The role of a new polyclonal competitive thyroglobulin assay in the follow-up of patients with differentiated thyroid cancer with structural disease but low levels of serum thyroglobulin by immunometric and LC-MS/MS methods.

PURPOSE: The aims of this study were to assess the role of an in-house competitive thyroglobulin assay (Tg-c) in the follow-up of metastatic differentiated thyroid carcinoma (DTC) patients who presented underestimated Tg measurements by immunometric assays (Tg-IMA) and to compare the results with IMA and LC-MS/MS Tg methods. METHODS: This prospective study included 40 patients. Twenty-one with metastatic disease: 14 had Tg-IMA levels inappropriately low or undetectable (eight patients with positive and six with borderline TgAb) and seven had high Tg-IMA levels. Nineteen had an excellent response to therapy. The competitive assay employs a polyclonal antibody produced in rabbits immunized with human Tg, Tg labeled with biotin, and for the solid phase separation, a monoclonal anti-rabbit IgG antibody adsorbed to microtiter plates. RESULTS: All 14 patients with structural disease and underestimated levels of Tg-IMA presented detectable Tg-c levels. The median Tg-c level in the group with positive TgAb was 183 µg/L (range: 22-710 µg/L), and 58 µg/L (range 23-148 µg/L) in the borderline TgAb group. The levels of Tg-LC-MS/MS were detectable in some patients (range < 0.5-18 µg/L). All seven patients with high Tg-IMA presented also high levels of Tg-c. Only 2/19 patients with excellent response had Tg-c levels above the functional sensitivity. CONCLUSIONS: The competitive assay was able to detect Tg in all patients, even in the presence of serum TgAb, and may be an option in patients with underestimated Tg-IMA and relevant structural disease.

Bethesda Classification and Cytohistological Correlation of Thyroid Nodules in a Brazilian Thyroid Disease Center.

BACKGROUND: The Bethesda System has been used to classify thyroid cytology in 6 categories besides presenting malignancy rates and respective approaches. Reference centers have validated its use by comparing its proposed malignancy rates with those in in their populations. However, to the best of our knowledge, there has been no corresponding study in Brazil. OBJECTIVES: To evaluate the performance of the Bethesda classification in a Brazilian thyroid reference center and correlate the results with cytohistological reports in patients referred to surgery. METHODS: Data records from 980 fine-needle aspiration (FNA) results were retrospectively analyzed, and, in patients who underwent surgery, the results were correlated with the cytohistological findings. RESULTS: 980 FNAs and 585 patients were evaluated. The incidence of each cytological category was: 11% nondiagnostic (ND), 59.6% benign, 7.1% (atypia of undetermined significance or follicular lesion of undetermined significance (AUS/FLUS), 8.5% follicular neoplasm or suspicious for follicular neoplasm (FN/SFN), 5.1% suspicious for malignancy (SM), and 8.3% malignant. The surgery rate was 41.8% (245/585). The malignancy rate in each category was: 6% benign, 12% AUS/FLUS, 20.8% FN/SFN, 72.5% SM, and 97.3% malignant. For ND nodules, the malignancy rate was 25.7% (66.6% multifocal and papillary microcarcinomas), a higher rate than in the literature. In this category, surgery was performed in multinodular goiters presenting with another nodule > 3.0 cm and/or with an FN/SFN, SM, or malignant cytological result. CONCLUSION: The Bethesda System can be applied to the Brazilian population, since the frequency and malignancy rates of each category were similar to those described by its classification. It is noteworthy that a higher risk of malignancy was observed in the ND cytological category.

Clinical utility of 18F-FDG PET/CT in the follow-up of a large cohort of patients with high-risk differentiated thyroid carcinoma.

OBJECTIVE: To evaluate the clinical utility of 18F-FDG PET/CT in patients with high-risk DTC. SUBJECTS AND METHODS: Single-center retrospective study with 74 patients with high-risk differentiated thyroid cancer (DTC), classified in 4 groups. Group 1: patients with positive sTg or TgAb, subdivided in Group 1A: negative RxWBS and no foci of metastases identified at conventional image (n = 9); Group 1B: RxWBS not compatible with suspicious foci at conventional image or not proportional to sTg level (n = 13); Group 2: patients with histological findings of aggressive DTC variants (n = 21) and Group 3: patients with positive RxWBS (n = 31). RESULTS: 18F-FDG PET/CT identified undifferentiated lesions and helped restage the disease in groups 1B and 2. The scan helped guide clinical judgment in 9/13 (69%) patients of group 1B, 10/21 (48%) patients of group 2 and 2/31 (6%) patients of group 3. There was no clinical benefit associated with group 1A. 18F-FDG PET/CT was associated with progressive disease. CONCLUSION: 18F-FDG PET/CT is a useful tool in the follow-up of patients with high-risk DTC, mainly in the group of RxWBS not compatible with suspicious foci at conventional image or not proportional to sTg level and in those with aggressive DTC variants. Additionally, this study showed that 18F-FDG PET/CT was associated with progression and helped display undifferentiated lesions guiding clinical assessments regarding surgeries or expectant treatments.

