RET fusion genes in pediatric and adult thyroid carcinomas: cohort characteristics and prognosis

Thyroid cancer is associated with a broad range of different mutations, including RET (rearranged during transfection) fusion genes. The importance of characterizing RET fusion-positive tumors has recently increased due to the possibility of targeted treatment. The aim of this study was to identify RET fusion-positive thyroid tumors, correlate them with clinicopathological features, compare them with other mutated carcinomas, and evaluate long-term follow-up of patients. The cohort consisted of 1564 different thyroid tissue samples (including 1164 thyroid carcinoma samples) from pediatric and adult patients. Samples were analyzed for known driver mutations occurring in thyroid cancer. Negative samples were subjected to extensive RET fusion gene analyses using next-generation sequencing and real-time PCR. RET fusion genes were not detected in any low-risk neoplasm or benign thyroid tissue and were detected only in papillary thyroid carcinomas (PTCs), in 113/993 (11.4%) patients, three times more frequently in pediatric and adolescent patients (29.8%) than in adult patients (8.7%). A total of 20 types of RET fusions were identified. RET fusion-positive carcinomas were associated with aggressive tumor behavior, including high rates of lymph node (75.2%) and distant metastases (18.6%), significantly higher than in NTRK fusion, BRAF V600E and RAS-positive carcinomas. Local and distant metastases were also frequently found in patients with microcarcinomas positive for the RET fusions. 'True recurrences' occurred rarely (2.4%) and only in adult patients. The 2-, 5-, 10-year disease-specific survival rates were 99%, 96%, and 95%, respectively. RET fusion-positive carcinomas were associated with high invasiveness and metastatic activity, but probably due to intensive treatment with low patient mortality.

NTRK Fusion Genes in Thyroid Carcinomas: Clinicopathological Characteristics and Their Impacts on Prognosis

Chromosomal rearrangements of NTRK genes are oncogenic driver mutations in thyroid cancer (TC). This study aimed to identify NTRK fusion-positive thyroid tumors and to correlate them with clinical and pathological data and determine their prognostic significance. The cohort consisted of 989 different TC samples. Based on the detected mutation, samples were triaged, and those that were positive for a BRAF, HRAS, KRAS, NRAS, RET, RET/PTC or PAX8/PPARγ mutation were excluded from further analyses. NTRK fusion gene testing was performed in 259 cases, including 126 cases using next-generation sequencing. NTRK fusion genes were detected in 57 of 846 (6.7%) papillary thyroid carcinomas and in 2 of 10 (20.0%) poorly differentiated thyroid carcinomas. A total of eight types of NTRK fusions were found, including ETV6/NTRK3, EML4/NTRK3, RBPMS/NTRK3, SQSTM1/NTRK3, TPM3/NTRK1, IRF2BP2/NTRK1, SQSTM1/NTRK1 and TPR/NTRK1.NTRK fusion-positive carcinomas were associated with the follicular growth pattern, chronic lymphocytic thyroiditis and lymph node metastases. NTRK1-rearranged carcinomas showed a higher frequency of multifocality and aggressivity than NTRK3-rearranged carcinomas. Tumor size, presence of metastases, positivity for the NTRK3 or NTRK1 fusion gene and a late mutation event (TERT or TP53 mutation) were determined as factors affecting patient prognosis. NTRK fusion genes are valuable diagnostic and prognostic markers.

A selective p53 activator and anticancer agent to improve colorectal cancer therapy

Impairment of the p53 pathway is a critical event in cancer. Therefore, reestablishing p53 activity has become one of the most appealing anticancer therapeutic strategies. Here, we disclose the p53-activating anticancer drug (3S)-6,7-bis(hydroxymethyl)-5-methyl-3-phenyl-1H,3H-pyrrolo[1,2-c]thiazole (MANIO). MANIO demonstrates a notable selectivity to the p53 pathway, activating wild-type (WT)p53 and restoring WT-like function to mutant (mut)p53 in human cancer cells. MANIO directly binds to the WT/mutp53 DNA-binding domain, enhancing the protein thermal stability, DNA-binding ability, and transcriptional activity. The high efficacy of MANIO as an anticancer agent toward cancers harboring WT/mutp53 is further demonstrated in patient-derived cells and xenograft mouse models of colorectal cancer (CRC), with no signs of undesirable side effects. MANIO synergizes with conventional chemotherapeutic drugs, and in vitro and in vivo studies predict its adequate drug-likeness and pharmacokinetic properties for a clinical candidate. As a single agent or in combination, MANIO will advance anticancer-targeted therapy, particularly benefiting CRC patients harboring distinct p53 status.

