Clinical-pathological changes in differentiated thyroid cancer (DTC) over time (1997-2010): data from the University Hospital "Maggiore della Carità" in Novara

Thyroid Cancer Diagnostics Related to Occupational and Environmental Risk Factors: An Integrated Risk Assessment Approach

There are still many questions remaining about the etiopathogenesis of thyroid cancer, the most common type of endocrine neoplasia. Numerous occupational and environmental exposures have been shown to represent important risk factors that increase its incidence. Updated information about thyroid cancer diagnostics related to occupational and environmental risk factors is reviewed here, considering an integrated risk assessment approach; new data concerning thyroid cancer etiology and pathogenesis mechanisms, diagnostic biomarkers and methodologies, and risk factors involved in its pathogenesis are presented. A special emphasis is dedicated to specific occupational risk factors and to the association between environmental risk agents and thyroid cancer development. The occupational environment is taken into consideration, i.e., the current workplace and previous jobs, as well as data regarding risk factors, e.g., age, gender, family history, lifestyle, use of chemicals, or radiation exposure outside the workplace. Finally, an integrative approach is presented, underlying the need for an accurate Risk Assessment Matrix based on a systematic questionnaire. We propose a complex experimental design that contains different inclusion and exclusion criteria for patient groups, detailed working protocols for achieving coherent and sustainable, well-defined research stages from sample collection to the identification of biomarkers, with correlations between specific oncometabolites integrated into the Risk Assessment Matrix.

Case-Control Study of Papillary Thyroid Carcinoma on Urinary and Dietary Iodine Status in South Korea

BACKGROUND

The association between iodine levels and the risk of papillary thyroid cancer (PTC) has been suggested, but not definitively established. This study is to compare the iodine status of a group of patients with PTC (with and without BRAF ^V600E) with that of a healthy population cohort.

METHODS

A cohort of patients scheduled for thyroidectomy was enrolled, along with a community-based health-screening cohort with no known history of thyroid disease. Median urinary iodine (UI) levels, creatinine-adjusted median UI levels, and food frequency questionnaire (FFQ) scores (mean ± SD) were compared. In a subgroup analysis, these values were compared between BRAF ^V600E-positive and BRAF ^V600E-negative patients in the PTC group.

RESULTS

The PTC group consisted of 210 patients, and the control group consisted of 90 healthy individuals. Among the 191 PTC patients whose BRAF ^V600E mutational status was reported, 169 (88.5%) were revealed positive for the mutation. The median UI levels were significantly higher in the PTC group (786.0 μg/l) than the control group (112.0 μg/l; p < 0.001), as was the case with creatinine-adjusted median UI levels (884.6 μg/g creatinine versus 182.0 μg/g creatinine; p < 0.001) and FFQ scores (66.2 ± 17.5, range 13-114 versus 54.6 ± 21.5, range 16-134; p < 0.001). No significant differences were seen in the subgroup analysis between BRAF ^V600E-positive and BRAF ^V600E-negative patients.

CONCLUSIONS

Our results indicate that iodine status differs significantly between patients with PTC and healthy controls, suggesting that iodine may be involved in the occurrence of PTC, although the association between iodine levels and BRAF mutational status did not reach statistical significance.

Clinicopathologic features of familial nonmedullary thyroid carcinoma

BACKGROUND

Familial nonmedullary thyroid carcinoma (FNMTC) is a variant of nonmedullary thyroid carcinoma(NMTC) with particular clinicopathologic features. In recent years, a number of studies have shown that FNMTC is more invasive than sporadic NMTC(SNMTC). The purpose of this study was to explore the differences in clinicopathologic features of FNMTC between different types of families and to determine in which of these families more invasive FNMTC occurred.