Clinical utility of 18F-FDG PET/CT in the follow-up of a large cohort of patients with high-risk differentiated thyroid carcinoma

ABSTRACT Objective To evaluate the clinical utility of 18F-FDG PET/CT in patients with high-risk DTC. Subjects and methods Single-center retrospective study with 74 patients with high-risk differentiated thyroid cancer (DTC), classified in 4 groups. Group 1: patients with positive sTg or TgAb, subdivided in Group 1A: negative RxWBS and no foci of metastases identified at conventional image (n = 9); Group 1B: RxWBS not compatible with suspicious foci at conventional image or not proportional to sTg level (n = 13); Group 2: patients with histological findings of aggressive DTC variants (n = 21) and Group 3: patients with positive RxWBS (n = 31). Results 18F-FDG PET/CT identified undifferentiated lesions and helped restage the disease in groups 1B and 2. The scan helped guide clinical judgment in 9/13 (69%) patients of group 1B, 10/21 (48%) patients of group 2 and 2/31 (6%) patients of group 3. There was no clinical benefit associated with group 1A. 18F-FDG PET/CT was associated with progressive disease. Conclusion 18F-FDG PET/CT is a useful tool in the follow-up of patients with high-risk DTC, mainly in the group of RxWBS not compatible with suspicious foci at conventional image or not proportional to sTg level and in those with aggressive DTC variants. Additionally, this study showed that 18F-FDG PET/CT was associated with progression and helped display undifferentiated lesions guiding clinical assessments regarding surgeries or expectant treatments.

Clinical impact of thyroglobulin (Tg) and Tg autoantibody (TgAb) measurements in needle washouts of neck lymph node biopsies in the management of patients with papillary thyroid carcinoma

ABSTRACT Objectives The presence of thyroglobulin (Tg) in needle washouts of fine needle aspiration biopsy (Tg-FNAB) in neck lymph nodes (LNs) suspected of metastasis has become a cornerstone in the follow-up of patients with papillary thyroid carcinoma (PTC). However, there are limited data regarding the measurement of anti-Tg antibodies in these washouts (TgAb-FNAB), and it is not clear whether these antibodies interfere with the assessment of Tg-FNAB or whether there are other factors that would more consistently justify the finding of low Tg-FNAB in metastatic LNs. Materials and methods We investigated 232 FNAB samples obtained from suspicious neck LNs of 144 PTC patients. These samples were divided according to the patient’s serum TgAb status: sTgAb- (n = 203 samples) and sTgAb+ (n = 29). The TgAb-FNAB levels were measured using two different assays. Tg-FNAB was also measured using two assays when low levels (< 10 ng/mL) were identified in the first assay of the metastatic LNs from the sTgAb+ samples. Results The TgAb-FNAB results were negative in both assays in all samples. Low levels of Tg-FNAB were identified in 11/16 of the metastatic LNs of the sTgAb+ patients and 16/63 of the sTgAb- patients (p < 0.05) using assay 1. The measurement of the Tg-FNAB levels using assay 2 indicated additional metastases in 5 LNs of the sTgAb+ patients. Conclusions Factors other than the presence of TgAb-FNAB may contribute to the higher number of metastatic LNs with undetectable Tg-FNAB in the sTgAb+ group. In addition, the measurement of Tg-FNAB using different assays was useful to enhance the diagnosis of metastatic LNs, particularly when cytological and Tg-FNAB results are discordant.

Clinical impact of thyroglobulin (Tg) and Tg autoantibody (TgAb) measurements in needle washouts of neck lymph node biopsies in the management of patients with papillary thyroid carcinoma.

