyzed the association of TSH levels with advanced disease stage and risk of recurrence. We analyzed the records of 353 patients who were followed at Hospital das Clínicas - São Paulo Medical School, between February 2002 and April 2010, and who subsequently underwent thyroidectomy. The total number of nodules in these patients was 392. The clinical and laboratory characteristics included in the analysis were age, gender, serum levels of TSH and free T4, and presence of serum thyroid anti-peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies. We evaluated the presence of ultrasonographic features suggestive of benignity (isoechoic or hyperechoic appearance, presence of hypoechoic peripheral halo, spongiform appearance) and malignancy (hypoechoic appearance, irregular border, presence of microcalcifications). Based on these ultrasonographic characteristics, we classified the nodules as benign, indeterminate or suspicious for malignancy. According to the FNAB cytology, we also subdivided the nodules into benign, indeterminate, suspicious and malignant. The combined analysis of ultrasonographic features and cytopathology was also evaluated. On histopathology, 200 nodules were malignant and 192 were benign. Our results showed that gender, age, serum levels of TSH and free T4, as well as the presence of anti-TPO and anti-TG were not associated with increased risk of malignancy. Similarly, serum TSH value was not associated with increased risk of recurrence or more advanced stage in patients with thyroid cancer. A large nodule size was associated with benignity. In multivariate analysis, after logistic regression, only malignant cytology, hypoechoic appearance and presence of microcalcifications were associated with malignancy. Furthermore, the ultrasonographic classification, wich was not based in only one feature but in a set of characteristics, showed a high predictive value for benignity and seems to be useful in identifying nodules with indeterminate cytology at risk for malignancy. The use of ultrassonographic classification has the potential to reduce the number of surgeries for nodules with indeterminate cytology

Orientador: Laura Sterian Ward / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-23T21:47:49Z (GMT). No. of bitstreams: 1 Araujo_PriscilaPereiraCosta_D.pdf: 10950387 bytes, checksum: 74db0b3262052fa67754f17b1d32c336 (MD5) Previous issue date: 2013 / Resumo: INTRODUÇÃO: As doenças da tireóide são bastante frequentes na população. O carcinoma diferenciado da tireóide tem aumentado significantemente nos últimos anos, além de ser o tipo mais comum na região da cabeça e pescoço, acometendo cerca de um a 13 indivíduos para cada mil habitantes com importantes diferenças geográficas de prevalência. Embora haja atualmente um melhor acesso ao sistema de saúde, bem como amplo uso de metodologias cada vez melhores e mais sensíveis na detecção das doenças tireoidianas (responsável por parte do aumento de sua incidência), há sabidamente a influência de fatores ambientais e outras comorbidades consideradas fatores de risco, como radiação ionizante, substâncias químicas, alterações dietéticas específicas (como a deficiência endêmica de iodo) e também inespecíficas (como doenças decorrentes do estilo de vida atual, potencializadas pelo sedentarismo e ingestão inadequada de nutrientes) agregando doenças que influem no estado imunológico, aumentando a suscetibilidade a doenças, dentre elas o câncer. A obesidade e sua crescente incidência, para além desses fatores ambientais, tem se mostrado fator de predisposição importante e independente para vários tipos de neoplasias malignas. No caso do câncer de tireóide, esta associação ainda é controversa. A literatura já demonstrou a relação entre obesidade em câncer de tireóide em subgrupos específicos, mas ainda carece de dados mais concretos e marcadores que possam rastrear estas populações de risco em nível global. O peptídeo grelina é um peptídeo orexígeno produzido nas células gástricas com liberação sérica e ação central e periférica, com funções relacionadas ao mecanismo de obesidade. Por este motivo, apresenta-se como um bom candidato a marcador da relação entre obesidade e câncer. SUJEITOS E MÉTODOS: Este trabalho analisou a associação entre pacientes portadores de sobrepeso ou obesidade e carcinoma diferenciado da tireóide através das técnicas de ELISA (enzyme-linked immunosorbent assay) e imunoistoquimica para a determinação de níveis séricos e expressão de grelina tecidual em um grupo de 112 pacientes portadores de nódulos tireoidianos, dos quais 59 eram benignos e 53 malignos, todos submetidos à tireoidectomias e seguidos por 10 a 216 meses (82,28 ± 43,85 meses). Correlacionou-se a ocorrência de alterações deste peptídeo com a susceptibilidade e a predisposição ao câncer da tireóide para obesos e não obesos e para o subgrupo microcarcinoma (?10 mm). RESULTADOS: Dos 112 pacientes da casuística, 26,7% eram obesos (IMC >29,9 Kg/m2), com média de idade de 29,2 ± 1,7 anos para o sexo masculino e de 32,9 ± 1,2 anos para o feminino; como esperado, houve correlação positiva entre grelina e obesidade (p<0,001), porém a curva ROC não apresentou poder discriminatório para malignidade na amostra estudada (p = 0,4492). Verificou-se baixa sensibilidade (67,9%) e especificidade (39%), porém a expressão imunoistoquímica foi capaz de diferenciar malignidade na amostra estudada (p-0,024). Não houve correlação significativa entre níveis séricos e/ou da expressão de grelina com nenhuma das variáveis clínicas. Apenas a presença de auto-anticorpos apresentou tendência significativa (p=0,09). CONCLUSÃO: Os níveis séricos de grelina dosados na amostra estudada não auxiliaram na discriminação de malignidade, porém sua expressão imunoistoquímica apresentou importante relação entre esta e o diagnóstico de malignidade. As concentrações séricas de grelina diferiram quantitativamente e apresentaram baixa especificidade como marcadoras, tanto para o grupo maligno em geral quanto para o subgrupo dos microcarcinomas. Apesar da ausência de correlação entre os níveis séricos e câncer, quando analisamos os dados de expressão observa-se que há poder discriminatório para malignidade na amostra estudada / Abstract: BACKGROUND: Thyroid diseases are very frequent. Differentiated thyroid cancer has significantly improved in the last twenty years, being the most common cancer on head and neck region, ranging from 1 to 13/1000 inhabitants on average, with importante prevalence features. There is an influence of environmental factors like radiation, chemical components, iodine deficiency, as well as other morbidities and actual changes in lifestyle, in which sedentary lifestyle and diet changes take place causing a synergistic effect, with improvement of risk factors for various diseases including cancer. The recent epidemy of obesity and its rising incidence has been shown to be a very important susceptibility factor to many malignant neoplasms. Regarding thyroid cancer, this association is still controversial, and so far is known that during tumor progression thyroid cells are certainly influenced by the proinflammatory status commonly observed in these patients. Data on literature has demonstrated the relationship between obesity and thyroid cancer in specific subgroups, but there is lack of concrete data about susceptibility markers to globally screen this population at risk. Ghrelin is an orexigen peptide produced by gastric cells with central and peripherical actions, released on blood stream with obesity control functions. Because of these features, it is a good potential marker of the obesity-cancer relationship. ESPÉCIME/METHODS: Association between obese and overweight patients and differentiated thyroid cancer was analyzed using ELISA (enzyme-linked immunossorbent assay) and immunohistochemical techniques, to verify the expression and serum levels of ghrelin protein in 112 patients harboring thyroid nodules (59 benign and 53 malignant), all submitted to thyroidectomies and followed for 10 a 216 months (82,28 ± 43,85 months). Correlations among ghrelin alterations and diagnostic and susceptibility to thyroid cancer were made for obese and non-obese patients and for a micro carcinoma-specific group selected for study (?10mm). The findings of immunohistochemical expression and ghrelin serum levels in selected cases were used for comparisons and the formulation of hypothesis. RESULTS: 26,7% of the 112 patients were obese (BMI >29,9 Kg/m2), with average age 29,2 ± 1,7 years (male patients) and 32,9 ± 1,2 years (female). As postulated, there was a relationship between ghrelin levels and obesity (p<0,001), but ROC curve did not show discriminatory power for malignancy (p=0, 0492). Low sensitivity (67, 9%) and specificity (39%) rates were found, and there was no statistical association among ghrelin (expression and/or serum levels) and clinical variables. The presence of auto antibodies presented an important trend (p=0, 09). The relationship between immunohistochemical expression and cancer was significant (p=0,024). CONCLUSION: Ghrelin serum levels did not help to discriminate malignancy on this serie, but the immunohistochemical expression showed important correlation between malignancy and cancer risk. Serum levels differed quantitatively and presented low sensitivity and specificity, not only for micro carcinoma but also for the whole tumors group. Despite the absence of association between serum levels and cancer, the expression data shows discriminatory power at the study and can be a potential marker for thyroid malignancy / Doutorado / Clinica Medica / Doutora em Clínica Médica

Pre-surgical diffusion weighted imaging (DWI) is increasingly important in the context of thyroid cancer for identification of the optimal treatment strategy. It has exemplarily been shown that DWI at 3T can distinguish undifferentiated from well-differentiated thyroid carcinoma, which has decisive implications for the magnitude of surgery. This study used DWI histogram analysis of whole tumor apparent diffusion coefficient (ADC) maps. The primary aim was to discriminate thyroid carcinomas which had already gained the capacity to metastasize lymphatically from those not yet being able to spread via the lymphatic system. The secondary aim was to reflect prognostically important tumor-biological features like cellularity and proliferative activity with ADC histogram analysis. Fifteen patients with follicular-cell derived thyroid cancer were enrolled. Lymph node status, extent of infiltration of surrounding tissue, and Ki-67 and p53 expression were assessed in these patients. DWI was obtained in a 3T system using b values of 0, 400, and 800 s/mm2 . Whole tumor ADC volumes were analyzed using a histogram-based approach. Several ADC parameters showed significant correlations with immunohistopathological parameters. Most importantly, ADC histogram skewness and ADC histogram kurtosis were able to differentiate between nodal negative and nodal positive thyroid carcinoma. Conclusions: histogram analysis of whole ADC tumor volumes has the potential to provide valuable information on tumor biology in thyroid carcinoma. However, further studies are warranted.