METHODS

We retrospectively reviewed all patients with thyroid carcinoma admitted to Peking Union Medical College Hospital from January 2009 to July 2013 in the database. Of all 2000 cases, 55 met the inclusive criteria for FNMTC and were studied. There are two different grouping methods. The first is that all samples were allocated to families with three or more first-degree relatives affected (FNMTC-3 group) and families with only two affected first-degree relatives (FNMTC-2 group). The second is that all patients were divided into families with three or more affected first-degree relatives over two generations (FNMTC-3-2 group) and the other families. We compared the clinicopathologic features such as sex, age, tumor size, multifocality, location, complications by thyroiditis, complications by benign thyroid nodules, surgical procedure, capsule invasion, histological type, lymph node metastases, tumor node metastasis stage, and BRAF mutation between FNMTC-2 group and FNMTC-3 group. We also made the same comparison between FNMTC-3-2 group and other families.

RESULTS

No pronounced differences in clinicopathological features were present between FNMTC-2 group and FNMTC-3 group. The proportion of FNMTC-3-2 group aged <45 years was significantly higher than that in the other families (58.8% vs. 26.3%, P = 0.021). A similar difference was found in the proportion of lymph node metastasis (64.7% vs. 34.2%, P = 0.035).

CONCLUSIONS

FNMTC-3-2 is more invasive than the other families. Early screening and positive treatment for members of these families are recommended.

Increased prevalence of chronic lymphocytic thyroiditis in Korean patients with papillary thyroid cancer

Background

In recent years, some reports have suggested that papillary thyroid cancers are more frequently associated with lymphocytic thyroiditis or Hashimoto's thyroiditis. This study investigated a potential increase in the prevalence of chronic lymphocytic thyroiditis among papillary thyroid cancer patients.

Materials and Methods

We used national epidemiological survey data on thyroid cancer patients diagnosed in 1999, 2005, and 2008. A retrospective medical record survey was conducted by representative sampling of a national cancer incidence database. The analysis included 5,378 papillary thyroid cancer patients aged 20–79 years. We calculated the age-standardized prevalence and age-adjusted prevalence ratios using a binomial regression model with a log link for the prevalence of chronic lymphocytic thyroiditis among papillary thyroid cancer patients by sex for each year.

Results

The prevalence of chronic lymphocytic thyroiditis among papillary thyroid cancer patients was 4.0% and 12.8% for men and women in 1999, 6.5% and 24.6% in 2005, and 10.7% and 27.6% in 2008, respectively. Between 1999 and 2008, the age-standardized prevalence of chronic lymphocytic thyroiditis increased 4.1-fold in male patients and 2.0-fold in female patients with papillary thyroid cancer. The prevalence of other thyroid diseases, however, did not increase in either gender.

Conclusions

Among Korean papillary thyroid cancer patients, the prevalence of chronic lymphocytic thyroiditis increased between 1999 and 2008, whereas the prevalence of other thyroid disorders did not change.

"Is there any association between insulin resistance and thyroid cancer? : A case control study"

Insulin stimulates proliferation of thyroid cells in culture. The presence of insulin resistance (IR) is associated with larger thyroid gland volume and an increased prevalence of thyroid nodules. The aim of this study was to investigate the presence of any possible association between IR and thyroid cancer. Forty-one patients with diffuse thyroid cancer (Group 1) were matched for age and gender with 41 patients with nodular goiter (Group 2). Both groups were compared in terms of frequency of IR, as estimated by the homeostasis model assessment, as well as other parameters of the metabolic syndrome (MetS). Fourteen patients (34.1 %) in each group had MetS. Twelve patients (29.3 %) in group 1 had IR compared to 10 (24.4 %) in group 2. Mean HOMA-IR scores in group 1 and 2 were 2.5 ± 2.2 and 1.8 ± 1.1, respectively. Thirty-two patients (78 %) in group 1 had a body mass index (BMI) of more than 25 compared to 33 patients (80.5 %) in group 2. The difference between groups with regard to HOMA-IR, the frequency of IR, BMI, and any of the parameters of MetS was statistically insignificant (p > 0.05). A subgroup analysis based on tumor size did not reveal a significant difference between patients with microcarcinoma (≤10 mm) and macrocarcinoma (>10 mm) in terms of any of the study parameters (p > 0.05). Neither MetS nor IR was a significant risk factor for thyroid cancer following logistic regression analysis (p > 0.05). IR is not more prevalent in patients with thyroid cancer. Some other pathologic mechanisms may be more prominent during thyroid carcinogenesis.

