Current diagnosis and management of medullary thyroid carcinoma

Predictive and prognostic value of aurora kinase A combined with tumor-infiltrating lymphocytes in medullary thyroid carcinoma

Background

Aurora kinase A (AURKA) and tumor-infiltrating lymphocytes (TILs) are both known to play an essential role in tumorigenesis. However, the expression and prognostic value of the AURKA and TILs in medullary thyroid carcinoma (MTC) have not yet been investigated.

Patients and methods

Surgical specimens and clinical data of 137 patients diagnosed with MTC were collected. AURKA expression and TILs infiltration were quantified by immunohistochemistry and hematoxylin-eosin staining. Subsequently, the prognostic value of AURKA expression and TIL infiltration in MTC was evaluated.

Results

AURKA was highly expressed in patients with multifocal tumor, cervical lymph node metastasis, and an advanced TNM stage, indicating a high probability of recurrence. AURKA further exhibited a positive correlation with TILs (R = 0.44, P < 0.001). High expression of AURKA combined with a low numbers of TILs (AURKAhigh/TILslow) was identified as an independent prognostic factor for biochemical recurrence (odds ratio: 4.57, 95% confidence interval: 1.54-14.66, P < 0.01) and recurrence-free survival (hazard ratio: 3.64, 95% confidence interval: 1.52-8.71, P < 0.001). The combination of AURKA and TILs apparently improves the prognostic value for biochemical recurrence (area under the curve: 0.751) and structural recurrence (area under the curve: 0.836) of MTC. Notably, AURKAhigh/TILslow demonstrated a high value for prediction of distant or unresectable locoregional recurrence, with an overall accuracy of 86.9%.

Conclusion

AURKAhigh is associated with the MTC malignancy. The combination of AURKAhigh/TILslow was identified as novel independent prognostic marker in MTC, predicting incurable disease recurrence with high accuracy.

Strategies for Treatment of Thyroid Cancer

More people are diagnosed with thyroid cancer than any other endocrine tumor. Differentiated thyroid cancer is often treated by removing the thyroid gland (thyroidectomy), iodizing radiation, or inhibiting thyroid stimulating hormone (TSH). Advanced thyroid carcinomas are notoriously resistant to chemotherapy, thus the pursuit of alternative treatments is vital. The best methods for treating individuals with advanced nonmedullary and medullary thyroid carcinomas are discussed in this post. Numerous tyrosine kinase inhibitors and antiangiogenic inhibitors, two types of novel target therapy, have shown promise in studies for individuals with thyroid cancer. Both the positive and unfavourable outcomes of clinical studies of these drugs were addressed. The findings presented here are encouraging, but more study is required to establish whether or not this method is effective in the treatment of thyroid cancer.

The role of external beam radiation therapy in the management of thyroid carcinomas: A retrospective study in Iran Cancer Institute

BACKGROUND

Thyroid cancers are histologically classified into three types; differentiated thyroid carcinoma (DTC), medullary thyroid carcinoma (MTC), and anaplastic thyroid carcinoma (ATC). Among the several therapeutic strategies for treatment and management of thyroid cancer, surgical resection in combination with radioactive iodine therapy (RAI) is indicated for moderate to high-risk differentiated thyroid cancer (DTC) patients- according to current guidelines. However, external radiation therapy (EBRT) can be a viable alternative treatment option for these patients and scarce evidence is available regarding the efficacy and effectiveness of EBRT on thyroid cancer.

AIM

This study aims at evaluating the role of EBRT in the management of thyroid carcinomas.

METHODS AND RESULTS

In this retrospective cohort study, the records of 59 patients with thyroid cancer were accessed who were treated by EBRT from 2008 to 2016. The indications for EBRT included unresectable primary (definitive) or loco-regional recurrences (salvage) not suitable for RAI, palliation for local disease or metastatic foci (palliative), and the adjuvant treatment for suspected residual disease following resection. Progression-free survival (PFS) and overall survival (OS) were calculated for different types of cancer. PFS was measured from the start of EBRT to the last uneventful follow-up, recurrence, or death. Kaplan-Meier model was used for the survival analysis. Fifty-nine patients were evaluated. The histopathology of the tumors was differentiated and poorly-differentiated, medullary and anaplastic thyroid carcinomas in 22 and 6, 15 and 16 patients, respectively. Twenty-seven patients received external beam radiotherapy (EBRT) as adjuvant therapy and 18 of the cases as palliative therapy while the remaining received salvage or definitive primary EBRT. The stage of patients' cancer was as follows: stage II in 3 and III in 1, IVA in 18 and IVB in 18 and IVC in 19. Stage-based median overall survival was 26 months for IVA, 44 for IVB, and 29 for IVC. The median PFS was 18, 22 and 21 months for stages IVA, IVB and IVC, respectively.

CONCLUSION

Based on our findings, EBRT may still play a role in the management of patients with thyroid carcinoma and should be considered in the armamentarium against thyroid cancers.

Development and Validation of a Nomogram for Predicting Survival in Patients with Thyroid Cancer

BACKGROUND The AJCC staging system is inadequate for use in patients with thyroid carcinomas. Here, we aimed to establish a nomogram for thyroid cancer, and we compare its prognostic value with the AJCC staging system in adults diagnosed with thyroid carcinoma. MATERIAL AND METHODS Patient records were obtained from the Surveillance, Epidemiology, and End Result database. The 8491 included patients were divided into a modeling cohort (n=5943) and a validation cohort (n=2548). The variables included in the modeling cohort were selected using a backward stepwise selection method with Cox regression, and the prognosis nomogram was constructed. In the validation cohort, we compared our survival model with the AJCC prognosis model using the concordance index, the area under the time-dependent receiver operating characteristic curve, the net reclassification improvement, the integrated discrimination improvement, calibration plotting, and decision curve analysis. RESULTS Twelve independent prognostic factors were identified and used to establish the nomogram. In particular, marital status was included in a survival prediction model of thyroid cancer for the first time. The concordance index, area under the time-dependent receiver operating characteristic curve, net reclassification improvement, integrated discrimination improvement, calibration plotting, and decision curve analysis for the nomogram showed better performance compared to the AJCC staging system. CONCLUSIONS We have developed and validated a highly accurate thyroid cancer prognosis nomogram. The prognostic value of the nomogram is better than that of the AJCC staging system alone.

MiR-let-7e inhibits invasion and magration and regulates HMGB1 expression in papillary thyroid carcinoma

Thyroid cancer keeps rapidly increasing worldwide and the most frequent type is papillary thyroid carcinoma (PTC). MicroRNAs (miRNAs) are proved dysregulated in many types of malignancies, including thyroid cancer. Although miR-let-7e has been implicated in several types of cancer regulation, relatively little is known about the function of miR-let-7e in PTC. In this study, we showed that the overexpression of miR-let-7e or knockdown of high mobility group box 1 (HMGB1) inhibited cell migration and invasion. MiR-let-7e downregulates HMGB1 expression by directly targeting the HMGB1 3'-UTR. Furthermore, HMGB1 reintroduction reversed the anti-proliferation, anti-migration, and anti-invasion roles of miR-let-7e. miR-let-7e might function as a tumor suppressor in papillary thyroid carcinoma through HMGB1. Therefore, our study demonstrates that miR-let-7e plays an important role in papillary thyroid carcinoma progression and might represent a new potential therapeutic target for treatment.

