Papel da arquitetura nuclear no manejo do carcinoma de tiroide / Role of nuclear architecture in the management of thyroid carcinoma

One of the biggest dilemmas facing a cytopathology slide is the differential diagnosis of follicular thyroid lesions, grouped as follicular pattern lesions, which include goiter, follicular adenoma and follicular carcinoma, follicular variant of papillary thyroid carcinoma and non-invasive follicular thyroid neoplasm with papillary like nuclear features. Such lesions share many characteristics, which makes the proper identification of malignant follicular lesions a challenge. The cytology obtained through fine needle aspiration puncture is the most effective standard method for diagnosis of thyroid nodules, but its diagnostic efficacy clearly decreases in lesions of thyroid follicular pattern. Thus, a series of auxiliary tools for diagnoses, such as morphometry and nuclear texture analysis, have been increasingly used in the pathologist's practice, as an objective and reproducible tool. These are techniques, which depend on the incorporation of software to digital image analysis and can add accuracy to classical morphological analysis and immunohistochemistry in the evaluation of follicular pattern lesions. In addition to immunocytochemistry and molecular techniques, morphometry allows the estimation of parameters identified in individual cells and represents a tool that, based on quantitative parameters, translates reliable parameters for objective classification of the malignancy. This study aims to review the nuclear characteristics and their role in the diagnosis of follicular thyroid lesions.

Um dos maiores dilemas diante de uma lâmina de citopatologia é o diagnóstico diferencial de lesões foliculares da tiroide agrupadas como lesões de padrão folicular e que incluem; bócio, adenoma e carcinoma foliculares, carcinoma papilífero variante folicular e a neoplasia folicular não invasiva com características nucleares papilares (Uno de los mayores dilemas que presenta una muestra de citopatología es el diagnóstico diferencial de las lesiones foliculares tiroideas reunidas como lesiones de patrón folicular, que incluyen: bocio, adenoma folicular, carcinoma folicular, variante folicular del carcinoma papilar y la neoplasia folicular no invasiva con características nucleares de tipo papilar). Tais lesões compartilham muitas características, o que faz com que a identificação adequada de lesões foliculares malignas represente um desafio. A citologia obtida através de punção aspirativa por agulha fina é o método padrão mais efetivo para diagnóstico em nódulos de tiroide, mas sua eficácia diagnóstica diminui nitidamente em lesões de padrão folicular da tiroide (La citología por punción y aspiración con aguja fina es el método estándar más eficaz para el diagnóstico de los nódulos tiroideos, pero su eficacia diagnóstica se ve notablemente reducida en las lesiones de patrón folicular de la tiroides). Assim, uma série de ferramentas auxiliares ao diagnóstico, como a morfometria e a análise de textura nuclear, têm sido utilizadas cada vez mais na prática do patologista, como ferramenta objetiva e reproduzível. São técnicas que dependem da incorporação de softwares para análise digital de imagens e podem agregar acurácia à análise morfológica clássica e à imunohistoquímica na avaliação de lesões de padrão folicular (para el análisis de imágenes digitales y puede agregar precisión al análisis morfológico clásico y la inmunohistoquímica en la evaluación de lesiones de patrón folicular). Somando-se à imunocitoquímica e às técnicas moleculares, a morfometria permite a estimativa de parâmetros identificados em células individuais e representam uma ferramenta que, a partir de parâmetros quantitativos, traduz parâmetros confiáveis para classificação objetiva de malignidade. O objetivo deste estudo é rever as características nucleares e seu papel no diagnóstico de lesões foliculares da tiroide (es revisar las características nucleares y su papel en el diagnóstico de las lesiones foliculares tiroideas).

The immune landscape of the microenvironment of thyroid cancer is closely related to differentiation status.