RET, NTRK, ALK, BRAF, and MET Fusions in a Large Cohort of Pediatric Papillary Thyroid Carcinomas

Background: Pediatric papillary thyroid carcinoma (PTC) is a rare malignancy, but with increasing incidence. Pediatric PTCs have distinct clinical and pathological features and even the molecular profile differs from adult PTCs. Somatic point mutations in pediatric PTCs have been previously described and studied, but complex information about fusion genes is lacking. The aim of this study was to identify different fusion genes in a large cohort of pediatric PTCs and to correlate them with clinical and pathological data of patients. Methods: The cohort consisted of 93 pediatric PTC patients (6-20 years old). DNA and RNA were extracted from fresh frozen tissue samples, followed by DNA and RNA-targeted next-generation sequencing analyses. Fusion gene-positive samples were verified by real-time polymerase chain reaction. Results: A genetic alteration was found in 72/93 (77.4%) pediatric PTC cases. In 52/93 (55.9%) pediatric PTC patients, a fusion gene was detected. Twenty different types of RET, NTRK3, ALK, NTRK1, BRAF, and MET fusions were found, of which five novel, TPR/RET, IKBKG/RET, BBIP1/RET, OPTN/BRAF, and EML4/MET, rearrangements were identified and a CUL1/BRAF rearrangement that has not been previously described in thyroid cancer. Fusion gene-positive PTCs were significantly associated with the mixture of classical and follicular variants of PTC, extrathyroidal extension, higher T classification, lymph node and distant metastases, chronic lymphocytic thyroiditis, and frequent occurrence of psammoma bodies compared with fusion gene-negative PTCs. Fusion-positive patients also received more doses of radioiodine therapy. The most common fusion genes were the RET fusions, followed by NTRK3 fusions. RET fusions were associated with more frequent lymph node and distant metastases and psammoma bodies, and NTRK3 fusions were associated with the follicular variant of PTC. Conclusions: Fusion genes were the most common genetic alterations in pediatric PTCs. Fusion gene-positive PTCs were associated with more aggressive disease than fusion gene-negative PTCs.

Somatic genetic alterations in a large cohort of pediatric thyroid nodules

There is a rise in the incidence of thyroid nodules in pediatric patients. Most of them are benign tissues, but part of them can cause papillary thyroid cancer (PTC). The aim of this study was to detect the mutations in commonly investigated genes as well as in novel PTC-causing genes in thyroid nodules and to correlate the found mutations with clinical and pathological data. The cohort of 113 pediatric samples consisted of 30 benign lesions and 83 PTCs. DNA from samples was used for next-generation sequencing to identify mutations in the following genes: HRAS, KRAS, NRAS, BRAF, IDH1, CHEK2, PPM1D, EIF1AX, EZH1 and for capillary sequencing in case of the TERT promoter. RNA was used for real-time PCR to detect RET/PTC1 and RET/PTC3 rearrangements. Total detection rate of mutations was 5/30 in benign tissues and 35/83 in PTCs. Mutations in RAS genes (HRAS G13R, KRAS G12D, KRAS Q61R, NRAS Q61R) were detected in benign lesions and HRAS Q61R and NRAS Q61K mutations in PTCs. The RET/PTC rearrangement was identified in 18/83 of PTCs and was significantly associated with higher frequency of local and distant metastases. The BRAF V600E mutation was identified in 15/83 of PTCs and significantly correlated with higher age of patients and classical variant of PTC. Germline variants in the genes IDH1, CHEK2 and PPM1D were found. In conclusion, RET/PTC rearrangements and BRAF mutations were associated with different clinical and histopathological features of pediatric PTC. RAS mutations were detected with high frequency in patients with benign nodules; thus, our results suggest that these patients should be followed up intensively.

Natural history, treatment, and long-term follow up of patients with multiple endocrine neoplasia type 2B: an international, multicentre, retrospective study

BACKGROUND

Multiple endocrine neoplasia type 2B is a rare syndrome caused mainly by Met918Thr germline RET mutation, and characterised by medullary thyroid carcinoma, phaeochromocytoma, and extra-endocrine features. Data are scarce on the natural history of multiple endocrine neoplasia type 2B. We aimed to advance understanding of the phenotype and natural history of multiple endocrine neoplasia type 2B, to increase awareness and improve detection.

METHODS

This study was a retrospective, multicentre, international study in patients carrying the Met918Thr RET variant with no age restrictions. The study was done with registry data from 48 centres globally. Data from patients followed-up from 1970 to 2016 were retrieved from May 1, 2016, to May 31, 2018. Our primary objectives were to determine overall survival, and medullary thyroid carcinoma-specific survival based on whether the patient had undergone early thyroidectomy before the age of 1 year. We also assessed remission of medullary thyroid carcinoma, incidence and treatment of phaeochromocytoma, and the penetrance of extra-endocrine features.

