Selenium Supplementation, Body Mass Composition, and Leptin Levels in Patients with Obesity on a Balanced Mildly Hypocaloric Diet: A Pilot Study

BACKGROUND

Adequate levels of selenium (Se) have protective effects against several chronic diseases, such as obesity. The aim of this study was to assess the effect of Se supplementation in a selected group of patients with obesity.

METHODS

This randomized prospective study included 37 overweight/obese individuals aged 18-65 years, who adopted a slightly hypocaloric diet for 3 months. An intervention group received 240 μg/day of L-selenomethionine for 3 months; a control group received a placebo. Clinical and biochemical parameters, body composition measurements, and the Psychological General Well-Being Index (PGWBI) questionnaire were tested at the beginning and end of the treatment.

RESULTS

A comparison of the two groups showed a significant change in body composition, involving a decrease in body fat mass, between the baseline and the end of the follow-up, in the intervention group. Unlike the placebo group, the group given Se had a significant increase in lean body and muscle mass and a significant decrease in leptin levels after 3 months on diet. At the end of the follow-up, the group given Se scored higher on the PGWBI than those who did not.

CONCLUSION

Se could reinforce the effects of diet for overweight and obesity. This work was registered in the ISRCTN registry with study ID ISRCTN6106073.

Epidemiology of Simultaneous Medullary and Papillary Thyroid Carcinomas (MTC/PTC): An Italian Multicenter Study

Background: The concomitant presence of papillary thyroid cancer (PTC) and medullary TC (MTC) is rare. In this multicentric study, we documented the epidemiological characteristics, disease conditions and clinical outcome of patients with simultaneous MTC/PTC. Methods: We collected data of patients with concomitant MTC/PTC at 14 Italian referral centers. Results: In total, 183 patients were enrolled. Diagnosis was mostly based on cytological examination (n = 58, 32%). At diagnosis, in the majority of cases, both PTC (n = 142, 78%) and MTC (n = 100, 54%) were at stage I. However, more cases of stage II–IV were reported with MTC (stage IV: n = 27, 15%) compared with PTC (n = 9, 5%). Information on survival was available for 165 patients: 109 patients (66%) were disease-free for both PTC and MTC at the last follow-up. Six patients died from MTC. Median time to progression was 123 months (95% confidence interval (CI): 89.3–156.7 months). Overall, 45% of patients were disease-free after >10 years from diagnosis (125 months); this figure was 72.5% for PTC and 51.1% for MTC. Conclusions: When MTC and PTC are concurrent, the priority should be given to the management of MTC since this entity appears associated with the most severe impact on prognosis.

Bone turnover markers, BMD and TBS after short-term, high-dose glucocorticoid therapy in patients with Graves' orbitopathy: a small prospective pilot study

PURPOSE

Chronic GC administration has numerous side effects, but little is known about the side effects of their short-term use (< 3 months)-particularly, when high doses are involved, as in the treatment of Graves' orbitopathy (GO). We investigated the effects of short-term, high-dose GC on bone turnover markers, bone mineral density (BMD), and trabecular bone scores (TBS).

METHODS

Eleven patients (10 females and 1 male; median age 56 years) with active GO who were candidates for treatment with intravenous (iv) methylprednisone were consecutively enrolled. All patients were pretreated with a loading dose of 300,000 units of cholecalciferol, then given a median cumulative dose of 4.5 g (range 1.5-5.25 g) iv methylprednisone. Biochemical parameters of bone metabolism (25OHD3, PTH, P1NP, CTX and bALP) were measured at the baseline, and then 1 week and 1, 3, 6 and 12 months. BMD and TBS were obtained by X-ray absorptiometry (DXA) at the baseline and at 6 and 12 months. On DXA image, morphometric vertebral fracture assessment (VFA) was done.

RESULTS

There were no significant changes in PTH, bALP or P1NP. A significant drop in CTX was seen at 1 month (down Δ49.31% from the baseline, p = 0.02), with a return to the baseline at the 3-month measurement. There was a moderate (not significant), but persistent reduction in P1NP. No changes in BMD or TBS came to light. No vertebral fractures were documented.

CONCLUSIONS

Short-term, high-dose GC treatment caused a rapid, transient suppression of bone resorption, with no effects on BMD or bone micro-architecture (TBS).

Unique Case of a Large Indolent Medullary Thyroid Carcinoma: Time to Reconsider the Medullary Thyroid Adenoma Entity?