Should patients with remnants from thyroid microcarcinoma really not be treated with iodine-131 ablation?

Remnant ablation by radioiodine is generally not recommended in patients presenting uni- or multifocal cancer <1 cm, in the absence of other higher risk features. We retrospectively studied low-risk patients (pts) with differentiated thyroid cancer (DTC) less than 1 cm recruited for radioiodine therapy (RAI).

METHODS

91 pts (79 women, age 48.4 ± 12 yrs) with DTC were enrolled for RAI. Patients underwent pre-therapy ultrasonography (US), those with suspected/ambiguous lymph-nodes were excluded and proposed for cytology. Treated pts underwent post-therapeutic whole body scan (WBSt) completed by neck/chest SPECT/CT, when necessary (e.g. evidence of uptake outside of thyroid bed). A target lesion on SPECT/CT was defined as an identifiable lymph-nodal site presenting a matched significant iodine uptake. The patients were followed up for 14 ± 2 months thereafter.

RESULTS

All pts/cancers were pT1. The mean histological diameter was 0.68 ± 0.23 cm. Six patients were excluded because of suspected nodal involvement at US. Thirty (35 %) out of 85 pts had suspicious WBSt as per lymph-nodal involvement which was confirmed at the subsequent SPECT/CT acquisition in most part of pts (26/30; 86 %). Overall detected target lesions was 34, and nine (26 %) had interim positive fine needle cytology.

CONCLUSIONS

a significant part of low risk DTC patients, for whom RAI is not recommended, presents an incidental suspicion of lymph-nodal involvement at WBSt confirmed by subsequent SPECT/CT. Such setting would have not been treated by I-131.

Total thyroidectomy, without prophylactic central lymph node dissection, in the treatment of differentiated thyroid cancer. Clinical retrospective study on 221 cases

Total thyroidectomy (TT) is the standard of care for differentiated thyroid cancer (DTC), but still there is no consensus about the role of routine use of prophylactic central lymph node dissection. The aim of this study was to analyze our results of TT without prophylactic central lymphadenectomy in the treatment of DTC. Clinical records, between January 1998 and December 2005, of 221 patients undergoing TT, without prophylactic central lymph node dissection, were retrospectively evaluated. Two hundred and eleven patients (95.47 %) also underwent radioiodine (RAI) ablation followed by thyroid stimulating hormone (TSH) suppression therapy. In patients with loco-regional lymph nodal recurrence, lateral and central lymph node dissection was performed. The incidence of permanent hypoparathyroidism (iPTH <10 pg/ml) and permanent vocal fold paralysis were, respectively, 0.91 and 0.91 %. After a 9.6 ± 3.5 years mean follow-up, the rate of loco-regional recurrence, with positive cervical lymph nodes, was 3.16 % (7/221 patients). In these cases a lateral and central lymphadenectomy was carried out without significant complications. Our results showed that TT without prophylactic central lymph node dissection, followed by RAI ablation, was associated with low morbidity and low loco-regional recurrence rate, even if the lack of a control group treated with TT plus prophylactic central lymphadenectomy suggests caution against generalization of our assumption. Such last combined procedure could be indicated in high-risk patients, in whom loco-regional recurrence is more frequent. However, given the trend in the literature toward prophylactic lymphadenectomy and the avoidance of RAI treatment, prospective randomized trials should be conducted to better clarify this issue.