FINDINGS

345 patients were included, of whom 338 (98%) had a thyroidectomy. 71 patients (21%) of the total cohort died at a median age of 25 years (range <1-59). Thyroidectomy was done before the age of 1 year in 20 patients, which led to long-term remission (ie, undetectable calcitonin level) in 15 (83%) of 18 individuals (2 patients died of causes unrelated to medullary thyroid carcinoma). Medullary thyroid carcinoma-specific survival curves did not show any significant difference between patients who had thyroidectomy before or after 1 year (comparison of survival curves by log-rank test: p=0·2; hazard ratio 0·35; 95% CI 0.07-1.74). However, there was a significant difference in remission status between patients who underwent thyroidectomy before and after the age of 1 year (p<0·0001). There was a significant difference in remission status between patients who underwent thyroidectomy before and after the age of 1 year (p<0·0001). In the other 318 patients who underwent thyroidectomy after 1 year of age, biochemical and structural remission was obtained in 47 (15%) of 318 individuals. Bilateral phaeochromocytoma was diagnosed in 156 (50%) of 313 patients by 28 years of age. Adrenal-sparing surgery was done in 31 patients: three (10%) of 31 patients had long-term recurrence, while normal adrenal function was obtained in 16 (62%) patients. All patients with available data (n=287) had at least one extra-endocrine feature, including 106 (56%) of 190 patients showing marfanoid body habitus, mucosal neuromas, and gastrointestinal signs.

INTERPRETATION

Thyroidectomy done at no later than 1 year of age is associated with a high probability of cure. The reality is that the majority of children with the syndrome will be diagnosed after this recommended age. Adrenal-sparing surgery is feasible in multiple endocrine neoplasia type 2B and affords a good chance for normal adrenal function. To improve the prognosis of such patients, it is imperative that every health-care provider be aware of the extra-endocrine signs and the natural history of this rare syndrome. The implications of this research include increasing awareness of the extra-endocrine symptoms and also recommendations for thyroidectomy before the age of 1 year.

FUNDING

None.

Coincidence of Thyroid Tumor and Thyroglossal Duct Remnants. Review of the Literature and Presentation of Three Cases

Aims and Background

The coincidence of benign or malignant thyroid tumors with thyroglossal duct remnant (TDR) cysts is rare. Although the precise etiology is still unclear, thyroid origin and spread from a primary site have been suggested and this obviously has important implications for the therapeutic approach. Three cases of thyroglossal duct carcinoma are presented and its management is discussed on the basis of the current rationale for treatment of thyroid cancer. The indication for surgery depends on positive findings in the thyroid gland (nodules, FNAB). The aim of this study was to review our experience in the management of papillary thyroid diseases associated with TDR.

Materials and Methods

The records of three patients with thyroid tumors associated with TDR treated at the Department of ENT and Head and Neck Surgery of the First Medical Faculty UK of Prague between January 1991 and January 2001 were analyzed. We searched for risk factors of thyroid carcinoma: history of ionizing radiation, history of thyroid diseases, age, tumor size, tumor spread and histopathological factors.

Results

We used a triple approach consisting of clinical and ultrasound examination and fine-needle aspiration biopsy for preoperative assessment. Our diagnostic and therapeutic procedures included TDR excision (Sistrunk or Schlange procedure) and total thyroidectomy. Although the therapeutic approach could be a matter of discussion, most patients agreed with our suggestion of relatively radical but non-mutilating treatment. Postoperative radiation or radioiodine ablation is considered in cases of TDR carcinoma or thyroid carcinoma associated with TDR. Oncological follow-up included clinical and ultrasound examination three times during the first year, twice in the second year, and once yearly thereafter. Tumor marker evaluation and/or scintigraphy were performed 6, 12 and/or 24 months following surgery.

Solitary Metastasis of Clear Renal Cell Carcinoma to Thyroid Gland: Three reported cases with review of the literature

Metastasis to the head and neck and more specifically to the thyroid gland from distant primary tumors is less common in comparison to the local regional metastasis of squamous cell carcinomas of the upper aero-digestive tract. Preoperative diagnosis of these cases can be difficult. The authors present three cases with distant solitary metastases of clear renal cell carcinoma to the thyroid gland with ambiguous mechanism of tumor spread to the thyroid. Solitary metastases of clear renal cell carcinomas are an uncommon variant of metastasis of this tumor and may imitate thyroid well differentiated carcinoma which most commonly affects the thyroid gland. Therefore, thorough endocrinological investigation of the thyroid gland is necessary. The recommended therapy of renal cell carcinoma metastasis includes surgical removal of all cancerous tissues - i.e. of the gland with the possibly infiltrated adjacent tissues, as well as removal of the affected lymph nodes - selective radical neck dissection. In our study, we discuss the clinical picture, pathology, diagnosis, differential diagnosis and prognosis together with literature review.