BACKGROUND

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine cancer originating from parafollicular, calcitonin (Ctn)-producing C-cells. Prognosis correlates with primary tumor stage and Ctn levels.

PATIENT

We describe a case of MTC involving a mass 7 cm in its largest dimension, associated with high Ctn concentrations (> 5,000 pg/mL), but normal carcinoembryonic antigen levels, and with no lymph nodes or distant metastases, in complete remission after thyroid surgery. The MTC had very peculiar histological features, with an expansive, noninfiltrating growth around the thyroid follicles, and no signs of invasion. These histopathological characteristics are reminiscent of the C-cell adenoma described in animals. The tumor also revealed an ossifying extracellular matrix unlike the classical amyloid. Despite the size of the tumor and the patient's high Ctn levels at diagnosis, the case described here reached complete remission after surgery.

CONCLUSIONS

Further studies are needed to clarify the characteristics of MTC and better predict its behavior at diagnosis.

Novel Prognostic Factors Associated with Cell Cycle Control in Sporadic Medullary Thyroid Cancer Patients

BACKGROUND

Medullary thyroid cancer (MTC) is a rare neuroendocrine-derived malignancy. It is represented by sporadic and familiar forms, and both can have RET oncogene mutations. Numerous markers can be used to define MTC; however, none is generally approved for predicting the outcome of sporadic MTC.

AIM

The aim of this work was to analyze PTTG1/securin and Aurora kinase A expressions in MTC patients, both at the gene and protein levels, and to define their prognostic role in MTC assessing their association with lab and clinical parameters.

PATIENTS AND METHODS

Seventy-one sporadic MTC human samples were analyzed for RET mutations and by qPCR for PTTG1 and AURKA (Aurora kinase A) expression. Ki-67 levels and western blot reactivity for PTTG1 and Aurora kinase A were also determined in a selected cohort of patients.

RESULTS

RET somatic mutations were found in 48% of the patients (34/71). PTTG1 expression was statistically different among the groups with or without regional lymph node metastasis (p < 0.0001) and advanced stage disease (p < 0.01). PTTG1 and AURKA expressions were statistically higher than those of controls (p = 0.01 and p < 0.002, respectively). PTTG1 expression and Ki-67 levels were statistically different among the groups with remitted or persistent disease (p < 0.05 and p < 0.01, respectively). We found a significant correlation between the expressions of AURKA and PTTG1 (p < 0.0002, r = 0.5298) and between the expressions of PTTG1 and Ki-67 (p = 0.01). Ki-67 levels were statistically different among the groups with or without metastatic lymph nodes (p = 0.01) or distant metastases (p = 0.003).

CONCLUSION

The presence of an altered expression of PTTG1 and AURKA is a negative prognostic factor associated with a more aggressive course of disease, such as an advanced stage or disease persistence. It emerges as a cell cycle process mediated by the 2 factors, in addition to the RET pathway, which can be altered in MTC patients.

EF24 (a Curcumin Analog) and ZSTK474 Emphasize the Effect of Cabozantinib in Medullary Thyroid Cancer

XL184 is a small-molecule kinase inhibitor recently included in first-line systemic therapy for patients with advanced, progressive medullary thyroid cancer (MTC). EF24 is a curcumin analog with a high bioavailability, and ZSTK474 is an inhibitor of the phosphatidylinositol 3-kinase signaling pathway. We investigated the effect of these compounds, alone and in combination, in two rearranged during transfection (RET)-mutated TT and MZ-CRC-1 MTC cell lines and in six mostly RET wild-type human MTC primary cultures. Low IC50 values demonstrated the efficacy of the drugs, whereas the combination index revealed an important synergistic effect of combinations of XL184 + ZSTK474 and XL184 + EF24. Cell-cycle changes and the induction of apoptosis or necrosis were modulated by single compounds or combinations thereof. Both XL184 and EF24, alone or combined, were effective in reducing calcitonin secretion. Western blot and in-cell Western analysis showed that the compounds prompted a decrease in general reactivity to phosphorylated antibodies. Our data confirm XL184 alone as the reference drug for RET-mutated MTC, but we also demonstrated that EF24 alone is effective in inhibiting MTC cell viability. We tested the combinations XL184 + ZSTK474 and XL184 + EF24 too, finding that they act synergistically, irrespective of RET mutation status.