We have read with great interest the article entitled "Identification of an immune-related signature indicating the dedifferentiation of thyroid cells" by Wang et al. Their data reinforce our own previous results, here compiled. Anaplastic thyroid carcinoma had higher stromal scores, immune scores and enrichment of most immune cells than the control groups, suggesting that the immune microenvironment may correlate with differentiation status in thyroid cancer. We previously demonstrated that the differentiation status expressed by the pattern of protein expression may be related to the profile of immune cell infiltration of differentiated thyroid carcinoma. Wang et al. also explored the differences between the high-risk and low-risk score groups of samples. Among the distinct signaling pathways enriched in the high-risk score group, the epithelial to mesenchymal transition, TNFα signaling, and some common immune-related signaling pathways, including the IL-6/JAK/STAT3 pathway, interferon alpha response, interferon gamma response and inflammatory response were observed with high normalized enrichment score. We also investigated the IL-6 protein immune-histochemical expression in a retrospective study of 114 patients with papillary thyroid carcinoma and 39 patients with follicular thyroid carcinoma. We also obtained samples of 14 normal thyroid tissues from autopsies, 50 goiters and 43 follicular adenoma. We found IL-6 more frequently positive among malignant tumors than non-malignant samples. We demonstrated that IL-6 positivity was associated with infiltration of CD3 + cells, CD16 + cells and CD68 + macrophages. In addition, IL-6 expression was associated with infiltration of activated lymphocytes such as Granzyme B + cells and CD69 + cells. IL-6 positivity was not associated with infiltration of CD4+, CD8+, CD20+, FOXP3+, CD25 + cells but IL-6 was associated with tumor expression of PD-L1, FOXP3, IL-17, COX2, IL-1ß, IL-10, CD134, IL-23. In summary, Wang et al. beautiful data reinforce the seminal idea that the immune landscape is closely related to the differentiation status of the tumor. This concept may help select individuals who deserve more careful attention, an essential point in the management of patients with mostly indolent tumors such as those of the thyroid. In fact, our results, here compiled, were obtained with immune-histochemistry, a routine laboratory technique that offers the possibility of simpler and practical execution.

Clinical utility of the imunohistochemical co-expression of p53 and MDM2 in thyroid follicular lesions.

In order to investigate the possible correlation between p53 and MDM2 co-expression with clinicopathological features of differentiated thyroid cancer (DTC) and its use as diagnostic and/or prognostic markers, we used immunohistochemistry to evaluate 317 thyroid samples including 208 DTC and 94 benign nodules, in addition to 15 normal tissues. MDM2 and p53 expression were highly associated (r = 0.7161; p < 0.0001). The co-expression of p53-MDM2 was observed more frequently in malignant lesions (p < 0.0001) and helped characterize follicular patterned lesions distinguishing FVPTC from FA (p < 0.0001) and FVPTC from FTC (p < 0.0001). In addition, p53-MDM2 co-expression was associated with characteristics of less aggressiveness. It was more frequent in patients ≤45 years old (p = 0.0035), with unique tumors (p = 0.0095), tumors <2 cm (p < 0.0001), tumors without extrathyroid invasion (p = 0.0425), without metastasis at evolution (p = 0.0179), and in patients evolving free of disease after treatment (p = 0.0485). We suggest that p53-MDM2 co-expression profile analysis might help establishing diagnostic and determining prognostic of DTC patients.

RORγt may Influence the Microenvironment of Thyroid Cancer Predicting Favorable Prognosis.

We aimed to investigate the role of RORγt (Retinoic acid-related orphan receptor gamma) in the tumor microenvironment of differentiated thyroid carcinoma. We retrospectively analyzed 56 patients (48 papillary and 8 follicular thyroid carcinomas). Immunohistochemical expression of RORγt was compared to other immune markers previously investigated by our group, clinical and pathological information. All patients presented cytoplasmic expression of RORγt in thyroid tumor cells. Seven (12.5%) patients presented no nuclear expression of RORγt. Positivity was few (up to 10%) in 14 patients; 10 to 50% in 5 patients (8.9%); and more than 50% in 30 patients (53.6%). Nuclear RORγt positivity was associated with absence of distant metastasis at diagnosis (p = 0.013) and the need of less cumulative doses of radioactive iodine (p = 0.039). Patients whose tumors were positive for nuclear RORγt presented higher 10-years relapse-free survival rate than those patients who were negative for RORγt (p = 0.023). We classified the patients according to the clustering of immunological immunohistochemical markers. We were able to distinguish a subset (A) of 38 patients who presented high expression of nuclear RORγt and tended to be scarce in proinflammatory immune markers. Other 16 patients integrated a second subset (B) whose tumor microenvironment accumulated proinflammatory markers and presented low expression of nuclear nuclear RORγt. Distant metastasis at diagnosis were more frequent among patients from cluster B than from cluster A (p = 0.008). Our results reinforce that the expression of RORγt together with other immune markers might help predict the prognosis of patients with thyroid cancer and help individualize clinical management.