OBJECTIVES: The presence of thyroglobulin (Tg) in needle washouts of fine needle aspiration biopsy (Tg-FNAB) in neck lymph nodes (LNs) suspected of metastasis has become a cornerstone in the follow-up of patients with papillary thyroid carcinoma (PTC). However, there are limited data regarding the measurement of anti-Tg antibodies in these washouts (TgAb-FNAB), and it is not clear whether these antibodies interfere with the assessment of Tg-FNAB or whether there are other factors that would more consistently justify the finding of low Tg-FNAB in metastatic LNs. MATERIALS AND METHODS: We investigated 232 FNAB samples obtained from suspicious neck LNs of 144 PTC patients. These samples were divided according to the patient's serum TgAb status: sTgAb- (n = 203 samples) and sTgAb+ (n = 29). The TgAb-FNAB levels were measured using two different assays. Tg-FNAB was also measured using two assays when low levels (< 10 ng/mL) were identified in the first assay of the metastatic LNs from the sTgAb+ samples. RESULTS: The TgAb-FNAB results were negative in both assays in all samples. Low levels of Tg-FNAB were identified in 11/16 of the metastatic LNs of the sTgAb+ patients and 16/63 of the sTgAb- patients (p < 0.05) using assay 1. The measurement of the Tg-FNAB levels using assay 2 indicated additional metastases in 5 LNs of the sTgAb+ patients. CONCLUSIONS: Factors other than the presence of TgAb-FNAB may contribute to the higher number of metastatic LNs with undetectable Tg-FNAB in the sTgAb+ group. In addition, the measurement of Tg-FNAB using different assays was useful to enhance the diagnosis of metastatic LNs, particularly when cytological and Tg-FNAB results are discordant.

A Prospective Study Showing an Excellent Response of Patients with Low-Risk Differentiated Thyroid Cancer Who Did Not Undergo Radioiodine Remnant Ablation after Total Thyroidectomy.

OBJECTIVES: To prospectively evaluate the outcome of patients with low-risk papillary thyroid carcinoma treated with total thyroidectomy (TT) who did not undergo radioiodine remnant ablation (RRA). STUDY DESIGN: We prospectively followed up 57 patients; 3 months after TT, thyroglobulin (Tg) assessment and neck ultrasonography (US) were performed while patients were taking l-T4, presenting suppressed TSH. Six months after TT, patients underwent stimulated Tg testing and whole-body scan (WBS) after recombinant TSH (rhTSH). Then, 18 months after TT, the patients were evaluated by neck US and Tg under TSH between 0.5 and 2.0 mIU/ml. Two years after TT, we performed another rhTSH assessment, measuring Tg and making a WBS. The patients were then annually monitored with neck US and Tg measurement under TSH between 0.5 and 2.0 mIU/l for 36-84 months. RESULTS: Neck US of all patients, 3 months after TT, presented no evidence of abnormal residual tissues or metastatic lymph nodes (negative neck US); at this time, the mean Tg level was 0.42 ng/ml. Six months after surgery, after rhTSH, the mean thyroid bed uptake was 1.82%, and Tg levels ranged from 0.10 to 22.30 ng/ml (mean, 2.89 ng/ml). The patients were followed up without any sign of recurrence (negative neck US and stable or decreasing Tg levels). During the ongoing follow-up, the Tg trend was stable or decreasing, independently of the initial suppressed or stimulated Tg level, or WBS uptake. CONCLUSIONS: In patients with low-risk differentiated thyroid cancer, who were operated by TT and who did not undergo RRA, an excellent response to treatment may be confirmed by annual neck US and Tg trend.

Basal serum thyroglobulin measured by a second-generation assay is equivalent to stimulated thyroglobulin in identifying metastases in patients with differentiated thyroid cancer with low or intermediate risk of recurrence.

BACKGROUND: Guidelines for the follow-up of differentiated thyroid cancer (DTC) recommend the measurement of TSH-stimulated thyroglobulin (s-Tg) instead of basal Tg on T4 therapy (b-Tg). However, these guidelines were established using first-generation Tg assays with a functional sensitivity (FS) of 0.5-1.0 ng/ml. Current more sensitive second-generation Tg assays (Tg2G; FS 0.05-0.10 ng/ml) have shown that low-risk DTC patients with undetectable b-Tg rarely have recurrences. OBJECTIVES: This study was undertaken to compare b-Tg using a chemiluminescent Tg2G assay (Tg2GICMA; FS 0.1 ng/ml) with s-Tg in DTC patients with an intermediate risk of recurrence. METHODS: We evaluated 168 DTC patients with a low (n = 101) and intermediate (n = 67) risk of recurrence treated by total thyroidectomy (147 also treated with radioiodine), with a mean follow-up of 5 years. RESULTS: b-Tg was undetectable with the Tg2GICMA in 142 of 168 patients. s-Tg was <2 ng/ml in 138 of these 142 patients, and only 3 of these 138 (2%) presented metastases on cervical ultrasound (US). Of the 4 of 142 patients with s-Tg >2 ng/ml, 1 had cervical metastases seen after radioiodine. Furthermore, 26 of 168 patients presented detectable b-Tg with the Tg2GICMA; 17 of these 26 patients also presented s-Tg >2 ng/ml. In 10 of these 17 patients, metastases were detected. Cervical US or b-Tg were positive in 14 of 15 patients with recurrent disease. Globally, the sensitivity and negative predictive value of the Tg2GICMA plus US were 93 and 99%, respectively. CONCLUSION: b-Tg measured with a Tg2GICMA and cervical US, used together, are equivalent to s-Tg in identifying metastases in patients with DTC with a low or intermediate risk of recurrence.