A 3-bp Deletion VK600-1E in the BRAF Gene Detected in a Young Woman with Papillary Thyroid Carcinoma

Papillary thyroid cancer (PTC) derived from follicular cells is a frequent thyroid tumor. The incidence of this type of malignancy is still growing worldwide. Several major genetic causes are recognized to cause PTC-mutations in the BRAF and RAS genes or rearrangements with the RET proto-oncogene. The most common genetic change found in PTC is a V600E mutation in the BRAF gene presented in 36-69 % of all PTC cases. For routine purposes, several methods were developed to selectively detect only this mutation. However, these methods miss other mutations in the BRAF gene located elsewhere. We focused on the analysis of the exon 15 of the BRAF gene by next-generation sequencing. Here we report a three nucleotide deletion VK600-1E in one patient and present this finding in the context of 13 previously described PTC cases with this deletion. Our patient is the second youngest one among the reported cases. Clinical features of PTC patients with VK600-1E are summarized. For the future, it is important to evaluate genotype-phenotype characteristics of patients with rare BRAF mutations and to follow up them for years.

Search for new genetic biomarkers in poorly differentiated and anaplastic thyroid carcinomas using next generation sequencing

BACKGROUND

Poorly differentiated thyroid carcinoma (PDTC) and anaplastic thyroid carcinoma (ATC) are very rare tumors with extremely aggressive behavior. Their comprehensive genetic background is still unclear. Some of the main genetic changes of differentiated thyroid carcinomas, such as mutations in BRAF and RAS genes, as well as changes in CTNNB1, PIK3CA, TP53, AXIN1, PTEN or APC genes leading to the dedifferentiation of the tumors, are described.

MATERIALS AND METHODS

DNAs from fresh frozen thyroid tissues of 3 PDTCs and 5 ATCs were extracted. The next-generation sequencing (NGS) approach was used to target 94 genes involved in cancer. The samples were prepared using a TruSight Cancer panel and sequenced with a MiSeq sequencer. Analysis of variants was performed by the MiSeq Reporter and NextGENe software and stringent criteria for prioritization of the variants were used in the Illumina VariantStudio software.

RESULTS

Using NGS, we identified 26 genetic changes in 18 genes, novel variants included.

CONCLUSION

NGS is a useful tool for searching for new variants and genes involved in PDTC and ATC. It seems that each of these rare tumor types has its own specific genetic background. These data could be helpful for recognizing new genetic markers and targets for future personalized therapy.

Evaluation of three purely polypropylene meshes of different pore sizes in an onlay position in a New Zealand white rabbit model

BACKGROUND

The aim of the study was to evaluate the influence of the pore size of a polypropylene mesh on the shrinkage and elasticity of the mesh-tissue complex and the inflammatory reaction to the implant in an open onlay hernia repair.

MATERIALS AND METHODS

Twenty-one 10 × 10 cm samples of polypropylene meshes of a different pore size (3.0 × 2.8 mm-PP3, 1.0 × 0.8 mm-PP1 and 0.6 × 0.5 mm-PP.5) were implanted in an onlay position in 21 New Zealand white rabbits. After 90 days of implantation the shrinkage, elasticity and foreign body reaction (FBR) were assessed.

RESULTS

The shrinkage of PP3 was 30.6 ± 4.3 %, PP1 49.3 ± 2.9 % and PP.5 49.5 ± 2.6 %. The shrinkage of PP3 was significantly lower (PP3 × PP1 p = 0.007, PP3 × PP.5 p = 0.005), PP1 and PP.5 were similar. The elasticity was similar. The strength of FBR in mesh pores was similar. The width of foreign body granuloma layers at the mesh-tissue interface was significantly reduced with increasing pore size (inner: PP3 10.1 ± 1.2; PP1 12.5 ± 2.9; PP.5 17.4 ± 5.2 and outer: PP3 21.2 ± 2.5; PP1 30.6 ± 6.3; PP.5 60.4 ± 14.9). All differences between the widths of granuloma layers were statistically significant (p < 0.010). One animal (PP1) was excluded because of a mesh infection.

CONCLUSIONS

Implantation of polypropylene mesh of a pore size of 3 mm in an onlay position is associated with a significant reduction of shrinkage in comparison to a 1 mm pore lightweight and 0.5 mm pore heavyweight mesh. A pore size increase to 3 mm is not sufficient for an improvement of mesh-tissue complex elasticity in comparison to a 1 mm pore lightweight and 0.5 mm heavyweight mesh. Polypropylene mesh with enlarged pores to 3 mm is associated with a similar strength of FBR in mesh pores and a reduced foreign body granuloma in comparison to a 1 mm pore lightweight and 0.5 mm pore heavyweight mesh.

Outcomes of adrenal-sparing surgery or total adrenalectomy in phaeochromocytoma associated with multiple endocrine neoplasia type 2: an international retrospective population-based study

BACKGROUND

The prevention of medullary thyroid cancer in patients with multiple endocrine neoplasia type 2 syndrome has demonstrated the ability of molecular diagnosis and prophylactic surgery to improve patient outcomes. However, the other major neoplasia associated with multiple endocrine neoplasia type 2, phaeochromocytoma, is not as well characterised in terms of occurrence and treatment outcomes. In this study, we aimed to systematically characterise the outcomes of management of phaeochromocytoma associated with multiple endocrine neoplasia type 2.