External beam radiotherapy in thyroid carcinoma: clinical review and recommendations of the AIRO "Radioterapia Metabolica" Group

The therapeutic approach to thyroid carcinoma usually involves surgery as initial treatment. The use of external beam radiotherapy (EBRT) is limited to high-risk patients and depends on clinical stage and histologic type. Different behavior patterns and degrees of aggressiveness of thyroid carcinomas require different management for differentiated, medullary, and anaplastic carcinoma. However, the role of EBRT is an issue of debate. Most clinical studies are retrospective and based on single-institution experiences. In this article, we review the main literature and give recommendations for the use of EBRT in thyroid carcinoma on behalf of the "Radioterapia Metabolica" Group of the Italian Radiation Oncology Association.

Lentivirus-mediated silencing of MPHOSPH8 inhibits MTC proliferation and enhances apoptosis

Thyroid carcinoma (TC) is the most common malignancy of the endocrine organs, and its incidence rate has steadily increased over the last decade. For medullary thyroid cancer (MTC), a type of TC, a high mortality rate has been reported. In previous studies, M-phase phosphoprotein 8 (MPHOSPH8) displayed an elevated expression in various human carcinoma cells. Thus, MPHOSPH8 may be a sensitive biomarker that could be used for the diagnosis and follow-up of MTC. In the present study, plasmids of RNA interference targeting the MPHOSPH8 gene were constructed. Once these lentiviruses targeting MPHOSPH8 were transfected into the MTC cell line TT, cell viability and proliferation were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Flow cytometry was used to assess the cell cycle distribution and apoptosis. The expression levels of MPHOSPH8 were detected by reverse transcription quantitative-polymerase chain reaction and western blot analyses. Depletion of MPHOSPH8 significantly inhibited cell proliferation. Furthermore, knockdown of MPHOSPH8 in TT cells led to G0/G1 phase cell cycle arrest and apoptosis. The results of the present study suggest that MPHOSPH8 promotes cell proliferation and may be a potential target for anticancer therapy of MTC.

Comparison of serum calcitonin and procalcitonin in detecting medullary thyroid carcinoma among patients with thyroid nodules

BACKGROUND

To prospectively evaluate the role of procalcitonin (PCT) in detecting or excluding medullary thyroid carcinoma (MTC) among patients with thyroid nodules and increased calcitonin (CT) levels.

METHODS

Fourteen of 1236 patients referred for thyroid nodules had increased serum CT >10 pg/mL. A stimulation test with pentagastrin was done and both CT and PCT were measured after stimulation. All patients underwent thyroid ultrasound, fine-needle cytology and, if indicated, surgery with histological and immunohistochemical examination of the surgical specimens.

RESULTS

After follow-up, two MTCs were found. These two patients had basal CT >100 pg/mL and detectable (>0.1 ng/mL) PCT, with 100% sensitivity. Pentagastrin stimulated CT achieved values above 100 pg/mL in two MTCs and in other two cases with no MTC outcome (50% PPV and 83% NPV). On the contrary, all patients with no MTC had both basal and stimulated undetectable PCT (100% PPV and 100% NPV).

CONCLUSIONS

The addition of basal PCT measurement in patients with thyroid nodule(s) and increased CT may significantly improve accuracy of CT measurement without needing a PG stimulation test.

New treatment in advanced thyroid cancer

Thyroid cancer is the most common endocrine tumor. Thyroidectomy, radioactive iodine, and TSH suppression represent the standard treatment for differentiated thyroid cancer. Since chemotherapy has been shown to be unsuccessful in case of advanced thyroid carcinomas, the research for new therapies is fundamental. In this paper, we reviewed the recent literature reports (pubmed, medline, EMBASE database, and abstracts published in meeting proceedings) on new treatments in advanced nonmedullary and medullary thyroid carcinomas. Studies of many tyrosine kinase inhibitors as well as antiangiogenic inhibitors suggest that patients with thyroid cancer could have an advantage with new target therapy. We summarized both the results obtained and the toxic effects associated with these treatments reported in clinical trials. Reported data in this paper are encouraging, but further trials are necessary to obtain a more effective result in thyroid carcinoma treatment.

Efficacy of adding high-dose In-111 octreotide therapy during Sandostatin treatment in patients with disseminated neuroendocrine tumors: clinical results of 14 patients

PURPOSE

This study aimed to assess the outcome of high-dose In-111 octreotide treatment and efficacy of long-acting Sandostatin LAR in patients with disseminated neuroendocrine tumors.

MATERIALS AND METHODS

A total of 14 patients (mean age 51.8 ± 13.2 years; 10 female, 4 male) receiving high-dose In-111 octreotide in our centre for the treatment of neuroendocrine tumors were included in the study. Monthly treatment with long-acting somatostatin analogue [Sandostatin long-acting release (Novartis Pharmaceuticals)] was continued in nine cases.

RESULTS

During a 3-year period, a total of 45 courses of high-dose In-111 octreotide treatment were delivered to 14 patients. In seven patients receiving an average of four treatment courses (6 carcinoid tumors, 1 thymoma, patients: 2, 4, 5, 11-14) stable disease was achieved (50%). In two patients with carcinoid tumors (patients 1 and 3) who received four treatment courses, partial response was observed (14%). Five patients (36%; 4 NET, 1 gastrinoma; patients 6-10) died due to progressive disease following on average two treatment courses. On average, deaths occurred 2 months after the last treatment dose. No complete responses were seen. Partial response was achieved in two of the nine patients receiving Sandostatin LAR, while four had stable disease. Both treatments were associated with acceptable tolerability.

CONCLUSIONS

High-dose In-111 octreotide can be safely administered in conjunction with somatostatin analogue in patients with disseminated NET and this treatment may help to stabilize the disease.

Resveratrol induces Notch2-mediated apoptosis and suppression of neuroendocrine markers in medullary thyroid cancer

BACKGROUND

Currently, complete surgical resection is the only curative option for medullary thyroid cancer (MTC). Previous work has shown the Notch pathway is a potent tumor suppressor in MTC and that resveratrol activates the Notch pathway in carcinoid cancer, a related neuroedocrine malignancy. In this study, we hypothesized that the effects observed on carcinoid cells could be extended to MTC.