Development, characterization and clinical validation of new sensitive immunofluorometric assay for the measurement of serum thyroglobulin / Desenvolvimento, caracterização e validação clínica de um novo ensaio sensível para a dosagem da tiroglobulina sérica

OBJECTIVE: In the last decade, data published stressed the role of highly-sensitive thyroglobulin (Tg) assays in the follow-up of differentiated thyroid carcinoma (DTC) patients. The present study describes a new, highly-sensitive Tg assay, compares it with an available commercial assay, and validates it in the follow-up of DTC patients. SUBJECTS AND METHODS: The immunofluorometric high-sensitivity Tg assay is based on monoclonal and polyclonal antibodies produced at our laboratories. It was validated in 100 samples of 87 patients with DTC submitted to total thyroidectomy, 87% of whom also received radioiodine. For correlation, all samples were also tested using a commercial Tg assay (Beckman Access) with functional sensitivity (FS) of 0.1 ng/mL. RESULTS: The new method showed FS of 0.3 ng/mL. The correlation between the two methods was good (r = 0.74; p < 0.0001). The diagnostic sensitivity was 88.9%, and it was increased to 100% when combined with neck US. CONCLUSION: This new, high-sensitivity Tg assay presented a good correlation with Beckman Access assay and with the clinical outcome of the patients. The continuous availability of a validated assay is an additional advantage for long term follow-up of DTC patients. Arq Bras Endocrinol Metab. 2012;56(9):658-65.

OBJETIVO: Na última década, estudos mostraram a importância dos ensaios de tiroglobulina (Tg) com melhor sensibilidade funcional no seguimento dos pacientes com carcinoma diferenciado de tiroide (CDT). Neste estudo, descrevemos o desenvolvimento de um novo ensaio de Tg de alta sensibilidade, que foi validado no seguimento de pacientes com CDT e correlacionado com um ensaio comercialmente disponível. SUJEITOS E MÉTODOS: O ensaio imunofluorométrico de Tg baseia-se em anticorpos, um monoclonal e um policlonal desenvolvidos em nosso laboratório. Avaliamos 100 amostras de soro de 87 pacientes com CDT submetidos à tiroidectomia total, sendo que 87% deles também receberam 131I. A Tg foi dosada também em ensaio comercial (Beckman Access). RESULTADOS: A correlação entre os dois métodos foi de 0,74 (p < 0,0001). O novo ensaio mostrou uma sensibilidade funcional de 0,3 ng/mL. A sensibilidade diagnóstica foi de 88,9%, que aumentou para 100% quando associada ao ultrassom cervical (US). CONCLUSÃO: O novo método de dosagem de Tg mostra boa correlação com o ensaio comercial Beckman Access e com a evolução clínica dos pacientes. O novo ensaio será fundamental no seguimento dos nossos pacientes com CDT. Arq Bras Endocrinol Metab. 2012;56(9):658-65.

One month is sufficient for urinary iodine to return to its baseline value after the use of water-soluble iodinated contrast agents in post-thyroidectomy patients requiring radioiodine therapy.