Interleukin 10 expression is related to aggressiveness and poor prognosis of patients with thyroid cancer.

Most patients with thyroid cancer will evolve very well with current therapies. However, 10-30% of these patients will present recurrent disease and some of them will eventually die. IL-10 is an anti-inflammatory and immunosuppressive cytokine that can contribute to the immune escape of neoplastic cells. We aimed to investigate IL-10 as a molecular marker to improve the clinical management of patients with thyroid cancer. We retrospectively studied 162 patients with follicular cell-derived thyroid cancer who attended to our institution, including 63 classic papillary thyroid carcinomas, 46 follicular variant of papillary thyroid carcinomas, 11 poorly differentiated thyroid carcinomas and 42 follicular thyroid carcinomas. Patients were treated according to current guidelines and followed-up for 1-150 months. Additionally, we studied 96 samples of non-malignant tissues. We investigated the expression of IL-10 in tumor cells by semiquantitative and quantitative methods. Malignant tissues presented higher positivity (0.773 ± 0.140) than non-malignant samples (0.623 ± 0.190; p < 0.001). Tumors with extrathyroidal invasion at diagnosis presented higher levels of positivity for IL-10 (0.802 ± 0.125) than tumors without extrathyroidal invasion (0.731 ± 0.147; p = 0.004). We observed a positive correlation between tumor size and IL-10 positivity (correlation coefficient = 0.407; p < 0.001). Patients with IL-10 positivity above the median presented lower relapse-free survival rate compared to those patients whose tumors presented IL-10 positivity below the median. We suggest that a simple IL-10 IHC analysis could help selecting patients who would benefit from a more intensive approach.

CD8+ tumour-infiltrating lymphocytes and COX2 expression may predict relapse in differentiated thyroid cancer.

BACKGROUND/OBJECTIVE: There is an increasing rate of papillary thyroid carcinomas that may never progress to cause symptoms or death. Predicting outcome and determining tumour aggressiveness could help diminish the number of patients submitted to aggressive treatments. We aimed to evaluate whether markers of the immune system response and of tumour-associated inflammation could predict outcome of differentiated thyroid cancer (DTC) patients. DESIGN: Retrospective cohort study. PATIENTS: We studied 399 consecutive patients, including 325 papillary and 74 follicular thyroid carcinomas. MEASUREMENTS: Immune cell markers were evaluated using immunohistochemistry, including tumour-associated macrophages (CD68) and subsets of tumour-infiltrating lymphocytes (TIL), such as CD3, CD4, CD8, CD16, CD20, CD45RO, GRANZYME B, CD69 and CD25. We also investigated the expression of cyclooxygenase 2 (COX2) in tumour cells and the presence of concurrent lymphocytic infiltration characterizing chronic thyroiditis. RESULTS: Concurrent lymphocytic infiltration characterizing chronic thyroiditis was observed in 29% of the cases. Among all the immunological parameters evaluated, only the enrichment of CD8+ lymphocytes (P = 0·001) and expression of COX2 (P =0·01) were associated with recurrence. A multivariate model analysis identified CD8+ TIL/COX2 as independent risk factor for recurrence. A multivariate analysis using Cox's proportional-hazards model adjusted for the presence of concurrent chronic thyroiditis demonstrated that the presence of concurrent chronic thyroiditis had no effect on prognostic prediction mediated by CD8+ TIL and COX2. CONCLUSION: In conclusion, we suggest the use of a relatively simple pathology tool to help select cases that may benefit of a more aggressive approach sparing the majority of patients from unnecessary procedures.

CD8+ TIL recruitment may revert the association of MAGE A3 with aggressive features in thyroid tumors.