METHODS

MTC cells treated with varying doses of resveratrol were assayed for viability by the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. Western blot analysis for achaete-scute complex-like 1 (ASCL1), chromogranin A (CgA), full-length and cleaved caspase 3, and poly-ADP ribose polymerase (PARP) was performed. Quantitative real-time polymerase chain reaction (qPCR) was used to measure relative mRNA expression.

RESULTS

Treatment with resveratrol resulted in growth suppression and an increase in the cleavage of caspase-3 and PARP. A dose-dependent inhibition of ASCL1, a neuroedocrine transcription factor, was observed at the protein and mRNA levels. Protein levels of CgA, a marker of hormone secretion, were also reduced after treatment with resveratrol. A dose-dependent induction of Notch2 mRNA was observed by qPCR.

CONCLUSIONS

Resveratrol suppresses in vitro growth, likely through apoptosis, as demonstrated by cleavage of caspase-3 and PARP. Furthermore, resveratrol decreased neuroedocrine markers ASCL1 and chromogranin A. Induction of Notch2 mRNA suggests that this pathway may be central in the anti-MTC effects observed.

Medullary thyroid carcinoma with micronodular lung metastases: a case report with an emphasis on the imaging findings

Medullary thyroid carcinoma is a rare malignancy that arises from calcitonin-producing C-cells and frequently metastasizes to lymph nodes in the neck. Distant metastases may involve bone, lung, and liver. The infrequent number of cases limits the clinical nature and ability to optimize diagnostic tools. Here, we present a case of a micronodular radiographic pattern in metastatic medullary thyroid cancer in order to enhance awareness of the disease process. A case discussion and relevant review of the literature are provided.

Procalcitonin: a marker for the diagnosis and follow-up of patients with medullary thyroid carcinoma

CONTEXT

Calcitonin (CT) is the main medullary thyroid carcinoma (MTC) tumor marker. However, it has several limitations, including a concentration-dependent biphasic half-life, sensitivity to rapid in vitro degradation, and the presence of different isoforms/fragments. Procalcitonin (PCT), the prohormone of calcitonin, is free of these limitations but is currently used only as a sepsis marker.

OBJECTIVES

The objective of the study was to determine whether PCT is suited as a MTC tumor marker by comparing the diagnostic performance of PCT with that of CT in MTC.

DESIGN

PCT and CT were measured in a total of 835 subjects, including normal volunteers (n = 197) and patients with active-MTC (n = 91), cured-MTC (n = 42), neuroendocrine tumors (n = 225), mastocytosis (n = 48), follicular cell-derived thyroid carcinoma (cured = 120, persistent/recurrent = 55), and benign thyroid disease (n = 57).

RESULTS

PCT levels were significantly higher in the active-MTC patients (mean 126.4 ng/ml) than the cured-MTC patients (mean <0.1 ng/ml). The overall concordance between the two markers was 95.7% (kappa = 0.81). Receiver-operating characteristic curve analysis showed no significant difference in diagnostic performance between CT and PCT. PCT's diagnostic sensitivity and specificity were 91 and 96%, respectively. The corresponding values for CT were 99 and 98%. Analyte stability studies showed that CT is very unstable in vitro with a decrease of 35-50% from the original value 24 h after the blood draw, whereas PCT levels did not significantly change during this time.

CONCLUSIONS

A strong correlation was observed between PCT and CT levels in patients with MCT. Given PCT's greater analytical stability, we conclude that it represents a promising complementary MTC tumor marker.

Functional nuclear medicine imaging of medullary thyroid cancer

Medullary thyroid cancer (MTC) originates from parafollicular C cells of the thyroid and accounts for 3-12% of all thyroid cancers. As opposed to other types of dedifferentiated thyroid tumours, MTC cells are highly functional, producing and secreting high amounts of calcitonin and carcinoembryonic antigen. As parafollicular C cells are of neural crest origin, MTC acts as a neuroendocrine tumour also and expresses somatostatin receptors. Although conventional radiological methods such as ultrasonography, computed tomography and magnetic resonance imaging are widely used in the primary diagnosis and staging, they often fail to localize the residual or recurrent disease because the majority of MTC recurrence presents as occult disease. Thus, owing to functional characteristics of MTC, functional imaging modalities of nuclear medicine play a major role in the diagnostic and therapeutic strategies for MTC. Among nuclear medicine modalities, Tc(V) -dimercaptosuccinic acid, In-octreotide and I/I-meta-iodobenzylguanidine are commonly used in the diagnostic and even more in postoperative work-up of MTC. Alternatively, F-fluorodeoxyglucose and other positron emission tomography radiopharmaceuticals such as F-fluorodopa or F-fluorodopamine as well as radiolabelled antibodies such as Tc/I/I anticarcinoembryonic antigen, antigastrin, and anticholecystokinin-B have promising results. Functional imaging has a great advantage for nuclear medicine techniques in the routine work-up of MTC patients and also has a wide use in experimental studies.

A new germline point mutation in Ret exon 8 (cys515ser) in a family with medullary thyroid carcinoma

BACKGROUND

A novel Cys-Ser Ret germline point mutation in a 58-year-old woman with bilateral medullary thyroid carcinoma (MTC) prompted us to perform genetic analysis of the family and evaluate the biological consequences of such a mutation.

METHODS

Ret analysis by direct sequencing was performed in five family members. The biological activity and biochemical properties of the Ret- Cys515Ser mutant were analyzed in NIH-3T3 cells.

RESULTS

The proband's son, age 35, had the Ret- Cys515Ser mutation and the L769 CTT/CTG exon 13 polymorphic variant, which was also found in his father. Clinical evaluation of the son also revealed bilateral multifocal microscopic MTC and papillary thyroid carcinoma (PTC). In vitro and in vivo analysis indicated ligand-independent activation of the Ret-Cys515Ser mutant due to aberrant disulfide homodimerization, increased mitogenic activity, and ability to induce anchorage-independent growth in NIH-3T3 cells in comparison to wild-type Ret, suggesting a possible role of Cys515Ser in tumor development.

CONCLUSIONS

The Cys515Ser mutation adds to cysteine substitution groups that have been described in association with MTC. Our data also highlight the importance of performing a complete genetic analysis in patients who present with MTC.

The role of somatostatin analogues in the treatment of neuroendocrine tumours

Neuroendocrine tumours belong to a heterogeneous family of neoplasms, originating in endocrine glands (such as the pituitary, parathyroid or the neuroendocrine adrenal glands), in endocrine islets (within the thyroid or pancreas) as well as in endocrine cells dispersed between exocrine cells throughout the digestive or respiratory tracts. The clinical behaviour of neuroendocrine tumours is variable; they may be functioning or not functioning, ranging from well-differentiated slow growing neuroendocrine tumours to poorly differentiated neuroendocrine tumours, which are highly aggressive malignant tumours. The development of somatostatin analogues as important diagnostic and treatment tools have revolutionised the clinical management of patients with neuroendocrine tumours. However, although symptomatic relief and stabilisation of tumour growth for various periods of time are observed in many patients treated with somatostatin analogues, tumour regression is rare. Development of new somatostatin analogues and new drug combination therapies should further improve the clinical management of these patients.