BACKGROUND: There is a concern regarding the use of iodinated contrast agents (ICA) for chest and neck computed tomography (CT) to localize metastatases in patients with differentiated thyroid cancer (DTC). This is because the iodine in ICA can compete with (131)I and interfere with subsequent whole scans or radioactive iodine treatment. The required period for patients to eliminate the excess iodine is not clear. Therefore, knowing the period for iodine levels to return to baseline after the injection of ICA would permit a more reliable indication of CT for DTC patients. The most widely used marker to assess the plasmatic iodine pool is the urinary iodine (UI) concentration, which can be collected over a period of 24 hours (24U) or as a single-spot urinary sample (sU). As 24U collections are more difficult to perform, sU samples are preferable. It has not been established, however, if the measurement of iodine in sU is accurate for situations of excess iodine. METHODS: We evaluated 25 patients with DTC who received ICA to perform chest or neck CT. They collected 24U and sU urinary samples before the CT scan and 1 week and 1, 2, and 3 months after the test. UI was quantified by a semiautomated colorimetric method. RESULTS: Baseline median UI levels were 21.8 µg/dL for 24U and 26 µg/dL for sU. One week after ICA, UI median levels were very high for all patients, 800 µg/dL. One month after ICA, however, UI median levels returned to baseline in all patients, 19.0 µg/dL for 24U and 20 µg/dL for sU. Although the values of median UI obtained from sU and 24U samples were signicantly different, we observed a significant correlation between samples collected in 24U and sU in all evaluated periods. CONCLUSION: One month is required for UI to return to its baseline value after the use of ICA and for patients (after total thyroidectomy and radioiodine therapy) to eliminate the excess of iodine. In addition, sU samples, although not statistically similar to 24U values, can be used as a good marker to evaluate patients suspected of contamination with iodine.

Development, characterization and clinical validation of new sensitive immunofluorometric assay for the measurement of serum thyroglobulin.

OBJECTIVE: In the last decade, data published stressed the role of highly-sensitive thyroglobulin (Tg) assays in the follow-up of differentiated thyroid carcinoma (DTC) patients. The present study describes a new, highly-sensitive Tg assay, compares it with an available commercial assay, and validates it in the follow-up of DTC patients. SUBJECTS AND METHODS: The immunofluorometric high-sensitivity Tg assay is based on monoclonal and polyclonal antibodies produced at our laboratories. It was validated in 100 samples of 87 patients with DTC submitted to total thyroidectomy, 87% of whom also received radioiodine. For correlation, all samples were also tested using a commercial Tg assay (Beckman Access) with functional sensitivity (FS) of 0.1 ng/mL. RESULTS: The new method showed FS of 0.3 ng/mL. The correlation between the two methods was good (r = 0.74; p < 0.0001). The diagnostic sensitivity was 88.9%, and it was increased to 100% when combined with neck US. CONCLUSION: This new, high-sensitivity Tg assay presented a good correlation with Beckman Access assay and with the clinical outcome of the patients. The continuous availability of a validated assay is an additional advantage for long term follow-up of DTC patients.

[Evaluation of clinical, laboratorial and ultrasonographic predicting factors of malignancy in thyroid nodules]. / Avaliação de fatores clínicos, laboratoriais e ultrassonográficos preditores de malignidade em nódulos tiroidianos.

OBJECTIVE: To evaluate the risk of malignancy in thyroid nodules through clinical, laboratory, ultrasonographic and cytological aspects. PATIENTS AND METHODS: 741 nodules of 407 patients. RESULTS: The cytology was benign (60,5%), indeterminate (23,3%), malignant (8,3%) or nondiagnostic (7,6%). The prevalence of cancer in indeterminate citology was 18,5% (16% in follicular lesions, 44% in suspicious). The diagnosis of malignancy was 17,2% (n = 70). The frequency of cancer in women (15,2%) was lower than in men (27,9%). There was an inverse relation between age and cancer risk. There was no statistical significance in the prevalence of cancer according to number, size of nodules or TSH levels. Hypoechogenicity and microcalcifications on ultrasound were risk factors. CONCLUSION: The risk of malignancy was higher in men, hypoechoic nodules, with microcalcifications and was inversely related to age. The TSH level was not an independent factor predictive of malignancy.

Avaliação de fatores clínicos, laboratoriais e ultrassonográficos preditores de malignidade em nódulos tiroidianos / Evaluation of clinical, laboratorial and ultrasonographic predicting factors of malignancy in thyroid nodules

OBJETIVO: Avaliar risco de malignidade de nódulos tiroidianos por meio de aspectos clínicos, laboratoriais, ultrassonográficos e citológicos. PACIENTES E MÉTODOS: 741 nódulos de 407 pacientes. RESULTADOS: A citologia foi benigna (60,5 por cento), indeterminada (23,3 por cento), maligna (8,6 por cento) ou não diagnóstica (7,6 por cento). A prevalência de câncer nas citologias indeterminadas foi 18,5 por cento (16 por cento nas lesões foliculares, 44 por cento nas suspeitas). O diagnóstico de malignidade foi 17,2 por cento (n = 70). A frequência de câncer em mulheres (15,2 por cento) foi menor do que em homens (27,9 por cento). Houve uma relação inversa entre idade e risco de câncer. Não houve significância estatística na prevalência de câncer de acordo com número, tamanho dos nódulos ou níveis de TSH. Hipoecogenicidade e microcalcificações ao ultrassom foram fatores de risco. CONCLUSÃO: O risco de malignidade foi maior em homens, nódulos hipoecogênicos, com microcalcificações e inversamente relacionado à idade. O nível de TSH não foi um preditor independente de malignidade.