BACKGROUND: We aimed to investigate a possible role of MAGE A3 and its associations with infiltrated immune cells in thyroid malignancy, analyzing their utility as a diagnostic and prognostic marker. MATERIALS AND METHODS: We studied 195 malignant tissues: 154 PTCs and 41 FTCs; 102 benign tissues: 51 follicular adenomas and 51 goiter and 17 normal thyroid tissues. MAGE A3 and immune cell markers (CD4 and CD8) were evaluated using immunohistochemistry and compared with clinical pathological features. RESULTS: The semiquantitative analysis and ACIS III analysis showed similar results. MAGE A3 was expressed in more malignant than in benign lesions (P < 0.0001), also helping to discriminate follicular-patterned lesions. It was also higher in tumors in which there was extrathyroidal invasion (P = 0.0206) and in patients with stage II disease (P = 0.0107). MAGE A3+ tumors were more likely to present CD8+ TIL (P = 0.0346), and these tumors were associated with less aggressive features, that is, extrathyroidal invasion and small size. There was a trend of MAGE A3+ CD8+ tumors to evolve free of disease. CONCLUSION: We demonstrated that MAGE A3 and CD8+ TIL infiltration may play an important role in malignant thyroid nodules, presenting an interesting perspective for new researches on DTC immunotherapy.

P53 and expression of immunological markers may identify early stage thyroid tumors.

BACKGROUND: Besides its major role in cell proliferation, DNA repair, and apoptosis, functional p53 protein is involved in the induction of antitumor cytotoxic-T-cell activity against carcinoma cells. We aimed to investigate p53 and immune cell markers utility as diagnostic and prognostic markers of differentiated thyroid cancer (DTC). METHODS: ACIS-III system was used to evaluate p53 and immune cell markers including tumor-associated macrophages (TAM); CD68 and tumor-infiltrating lymphocytes (TIL) subsets such as CD3, CD4, CD8, and CD20 in 206 thyroid carcinomas, 105 benign nodules, and 18 normal tissues. Also, TP53 was sequenced in 78 out of 164 patients with papillary thyroid carcinoma. RESULTS: P53 expression was observed more frequently in malignant than in benign lesions (P < 0.0001) and helped discriminate follicular patterned lesions. In addition, p53 was more frequent in smaller (P = 0.0015), unique tumors (P = 0.0286), with thyroiditis (P = 0.0486) and without metastasis at diagnosis (P = 0.0201). TAM was more frequent in P53 negative tumors (P = 0.002). Infiltration of CD8+ TIL was found in 61.7% of P53 positive and 25.6% of P53 negative DTC (P < 0.001). CONCLUSIONS: We suggest that p53 and CD8+ TIL immune profile analysis might be useful in DTC.

Clinical utility of KAP-1 expression in thyroid lesions.

Although there are evidences of the involvement of KAP-1 in other tumors, data on differentiated thyroid carcinomas (DTC) are still lacking. We aimed to evaluate KAP-1 clinical utility in the diagnosis and prognosis of DTC. We used both visual immunohistochemistry and a semiquantitative analysis to evaluate KAP-1 expression in 230 thyroid carcinomas and 131 noncancerous thyroid nodules. There were 43 follicular carcinomas (FC) and 187 papillary thyroid carcinomas (PTC), including 130 classic (CPTC), 4 tall cells (TCPTC), and 53 follicular variants (FVPTC). Patients were followed up for 53.8 ± 41 months. They were classified as free-of-disease (142 cases) or poor outcome (25 cases--10 deaths), according to their serum Tg levels and image evidences. KAP-1 was identified in 78 % PTC, 75 % TCPTC, 74 % FC, 72 % FVPTC, 55 % FA, 44 % hyperplasia, and 11 % normal thyroid tissues. A ROC analysis identified malignant nodules with 69 % sensitivity and 75 % specificity, using a cutoff of 73.19. In addition to distinguishing benign from malignant thyroid tissues (p < 0.0001), KAP-1 expression differentiated CPTC from nodular hyperplasia (p < 0.0001), CPTC from FA (p = 0.0028), FVPTC from hyperplasia (p = 0.0039), and FC from hyperplasia (p = 0.0025). Furthermore, KAP-1 was more expressed in larger tumors (>4 cm; p = 0.0038) and in individuals who presented recurrences/metastases (p = 0.0130). We suggest that KAP-1 may help diagnose thyroid nodules, characterize follicular-patterned thyroid lesions, and identify individuals with poor prognosis.

An antibody-like peptide that recognizes malignancy among thyroid nodules.