Efficacy of educational intervention to improve awareness of the importance of iodine, use of iodized salt, and dietary iodine intake in northeastern Italian schoolchildren

OBJECTIVE

An educational program was conducted among school-aged children to improve their knowledge about iodine prophylaxis, their iodine status, and their dietary habits.

METHODS

At the baseline (T0) and after 6 mo (T1), participants (970 at T0 and 949 at T1) answered questionnaires testing their knowledge about iodine prophylaxis and their eating habits. Urine samples were collected from a randomly selected subgroup of participants (313 at T0 and 312 at T1).

RESULTS

From T0 to T1 there was a significant improvement in respondents' knowledge about iodine prophylaxis (from 44% to 70%), iodized salt consumption (from 78% to 84%), and median urine iodine concentrations (from 70 µg/L to 91 µg/L). Milk and iodized salt intakes were associated with a better iodine status per se, and more so when used simultaneously. Girls drank milk less often than boys did (daily in 52% and 59% of cases, respectively). Children of foreign origin ate sodium-rich food more often than Italians did.

CONCLUSION

Educational intervention improved the children's knowledge about iodine prophylaxis and use of iodized salt. Consuming salt in addition to milk improves iodine status. Children of foreign origin have different eating habits.

The Hobnail Variant of Papillary Thyroid Carcinoma: Clinical/Molecular Characteristics of a Large Monocentric Series and Comparison with Conventional Histotypes

BACKGROUND

The hobnail variant of papillary thyroid carcinoma (HPTC) has an aggressive behavior. The aims of this prospective study were to define the clinical/molecular characteristics of HPTC, and to compare them to those of conventional papillary thyroid carcinoma (PTC).

METHODS

From 2010 to 2016, 25 cases of HPTC, characterized clinically and molecularly (BRAF, RAS, TERT promoter, and TP53 mutations), were compared to a series of 165 consecutive cases of PTC. All patients underwent total thyroidectomy and received radioactive iodine treatment. Follow-up was available for 19 HPTC patients.

RESULTS

Among the HPTC patients, 64% had a hobnail component ≥30%, and 64% had multifocal disease. The mean tumor size was 30 mm; 96% of tumors were angio-invasive; 68% were N1, and 12% were M1; 58% harbored the BRAF^V600E mutation, 12% had a mutation in the TERT promoter, 17% had a TP53 mutation, and not had a RAS mutation. At a mean follow-up of 39 months, 32% of patients had biochemical and/or structural disease. Tumor size was the only significant difference between patients with persistent disease and those with an excellent response (40 mm and 24 mm, respectively; p = 0.02). Compared to the PTC control group, the HPTC patients had larger tumors (30 mm vs. 16 mm; p < 0.001), more frequent lymph node involvement (68% vs. 38%; p = 0.01), and remote disease (16% vs. 3%; p < 0.0001), a similar prevalence of the BRAF^V600E mutation (58% vs. 59%), a higher prevalence of TP53 mutations (17% vs. 1%; p < 0.05), and a worse outcome (structural/biochemical disease: 32% vs. 9%; p < 0.0001).

CONCLUSIONS

HPTC is an aggressive variant, characterized by large tumor size, lymph node involvement, a tendency to metastasize, and a worse outcome.

Calcitonin measurement and immunoassay interference: a case report and literature review

Calcitonin (CT) is currently the most sensitive serological marker of C-cell disease [medullary thyroid carcinoma (MTC) and C-cell hyperplasia]. Starting with a report on a case that occurred at our institution, this review focuses on trying to explain the reasons behind the poor specificity and sensitivity of the various CT immunoassays. A 15-year-old patient was referred to our institution in May 2014 for moderately elevated CT levels. Thyroid ultrasonography (US) documented a colloidal goiter. Secondary causes of the hypercalcitoninemia (hyperCT) were ruled out. The mismatch between the clinical picture and the laboratory results prompted us to search for other reasons for the patient's high CT levels, so we applied the heterophilic blocking tube (HBT) procedure to the patient's sera before the CT assay. Using this pretreatment step, his serum CT concentration dropped to <1 ng/L, as measured at the same laboratory. Measuring plasma CT has an important role in screening for C-cell disease, but moderately elevated serum CT levels need to be placed in their clinical context, bearing in mind all the secondary causes of C-cell hyperplasia and the possibility of laboratory interference, before exposing patients to the risks and costs of further tests.