METHODS

This multinational observational retrospective population-based study compiled data on patients with multiple endocrine neoplasia type 2 from 30 academic medical centres across Europe, the Americas, and Asia. Patients were included if they were carriers of germline pathogenic mutations of the RET gene, or were first-degree relatives with histologically proven medullary thyroid cancer and phaeochromocytoma. We gathered clinical information about patients'RET genotype, type of treatment for phaeochromocytoma (ie, unilateral or bilateral operations as adrenalectomy or adrenal-sparing surgery, and as open or endoscopic operations), and postoperative outcomes (adrenal function, malignancy, and death). The type of surgery was decided by each investigator and the timing of surgery was patient driven. The primary aim of our analysis was to compare disease-free survival after either adrenal-sparing surgery or adrenalectomy.

FINDINGS

1210 patients with multiple endocrine neoplasia type 2 were included in our database, 563 of whom had phaeochromocytoma. Treatment was adrenalectomy in 438 (79%) of 552 operated patients, and adrenal-sparing surgery in 114 (21%). Phaeochromocytoma recurrence occurred in four (3%) of 153 of the operated glands after adrenal-sparing surgery after 6-13 years, compared with 11 (2%) of 717 glands operated by adrenalectomy (p=0.57). Postoperative adrenal insufficiency or steroid dependency developed in 292 (86%) of 339 patients with bilateral phaeochromocytoma who underwent surgery. However, 47 (57%) of 82 patients with bilateral phaeochromocytoma who underwent adrenal-sparing surgery did not become steroid dependent.

INTERPRETATION

The treatment of multiple endocrine neoplasia type 2-related phaeochromocytoma continues to rely on adrenalectomies with their associated Addisonian-like complications and consequent lifelong dependency on steroids. Adrenal-sparing surgery, a highly successful treatment option in experienced centres, should be the surgical approach of choice to reduce these complications.

[Is pneumonectomy justified in the management of lung metastases?]

The authors discuss about questions of possibility pneumonectomy in concept of lung metastasis therapy. They analysed in detail indications, surgery, complications, survival and factors of survival. The authors also introduce case report of one patient with pneumonectomy in your group of patients.

[Thyreopathy in primary care]

Thyroid gland disorders, as the core of all endocrinopathies, affect 5-7% of the population of the Czech Republic, with women being affected 6-8 times more often than men. Clinically, thyreopathies are divided into hormonal production disorders and morphology disorders. Thyroid hormones fT3, fT4 and TSH serum levels determine the diagnosis of a thyroid gland disorder. Primary hypothyreosis is characterized by reduced fT4 and increased TSH. Low T3 syndrome is a protective reaction of the organism and is associated with conversion of T4 into hormonally inactive triiodothyronine (rT3). Primary hyperthyreosis is characterized by higher fT4 and low TSH levels. Acute thyreoiditis: Inflammatory signs and normal thyroid function, anti-TPO as well as anti-TG are not elevated. Subacute thyreoiditis is manifested as an inflammation, normal anti-TPO and anti-TG, sometimes also hyperthyreosis. Chronic thyreoiditis, Hashimoto's struma is among the most frequent causes ofhypothyreosis in the Czech Republic and it is diagnosed through high anti-TPO and anti-TG levels and higher TSH. Thyreoidal adenomas and carcinomas are clinically usually euthyroid. Determination of tumour markers - thyreoglobulines in papillary and follicular carcinomas and calcitonin in medullar carcinoma that requires genetic assessment (determination of germinal mutations, usually with PCR)--is essential.

Endoscopic approach in diagnosis and treatment of biliary complications after laparoscopic cholecystectomy

BACKGROUND/AIMS

The aim of this retrospective study is to follow the main parameters such as the success of performing diagnostic endoscopic retrograde cholangiopancreatography (ERCP) and to determine the effectiveness and morbidity of therapeutic ERCP.

METHODOLOGY

The study of the group took 12 years (January 1997-December 2008). The paper assesses in retrospect 138 patients who underwent laparoscopic cholecystectomy (LCE). Signs leading to the suspicion of possible biliary complications (BC) after previous LCE appeared in these patients in the postoperative period, indicating the performance of ERCP.

RESULTS

Diagnostic ERCP was successful in all 138 patients (i.e. in 100% of cases). There were normal ERCP results in 8 patients and pathological results in the sense of some of the BC in the remaining 130 patients. Endoscopic therapy was performed after diagnostic ERCP in 115 of 130 patients with proved BC. Therapeutic ERCP was absolutely successful in altogether 111 of 130 patients (85.38%) with BC after LCE.