Diagnostic performance of (99m)Tc-MIBI scan in predicting the malignancy of thyroid nodules: a meta-analysis

Several studies have investigated the diagnostic performance of (99m)Tc-MIBI scan in the evaluation of thyroid nodules suspicious for malignancy with conflicting results. The aim of our study is to meta-analyze published data on this topic. A comprehensive literature search of studies published through December 2012 regarding the diagnostic performance of (99m)Tc-MIBI scan in the evaluation of thyroid nodules suspicious for malignancy was carried out. Pooled sensitivity and specificity of (99m)Tc-MIBI scan on a per lesion-based analysis and the area under the ROC curve were calculated. Pathological reports of thyroid nodules were considered as reference standard. Twenty-one studies were included in the meta-analysis. Pooled sensitivity and specificity of (99m)Tc-MIBI scan in detecting malignant thyroid nodules were 85.1 % [95 % confidence interval (95 % CI): 81.1-88.5 %] and 45.7 % (95 % CI: 42.7-48.7 %), respectively, on a per lesion-based analysis, irrespective of eventual results of previous technetium pertechnetate ((99m)TcO4) or iodine-123 ((123)I) scan. The area under the ROC curve was 0.78. A sub-analysis restricted to data on hypofunctioning nodules on (99m)TcO4 or (123)I scans was performed: pooled sensitivity and specificity of (99m)Tc-MIBI scan in these nodules were 82.1 % (95 % CI: 77.2-86.3 %) and 62.8 % (95 % CI: 58.9-66.7 %), respectively, on a per lesion-based analysis. The area under the ROC curve was 0.81. (99m)Tc-MIBI scan is a sensitive diagnostic tool in predicting the malignancy of thyroid nodules. Therefore, this imaging method could be helpful in patients with thyroid nodules in which malignancy is suspected on the basis of conventional diagnostic techniques. Higher specificity can be reached when hypofunctioning thyroid nodules are considered.

Regulatory T cells and plasmacytoid dendritic cells contribute to the immune escape of papillary thyroid cancer coexisting with multinodular non-toxic goiter

Immunosuppressive lymphocytes, such as regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs), play crucial roles in tumor escape. To investigate the roles of Tregs and pDCs in papillary thyroid cancer (PTC) plus multinodular non-toxic goiter (MNG), thyroid tissue and blood samples from 30 patients with PTC plus MNG and 30 MNG alone were analyzed for CD4(+) T cell, CD8(+) T cell, FoxP3(+) Treg, ICOS(+)FoxP3(+) Treg, and pDC numbers by immunohistochemistry (IHC), immunofluorescence, and flow cytometry. Plasma concentration of the cytokines interleukin 10 (IL-10) and transforming growth factor β (TGF-β) were measured by enzyme-linked immunosorbent assay as well. Both in thyroid tissue and peripheral blood, the numbers of Foxp3(+) Treg were significantly higher in patients with PTC plus MNG compared to patients with MNG alone; and as a prognostic marker, ICOS(+)Foxp3(+) Tregs represent a stronger predictor of disease progression than the total numbers of Foxp3(+) Tregs. Furthermore, a positive correlation between pDC and ICOS(+)Foxp3(+) Treg numbers in tissue of patients with PTC plus MNG was observed, suggesting that PTC-derived pDCs may induce the differentiation of naive CD4(+) T cells into ICOS(+)Foxp3(+)Tregs. This may be one of the mechanisms underlying tumor escape in PTC plus MNG patients. Our results suggest that Tregs and pDCs together contribute to the tumor escape in patients with PTC plus MNG.

Pituitary metastasis of thyroid cancer

Pituitary metastases (PM) from thyroid cancer are rare, but their management can represent a difficult challenge for the endocrinologist. Our aim was to review all reported cases of PM from thyroid cancer. PubMed was consulted and 19 papers reporting 20 cases were found. We moreover discuss two of our own cases, which had come to our attention within a few months of one another. Eleven cases were follicular cancer, eight cases were papillary cancer, two cases were medullary cancer, and one case was an insular cancer. In nine cases, PM was the first sign of the disease. Cranial nerve involvement was the most common sign of its presence, and no neuroradiological imaging could lead to a sure diagnosis of PM. Neurosurgical intervention was performed in almost all cases, and post-surgical treatment comprised radioiodine, external beam radiotherapy, and radiosurgery. Prognosis was poor for larger metastases, cranial nerve palsy disappeared in only one case, and in only one case of intrasellar metastasis was the disease cured. PM from thyroid cancer are rare, but are burdened by a poor prognosis. An early diagnosis appears important, and a comprehensive strategy for treatment (neurosurgery, radioiodine, external radiotherapy, and radiosurgery) appears advisable.