Frequency and Significance of Ras, Tert Promoter, and Braf Mutations in Cytologically Indeterminate Thyroid Nodules: A Monocentric Case Series at a Tertiary-Level Endocrinology Unit

PURPOSE

The management of thyroid nodules of indeterminate cytology is controversial. Our study aimed to establish the frequency and significance of H-,K-,N-RAS, TERT promoter, and BRAF gene mutations in thyroid nodes of indeterminate cytology and to assess their potential usefulness in clinical practice.

METHODS

H-,K-,N-RAS, TERT promoter and BRAF gene mutations were examined in a series of 199 consecutive nodes of indeterminate cytology referred for surgical excision.

RESULTS

69/199 (35%) were malignant on histopathological review. RAS mutations were detected in 36/199 (18%), and 19/36 cases (53%) were malignant on histological diagnosis. TERT promoter mutations were detected in 7/199 (4%) nodules, which were all malignant lesions. BRAF mutations were detected in 15/199 (8%), and a BRAF K601E mutation was identified in 2 follicular adenomas and 1 noninvasive follicular thyroid neoplasm with papillary-like nuclear features. Altogether, this panel was able to identify 48% of the malignant lesions, achieving a specificity, positive predictive value, and negative predictive value for malignancy of 85, 62, and 75%, respectively.

CONCLUSION

The residual malignancy risk in mutation-negative nodes is 25%. These nodes still need to be resected, but mutation analysis could help to orient the appropriate surgical strategy.

Prognostic Impact of miR-224 and RAS Mutations in Medullary Thyroid Carcinoma

Little is known about the function of microRNA-224 (miR-224) in medullary thyroid cancer (MTC). This study investigated the role of miR-224 expression in MTC and correlated it with mutation status in sporadic MTCs. A consecutive series of 134 MTCs were considered. Patients had a sporadic form in 80% of cases (107/134). In this group, REarranged during transfection (RET) and rat sarcoma (RAS) mutation status were assessed by direct sequencing in the tumor tissues. Quantitative real-time polymerase chain reaction was used to quantify mature hsa-miR-224 in tumor tissue. RAS (10/107 cases, 9%) and RET (39/107 cases, 36%) mutations were mutually exclusive in sporadic cases. miR-224 expression was significantly downregulated in patients with the following: high calcitonin levels at diagnosis (p = 0.03, r = -0.3); advanced stage (p = 0.001); persistent disease (p = 0.001); progressive disease (p = 0.002); and disease-related death (p = 0.0001). We found a significant positive correlation between miR-224 expression and somatic RAS mutations (p = 0.007). Patients whose MTCs had a low miR-224 expression tended to have a shorter overall survival (log-rank test p = 0.005). On multivariate analysis, miR-224 represented an independent prognostic marker. Our data indicate that miR-224 is upregulated in RAS-mutated MTCs and in patients with a better prognosis and could represent an independent prognostic marker in MTC patients.

Overexpression of L-Type Amino Acid Transporter 1 (LAT1) and 2 (LAT2): Novel Markers of Neuroendocrine Tumors

Background

6-18F-fluoro-L-3,4-dihydroxyphenylalanine (¹⁸F-FDOPA) PET is a useful tool in the clinical management of pheochromocytoma (PHEO) and medullary thyroid carcinoma (MTC). ¹⁸F-FDOPA is a large neutral amino acid biochemically resembling endogenous L-DOPA and taken up by the L-type amino acid transporters (LAT1 and LAT2). This study was conducted to examine the expression of the LAT system in PHEO and MTC.

Methods

Real-time PCR and Western blot analyses were used to assess LAT1 and LAT2 gene and protein expression in 32 PHEO, 38 MTC, 16 normal adrenal medulla and 15 normal thyroid tissue samples. Immunohistochemistry method was applied to identify the proteins’ subcellular localization.

Results

LAT1 and LAT2 were overexpressed in both PHEO and MTC by comparison with normal tissues. LAT1 presented a stronger induction than LAT2, and their greater expression was more evident in PHEO (15.1- and 4.1-fold increases, respectively) than in MTC (9.9- and 4.1-fold increases, respectively). Furthermore we found a good correlation between LAT1/2 and GLUT1 expression levels. A positive correlation was also found between urinary noradrenaline and adrenaline levels and LAT1 gene expression in PHEO. The increased expression of LAT1 is also confirmed at the protein level, in both PHEO and MTC, with a strong cytoplasmic localization.