There is an urgent need for biomarkers to identify malignant thyroid nodules from indeterminate follicular lesions. We have used a subtractive proteomic strategy to identify novel biomarkers by selecting ligands to goiter tissue from a 12-mer random peptide phage-displayed library using the BRASIL method (Biopanning and Rapid Analysis of Selective Interactive Ligands). After three rounds of selection, two highly reactive clones to the papillary thyroid tumor cell line NPA were further evaluated, and their specific binding to tumor proteins was confirmed using phage-ELISA. The antibody-like peptide CaT12 was tumor-specific, which was further tested by immunohistochemistry against TMAs (tissue microarrays) comprised of 775 human benign and malignant tissues, including 232 thyroid nodular lesions: 15 normal thyroid tissues, 53 nodular goiters (NG), 54 follicular adenomas (FA); 69 papillary thyroid carcinomas (PTC); and 41 follicular carcinomas (FC). CaT12 was able to identify PTC among thyroid nodular lesions with 91.2% sensitivity and 85.1% specificity, despite its non-specificity for thyroid tissues. Additionally, the CaT12 peptide helped characterize follicular lesions distinguishing the follicular variant of PTC (FVPTC) from FA with 91.9% accuracy; FVPTC from NG with 83.1% accuracy; FVPTC from the classic PTC with 57.7% accuracy; and FVPTC from FC with 88.7% accuracy. In conclusion, our strategy to select differentially expressed ligands to thyroid tissue was highly effective and resulted in a useful antibody-like biomarker that recognizes malignancy among thyroid nodules and may help distinguish follicular patterned lesions.

Differentiated thyroid carcinomas may elude the immune system by B7H1 upregulation.

B7H1 is consistently associated with inhibition of the immune system in many solid tumors. However, there is no report about its impact on differentiated thyroid carcinoma (DTC) presentation, aggressiveness, or evolution. Aiming to investigate the role of B7H1 in DTC and correlate this protein with other tumor-infiltrating immune cells, we studied 407 thyroid nodule tissue samples including 293 from DTC patients, all managed according to a same standard protocol. In addition, we obtained 5 normal and 114 benign thyroid lesions. Eighteen out of the 253 papillary thyroid carcinomas were paired with respective metastatic lymph node tissues. B7H1 (CD274) protein expression was assessed by immunohistochemistry and the gene expression was quantified by real-time PCR. Malignant tissues displayed a more intense B7H1 staining and higher mRNA levels than benign tissues (both P<0.0001). We observed a positive linear correlation between higher age at diagnosis and B7H1 mRNA levels (P=0.02896). Elevated levels of B7H1 protein were associated with the presence of CD4+, CD8+, CD20+, and FoxP3+ lymphocytes (all P<0.05); tumor-associated macrophages (P<0.0001); and the presence of myeloid-derived suppressor cells (P=0.03256). Stage II-IV patients presented higher B7H1 mRNA levels than stage I cases (P=0.03522). On the contrary, a decreased expression of B7H1 protein was observed in lymph node metastasis (P=0.0152). In conclusion, our data demonstrate that B7H1 expression is associated with features of aggressiveness, suggesting that this is an immune evasion mechanism of DTC cells.

mRNA BRAF expression helps to identify papillary thyroid carcinomas in thyroid nodules independently of the presence of BRAFV600E mutation.

Literature has consistently shown associations of BRAFV600E mutation with papillary thyroid cancer clinical features. However, the clinical utility of BRAF expression has not been clinically explored so far. We studied 67 thyroid nodules (32 benign nodules and 35 PTC cases). BRAF mRNA expression levels measured by a quantitative real-time PCR and a PCR-RFLP were used to identify BRAFV600E mutation. BRAF mRNA expression was significantly higher in malignant (198.2±373.9 AU) than in benign (4.1±6.9 AU) nodules (p<0.0001). BRAF expression identified malignancy with a sensitivity of 80.6%, specificity of 77.1%, positive predictive value of 75.8%, and negative predictive value of 81.8%. A cut-point of 4.712, identified by the ROC curve, was able to sort out malignant nodules with an accuracy of 78.8%. Although we did not find any correlation between the presence of BRAF V600E mutation and clinical or tumor features such as age (p=0.309), gender (p=0.5453), ethnicity (p=0.9820), tumor size (p=1.000), multifocality (p=0.2530) or mRNA levels (p=0.7510), the study power for BRAF expression and diagnosis (99%; FPRP=0.85) indicated that data is noteworthy despite the relative small number of patients investigated. We concluded that BRAF mRNA expression may help to identify PTC among thyroid nodules independently of the presence of BRAFV600E mutation.

Foxp3 expression is associated with aggressiveness in differentiated thyroid carcinomas.