Neck management in medullary thyroid carcinoma

AIMS

The aims of this study were to retrospectively evaluate incidence and patterns of lymph node metastases, surgical treatment and prognostic factors of medullary thyroid carcinoma.

METHODS

Out of a group of 70 MTC patients data of 67 patients were collected. Sixty-two of these patients underwent surgery. Apart from thyroidectomy, 16 patients underwent a bilateral neck dissection, 21 a unilateral neck dissection and 29 a paratracheal dissection or node-picking operation. Thirty-six patients were irradiated, of which 31 postoperatively and five with palliative intent.

RESULTS

Lymph node metastases were found in 91% of the ipsilateral neck dissection specimens, 91% of the paratracheal dissections and 63% of the contralateral dissections. Of the 12 elective neck dissections, 5 were tumor positive. Level VI was positive in 91% of the cases where a dissection was done, whereas preoperatively only 16% were scored tumor positive. During follow-up 22 of the 67 patients developed one or more locoregional recurrences (in total 28 recurrences). The most important factors that were correlated with a worse prognosis of survival were late stage of disease (stage III and IV) (p=0.0014), high number of positive lymph nodes (p=0.0023) and incomplete surgical resection (p=0.0002).

CONCLUSIONS

The high rate of locoregional recurrences in this study are a strong argument for a more aggressive approach to the primary and neck. A routine central and ipsilateral selective neck dissection of levels II-V should be considered in all MTC patients based on the high incidence of metastases and the relative low morbidity of a unilateral neck dissection. Patients referred after thyroidectomy alone with elevated (stimulated) calcitonin levels should be re-operated, performing an elective or therapeutic central and unilateral neck dissection.

Palliation of advanced thyroid malignancies

While most thyroid cancers are slow-growing and have an excellent prognosis after appropriate treatment, a subset of thyroid cancers behave aggressively, and approximately 1500 individuals in the US will die of the disease in the year 2007. Advanced thyroid malignancies can cause distressing and life-threatening symptoms by local invasion in the neck, growth of distant metastases in the lung, bone, and other organs, and tumor production of bioactive substances in the case of medullary thyroid cancer. This article will review palliative modalities, including surgery, radioactive iodine, external beam radiation, and chemotherapy, as well as novel targeted therapies, for the treatment of patients with advanced thyroid malignancies.

Nuclear medicine procedures in the diagnosis and therapy of medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare neuroendocrine tumor originating in the parafollicular cells (C cells) of the thyroid and secretes both calcitonin and carcino-embryonic antigen (CEA). Genetic and biochemical testing allow early pre-clinical identification of familial forms. Sporadic MTC usually presents as a solitary thyroid nodule; the diagnosis can be made preoperatively by fine-needle aspiration or by calcitonin assay, though it is usually established at the time of surgery. In the diagnostic assessment of MTC, nuclear medicine imaging provides its contribution mainly in the post-operative work-up to detect residual/recurrent tumor. For such purpose a number of radiopharmaceuticals, which take advantage of the specific expression of receptors (the somatostatin analogue (111)In-octreotide), hormone transporters (radiolabelled MIBG) or molecular targets (radiolabelled anti-CEA monoclonal antibodies) by MTC lesions are available; these tracers may be used also for the palliative treatment of advanced MTC. Interesting perspectives for MTC imaging are offered by PET radiopharmaceuticals.

Initial Lymph Node Dissection Increases Cure Rates in Patients with Medullary Thyroid Cancer

OBJECTIVE

Medullary thyroid carcinoma (MTC) is the third most common type of thyroid cancer. MTC spreads early to local lymph nodes, and most endocrine surgeons recommend total thyroidectomy with central lymph node dissection (CLND) as the minimum initial operation. We reviewed our experience to determine if the initial operation influences clinical outcomes.

METHODS

Twenty-two patients with sporadic or inherited MTC who received surgery at one academic centre between 1994 and 2004 were identified. Clinical, operative, and pathology findings were reviewed.

RESULTS

Ten patients had prophylactic thyroidectomy for hereditary MTC, while 12 patients underwent therapeutic operations for sporadic MTC. The average age of the prophylactic group was 11 +/- 3, and 43 +/- 6 years for the therapeutic group. All patients in the prophylactic group received thyroidectomy without neck dissection. No patient in the prophylactic group had residual disease or required re-operation. In the therapeutic surgery group, three patients were treated with thyroidectomy plus CLND, and nine patients received thyroidectomy alone. The CLND group had a significantly higher cure rate as demonstrated by a lower incidence of residual disease (0% vs. 89%, p = 0.018), and re-operations (0% vs. 78%, p = 0.045).

CONCLUSION

Initial CLND for MTC increases cure rates by reducing residual disease and re-operations.

Heat shock treatment of tumor lysate-pulsed dendritic cells enhances their capacity to elicit antitumor T cell responses against medullary thyroid carcinoma

BACKGROUND

In vitro and in vivo studies have shown that dendritic cells (DCs) can stimulate antitumor T cell responses against medullary thyroid carcinoma (MTC). However, despite promising results in selected cases, the clinical efficacy of DC immunotherapy in patients with MTC has been limited. Recently, it has been demonstrated in mice that heat shock enhances the capacity of bone-marrow-derived DCs to stimulate antigen-specific T cells. The aim of our investigations was to evaluate whether heat shock also increases the capacity of human monocyte-derived DCs to stimulate antitumor T cell responses against MTC tumor cells.

METHODS

DCs from six patients with metastatic MTC were pulsed with tumor lysate derived from allogeneic MTC tumor cells and were heat shocked for 12 h at 40 C or kept at 37 C. Thereafter, the DCs were matured and cocultured with T cells. Finally, the cytotoxic activity of T cells against MTC tumor cells was measured in vitro.

RESULTS

In all patient samples, cytotoxic T cell responses against MTC tumor cells could be induced. Notably, heat-shocked DCs were more potent stimulators of cytotoxic T cell responses than control DCs, with T cells stimulated with heat-shocked DCs displaying a significantly increased cytotoxic activity against MTC tumor cells as compared with T cells stimulated with control DCs. In none of the experiments was a cytotoxic T cell response against unrelated pancreatic tumor cells (PANC-1) observed, using both control and heat-shocked DCs.

CONCLUSIONS

Our study shows that heat-shocking DCs may be a valuable strategy to increase the immunostimulatory capacity of DCs used for immunotherapy of MTC.