Conclusions

The present study is the first to provide experimental evidence of the overexpression in some NET cancers (such as PHEO or MTC) of L-type amino acid transporters, and the LAT1 isoform in particular, giving the molecular basis to explain the increase of the DOPA uptake seen in such tumor cells.

Synergistic antitumour activity of RAF265 and ZSTK474 on human TT medullary thyroid cancer cells

Medullary thyroid cancer (MTC) is an aggressive malignancy responsible for up to 14% of all thyroid cancer-related deaths. It is characterized by point mutations in the rearranged during transfection (RET) proto-oncogene. The activated RET kinase is known to signal via extracellular signal regulated kinase (ERK) and phosphoinositide 3-kinase (PI3K), leading to enhanced proliferation and resistance to apoptosis. In the present work, we have investigated the effect of two serine/threonine-protein kinase B-Raf (BRAF) inhibitors (RAF265 and SB590885), and a PI3K inhibitor (ZSTK474), on RET-mediated signalling and proliferation in a MTC cell line (TT cells) harbouring the RETC634W activating mutation. The effects of the inhibitors on VEGFR2, PI3K/Akt and mitogen-activated protein kinases signalling pathways, cell cycle, apoptosis and calcitonin production were also investigated. Only the RAF265+ ZSTK474 combination synergistically reduced the viability of treated cells. We observed a strong decrease in phosphorylated VEGFR2 for RAF265+ ZSTK474 and a signal reduction in activated Akt for ZSTK474. The activated ERK signal also decreased after RAF265 and RAF265+ ZSTK474 treatments. Alone and in combination with ZSTK474, RAF265 induced a sustained increase in necrosis. Only RAF265, alone and combined with ZSTK474, prompted a significant drop in calcitonin production. Combination therapy using RAF265 and ZSTK47 proved effective in MTC, demonstrating a cytotoxic effect. As the two inhibitors have been successfully tested individually in clinical trials on other human cancers, our preclinical data support the feasibility of their combined use in aggressive MTC.

Iodine status from childhood to adulthood in females living in North-East Italy: Iodine deficiency is still an issue

PURPOSE

This survey aimed to assess iodine status in a female population at different ages, also investigating their eating habits.

METHODS

We measured urinary iodine concentrations (UIC) in: 634 females at puberty and 361 fertile women in 246 of whom were considered also their children (134 daughters and 120 sons). All subjects completed a food frequency questionnaire.

RESULTS

Median UIC decreased from childhood to adulthood (median UIC 107, 77 and 55 μg/l in the young girls, females at puberty and fertile women, respectively). Though using iodized salt improved iodine status in all groups, a significantly higher UIC was only noted in females at puberty. Milk consumption significantly increased UIC at all ages. In mother-child (both daughters and sons) pairs, the children's median UIC was nearly twice as high as their mothers' (UIC 115 vs. 57 μg/l). Milk consumption varied significantly: 56% of the mothers and 76% of their children drank milk regularly. The children (both daughters and sons) and mothers who drank milk had UIC ≥100 μg/l in 59 and 34% of cases, respectively, among the pairs who did not drink milk, 44% of the children and 19% of the mothers had UIC ≥100 μg/l. On statistical regression, 3.6% of the variability in the children's UIC depended on that of their mothers.

CONCLUSIONS

Dietary iodine status declines from childhood to adulthood in females due to different eating habits. A mild iodine deficiency emerged in women of child-bearing age that could have consequences during pregnancy and lactation.