CONCLUSIONS

The success rate of therapeutic ERCP in our group was 85.38%. Morbidity in relation to therapeutic ERCP was 4.2%. ERCP appears to be highly effective diagnostic and primarily therapeutic method in solving BC after LCE.

The anatomical relationship between the saphenous nerve and the great saphenous vein

OBJECTIVE

Damage to the saphenous nerve (SN) has been a known complication during varicose vein surgeries. We tested whether a better knowledge of the anatomy of the SN and the great saphenous vein (GSV) can prevent such damage.

METHODS

We conducted a morphological and histological examination on 86 limbs from 43 cadavers in order to analyse the anatomical interrelation between the SN and the GSV in the lower leg and we also measured the distance between the nerve and the vein in a sample of 42 sections from three parts of the lower leg.

RESULTS

The anatomical relationship between the SN and the GSV is varied and the two structures run close to each other so a better knowledge of their anatomy in itself proved insufficient in preventing damage to the SN.

CONCLUSION

However, in the case of endovenous laser therapy and radiofrequency ablation tumescent anaesthesia decreases the risk of damage to the SN.

BRAFV600E mutation in the pathogenesis of a large series of papillary thyroid carcinoma in Czech Republic

BACKGROUND

Activating point mutation of the BRAF gene, the most common genetic alteration reported in papillary thyroid carcinomas (PTC), has been associated with poor prognostic characteristics.

AIM

Our objective was to determine the frequency of BRAFV600E mutation in PTC tumor tissues from the period 1960-2007 and to correlate it with clinicopathological parameters.

SUBJECTS AND METHODS

DNAs were extracted from 242 PTCs, 23 sporadic medullary carcinomas, one anaplastic carcinoma and 6 poorly differentiated carcinomas. The presence of BRAFV600E mutation was determined using single strand conformation polymorphism method and verified by direct sequencing.

RESULTS

BRAFV600E mutation was detected in 81 of 242 PTCs (33.5%), in one of 6 poorly differentiated carcinomas (16.7%) and in anaplastic carcinoma. BRAFV600E mutation was much less frequent in the follicular variant compared to classical variant and mixed follicular- classical variant of PTCs (p=0.001). BRAFV600E mutation was significantly associated with presence of nodal metastasis (p=0.029), more advanced TNM stage (p=0.014) and recurrence of disease (p=0.008). The mutation correlated with a higher age at diagnosis (p=0.049) and with a greater tumor size (p=0.041). Multivariate analysis confirmed these findings. The prevalence of BRAFV600E mutation before 1986 was significantly lower than after it (p=0.008).

CONCLUSIONS

Our data suggest that BRAFV600E mutation is associated with high-risk clinicopathological characteristics of PTC and worse prognosis of patients. The frequency of the mutation significantly varied during the observed period but rather because of the different age distribution of patients in particular periods than as a consequence of Chernobyl accident.

[Evaluation of neoadjuvant chemo-radiotherapy with locally advanced rectal cancer by comparing tumour volume before and after treatment]

BACKGROUND

Neoadjuvant chemotherapy is a standard preoperative therapeutical procedure with locally advanced rectal adenocarcinoma. The aim of the study was to compare the tumour volume reduction before and after the oncological therapy in relation to the change in the CEA value and to the outcome of the histopathological evaluation of response to the treatment.

PATIENTS AND METHODS

In the years 2004-2008, 274 rectal cancer patients were evaluated, of which 64 underwent neoadjuvant CRT with subsequent surgery and had also completed other inclusion criteria. The tumour volume before and after the CRT, percentage reduction in the tumour volume and the relation to the change in the CAE value and the histopathological evaluation were evaluated.

RESULTS

The distance between the anus and the tumour was from 3 to 15 centimetres, the average value being 8.1 centimetres. In 5 cases the tumour was not histologically found in the resected specimen. Average value of the CEA value before the CRT was 18.12 ng/ml, range 0.7-98.1 ng/ml, after the CRT the average value was 7.00 ng/ml, range 0.5-18.7 ng/ml. The average tumour volume before CRT was 32.48, range 10.3-88.5, after the CRT the average volume was 20.13, range 4.7-55.1.

CONCLUSION

A relation between the change in the T value and the volume reduction before and after the CRT of statistical significance has been proven in this group of patients. This relation however has not been proved in the N value change. Only in one-third of the evaluated patients was there a positive change in both T and N classification. No relation between the CEA value and the tumour volume change has been proven.