Le carcinome médullaire de la thyroïde (CMT) est une tumeur neuroendocrine rare, se développant à partir des cellules sécrétant la calcitonine. Cette tumeur survient dans un contexte familial dans un tiers des cas. Toutes les formes germinales et près de 40% des formes sporadiques sont causées par une mutation ponctuelle activatrice de l’oncogène RET, codant pour un récepteur membranaire à activité tyrosine kinase. Les événements oncogéniques à l’origine des formes sporadiques non mutées RET restent mal définis, à l’exception de mutations activatrices des oncogènes RAS découvertes récemment.Le pronostic péjoratif du CMT est essentiellement lié à un envahissement ganglionnaire précoce. A ce titre, la chirurgie initiale est souvent insuffisante et les formes métastatiques ont longtemps été considérées en impasse thérapeutique. L’avènement récent des inhibiteurs séléctifs de tyrosine kinases (ITK) a apporté un nouvel élan à la prise en charge des tumeurs réfractaires, certains d’entre eux incluant dans leur spectre d’action le récepteur RET. Mais l’optimisation de ces traitements requiert une connaissance préalable des mécanismes moléculaires sous-jacents au développement tumoral.Dans ce contexte et en nous appuyant sur une collection importante de prélèvements humains, nous avons cherché à approfondir la decription du ‘paysage génomique’ du CMT.Dans un premier temps, nous avons évalué les anomalies structurales ponctuelles et chromosomiques présentées par les CMT. Nous avons montré, par optimisation de méthodes de séquençage, que les mutations des gènes RET et RAS interviennent dans plus de 96% des cas et que ces évènements sont mutuellement exclusifs. Ces mutations permettent de distinguer plusieurs groupes d’agressivité et de réponse aux traitements par ITK. Nous avons également observé - par technique d’hybridation génomique comparative - des anomalies de grande ampleur récurrentes dans cette pathologie : les délétions du bras court du chromosome 1 et des chromosomes entiers 4 et 22 apparaissent comme étant des évènements précoces et indépendants de la tumorigenèse du CMT.Dans un second temps, nous avons déterminé - par approche de type biopuce - les profils d’expression de microARN dans les CMT. Certains de ces régulateurs post-transcriptionnels majeurs semblent liés au caractère invasif de la tumeur, et notamment les miR-21, miR-199 et miR-129. Nous avons également démontré le potentiel d’utilisation des microARN miR-21 et miR-199 en tant que biomarqueurs circulants du CMT. L’impact fonctionnel des formes précurseurs mir-21 et mir-129 a ensuite été évalué par transfection dans les modèles cellulaires TT et MZ-CRC1.Les observations ainsi obtenues offrent de nombreuses perspectives d’études. Elles permettent la définition de marqueurs tissulaires distinguant a priori les tumeurs métastatiques et/ou réfractaires aux thérapies. Enfin, elles mettent en lumière de nouvelles pistes pour la découverte de cibles thérapeutiques additionnelles dans cette pathologie. / Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor, arising from calcitonin-secreting cells. This cancer occurs in a family context in a third of cases. All inherited forms and nearly 40% of sporadic forms are caused by activating point-mutations in the RET oncogene, coding for a tyrosine-kinase receptor. Other oncogenic events causing sporadic cases remain unclear, but activating mutations of RAS oncogenes have been discovered recently.Prognosis of MTC is essentially linked to early lymph node occurrence. Initial surgery of metastatic forms is often insufficient and patients are considered in therapeutic dead-end. The recent advent of selective tyrosine-kinase inhibitors (TKIs) has brought a new impetus to the management of refractory tumors, some of them targeting the RET receptor. Optimization of these treatments require improving knowledge of the underlying molecular mechanisms of tumor development.In this context and helped by a large collection of human specimens, we have sought to deepen the description of genomic landscape of MTC.At first, we evaluated the structural and chromosomal abnormalities presented by MTC. We showed, by optimizing sequencing methods, that RET and RAS mutations are involved in over 96% of the cases, these events are mutually exclusives. These mutations can distinguish several groups of aggressiveness and of response to TKI treatments. We also observed, by comparative genomic hybridization techniques, recurrent abnormalities such as deletion of the short arm of chromosome 1 and loss of entire chromosomes 4 and 22. These losses appear to be early events of tumorigenesis MTC.In a second step, we determined - by a microarray approach – the microRNA expression profile of MTC. Some of these post-transcriptional regulators seem related to tumor invasiveness, such as miR-21, miR-199 and miR-129. We demonstrated the potential of microRNAs miR-21 and miR-199 as circulating diagnosis biomarkers of MTC. The functional impact of the precursor forms mir-21 and mir-129 was then evaluated by transfection in TT and MZ- CRC1 cellular models.Observations obtained pave the way for a lot of new potential studies. They allow the definition of tissue biomarkers distinguishing metastatic forms or refractory patients. Finally, they highlight new pathways for the discovery of additional therapeutic targets in this disease.

