Thyroglobulin levels before radioactive iodine therapy and dynamic risk stratification after 1 year in patients with differentiated thyroid cancer

ABSTRACT Objectives: We sought to assess the relationship between stimulated thyroglobulin (sTg) before radioactive iodine therapy (RIT), and the dynamic risk stratification 1 year after treatment, and to establish the utility of the sTg as a predictor of response to therapy in these patients. A retrospective chart review of patients with differentiated thyroid cancer (DTC) who underwent RIT after surgery and were followed for at least 1 year, was carried out. Subjects and methods: Patients were classified according to the dynamic risk stratification 1 year after initial treatment. The sTg values before RIT were compared among the groups. ROC curve analysis was performed. Results: Fifty-six patients were enrolled (mean age 44.7 ± 14.4 years, 80.7% had papillary carcinoma). Patients with excellent response had sTg = 2.1 ± 3.3 ng/mL, those with indeterminate response had sTg = 8.2 ± 9.2 ng/mL and those with incomplete response had sTg = 22.4 ± 28.3 ng/mL before RIT (p = 0.01). There was a difference in sTg between excellent and incomplete response groups (p = 0.009) while no difference was found between indeterminate and either excellent or incomplete groups. The ROC curve showed an area under the curve of 0.779 assuming a sTg value of 3.75 ng/mL. Conclusion: Our study results suggest that the higher the sTg before RIT, the greater the likelihood of an incomplete response to initial treatment. A sTg cut-off of 3.75 ng/mL was found to be a good predictor of response to initial treatment in patients with DTC.

Nódulos de tireóide e câncer diferenciado de tireóide: consenso brasileiro / Thyroid nodules and differentiated thyroid cancer: brazilian consensus

Os nódulos tireoidianos constituem a principal manifestação clínica de uma série de doenças da tireóide com uma prevalência de aproximadamente 10 por cento na população adulta. O maior desafio é excluir o câncer da tireóide, que ocorre em 5 a 10 por cento dos casos. Os carcinomas diferenciados respondem por 90 por cento dos casos de todas as neoplasias malignas da tireóide. A maioria dos pacientes com carcinoma diferenciado apresenta, geralmente, um bom prognóstico quando tratada adequadamente, com índices de mortalidade similares à população geral. No entanto, alguns indivíduos apresentam doença agressiva, desafiando o conhecimento atual e ilustrando a complexidade do manejo dessa neoplasia. No presente trabalho, reunimos 8 membros do Departamento de Tireóide da Sociedade Brasileira de Endocrinologia & Metabologia, para elaborarmos, por consenso, as diretrizes brasileiras no manejo dos nódulos tireoidianos e do câncer diferenciado da tireóide. Os membros participantes representam diferentes Centros Universitários do Brasil, refletindo diferentes abordagens diagnósticas e terapêuticas. Inicialmente, cada participante ficou responsável pela redação de determinado tema a ser enviado ao Coordenador, que, após revisão editorial e elaboração da primeira versão do manuscrito, enviou ao grupo para sugestões e aperfeiçoamentos. Quando concluído, o manuscrito foi novamente enviado e revisado por todos. A elaboração dessas diretrizes foi baseada na experiência dos participantes e revisão pertinente da literatura.

Thyroid nodules are a common manifestation of thyroid diseases. It is estimated that ~10 percent of adults have palpable thyroid nodules with the frequency increasing throughout life. The major concern on nodule evaluation is the risk of malignancy (5-10 percent). Differentiated thyroid carcinoma accounts for 90 percent of all thyroid malignant neoplasias. Although most patients with cancer have a favorable outcome, some individuals present an aggressive form of the disease and poor prognostic despite recent advances in diagnosis and treatment. Here, a set of clinical guidelines for the evaluation and management of patients with thyroid nodules or differentiated thyroid cancer was developed through consensus by 8 member of the Department of Thyroid, Sociedade Brasileira de Endocrinologia e Metabologia. The participants are from different reference medical centers within Brazil, to reflect different practice patterns. Each committee participant was initially assigned to write a section of the document and to submit it to the chairperson, who revised and assembled the sections into a complete draft document, which was then circulated among all committee members for further revision. All committee members further revised and refined the document. The guidelines were developed based on the expert opinion of the committee participants, as well as on previously published information.

The role of estimation of the ratio of preoperative serum thyroglobulin to the thyroid mass in predicting the behaviour of well differentiated thyroid cancers.

Although serum thyroglobulin (STg) is a useful tumour marker to detect the recurrence of tumour in well differentiated thyroid carcinoma, it has as yet not been reported to be of value in predicting the behaviour of thyroid cancer. In the present study of 20 patients, the measurement of preoperative Stg/thyroid mass has been utilised to find out Tg synthesizing capacity of the tumour. This ratio was significantly higher in the patients with follicular variety than in papillary thyroid carcinoma. It was significantly higher in the metastasis group than in the group of patients without metastasis. The patients with functioning metastasis had a higher than average value of this 'ratio' than those with non functioning metastasis, though the difference was not statistically significant. Despite the limitation of a small number of patients included in this study, it is possible to highlight the possible utility of preoperative Stg estimation as a tumour marker in categorization of the patients of carcinoma of the thyroid gland.