OBJECTIVES: Forkhead box P3 (FoxP3) expression has been observed in human cancer cells but has not yet been reported in thyroid cells. We investigated the prognostic significance of both FoxP3 expression and intratumoral FoxP3(+) lymphocyte infiltration in differentiated thyroid carcinoma cells. METHODS: We constructed a tissue microarray with 385 thyroid tissues, including 266 malignant tissues (from 253 papillary thyroid carcinomas and 13 follicular carcinomas), 114 benign lesions, and 5 normal thyroid tissues. RESULTS: We determined the expression of FoxP3 in both tumor cells and tumor-infiltrating lymphocytes using immunohistochemical techniques. Cellular expression of FoxP3 was evident in 71% of benign and 91.9% of malignant tissues. The nuclear and cytoplasmic expression patterns were quantified separately. A multivariate logistic regression analysis indicated that cytoplasmic FoxP3 expression is an independent risk factor for thyroid malignancy. Cytoplasmic FoxP3 staining was inversely correlated with patient age. Nuclear FoxP3 staining was more intense in younger patients and in tumors presenting with metastasis at diagnosis. FoxP3(+) lymphocytes were more frequent in tumors smaller than 2 cm, those without extrathyroidal invasion, and in patients with concurrent chronic lymphocytic thyroiditis. CONCLUSIONS: We demonstrated FoxP3 expression in differentiated thyroid carcinoma cells and found evidence that this expression may exert an important influence on several features of tumor aggressiveness.

Functional variations in the ATM gene and susceptibility to differentiated thyroid carcinoma.

CONTEXT: ATM is critical in response to ionizing radiation-induced DNA damage. OBJECTIVE: Variations in ATM are hypothesized to affect individual susceptibility to thyroid cancer. Our objective was to evaluate the association between ATM polymorphisms and thyroid cancer risk. DESIGN, PARTICIPANTS, AND METHODS: Six ATM single nucleotide polymorphisms (SNP) were genotyped in two independent case-control series including 592 patients with differentiated thyroid carcinoma (DTC) and 885 healthy individuals. An unconditional logistic regression model was applied to calculate odds ratios (OR) and 95% confidence intervals (CI) for each SNP with respect to risk of DTC and the combination effect of SNP on cancer risk. RESULTS: The risk-allele frequencies of all the SNP were similar in the two case-control populations. Under a dominant model of inheritance, the G allele of ATM rs189037 exhibited a protective effect against DTC (adjusted OR = 0.8; 95% CI, 0.6-1.0; P = 0.04), and the G allele of rs1800057 was associated with increased risk of DTC (adjusted OR = 1.9; 95% CI, 1.1-3.1; P = 0.02). A protective haplotype (A-G-C-T-C-A) was associated with decreased risk of DTC in non-Hispanic whites (adjusted OR = 0.2; 95% CI, 0.0-0.8; P = 0.03). A significant dose-response relationship was observed between the total number of risk alleles of ATM and DTC risk (P = 0.01). Carriers of a combination of six to seven and eight to 10 risk alleles were at 30% (adjusted OR = 1.3; 95% CI, 1.0-1.7) and 50% (adjusted OR = 1.5; 95% CI, 1.1-2.1) increased risk of DTC, respectively. CONCLUSION: Individual susceptibility to DTC may be attributable to polymorphisms of ATM, and the associations warrant confirmation in independent studies.

Foxp3 expression is associated with aggressiveness in differentiated thyroid carcinomas

OBJECTIVES: Forkhead box P3 (FoxP3) expression has been observed in human cancer cells but has not yet been reported in thyroid cells. We investigated the prognostic significance of both FoxP3 expression and intratumoral FoxP3+ lymphocyte infiltration in differentiated thyroid carcinoma cells. METHODS: We constructed a tissue microarray with 385 thyroid tissues, including 266 malignant tissues (from 253 papillary thyroid carcinomas and 13 follicular carcinomas), 114 benign lesions, and 5 normal thyroid tissues. RESULTS: We determined the expression of FoxP3 in both tumor cells and tumor-infiltrating lymphocytes using immunohistochemical techniques. Cellular expression of FoxP3 was evident in 71% of benign and 91.9% of malignant tissues. The nuclear and cytoplasmic expression patterns were quantified separately. A multivariate logistic regression analysis indicated that cytoplasmic FoxP3 expression is an independent risk factor for thyroid malignancy. Cytoplasmic FoxP3 staining was inversely correlated with patient age. Nuclear FoxP3 staining was more intense in younger patients and in tumors presenting with metastasis at diagnosis. FoxP3+ lymphocytes were more frequent in tumors smaller than 2 cm, those without extrathyroidal invasion, and in patients with concurrent chronic lymphocytic thyroiditis. CONCLUSIONS: We demonstrated FoxP3 expression in differentiated thyroid carcinoma cells and found evidence that this expression may exert an important influence on several features of tumor aggressiveness.

