Avaliação de pacientes com carcinoma diferenciado de tiroide de alto risco: análise de tiroglobulina, no primeiro ano após tratamento inicial, como preditora de resposta
Data
2023-11-23
Autores
Mesquita, Juliana Bezerra 
Orientadores
Biscolla, Rosa Paula Mello
Tipo
Tese de doutorado
Título da Revista
ISSN da Revista
Título de Volume
Resumo
Introdução: O carcinoma diferenciado de tiroide (CDT) é a neoplasia tiroidiana mais frequente e, embora apresente uma alta taxa de cura e sobrevida, o manejo dos pacientes com alto risco de recorrência representa um desafio clínico significativo. Os pacientes de CDT de alto risco, são identificados com base em características histopatológicas e níveis elevados de tiroglobulina (Tg). A dosagem de Tg sérica é utilizada como marcador tumoral e seus níveis estão diretamente relacionados à resposta ao tratamento. O objetivo principal desta tese é avaliar os níveis de Tg em pacientes de CDT de alto risco de recorrência, durante o primeiro ano após o diagnóstico e correlacioná-los ao desfecho.
Métodos: Foi realizada análise retrospectiva de 56 pacientes com CDT de alto risco submetidos à tiroidectomia total (TT), dissecção de linfonodos cervicais (quando necessário) e tratamento com iodo radioativo (131I), acompanhados no ambulatório de Endocrinologia da Liga Norte Riograndense Contra o Câncer (LIGA) e no Centro de Doenças da Tiroide, da disciplina de Endocrinologia da Escola Paulista de Medicina, Universidade Federal de São Paulo (Unifesp). Os pacientes foram categorizados como de alto risco com base em características histopatológicas e/ou níveis elevados de Tg (>10 ng/mL). Foram avaliadas as dosagens de Tg em diferentes momentos durante o seguimento: Tg pré-ablação, dosagem de tiroglobulina estimulada colhida em hipotiroidismo, antes da administração da primeira dose de 131I; TgLT4, dosagem de Tg em supressão do TSH 6 meses após o tratamento inicial; Tgs1, dosagem de tiroglobulina estimulada em hipotiroidismo após um ano do tratamento inicial. Análises de regressão logística e curvas ROC foram realizadas para avaliar a relação entre os níveis de Tg e a resposta ao tratamento.
Resultados: O primeiro trabalho mostrou que 36/56 pacientes (64,3%) tiveram resposta incompleta, enquanto 20 (35,7%) tiveram resposta aceitável (p=0,03). A análise univariada revelou uma associação significativa entre a classificação de alto risco com base na dosagem da Tg e a resposta ao tratamento. As dosagens de TgLT4 e Tgs1 apresentaram correlações significativas com resposta incompleta. Valores de corte acima de 1,44 ng/mL e 2,25 ng/mL para TgLT4 e 61,15 ng/mL para Tgs1 foram estabelecidos como indicadores de resposta incompleta. Os pacientes categorizados como de alto risco com base na histopatologia tiveram menos probabilidade de alcançar uma resposta aceitável quando comparados àqueles categorizados somente pela dosagem elevada de Tg. Em relação ao segundo trabalho, realizado na mesma população, 41/56 pacientes receberam uma nova dose de 131I, após um ano do tratamento inicial, dos quais 20 alcançaram resposta aceitável e 21, resposta incompleta. Os valores de Tgs1 foram significativamente diferentes entre esses grupos. Foi identificado um valor de corte de Tg de 28,65 ng/mL, com 62% de sensibilidade e 81% de especificidade na previsão de uma resposta aceitável em pacientes que receberam uma nova dose de 131I. Para pacientes que não receberam uma nova dose de 131I, um valor de Tgs1 acima de 11,25 ng/mL indicou maior risco de resposta incompleta, porém sem significância estatística.
Conclusão: Concluímos que a dosagem de Tg realizada no primeiro ano de seguimento após tratamento inicial é fundamental na avaliação e predição de resposta ao tratamento de pacientes com carcinoma diferenciado de tiroide de alto risco de recorrência. Ainda nesta tese, apresentamos um relato de caso de Struma Ovarii maligno associado a hipertiroidismo.