Schilddrüsenhormone benötigen als geladene Proteine Transporter um Zellmembranen zu durchqueren. Ein sehr spezifisches Transportprotein ist der Monocarboxylattransporter 8 (Mct8). Mutationen in MCT8 führen beim Menschen zu einer schweren X-gekoppelten mentalen Retardierung, die mit sehr speziellen Veränderungen der Schilddrüsenhormonwerte im Serum einher geht. Zur genaueren Untersuchung der Funktion von Mct8 sowie Mechanismen der Erkrankung wurde ein Knock-out Mausmodell für Mct8 generiert und mit dem menschlichen Phänotyp verglichen. Mct8-defiziente Mäuse replizieren den humanen Phänotyp in Hinsicht auf veränderte Schilddrüsenhormonparameter im Serum. Dennoch weisen diese Mäuse keine morphologischen Veränderungen des Gehirns auf. Ein in dieser Arbeit erstmalig nachgewiesenes ähnlich einer Hyperthyreose verändertes Angstverhalten sowie ein ähnlich einer Hypothyreose verändertes Putzverhalten führte zu der Hypothese, dass es andere Transporter gibt, die den Verlust von Mct8 kompensieren. Ein Kandidat mit einem ähnlichen Expressionsmuster in verschiedenen Geweben und auch in Zelltypen des Gehirns ist der L-Typ Aminosäuretransporter 2 (Lat2). Mct8 ist bei der Maus und beim Menschen während der Entwicklung stark in Neuronen und anderen Zelltypen des Gehirns exprimiert. LAT2 ist jedoch anders als bei der Maus beim Menschen während der Entwicklung in Neuronen nicht nachweisbar. Lat2 könnte also bei der Maus, jedoch nicht beim Menschen den Verlust von Mct8 während der Gehirnentwicklung kompensieren und somit den Unterschied zwischen beiden Phänotypen erklären. Die Untersuchung von Mct8-defizienten Mäusen konnte jedoch auch einen neuen Phänotyp aufdecken: das Fehlen von Mct8 führt bei Mäusen mit zunehmendem Alter zu Hyperplasien der Schilddrüse, die als papilläre Schilddrüsenkarzinome klassifiziert wurden. Bei einem Patienten mit Allan-Herndon-Dudley-Syndrom konnten hierauf ebenfalls hyperplastische Veränderungen der Schilddrüse gefunden werden. / Thyroid hormones are charged molecules and therefore need transporters to cross the cell membrane. One very specific transport protein is the monocarboxylatetransporter 8 (Mct8). Mutations in MCT8 lead to a severe form of X-linked mental retardation in humans in combination with very specific changes in thyroid hormone serum parameters. A mouse model of Mct8-deficiency was generated and compared to the human phenotype to be able to precisely analyze functions of Mct8 and mechanisms of the disease. Mct8-deficient mice do replicate the human phenotype concerning changes of thyroid hormones in serum. However, these mice did not show any morphological changes in the brain. This work could show for the first time changes in anxiety-related behaviour indicative of hyperthyroidism as well as changes in grooming behaviour indicative of hypothyroidism. This led to the hypothesis that other transporters exist that can compensate for the loss of Mct8. One candidate that has a similar expression pattern in different tissues and cell types of the brain is the L-type amino acid transporter 2 (Lat2). Mct8 is highly expressed in neurons and other cell types of mice and humans during development. LAT2 is in contrast to the mouse not detectable in human developing neurons. Therefore, Lat2 could compensate in the mouse but not in the human for the loss of Mct8 during brain development. This could explain the differences between both phenotypes. Nevertheless, the analysis of Mct8-deficient mice could also disclose a new phenotype: the loss of Mct8 leads to thyroid hyperplasia in mice that increases with age and could be classified as papillary thyroid carcinoma. Thereupon, hyperplastic changes of the thyroid could also be detected in a patient with Allan-Herndon-Dudley syndrome.