RET mutation Tyr791Phe: the genetic cause of different diseases derived from neural crest

Activating germline RET mutations are presented in patients with familial medullary thyroid carcinoma (FMTC) and multiple endocrine neoplasia (MEN) types 2A and 2B, whereas inactivating germline mutations in patients with Hirschsprung's disease (HSCR). The aim of this study was to evaluate genotype-phenotype correlations of the frequently discussed Tyr791Phe mutation in exon 13 of the RET proto-oncogene. Screening of three groups of patients was performed (276 families with medullary thyroid carcinoma (MTC), 122 families with HSCR, and 29 patients with pheochromocytoma). We found this mutation in 3 families with apparently sporadic MTC, 3 families with FMTC/MEN2, 1 patient with pheochromocytoma, and 3 families with HSCR. All gene mutation carriers have a silent polymorphism Leu769Leu in exon 13. In three families second germline mutations were detected: Cys620Phe (exon 10) in MEN2A family, Met918Thr (exon 16) in MEN2B family, and Ser649Leu (exon 11) in HSCR patient. Detection of the Tyr791Phe mutation in MEN2/MTC and also in HSCR families leads to the question whether this mutation has a dual character (gain-of-function as well as loss-of-function). A rare case of malignant pheochromocytoma in a patient with the Tyr791Phe mutation is presented. This study shows various clinical characteristics of the frequently discussed Tyr791Phe mutation.

[Open pleural window at treatment of the advanced thoracic empyema: 20 high-risk patients' treatment experience]

The aim of the retrospective clinical study was the analysis of the 20 high-risk patients operated in our department within years 2000-2008 by the modified Eloesser procedure for the serious thoracic empyema.

MATERIAL AND METHODS

We have analyzed the data of the 17 men and 3 women. The most important objectives were the cause of the disease, type of procedure, perioperative mortality, length of stay and subsequent procedures. The underlying disease was the malignant intrathoracic disease in 40%, diabetes mellitus was found in 25%. The cause of empyema was pleuropneumonia in 45%, postresectional empyema occurred in 35%.

RESULTS

There were two perioperative deaths (10%), remaining patients were all dismissed in a stabilized condition the 22nd postoperative day at average. Six subsequent reconstructive procedures were performed. There was no early death for the postpneumonectomy empyema.

CONCLUSION

In case of the serious pleural empyema in a high-risk patient is the modified Eloesser procedure safe and life saving surgical operation. The timing of the procedure and correct indication for surgery are essential.

Somatic mutations in the RET proto-oncogene in sporadic medullary thyroid carcinomas

The frequency and prognostic relevance of RET proto-oncogene somatic mutations in sporadic medullary thyroid carcinoma (MTC) remain controversial. In order to study somatic mutations in the RET proto-oncogene in sporadic MTCs found in the Czech population and to correlate these mutations with clinical and pathological characteristics, we investigated 48 truly sporadic MTCs by sequencing classical risk exons 10, 11, 13, 14, 15 and 16. From the 48 tumors studied, 23 (48%) had somatic mutation in the RET proto-oncogene in exons 10, 11, 15 or 16. The classical somatic mutation Met918Thr in exon 16 was only found in 13 tumors (27%). In five cases, multiple somatic mutations and deletions were detected. A statistically significant correlation between the presence of somatic mutation with more advanced pathological TNM stages was observed. Other clinical and pathological characteristics did not show any statistical significant association with the presence or absence of somatic mutation.

[Robotic procedures in the colorectal surgery]

PURPOSE

The da Vinci surgical system (Intuitive Surgical, Sunnyvale, CA, USA) was developed specifically to compensate the technical limitations of laparoscopic instruments, such as two-dimensional vision, misalignment of hands and instruments, limited dexterity of instruments inside the patient, and fixed instrument tips. The da Vinci system provides a stable camera platform, three-dimensional imaging, excellent ergonomics, tremor elimination, ambidextrous capability, motion scaling, and instruments with multiple degrees of freedom.

METHODS

These advantages can be applied in the field of colorectal surgery, and that's why we are reporting 45 cases that underwent robotic colorectal surgery. We concluded that the da Vinci system may be useful in surgical procedures, such as splenic flexure takedown, dissection of the inferior mesenteric artery with identification of the nervous plexus, and dissection of a narrow pelvis. The major drawbacks of robotic systems are high cost, and a lack of tactile sensation and tensile feedback to the surgeon, who must depend on visual cues to estimate the tension exerted on tissue by the robotic arms.

RESULTS

In conclusion, robotic colorectal surgery can be performed safely and effectively, using the da Vinci surgical system, because this system has more dexterity and flexibility than conventional laparoscopic instruments. However, prospective randomized studies are necessary to evaluate the preservation of sexual and voiding function, as well as the oncological and functional (pelvic floor disorders) outcomes of this approach.