Introduction: Differentiated thyroid carcinoma (DTC) is the most common thyroid malignancy. Despite its high cure rate and favorable survival outcomes, managing patients with high-risk for recorrence DTC remains a significant clinical challenge. High-risk patients are typically identified based on histopathological features and elevated serum thyroglobulin (Tg) levels. Serum Tg serves as a reliable tumor marker and is closely associated with treatment response. This study aims to evaluate serum Tg levels in high-risk DTC patients during the first year following diagnosis and assess their correlation with treatment outcomes. Methods: A retrospective analysis was performed on 56 high-risk differentiated thyroid carcinoma (DTC) patients. All patients underwent total thyroidectomy (TT), cervical lymph node dissection when indicated, and radioactive iodine therapy (131I). Follow-up was conducted at the Endocrinology outpatient clinic of the Liga Norte Riograndense Contra o Câncer (LIGA) and the Thyroid Disease Center within the Endocrinology Department of Escola Paulista de Medicina, Universidade Federal de São Paulo (Unifesp). Patients were classified as high-risk based on histopathological features and/or serum thyroglobulin (Tg) levels exceeding 10 ng/mL.Tg levels were assessed at different time points during follow-up: Pre-ablation Tg, hypothyroid-stimulated thyroglobulin collected before the first 131I dose; TgLT4, Tg measurement under TSH suppression, taken six months after initial treatment; Tgs1, stimulated thyroglobulin collected one year after initial treatment. Logistic regression analyses and ROC curves were conducted to evaluate the correlation between Tg levels and treatment response. Results: The first study showed that 36/56 patients (64.3%) had an incomplete response, while 20 (35.7%) achieved an acceptable response (p=0.03). Univariate analysis revealed a significant association between high-risk classification, based on high Tg measurements, and treatment response. TgLT4 and Tgs1 measurements had significant correlations with an incomplete response. Cutoff values above 1.44 ng/mL and 2.25 ng/mL for TgLT4 and 61.15 ng/mL for Tgs1 were established as indicators of an incomplete response. Patients categorized as high-risk based on histopathological findings were more likely to achieve an incomplete response. In the second study, conducted within the same population, 41 out of 56 patients received a new dose of 131I one year after the initial treatment. Of these, 20 patients achieved an acceptable response, while 21 had an incomplete response. Tgs1 levels were significantly different between these groups. A Tg cutoff of 28.65 ng/mL was identified, with 62% sensitivity and 81% specificity, as a predictor of an acceptable response in patients who received a new dose of 131I. For patients who did not receive a new dose of 131I, a Tgs1 value above 11.25 ng/mL indicated a higher risk of an incomplete response, although this finding was not statistically significant. Conclusion: Tg measurements during the first year of follow-up after initial treatment are crucial for evaluating and predicting the treatment response of high-risk differentiated thyroid carcinoma patients. Additionally, this thesis presents a case report of malignant Struma Ovarii associated with hyperthyroidism.
Introduction: Differentiated thyroid carcinoma (DTC) is the most common thyroid malignancy. Despite its high cure rate and favorable survival outcomes, managing patients with high-risk for recorrence DTC remains a significant clinical challenge. High-risk patients are typically identified based on histopathological features and elevated serum thyroglobulin (Tg) levels. Serum Tg serves as a reliable tumor marker and is closely associated with treatment response. This study aims to evaluate serum Tg levels in high-risk DTC patients during the first year following diagnosis and assess their correlation with treatment outcomes. Methods: A retrospective analysis was performed on 56 high-risk differentiated thyroid carcinoma (DTC) patients. All patients underwent total thyroidectomy (TT), cervical lymph node dissection when indicated, and radioactive iodine therapy (131I). Follow-up was conducted at the Endocrinology outpatient clinic of the Liga Norte Riograndense Contra o Câncer (LIGA) and the Thyroid Disease Center within the Endocrinology Department of Escola Paulista de Medicina, Universidade Federal de São Paulo (Unifesp). Patients were classified as high-risk based on histopathological features and/or serum thyroglobulin (Tg) levels exceeding 10 ng/mL.Tg levels were assessed at different time points during follow-up: Pre-ablation Tg, hypothyroid-stimulated thyroglobulin collected before the first 131I dose; TgLT4, Tg measurement under TSH suppression, taken six months after initial treatment; Tgs1, stimulated thyroglobulin collected one year after initial treatment. Logistic regression analyses and ROC curves were conducted to evaluate the correlation between Tg levels and treatment response. Results: The first study showed that 36/56 patients (64.3%) had an incomplete response, while 20 (35.7%) achieved an acceptable response (p=0.03). Univariate analysis revealed a significant association between high-risk classification, based on high Tg measurements, and treatment response. TgLT4 and Tgs1 measurements had significant correlations with an incomplete response. Cutoff values above 1.44 ng/mL and 2.25 ng/mL for TgLT4 and 61.15 ng/mL for Tgs1 were established as indicators of an incomplete response. Patients categorized as high-risk based on histopathological findings were more likely to achieve an incomplete response. In the second study, conducted within the same population, 41 out of 56 patients received a new dose of 131I one year after the initial treatment. Of these, 20 patients achieved an acceptable response, while 21 had an incomplete response. Tgs1 levels were significantly different between these groups. A Tg cutoff of 28.65 ng/mL was identified, with 62% sensitivity and 81% specificity, as a predictor of an acceptable response in patients who received a new dose of 131I. For patients who did not receive a new dose of 131I, a Tgs1 value above 11.25 ng/mL indicated a higher risk of an incomplete response, although this finding was not statistically significant. Conclusion: Tg measurements during the first year of follow-up after initial treatment are crucial for evaluating and predicting the treatment response of high-risk differentiated thyroid carcinoma patients. Additionally, this thesis presents a case report of malignant Struma Ovarii associated with hyperthyroidism.
Descrição
Citação
MESQUITA, Juliana Bezerra. Avaliação de pacientes com carcinoma diferenciado de tiroide de alto risco: análise de tiroglobulina, no primeiro ano após tratamento inicial, como preditora de resposta. 2023. 93 f. Tese (Doutorado em Endocrinologia e Metabologia) - Escola Paulista de Medicina, Universidade Federal de São Paulo (UNIFESP), São Paulo, 2023.