OBJECTIVE: To evaluate the risk of malignancy in thyroid nodules through clinical, laboratory, ultrasonographic and cytological aspects. PATIENTS AND METHODS: 741 nodules of 407 patients. RESULTS: The cytology was benign (60,5 percent), indeterminate (23,3 percent), malignant (8,3 percent) or nondiagnostic (7,6 percent). The prevalence of cancer in indeterminate citology was 18,5 percent (16 percent in follicular lesions, 44 percent in suspicious). The diagnosis of malignancy was 17,2 percent (n = 70). The frequency of cancer in women (15,2 percent) was lower than in men (27,9 percent). There was an inverse relation between age and cancer risk. There was no statistical significance in the prevalence of cancer according to number, size of nodules or TSH levels. Hypoechogenicity and microcalcifications on ultrasound were risk factors. CONCLUSION: The risk of malignancy was higher in men, hypoechoic nodules, with microcalcifications and was inversely related to age. The TSH level was not an independent factor predictive of malignancy.

Development of a sensitive and specific quantitative reverse transcription-polymerase chain reaction assay for blood thyroglobulin messenger ribonucleic acid in the follow-up of patients with differentiated thyroid carcinoma.

CONTEXT: Serum thyroglobulin is a sensitive tumor marker in the follow-up of patients with differentiated thyroid carcinoma (DTC), but the presence of endogenous anti-thyroglobulin antibodies (TgAb) can interfere on its measurement. To prevent interference by TgAb, several investigators have tried to quantify blood mRNA Tg by real-time RT-PCR, but the results have been variable, not reporting a correlation between mRNA Tg and the presence of metastases. OBJECTIVE: The aim of the study was to evaluate the development of a sensitive and specific quantitative RT-PCR assay for blood mRNA Tg in the follow-up of patients with DTC. DESIGN AND PATIENTS: An assay employing primers located in a region not affected by alternative splicing or single nucleotide polymorphisms was developed to study 104 DTC patients (13 of 104 with positive TgAb). RESULTS: The assay is specific for thyroid tissue because we found mRNA Tg expression in normal thyroid tissue, but we did not find any mRNA Tg expression in any extrathyroidal tissues. Quantitative mRNA Tg levels were significantly different between patients "free of disease" (82 of 104) and those with metastases (22 of 104) (2.61 +/- 0.26 vs. 27.58 +/- 1.62 pg mRNA Tg/microg RNA) (P < 0.0001). A cutoff point of 5.51 was able to discriminate between the two groups. In addition, the measurement of mRNA Tg was not affected by the presence of TgAb. CONCLUSION: This new mRNA Tg quantification is a reliable method that allowed us to differentiate patients free of disease from those with metastases, and it could represent an appropriate molecular marker for the follow-up of patients with DTC, especially those with positive TgAb.

Seven-year follow-up of a juvenile female with papillary thyroid carcinoma with poor outcome, BRAF mutation and loss of expression of iodine-metabolizing genes / Sete anos de seguimento de uma paciente jovem com carcinoma papílfero de tireóide e mutação de BRAF e perda de expressão de genes do metabolismo de iodo

BACKGROUND: Recent studies reported that BRAF V600E mutation, the most prevalent genetic event found in papillary thyroid carcinoma, is an independent poor prognostic marker. Additionally, it correlates with a less differentiated tumor stage due to reduced expression of key genes involved in iodine metabolism. We previously described a patient with BRAF V600E mutation in primary tumor and a new mutation (V600E+K601del) in the matched-lymph node metastases. In the present study we report an unusual clinical behavior of PTC and correlate with BRAF mutational status and level of expression of TSHR and NIS. METHODS: Quantitative PCR (qPCR) was used to evaluate the NIS and TSHR level of expression in matched papillary thyroid carcinoma and adjacent normal tissue. RESULTS: In this study, we presented a seven-year follow up of a juvenile papillary thyroid carcinoma patient who had an aggressive tumor harboring BRAF mutation, and failed to conventional therapy. We found a markedly decrease of NIS and TSHR expression in primary PTC compared to adjacent normal thyroid tissue. CONCLUSION: Our findings suggest that BRAF mutational status and decreased NIS and TSHR expression in this patient may reduce radioiodine uptake and lead to a negative response to radioiodine therapy.