Muc-1 expression may help characterize thyroid nodules but does not predict patients' outcome.

Our purpose was to evaluate MUC1 clinical utility in the diagnosis and prognosis of thyroid cancer patients. We studied the protein expression of MUC1 in 289 thyroid carcinomas and 121 noncancerous thyroid nodules. There were 41 follicular carcinomas (FC) and 248 papillary thyroid carcinomas (PTC) including 149 classic (CPTC), 20 tall cell (TCPTC) and 79 follicular variants (FVPTC). In addition, we used a quantitative real-time PCR (q-PCR) method to measure MUC1 mRNA expression levels in 108 carcinomas, 23 hyperplasias, and 19 FA. According to their serum Tg levels and other evidences of recurrence/metastasis, the patients were classified as free-of-disease (185 cases) or bad outcome (56 cases, 10 deaths). MUC1 protein was identified in 80.2% PTC; 48.8% FC; 68.3% FVPTC; 70% TCPTC; 21.8% FA; 30% hyperplasias and 6% normal thyroid tissues. MUC1 distinguished benign from malignant thyroid tissues (sensitivity = 89%; specificity = 53%). MUC1 also differentiated FC from FA (p = 0.0083). q-PCR mRNA expression of MUC1 also distinguished malignant from benign nodules (Mann-Whitney test, p < 0.0001). However, neither IHC nor mRNA MUC1 expression was associated with any clinical or pathological feature of aggressiveness or outcome. We suggest that MUC1 expression may help differentiate follicular patterned thyroid lesions.

Carcinoma diferenciado da tiroide / Differentiated thyroid carcinoma

O carcinoma diferenciado da tiroide (CDT) é a neoplasia endocrinológica mais comum. Nos Estados Unidos da América do Norte se estimam que 33.000 pessoas sejam acometidas pela doença. Nos últimos anos se tem observado um aumento progressivo no número de casos por ano em todo o mundo. O CDT tem usualmente uma sobrevida acima de 90% em dez anos, todavia, aproximadamente 20% dos pacientes podem cursar com recorrências locais e a distância, aumentando a mortalidade pelo tumor e reduzindo o tempo livre de doença. Por esses motivos a correta classificação dos indivíduos com CDT, torna-se imprescindível para oferecer o melhor e mais adequado tratamento.

Alguns agentes virais se relacionam com neoplasias ou doenças autoimunes: [revisão] / Viral agents and their correlation with the genetic profile of predisposition to human neoplastic and autoimmune diseases: [review]

Os herpesvírus têm sido vistos como potenciais agentes carcinogênicos e identificados em diversas malignidades. Acometem indivíduos imunossuprimidos e também indivíduos saudáveis e possuem elevada prevalência. A capacidade de permanecerem latentes nas células do hospedeiro garante aos vírus sua sobrevivência até serem reativados. Células infectadas por herpes supostamente não seriam destruídas por apoptose em portadores de alterações no gene TP53. Nossos estudos comprovam uma maior prevalência de herpesvírus tipo 6 em pacientes transplantados renais do que numa população controle e mostram que polimorfismos no gene TP53 poderiam influenciar na suscetibilidade à infecção por este vírus. Observamos que os herpesvírus também podem aumentar o risco para o desenvolvimento de carcinomas da pele e isso se associa ao perfil genotípico GSTM1-GSTT1+. Mais recentemente, estudando doenças auto-imunes, observamos que a infecção pelo herpesvírus 6 aumentou a susceptibilidade para o desenvolvimento da doença de Graves. Estes estudos poderão ter utilidade na prevenção de doenças. Por exemplo, pacientes em imunodepressão que tenham infecção por herpesvírus devem ser particularmente mais cuidadosos em relação à exposição solar.