Thyroid Cancer Susceptibility and THRA1 and BAT-40 Repeats Polymorphisms

Although genetic and environmental factors have been identified in the etiology of thyroid cancer, the specific genetic implications in sporadic thyroid tumors are poorly understood but, as in other common cancers, low-penetrance susceptibility genes are believed to be crucial in the tumorigenesis processes. Here, we have carried out a case-control study to investigate whether there is an association between THRA1 CA repeat or BAT-40 A repeat polymorphisms and thyroid cancer risk. The THRA1 repeat resides in the thyroid hormone receptor-alpha1 gene, which is associated with thyroid cancer and whose expression depends on the THRA1 repeat size. We also analyzed the BAT-40 repeat that maps to chromosome 1, a region known to be involved in thyroid cancer. This repeat is located in the 3-beta-hydroxysteroid dehydrogenase gene that is associated with prostate cancer susceptibility. The THRA1 repeat was genotyped in 212 thyroid cancer patients and 141 controls of a Spanish population. From these individuals, 207 patients and 138 controls were also analyzed for the BAT-40 marker. No significant difference in the THRA1 allele distribution between patients and controls was found, although short alleles (<128 bp) might have some protective effect on thyroid cancer risk of carriers (odds ratio, 0.50; 95% confidence interval, 0.22-1.13; P = 0.094). By contrast, the BAT-40 allele distribution in patients was significantly different with respect to control (P = 0.035). Essentially, the difference were found in the genotypes involving the 111- to 115-bp allele range, which seem to be associated with a protective effect on thyroid cancer susceptibility in the studied population (odds ratio, 0.18; 95% confidence interval, 0.01-0.57; P = 0.02). Therefore, our results indicate that the BAT-40 containing region and to a less extend the thyroid hormone receptor-alpha1 gene are related to thyroid cancer susceptibility. To our knowledge, this is the first study reporting the identification of genetic factors for thyroid cancer susceptibility.

Dendritic cell vaccination in medullary thyroid carcinoma

PURPOSE

Prognosis and treatment effectiveness for medullary thyroid carcinoma (MTC) are strictly related to tumor stage. Palliative treatment options show no significant benefit. A promising treatment approach for human cancer is based on the vaccination of autologous dendritic cells (DCs).

EXPERIMENTAL DESIGN

The objective of this study was to evaluate the effectiveness of DC vaccines in MTC patients. Therefore, we generated autologous tumor lysate-pulsed DCs from 10 patients suffering from advanced MTC for repeated vaccination. Mature DCs were derived from peripheral blood monocytes by using CD14 magnetic bead selection and subsequent culture in the presence of granulocyte macrophage colony-stimulating factor, interleukin 4, and tumor necrosis factor alpha with or without addition of IFN-gamma. DCs were loaded with tumor lysate and further injected into a groin lymph node. Toxicity, tumor marker profile, immune response, and clinical response were determined.

RESULTS

Vaccination was well tolerated and induced a positive immunological response in all of the tested patients as evaluated by in vivo delayed-type hypersensitivity reactivity or in vitro intracytoplasmic IFN-gamma detection assay. Three patients had a partial response, 1 patient presented a minor response, and 2 patients showed stable disease. The remaining 4 patients had progressive disease.

CONCLUSIONS

These data provide strong evidence that vaccination with tumor-lysate pulsed DCs results in the induction of a specific immune response in patients suffering from MTC. Objective clinical responses could be observed even for far-advanced disease. Therefore, we suggest that MTC is particularly suited for DC-based immunotherapy.

The diagnosis and medical management of advanced neuroendocrine tumors

Neuroendocrine tumors (NETs) constitute a heterogeneous group of neoplasms that originate from endocrine glands such as the pituitary, the parathyroids, and the (neuroendocrine) adrenal, as well as endocrine islets within glandular tissue (thyroid or pancreatic) and cells dispersed between exocrine cells, such as endocrine cells of the digestive (gastroenteropancreatic) and respiratory tracts. Conventionally, NETs may present with a wide variety of functional or nonfunctional endocrine syndromes and may be familial and have other associated tumors. Assessment of specific or general tumor markers offers high sensitivity in establishing the diagnosis and can also have prognostic significance. Imaging modalities include endoscopic ultrasonography, computed tomography and magnetic resonance imaging, and particularly, scintigraphy with somatostatin analogs and metaiodobenzylguanidine. Successful treatment of disseminated NETs requires a multimodal approach; radical tumor surgery may be curative but is rarely possible. Well-differentiated and slow-growing gastroenteropancreatic tumors should be treated with somatostatin analogs or alpha-interferon, with chemotherapy being reserved for poorly differentiated and progressive tumors. Therapy with radionuclides may be used for tumors exhibiting uptake to a diagnostic scan, either after surgery to eradicate microscopic residual disease or later if conventional treatment or biotherapy fails. Maintenance of the quality of life should be a priority, particularly because patients with disseminated disease may experience prolonged survival.

Incidentally found medullary thyroid cancer: treatment rationale for small tumors

The object of this study was to assess the extent of surgery required for small sporadic medullary thyroid cancers (sMTCs). We retrospectively studied 261 patients with MTCs treated in our institution between 1986 and 2002 and identified 15 patients with small pT1 or pT2 sMTCs. The tumors were diagnosed incidentally, so surgical therapy was less than total thyroidectomy. Total thyroidectomy with or without neck dissection was applied to all other patients as standard surgical treatment of care. Patients were systematically followed up by postoperative ultrasonography, calcitonin, carcinoembryonic antigen levels, and pentagastrin stimulation tests. On long-term follow-up over a period of 4.6 years, the rate of biochemical cure in these patients who underwent less than total thyroidectomy for a sporadic incidentally diagnosed tumor was 100%. We concluded that completion thyroidectomy and neck dissection are not mandatory in patients in whom a solitary small sMTC is incidentally discovered by histologic diagnosis following operation so long as a genetic background is excluded. Nevertheless, such patients require systematic careful long-term follow-up.

Potential Absence of Prognostic Implications of Severe Preoperative Hypercalcitoninemia in Medullary Thyroid Carcinoma

OBJECTIVE

To evaluate preoperative hypercalcitonine-mia further as a marker of prognosis in patients with medullary thyroid carcinoma (MTC).

METHODS

We reviewed the clinical and laboratory data in six patients (four men and two women, 39 to 76 years old)--three with sporadic MTC, one with familial MTC, and two with multiple endocrine neoplasia type 2A--who had preoperative basal serum calcitonin levels of 400 to 16,000 pg/mL (normal, 0 to 19). Pentagastrin stimulation was performed in patients who had preoperative basal calcitonin levels less than 1,000 pg/mL, and responses ranged from 2,600 to 8,500 pg/mL. Thyroidectomy revealed intrathyroidal MTC in four patients; MTC and nodal metastatic lesions were present in two. The tumor cells were immunoreactive with anti-calcitonin immunoperoxidase staining.