INTRODUÇÃO: Estudos recentes demonstraram que a mutação V600E no gene BRAF é o evento genético mais freqüentemente encontrado em carcinoma papilífero da tiróide e um marcador de prognóstico independente. Adicionalmente, esta alteração genética tem sido correlacionada com a redução de expressão de genes envolvidos no metabolismo do iodo. Previamente, nosso grupo descreveu uma paciente com a mutação V600E no gene BRAF no tumor primário e uma mutação nova (V600E+K601del) em metástases pareadas. Neste estudo, reportamos um carcinoma papilífero com um comportamento clínico incomum e correlacionamos com a presença de mutação no gene BRAF e os níveis de expressão de TSHR e NIS. MÉTODO: Análise de expressão dos genes NIS e receptor de TSH (TSHR) através da técnica de PCR em tempo real. RESULTADOS: Descrevemos sete anos de acompanhamento de uma paciente jovem que apresentava um tumor com comportamento agressivo e baixa resposta aos tratamentos convencionais. Uma acentuada diminuição da expressão do TSHR e a ausência de expressão de NIS foram observadas no tumor primário desta paciente quando comparada com o tecido tiroidiano normal adjacente. CONCLUSÃO: Nossos dados sugerem que as mutações encontradas nesta paciente no gene BRAF com conseqüente perda de expressão dos genes NIS e TSHR podem ter reduzido a captação de iodo radioativo e a resposta ao tratamento.

Seven-year follow-up of a juvenile female with papillary thyroid carcinoma with poor outcome, BRAF mutation and loss of expression of iodine-metabolizing genes.

BACKGROUND: Recent studies reported that BRAF V600E mutation, the most prevalent genetic event found in papillary thyroid carcinoma, is an independent poor prognostic marker. Additionally, it correlates with a less differentiated tumor stage due to reduced expression of key genes involved in iodine metabolism. We previously described a patient with BRAF V600E mutation in primary tumor and a new mutation (V600E+K601del) in the matched-lymph node metastases. In the present study we report an unusual clinical behavior of PTC and correlate with BRAF mutational status and level of expression of TSHR and NIS. METHODS: Quantitative PCR (qPCR) was used to evaluate the NIS and TSHR level of expression in matched papillary thyroid carcinoma and adjacent normal tissue. RESULTS: In this study, we presented a seven-year follow up of a juvenile papillary thyroid carcinoma patient who had an aggressive tumor harboring BRAF mutation, and failed to conventional therapy. We found a markedly decrease of NIS and TSHR expression in primary PTC compared to adjacent normal thyroid tissue. CONCLUSION: Our findings suggest that BRAF mutational status and decreased NIS and TSHR expression in this patient may reduce radioiodine uptake and lead to a negative response to radioiodine therapy.

[Diagnosis of metastases in patients with papillary thyroid cancer by the measurement of thyroglobulin in fine needle aspirate]. / Diagnóstico de metástases de carcinoma papilífero de tiróide através da dosagem de tiroglobulina no líquido obtido da lavagem da agulha utilizada na punção aspirativa.

The widespread use of neck ultrasonography (US) during the follow-up of patients with papillary thyroid carcinoma (PTC) has led to the discovery of small cervical lymph nodes (LN). Although US has a high sensitivity for diagnosing LN, fine needle aspiration biopsy (FNA) and measurement of thyroglobulin in fine needle aspirates (FNA-Tg) have proven to be invaluable tools. The aim of this study is to determine the sensitivity of the combined use of neck US, FNA biopsy and FNA-Tg for diagnosis of cervical lymph nodes. We have studied 32 patients with 44 LN detected by US, 19 classified as inflammatory and 25 as suspicious. 15 of those 25 suspicious LN had high FNA-Tg (13 of the 15 had positive cytology and 2 indeterminate). All of these 15 LN (11 patients) were proven to be PTC metastasis by histopathology. All 19 inflammatory LN and those 10/25 suspicious LN, had cytology negative for malignancy and undetectable FNA-Tg. We conclude that fine needle aspiration biopsy and FNA-Tg combined with neck US are essential for detecting positive cervical lymph nodes due to its high sensitivity and specificity and it should be considered the standard for investigating locally recurrent disease in patients with PTC.