The PDCD4/miR-21 pathway in medullary thyroid carcinoma

Programmed cell death 4 (PDCD4) is a tumor suppressor gene involved in tumorogenesis. MicroRNA-21 (miR-21) specifically targets PDCD4, and recent studies suggest that PDCD4 is also regulated by Akt (antiapoptotic regulator within phosphatidylinositol 3-kinase). Medullary thyroid carcinoma (MTC) is a rare neuroendocrine cancer, and disease stage at diagnosis represents the main prognostic indicator. A consecutive series of 64 MTCs was considered. REarranged during Transfection (RET) and rat sarcoma (RAS) mutation status was assessed by direct sequencing. Quantitative real-time polymerase chain reaction was used to quantify mature hsa-miR-21. PDCD4 and Ki-67 immunostaining was performed with an automated platform. Immunoblot analysis of PI3K/Akt pathway was done on thyroid tissues. MTCs were consistently associated with miR-21 up-regulation (P < .0016) and featured significant PDCD4 nuclear down-regulation. An inverse correlation emerged between miR-21 overexpression and PDCD4 down-regulation (P = .0013). At enrollment, high miR-21 levels were associated with high calcitonin levels (P = .0003), lymph node metastases (P = .001), and advanced stages (P = .0003). At the end of follow-up, high miR-21 levels were associated with biochemically persistent disease (P = .0076). At enrollment, instead, PDCD4 nuclear down-regulation was associated with high calcitonin levels (P = .04), more advanced stages of disease (P < .01), and persistent disease after the follow-up (P = .02). p-Akt was more expressed in RAS-mutated MTC than in nonmutated cancers and normal tissue. This study showed, in MTCs, that miR-21 regulates PDCD4 expression and also that the miR-21/PDCD4 pathway correlates with clinicopathological variables and prognosis. Further studies should investigate the role of miR-21 as a prognostic biomarker and the feasibility of using PDCD4-restoring strategies as a therapeutic approach to MTC.

High-throughput mutation profiling improves diagnostic stratification of sporadic medullary thyroid carcinomas

Sporadic medullary thyroid carcinoma (MTC) harbors RET gene somatic mutations in up to 50 % of cases, and RAS family gene mutations occur in about 10 %. A timely and comprehensive characterization of molecular alterations is needed to improve MTC diagnostic stratification and design-tailored therapeutic approaches. Twenty surgically resected sporadic MTCs, previously analyzed for RET mutations by Sanger sequencing using DNA from formalin-fixed paraffin-embedded samples, were investigated for intragenic mutations in 50 cancer-associated genes applying a multigene Ion AmpliSeq next-generation sequencing (NGS) technology. Thirteen (65 %) MTCs harbored a RET mutation; 10 were detected at both Sanger and NGS sequencing, while 3 undetected by Sanger were revealed by NGS. One of the 13 RET-mutated cases also showed an F354L germline mutation in STK11. Of the seven RET wild-type MTCs, four cases (57.1 %) harbored a RAS mutation: three in HRAS (all Q61R) and one in KRAS (G12R). The three remaining MTCs (15 %) resulted as wild-type for all the 50 cancer-related genes. Follow-up was available in all but one RET-mutated case. At the end of follow-up, 7 of 12 (58 %) RET-mutated patients had relapsed, while the 4 RAS-mutated MTC patients were disease-free. Two of the three patients with MTC wild-type for all 50 genes relapsed during the follow-up period. Detection of mutations by NGS has the potential to improve the diagnostic stratification of sporadic MTC.

Refining calcium test for the diagnosis of medullary thyroid cancer: cutoffs, procedures, and safety

CONTEXT

Calcitonin (CT) measurement is crucial to the early diagnosis and the follow-up of medullary thyroid cancer (MTC). If the evaluation of stimulated CT levels is required, a provocative test can be performed, being the high-dose Ca test recently reintroduced in clinical practice.

OBJECTIVE

Our objective was to identify gender-specific thresholds for MTC diagnosis in a large series of patients who underwent the Ca test.

PATIENTS AND METHODS

A total of 91 patients (49 females and 42 males) underwent the Ca test (calcium gluconate, 25 mg/kg) before thyroidectomy and both basal CT (bCT) and stimulated CT (sCT) were compared with histological results by receiver operating characteristic plot analyses. To evaluate possible side effects of Ca administration, cardiac function has been extensively studied.

RESULTS

bCT levels were found to harbor the same accuracy as sCT in the preoperative diagnosis of MTC. The best Ca thresholds for the identification of MTC were >26 and >68 for bCT and >79 and >544 pg/mL for sCT in females and males, respectively. The high tolerability and safety of the Ca test was demonstrated and advice offered to be followed before and during the test.

CONCLUSIONS

Gender-specific bCT and sCT cutoffs for the identification of C-cell hyperplasia and/or MTC have been defined. The bCT and sCT were found to have a similar accuracy, indicating that serum CT assays with improved functional sensitivity may likely decrease the relevance of the stimulation test in several conditions. Finally, systematic cardiac monitoring confirms the safety of the Ca test.