F18-FDG-PET/CT thyroid incidentalomas: a wide retrospective analysis in three Italian centres on the significance of focal uptake and SUV value

Thyroid incidental uptake is defined as a thyroid uptake incidentally and newly detected by imaging techniques performed for an unrelated purpose and especially for non-thyroid diseases. Aim of the study was to establish the prevalence and pathological nature of focal thyroid incidentalomas detected at F18-FDG-PET/CT in patients studied for oncological purposes and not for thyroid disease. Secondary end point was to establish a possible maximum standardised uptake value cut-off over which a malignant lesion should be suspected. We have retrospectively evaluated 49519 patients who underwent F18-FDG-PET/CT for oncologic purposes in three Nuclear Medicine Centres (N.1 = 11278, N.2 = 31076, N.3 = 7165). A focal incidental thyroid uptake was diagnosed in 729 (1.5 %) patients (287-39.4 % male and 442-60.6 % female; average age: 65.26). Of 729 thyroid incidentalomas 211 (28.9 %) underwent further investigation to determine the nature of the nodule; 124/211 (58.8 %) incidentalomas were benign, 72/211 (34.1 %) malignant, 4/211 (1.9 %) non-diagnostic at cytological examination in the absence of surgery and histological evaluation and 11/211 (5.2 %) were indeterminate at cytological examination. A centre-based receiver operating curve (ROC) analysis of the patients with a definitive diagnosis was performed to identify a SUVmax cut-off useful in differentiating benign from malignant incidentalomas. In the centre N.1 it was 4.8 (sensitivity = 95.7 %, specificity = 46.4 %, area under the curve = 0.758); 5.3 in the centre N.2 (sensitivity = 76.3 %, specificity = 72.5 %, area under the curve = 0.815); 7 in the centre N.3 (sensitivity = 57.1 %, specificity = 79.3 %, area under the curve = 0.627). F18-FDG-PET/CT thyroid incidentalomas are a relevant diagnostic reality which requires further investigations and clinical management especially considering that, despite mainly benign, approximately one third of focal thyroid uptakes are malignant.

BRAF(V600E) mutation in Turkish patients with papillary thyroid cancer: strong correlation with indicators of tumor aggressiveness

Papillary thyroid cancer (PTC) constitutes more than 90% of the thyroid cancers. MAP kinase/ERK pathway plays an important role in the development of several cancers. BRAF which is a member of Raf-kinase family activates this way. BRAF gene activating mutations lead to neoplastic transformation in thyroid follicle cells. In PTC, this mutation itself is a poor prognostic sign independent of other clinicopathological characteristics. We evaluated BRAF(V600E) mutation and clinical-pathological characteristics in Turkish population with PTC. We assessed 109 patients with PTC (88 female, 21 male). The average age was 38.7 ± 9.9 (17-71). BRAF(V600E) mutation was detected using polymerase chain reaction and fluorescent melting curve analysis. The results show that BRAF(V600E) mutation rate was found in 39.45% of our patients. We observed that BRAF(V600E) mutation was significantly higher in men, in tumors larger than 1 cm in size, and in patients with classical PTC. Moreover, statistically significant correlations of BRAF(V600E) with indicators of tumor aggressiveness such as thyroid capsular invasion, multifocality, lymph node metastasis, and extrathyroidal spread were found. Patient groups below and over the age of 45 did not differ in mutation frequency. Patients with micro-PTC were evaluated separately, it was found that BRAF(V600E) mutation was more frequent in the classic type and that lymph node metastasis rate significantly increased when the mutation was present. We concluded that BRAF(V600E) was correlated with indicators of tumor aggressiveness in our study population. This fact is taken into consideration in treatment and follow-up of our patients with PTC and positive BRAF(V600E) mutation.