RESULTS

Serum calcitonin and carcinoembryonic antigen levels were normal postoperatively. In serial postoperative evaluation during a follow-up period of 2 to 9 years, stimulated peak plasma calcitonin levels after pentagastrin or calcium infusion were normal (in five patients) or near normal (in one patient), without clinical evidence of recurrent disease. The two patients with nodal metastatic disease have had normal calcitonin levels during a mean duration of follow-up of approximately 3 years.

CONCLUSION

Pronounced preoperative hypercalci-toninemia does not necessarily preclude a favorable short-term outcome in patients with MTC.

A population-based analysis of survival factors in differentiated and medullary thyroid carcinoma

OBJECTIVE

The study purpose was to determine survival and prognostic factors for differentiated thyroid carcinoma (DTC).

METHODS

Cases of DTC were extracted from the Surveillance, Epidemiology and End Results database from 1988 through 1998. Kaplan-Meier survival analysis was conducted for papillary, follicular, and medullary histologies. Cox proportional hazard analysis was used to examine the influence of age, gender, tumor size, local extension, and cervical node involvement on overall survival.

RESULTS

A total of 18,118 cases were identified, including 15,820 (87.3%) papillary carcinomas, 1799 (9.9%) follicular carcinomas, and 499 (2.8%) medullary carcinomas. Mean survival (10-year survival) was 122 (87.7%), 117 (80.2%), and 108 (73.7%) months for papillary, follicular, and medullary tumors, respectively. For each histology, increasing age, male gender, and degree of local extension substantially reduced survival. Cervical metastasis did not influence survival for papillary or follicular carcinomas but approached significance for medullary carcinoma (P = 0.065).

CONCLUSIONS

Degree of local extension in thyroid carcinoma should be subclassified to more accurately determine prognosis. Treatment of the neck should be considered for medullary thyroid carcinoma.

[Radiotherapy in malignant tumors of the thyroid gland]

The primary treatment of thyroid gland malignoma is surgery. Success of radiotherapy depends of extent of the previous surgery treatment. The types of radiotherapy are: curative (prophylactic and postoperative) and palliative. Tumor dose and radiotherapy tehnique depend on histologica type, extent of the previous surgery treatment, curative or paliative intent and general condition of patient, and they are from 40 Gy to 65 Gy by conventional fractionation. The basis of radiotherapy treatment planning and choice of radiotherapy treatment technique in survey of the region of interest by imaging procedure. On the basis of those data we determine therapeutic volume and structure of risk (spinal cord, lung) and protection of the risky structures is planned.

Medularni karcinom stitaste zlezde-uticaj postoperativne transkutane zracne terapije u lokalnoj kontroli i rezultatima lecenja

In the period of Octo. 01, 1987. up to Dec. 31, 1998. retrospective-prospective, non-randomized study was conducted at IORS, which included 36 patients diagnosed with thyroid gland medullar cancer. Our study had the following aims: evaluation of treatment results following probability of total survival, survival without signs of disease and disease-free interval until local reccurrence of the disease and influence of parameters of transcutaneous radiotherapy (intensity of total tumor dose and length of disease-free interval from date of performed operation to beginning of radiotherapy). After finished treatment, median of the patient follow-up was 37,75 months (3,5 up to 141 monts); probability of total five-year survival was 62,61% and of 10 year survival was 23,48%. Probability of 5-year survival, without signs of disease was 37,13%, and of 10-year survival 18,56%. As to radiotherapy parameters, intensity of total therapy dose was statisticaly insignificant, while time interval to beginning of transcutaneuos radiotherapy, shorter than 2 months, was statistically significant in relation to prognosis of disease outcome.

Polymerase chain reaction in the detection of tumor cells: new approaches in diagnosis and follow-up of patients with thyroid cancer

Thyroid cancers are the most common endocrine malignancies and are being diagnosed with increasing frequency. In addition to other measures, diagnosis is based on fine-needle aspiration cytology examination. Recently, new assays using reverse transcription-polymerase chain reaction (PCR) are being tested to improve sensitivity and specificity of primary diagnosis and detection of recurrent thyroid cancer. In the preoperative diagnosis of thyroid cancer, several tissue- and/or tumor-specific mRNA have been described and in several cases, a higher sensitivity and specificity could be achieved using molecular techniques compared to conventional methods. In the postoperative follow-up of patients with thyroid cancer, conflicting data have been published and the use of PCR techniques revealed several problems of the molecular approach, which are based on some technical as well as biologic limitations. Despite these problems, which are discussed in detail in this review, molecular techniques may nevertheless improve the sensitivity and accuracy of fine-needle aspiration of thyroid nodules, fine-needle aspiration of metastases, and detection of recurrent disease in peripheral blood samples.

Comparison of Two Provocative Tests for Calcitonin in Medullary Thyroid Carcinoma: Omeprazole vs Pentagastrin

Background: Provocative tests for calcitonin (CT) are fundamental in the diagnosis and follow-up of C-cell disease and in the detection of hereditary medullary thyroid carcinoma (MTC) carriers with unknown RET mutations. A recent report has proposed omeprazole, which can increase endogenous gastrin (GT), as a new provocative test for MTC.

Methods: We compared the omeprazole test (20 mg twice a day for 4 days) to the pentagastrin test (0.5 μg/kg of body weight) for the diagnosis and management of MTC. Twenty healthy individuals and 20 MTC patients with mildly or moderately increased basal CT serum concentrations underwent the pentagastrin and omeprazole tests.

Results: In MTC patients, the pentagastrin test produced a significantly higher increase in serum CT than did omeprazole. After the pentagastrin injection, several patients reported unpleasant side effects, including substantial tightness in 38 of 40 participants. No adverse effects were observed during the omeprazole test. A significant direct correlation was recorded between CT% (ratio of CT peak to basal value × 100) and GT% (ratio of GT peak to basal value × 100) during the omeprazole test in MTC patients (r = 0.73; P &lt;0.001).

Conclusions: In spite of several adverse effects, pentagastrin remains the best provocative test for the diagnosis of MTC. Omeprazole may be useful when pentagastrin is contraindicated or refused because of the unpleasant side effects, but further validation is needed.

Treatment of advanced neuroendocrine tumours using combination chemotherapy with lomustine and 5-fluorouracil

OBJECTIVE

Combination chemotherapy with the two agents streptozotocin (SZT), which is a nitrosurea, and 5-fluorouracil (5-FU), an alkylating agent, has a long-established role in the treatment of neuroendocrine tumours; however, it is often accompanied by considerable toxicity, and it has not been assessed in a comparative manner with other current chemotherapy regimens. In order to assess the therapeutic response and adverse effects using an alternative nitrosurea, lomustine (CCNU), which has a different side-effect profile, in combination with 5-FU, we have reviewed all patients with neuroendocrine tumours who received this form of treatment in our department.

DESIGN

Retrospective analysis of the case notes of patients with metastatic neuroendocrine tumours who received treatment with the combination of CCNU and 5-FU, and who were followed up according to a defined protocol in a given time frame.