Diagnóstico de metástases de carcinoma papilífero de tiróide através da dosagem de tiroglobulina no líquido obtido da lavagem da agulha utilizada na punção aspirativa / Diagnosis of metastases in patients with papillary thyroid cancer by the measurement of thyroglobulin in fine needle aspirate

Com a introdução da ultra-sonografia cervical (USC) no seguimento dos pacientes com carcinoma papilífero de tiróide (CPT), tornou-se freqüente o encontro de pequenos linfonodos (LNs) cervicais. Porém, apesar de a USC apresentar alta sensibilidade, o estudo citológico obtido por punção aspirativa (PAAF) e, nos últimos anos, a dosagem da tiroglobulina (Tg) no lavado da agulha da PAAF (Tg-PAAF) vêm assumindo papel importante no diagnóstico de LNs cervicais. O objetivo deste estudo é verificar a acurácia da combinação da USC, citologia e Tg-PAAF em LNs suspeitos. Estudamos 32 pacientes que apresentavam 44 LNs à USC, classificados como "inflamatórios" (19) ou "suspeitos" (25). Dos 25 LNs suspeitos, 15 apresentavam Tg-PAAF elevada (13 com citologia compatível com metástases e 2 com citologia não-diagnóstica). Esses 15 LNs (11 pacientes) foram confirmados como metástase de CP pelo exame histopatológico. Os 19 LNs "inflamatórios" e os 10/25 LNs "suspeitos" apresentaram citologia negativa e Tg-PAAF indetectável. Concluímos que a USC apresenta alta sensibilidade na detecção de linfonodos cervicais, porém citologia e dosagem de Tg-PAAF são fundamentais para o diagnóstico. A associação USC, citologia e Tg-PAAF pode ser considerada a abordagem mais sensível e específica na detecção de LNs metastáticos em pacientes com CPT.

The widespread use of neck ultrasonography (US) during the follow-up of patients with papillary thyroid carcinoma (PTC) has led to the discovery of small cervical lymph nodes (LN). Although US has a high sensitivity for diagnosing LN, fine needle aspiration biopsy (FNA) and measurement of thyroglobulin in fine needle aspirates (FNA-Tg) have proven to be invaluable tools. The aim of this study is to determine the sensitivity of the combined use of neck US, FNA biopsy and FNA-Tg for diagnosis of cervical lymph nodes. We have studied 32 patients with 44 LN detected by US, 19 classified as inflammatory and 25 as suspicious. 15 of those 25 suspicious LN had high FNA-Tg (13 of the 15 had positive cytology and 2 indeterminate). All of these 15 LN (11 patients) were proven to be PTC metastasis by histopathology. All 19 inflammatory LN and those 10/25 suspicious LN, had cytology negative for malignancy and undetectable FNA-Tg. We conclude that fine needle aspiration biopsy and FNA-Tg combined with neck US are essential for detecting positive cervical lymph nodes due to its high sensitivity and specificity and it should be considered the standard for investigating locally recurrent disease in patients with PTC.

Diagnosis of suspicious thyroid nodules using four protein biomarkers.

PURPOSE: Fine-needle aspiration (FNA) cytology, a standard method for thyroid nodule diagnosis, cannot distinguish between benign follicular thyroid adenoma (FTA) and malignant follicular thyroid carcinoma (FTC). Previously, using expression profiling, we found that a combination of transcript expression levels from DDIT3, ARG2, C1orf24, and ITM1 distinguished between FTA and FTC. The goal of this study was to determine if antibody markers used alone or in combination could accurately distinguish between a wider variety of benign and malignant thyroid lesions in fixed sections and FNA samples. EXPERIMENTAL DESIGN: Immunohistochemistry was done on 27 FTA, 25 FTC, and 75 other benign and malignant thyroid tissue sections using custom antibodies for chromosome 1 open reading frame 24 (C1orf24) and integral membrane protein 1 (ITM1) and commercial antibodies for DNA damage-inducible transcript 3 (DDIT3) and arginase II (ARG2). FNA samples were also tested using the same antibodies. RNA expression was measured by quantitative PCR in 33 thyroid lesions. RESULTS: C1orf24 and ITM1 antibodies had an estimated sensitivity of 1.00 for distinguishing FTA from FTC. For the expanded analysis of all lesions studied, ITM1 had an estimated sensitivity of 1.00 for detecting malignancy. Because all four cancer biomarkers did well, producing overlapping confidence intervals, not one best marker was distinguished. Transcript levels also reliably predicted malignancy, but immunohistochemistry had a higher sensitivity. Malignant cells were easily detected in FNA samples using these markers. CONCLUSIONS: We improved this diagnostic test by adding C1orf24 and ITM1 custom antibodies and showing use on a wider variety of thyroid pathology. We recommend that testing of all four cancer biomarkers now be advanced to larger trials. Use of one or more of these antibodies should improve diagnostic accuracy of suspicious thyroid nodules from both tissue sections and FNA samples.