MicroRNA profiles in familial and sporadic medullary thyroid carcinoma: preliminary relationships with RET status and outcome

BACKGROUND

MicroRNAs (miRNAs) are involved in the pathogenesis of human cancers, including medullary thyroid carcinoma (MTC). The aim of this study was to test the hypothesis that different miRNA profiles are related to RET status and prognosis in patients with hereditary MTC (hMTC) and sporadic MTC (sMTC).

METHODS

We analyzed the expression of nine miRNAs (miR-21, miR-127, miR-154, miR-224, miR-323, miR-370, miR-9*, miR-183, and miR-375) by quantitative real-time-polymerase chain reaction in 34 cases of sMTC, 6 cases of hMTC, and 2 cases of C-cell hyperplasia (CCH). We also analyzed the immunohistochemical expression of PDCD4, an miR-21 gene target. sMTC (n=34) was genotyped for somatic RET and RAS mutations. Disease status was defined on the basis of the concentration of serum calcitonin at the latest follow-up and other parameters as indicated in the results.

RESULTS

MTC and CCH were both characterized by a significant overexpression of the whole set of miRNAs (the increase being 4.2-fold for miR-21, 6.7-fold for miR-127, 8.8-fold for miR-154, 6.6-fold for miR-224, 5.8-fold for miR-323, 6.1-fold for miR-370, 13-fold for miR-9*, 6.7-fold for miR-183, and 10.1 for miR-375, p<0.0001). PDCD4 expression was significantly downregulated in MTC samples, consistent with miR-21 upregulation. Significantly lower miR-127 levels were observed in sMTC carrying somatic RET mutations in comparison to sMTC carrying a wild-type RET. In sMTC and familial MTC, the miR-224 upregulation correlated with the absence of node metastases, lower stages at diagnosis, and with biochemical cure during follow-up.

CONCLUSIONS

miRNAs are significantly dysregulated in MTC, and this dysregulation is probably an early event in C-cell carcinogenesis. miR-224 upregulation could represent a prognostic biomarker associated with a better outcome in MTC patients.

Effects of selenium supplementation on the natural course of autoimmune thyroiditis: a short review

Selenium (Se) is an important element that exerts its effects on the selenoproteins. It is an essential component of the glutathione peroxidase enzymes, which have anti-oxidant and anti-inflammatory properties, and a component of iodothyronine selenodeiodinases, which catalyze the extrathyroid production of T3 from T4. Se is important to several aspects of thyroid homeostasis and may influence the natural course of thyroid diseases such as autoimmune thyroiditis (AIT). This review analyzes the effects of Se supplementation in patients with AIT, based on the studies published on this issue to date.

Combined RET and Ki-67 assessment in sporadic medullary thyroid carcinoma: a useful tool for patient risk stratification

OBJECTIVE

Medullary thyroid carcinoma (MTC) derives from the parafollicular C cells, being sporadic in 75% of cases and familial in 25%, due to RET proto-oncogene germinal mutations. In sporadic forms, stage at diagnosis is the most important negative prognostic factor. The aim of this study was to evaluate the prognostic impact of molecular and immunohistochemical markers in sporadic MTC.

DESIGN AND METHODS

We studied 60 patients with sporadic MTC. For each case, we sought RET somatic mutations in the primary cancer and in lymph node metastases. The primary cancer also underwent immunohistochemical examination for Ki-67.

RESULTS

A somatic RET mutation was found in 38% of patients, being M918T in 52% of them. We observed a statistically significant association between RET mutations and male gender (P<0.01), tumor size (P<0.05), lymph nodes (P<0.05) and distant metastases (P<0.001), advanced stage (P<0.05), increased risk of persistent disease (P=0.01), and low overall survival (P<0.01). High Ki-67 levels were similarly associated with extra-thyroid spread (P<0.05), lymph nodes (P<0.05) and distant metastases (P<0.001), advanced stage (P=0.01), and low overall survival (P=0.01). Combining somatic RET analysis with Ki-67 assessment seems to be useful for increasing the specificity of Ki-67 assessment alone and identifying patients with a more aggressive cancer: in our series, only the patients who died during the follow-up had both a somatic RET mutation and a Ki-67 expression level >50 cells/mm(2).

CONCLUSIONS

The combined evaluation of RET and Ki-67 could act as an adjuvant prognostic marker useful for ameliorating the initial risk stratification of patients with sporadic MTC.