PATIENTS

Thirty-one patients with metastatic neuroendocrine tumours (18 with carcinoid tumours, five islet-cell tumours, five chromaffin-cell tumours and three medullary carcinoma of the thyroid) treated with the combination of CCNU and 5-FU, and when necessary additional therapy, over a 22-year period, were included in this analysis.

MEASUREMENTS

The symptomatic, hormonal and tumoural responses before and after chemotherapy with the combination of CCNU and 5-FU over a median follow-up duration of 25 months (range 9-348 months) were recorded. Of the 31 patients (16 males; median age 52 years, range 20-86 years), eight (four males; median age 61 years, range 30-74 years) were treated with the combination of CCNU and 5-FU alone (Group 1), whereas the other 23 patients (12 males; median age 47 years, range 20-86 years) received additional therapy with other chemotherapeutic regimens, somatostatin analogues, alpha-interferon or radiolabelled meta-iodobenzylguanidine (131I-MIBG) therapy (Group 2).

RESULTS

A total of 121 therapeutic cycles was administered (mean 3.9, range 1-14 cycles). None of the patients obtained a complete tumour response. A partial tumour response (not a complete but a 50% or greater reduction of all measurable tumour) was seen in six out of the 29 patients (21%) (four out of eight in Group 1 and two out of 21 in Group 2, respectively). There was no tumour progression in eight out of the 29 patients (27.5%) (one out of eight in Group 1 and seven out of 21 in Group 2, respectively). The median survival over the period of the study was 48 months (95% confidence interval, CI, 22-74 months). The overall 5-year survival rate was 42% (95% CI, 17-67%) for all patients and 50% (95% CI, 18-83%) for the carcinoid group alone, according to Kaplan-Meier analysis. A complete or partial symptomatic response was obtained in 12 out of 27 (44%) patients who presented with symptoms (four out of eight in Group 1 and eight out 19 in Group 2, respectively) and a complete or partial hormonal response in eight out of 19 patients (42.1%) who presented with hormonally active disease (two out of four in Group 1 and six out of 15 in Group 2, respectively). Nine out of the 15 (60%) patients with carcinoid tumours who presented with symptoms obtained a symptomatic response, five out of 10 patients (50%) a hormonal response, and four out of 16 (25%) patients a partial tumoural response, respectively. The combination of CCNU and 5-FU was safe and well tolerated. Serious side-effects necessitating the termination of CCNU and 5-FU were seen only in two patients, and mainly consisted of reversible bone marrow suppression. No chemotherapy-related death was recorded.

CONCLUSIONS

Chemotherapy with CCNU and 5-FU, either alone or in combination with other therapeutic modalities, produces considerable symptomatic and hormonal improvement and moderate tumour regression/stabilization according to currently accepted WHO criteria, particularly in patients with metastatic gastroenteropancreatic neuroendocrine tumours with minimal adverse effects. However, long-term survival was still relatively poor. It may therefore be a valuable additional therapl was still relatively poor. It may therefore be a valuable additional therapeutic option, particularly for well-differentiated carcinoid and islet-cell tumours, but mainly reserved for when there is no response or progression of the disease after currently available first-line treatment with somatostatin analogues or radiopharmaceuticals.

Providing information to patients with a rare cancer: using Internet discussion forums to address the needs of patients with medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare disease, and specific experience with the condition is not commonly found outside of major cancer centers. Because of the rarity and slow-growing natural history of the disease, patients with MTC frequently have many questions concerning prognosis, treatment, and follow-up care. Many of these patients have joined an e-mail group on the Internet through which they share information and concerns. The author has joined this group and shares her expert clinical knowledge about the disease. When individuals are armed with accurate and expert information, they can make informed decisions. The source of this information can be diverse. Nurses with expert knowledge can use opportunities such as e-mail groups to answer questions and respond openly about subjects about which they have unique perspectives.

The mdm2 proto-oncogene sensitizes human medullary thyroid carcinoma cells to ionizing radiation

We have analysed the radiation response of a human medullary thyroid carcinoma cell line (MTT), characterized by the absence of a functional p53 protein, and the consequences of MDM2 overexpression in this process. We show that the product of the mdm2 proto-oncogene is able to sensitize MTT cells to ionizing radiation. After radiation treatment, MTT cells display histograms consistent with a G2M arrest. MTT cells expressing MDM2 (MTT-mdm2) are unable to respond to DNA damage with G2M arrest, and display a high percentage of apoptosis. MTT-mdm2 cells show high levels of E2F-1 protein, suggesting that the induction of apoptosis observed upon MDM2 overexpression could be dependent on E2F-1. This observation is further supported with assays showing that E2F-1 binding to specific DNA sequences is enhanced in MTT-mdm2 cells. Likewise, transactivation of reporter constructs exclusively dependent on E2F-1 is also elevated after transfection with MDM2. This effect can be reverted by transient transfection with p19ARF. To link the expression of E2F-1 with the induction of apoptosis, we generated clonal cell lines overexpressing E2F-1. Transfection with E2F-1 results in a low number of outgrowing colonies with reduced proliferation rates, indicating that E2F-1 is deleterious for cell growth. This negative regulation correlates with an increase in the percentage of the cell population with DNA content below 2N, suggesting that E2F-1 promotes apoptosis. Finally, overexpression of E2F-1 sensitizes MTT cells to radiation exposure. We conclude that the effects observed by MDM2 overexpression could be mediated by E2F-1.

Interaction of bisphosphonates with calcitonin in monitoring medullary carcinoma of the thyroid

We report the case history of a patient with long standing recurrent medullary carcinoma of the thyroid. Elevation of the serum marker calcitonin coincided with the introduction of biphosphonate therapy and recurrence of tumour was not established. The interaction of biphosphonates with calcitonin is not previously recorded.

Current approaches and perspectives in the therapy of medullary thyroid carcinoma

BACKGROUND

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor derived from parafollicular cells. At present, surgery is the most important treatment for MTC.

METHODS

We describe the current approaches of MTC treatment (surgery, chemotherapy, radiation therapy, and biologic therapy).

RESULTS

MTC is currently approached surgically in the main part through total thyroidectomy and compartment-oriented microdissection of cervicomediastinal lymph nodes. Substitutive l-thyroxine administration together with close clinical monitoring and the measurement of basal and stimulated serum calcitonin are subsequently performed. Radiotherapy and chemotherapy play a marginal role in advanced MTC. Recently, it has been found that somatostatin analogs and type I interferon are able to control the neuroendocrine symptoms induced by advanced MTC and that they provide clinical benefit by improving the lifestyle of these patients.

CONCLUSION

Although these agents are poorly active in inducing a shrinkage in tumor mass, the combined use of different biologic agents and cytotoxic drugs needs to be explored in advanced MTC. However, at present, surgery is the only curative treatment for MTC.

Induction of a cellular and humoral immune response against preprocalcitonin by genetic i: a potential new treatment for medullary thyroid carcinoma

Currently, no effective therapy exists for patients suffering from progressive medullary thyroid carcinoma (MTC), a calcitonin (CT)-secreting C cell tumor. As CT, which arises from the precursor protein preprocalcitonin (PPCT), is expressed by almost all MTC cases, these molecules may represent target antigens for immunotherapy against MTC. In our study we investigated whether DNA immunization is able to induce cellular and humoral immune responses against human PPCT (hPPCT) in mice. Antigen-encoding expression plasmids were delivered intradermally by gene gun. One group of mice received DNA encoding hPPCT only. Two groups were coinjected with mouse cytokine genes. We observed in lymphocyte proliferative assays substantial proliferation against hPPCT in mice coinjected with the granulocyte-macrophage colony-stimulating factor (GM-CSF) gene, in contrast to mice vaccinated with hPPCT expression plasmid only. In addition, codelivery of the GM-CSF gene augmented the frequency of anti-hPPCT antibody seroconversions in sera of immunized animals, as shown by enzyme-linked immunosorbent assay. These results illustrate that cellular and humoral immune responses against hPPCT can be generated by DNA immunization and increased by coinjection of the GM-CSF gene. Our findings may have implications for the use of DNA immunization as a potential novel immunotherapeutic treatment for patients suffering from progressive MTC.

Multiple endocrine neoplasia type iia: report of a family with a study of three generations in qatar

OBJECTIVE

To study the pattern of multiple endocrine neoplasia type IIA (MEN IIA) and describe the clinical features and results of genetic testing and treatment in 21 members of the first reported family with MEN IIA in Qatar.

METHODS

After identification of the proband, we screened all her family members (21 members) with genetic testing for the RET proto-oncogene mutation. Those subjects with the mutation were further assessed for pheochromocytoma by measurement of the 24-hour urinary vanillylmandelic acid, metanephrines, and catecholamines, and those with high levels underwent a metaiodobenzylguanidine scan and adrenalectomy. The serum calcium was measured in a effort to detect hyperparathyroidism. Those family members who had the mutation and were eligible for surgical treatment underwent total thyroidectomy and central compartment dissection. In those patients with high postoperative calcitonin levels, residual disease was sought with radiologic imaging, and follow-up was done with pentagastrin stimulation tests.

RESULTS

Of the 21 family members screened, 10 had the RET proto-oncogene mutation (codon 634, TGC->GGC) (5 females and 5 males; 6 adults and 4 children). All the adults had bilateral medullary thyroid carcinoma (MTC); four of them had lymph node metastatic lesions, and one had metastatic involvement of the liver. Two adults had pheochromocytomas. Two family members were reported to have parathyroid hyperplasia, although both were normocalcemic.

CONCLUSION

This family with MEN IIA showed classic mendelian autosomal dominant inheritance. All adult patients had MTC, two had pheochromocytomas, and two had parathyroid hyperplasia. Although one child had a high stimulated calcitonin level, the histopathologic findings were normal; another child with high stimulated calcitonin levels showed C-cell hyperplasia on histopathologic examination.

RET proto-oncogene mutation in a mixed medullary-follicular thyroid carcinoma

A case of a patient with an uncommon thyroid carcinoma, showing histological and immunohistochemical features of both follicular and parafollicular cells is described. Somatic point mutation (ATG to ACG heterozygotic mutation at codon 918) of the RET proto-oncogene was detected in tumor tissue, as confirmed by immunohistochemical expression of RET oncoprotein. Our findings suggest that constitutive RET proto-oncogene activation may be involved in the development of mixed medullary-follicular thyroid carcinoma.

The MDM2 oncoprotein promotes apoptosis in p53-deficient human medullary thyroid carcinoma cells

The MDM2 oncoprotein has been shown to inhibit p53-mediated growth arrest and apoptosis. It also confers growth advantage to different cell lines in the absence of p53. Recently, the ability of MDM2 to arrest the cell cycle of normal human fibroblasts has also been described. We report a novel function for this protein, showing that overexpression of MDM2 promotes apoptosis in p53-deficient, human medullary thyroid carcinoma cells. These cells, devoid of endogenous MDM2 protein, exhibited a significant growth retardation after stable transfection with mdm2. Cell cycle distribution of MDM2 transfectants [medullary thyroid tumor (MTT)-mdm2] revealed a fraction of the cell population in a hypodiploid status, suggesting that MDM2 is sufficient to promote apoptosis. This circumstance is further demonstrated by annexin V labeling. MDM2-induced apoptosis is partially reverted by transient transfection with p53 and p19ARF. Both MTT and MTT-mdm2 cells were tumorigenic when injected into nude mice. However, the percentage ofapoptotic nuclei in tumor sections derived from MDM2-expressing cells was significantly higher relative to that in the parental cell line. MDM2-mediated programmed cell death is at least mediated by a down-regulation of the antiapoptotic protein Bcl-2. Protein levels of caspase-2, which are undetectable in the parental cell line, appear clearly elevated in MTT-mdm2 cells. Caspase-3 activation does not participate in MDM2-induced apoptosis, as determined by protein levels or poly(ADP-ribose) polymerase fragmentation. The results observed in this medullary carcinoma cell line show for the first time that the product of the mdm2 oncogene mediates cell death by apoptosis in p53-deficient tumor cells.

Paraganglioma as a systemic syndrome: pitfalls and strategies

Tumours of the neuroendocrine system in the head and neck region are mostly paragangliomas of the glomus tympanicum or jugulare, or of the carotid body. The majority of these tumours are benign, and the coexistence of multiple paragangliomas seems to be rare. Pre-operative embolization and surgery are regarded as primary therapy for these tumours. The treatment regimen in any patient depends on age, general health, hearing status and the function of the lower cranial nerves. Several presentations are possible in which paragangliomas occur as systemic disease. 1. Paragangliomas may occur bilaterally, or, in rare cases, in multiple areas. Pre-operative bilateral angiography is of utmost importance. In case of multicentricity, it might be necessary to proceed without, or just with, unilateral surgery for preservation of adjacent structures. In surgery of jugular vein paraganglioma, we usually perform a modified transmastoidal and transcervical approach with preservation of middle-ear structures and the ossicles. As an alternative or supplement to surgery, radiotherapy or definitive embolization may be used in the treatment of paragangliomas. 2. Paragangliomas may occur as multiple endocrine neoplasia (MEN) syndrome combined with medullary thyroid gland carcinoma, and, facultatively, pheochromocytoma. In these cases, endocrinological examination and magnetic resonance imaging (MRI) of the adrenal region, the thorax and the neck are required for an adequate therapeutic strategy. As MEN may be inherited, family history should be evaluated. 3. Paragangliomas can became malignant and metastasize. Thus, cervical lymph node metastases or distant metastases may occur. We recommend the removal of all ipsilateral lymph nodes and their histological examination.