Chromogranin A, a member of neuroendocrine secretory proteins as a selective marker for laboratory diagnosis of pheochromocytoma

The function of chromogranin A (CGA) is reviewed, and the radioimmunometric determination of plasma CGA was evaluated as a marker of pheochromocytoma using a comparison of pheochromocytoma patients immediately before surgery (group P, n=25, 635+/-451 ng/ml) with other groups of patients, i.e. pheochromocytoma patients approximately 1 year after removal of tumor (group PP, n=13, 69+/-33 ng/ml), medullary thyroid carcinoma patients (group M, n= 22, 106+/-59 ng/ml), congenital adrenal hyperplasy patients (n=33, 65+/-40 ng/ml), and controls (n=31, 66+/-29 ng/ml). A CGA level above cut off value 130 ng/ml was found in 24 of 25 patients in group P, 1 (relapse) of 13 patients in group PP, and 4 of 22 patients in group M. In the group P we found a significant association between the size of the tumors removed and plasma CGA concentrations (p=0.0016), and also a significant (p=0.0016) relationship between plasma CGA concentrations and PASS score rating the malignity of pheochromocytoma. We can conclude that plasma CGA concentration as determined by radioimmunometric assay (which is simple without the necessity of special laboratory equipment) is an effective marker of pheochromocytoma with association to malignity and tumor mass.

Robot-assisted pulmonary lobectomy

The authors present their first experience and the results of robot-assisted pulmonary lobectomies. The paper reports on the placement of the working channels, auxiliary minithoracotomies, the patient's position, the positions of the four-arm body of the da Vinci robotic system, and particularly the technique of lobectomy. In our institution, 4 robot-assisted lobectomies were performed in two women and two men (aged 45, 52, and 57, 67 years, respectively). The vessels were ligated mechanically with the use of the robot. An auxiliary minithoracotomy of a length of 5 cm was performed in the fifth intercostal area posterolaterally. The lower lobectomy was performed three times left and once right. The surgery was always supplemented with mediastinal lymphadenectomy. No serious complications were observed during the surgery or in the postoperative period. Robot-assisted lobectomy is a safe method of pulmonary resection in the early stages of bronchogenic carcinoma (Ia, Ib); it ensures a faster convalescence of the patient compared with open surgery (Ref. 14).

Free plasma metanephrines as a screening test for pheochromocytoma in low-risk patients

OBJECTIVES

Detection of free plasma metanephrines seems to be the most exact method for biochemical diagnosis of pheochromocytoma, but their diagnostic efficacy in the common low-risk clinical settings is debated.

METHODS

A cross-sectional multicentre study including 1260 subjects assessed the diagnostic efficacy of free plasma metanephrine and normetanephrine in low-risk patients screened for resistant or markedly accelerated hypertension, paroxysmal hypertension, 'flushes' and, in a small proportion, for adrenal incidentaloma or genetic predisposition to pheochromocytoma.

RESULTS

Pheochromocytoma was identified and verified by histology in 25 subjects (2%), with the diagnosis not confirmed by long-term follow-up or use of imaging techniques in the remaining 1235 individuals. The combined assay of free plasma metanephrines was a highly sensitive (100%) and specific (96.7%) measure, yielding a negative predictive value of 100%.

CONCLUSION

The satisfactory diagnostic efficacy of free plasma metanephrines allows their use as a single screening test in cases of suspected pheochromocytoma in the population with a low pretest probability.

[Multiple lung metastasectomy for the poor differentiated metastatic synovial sarcoma]

OBJECTIVES

Synovial sarcoma is the rare indication for the pulmonary metastasectomy due to its aggressive biologic behavior and early dissemination. The radical surgical approach in therapy of the multiple pulmonary metastases could improve quality of life and median survival in carefully selected patients.

METHODS

From the group of 7 patients with the lung metastases of the synovial sarcoma operated in our department during the last 5 years we are presenting the case of the 39 years old man with the previous history of the surgical removal of the synovial sarcoma near the cubital fossa one year before. Considering the lungs as the only organ involved, bilateral complete metastasectomy through muscle sparing vertical thoracotomies was done. There were 12 metastases from all lung lobes with the exception of the right middle lobe. Analysis of the pathologist showed biphasic metastatic synovial sarcoma with the high mitotic activity. The 6 cycles of the MAID regime succeeded.

RESULTS

Median survival of the whole group is 25 months, there are 3 patients alive. In the above mentioned patient 1 year after the metastasectomy PET-CT showed focus of the 4th left rib suspected to be malignant. Wide resection of the rib was done, but no malignancy was disclosed, there were only reparative changes. The patient has been tolerated the oncological treatment very well and 45 months after the lung metastasectomy there are no sings of a malignant disease.

CONCLUSION

Lung metastasectomy of the multiple lung metastases of the synovial sarcoma is of value despite of uncertain long-term prognosis. It is recommended to consider the metastasectomy even in low differentiated tumors. The prerequisite for the effective treatment is a complete resection.

[Radioisotope department in Motol--the flow of time]

The radioisotope department in Motol was established on the 1st of June 1957 as the part of The Research Institute of Endocrinology founded by Assoc. Prof. Karel Silink. In the beginning, the department included 20 beds and its main activity consisted of radioiodine treatment of hyperthyroidism. Since 1965 the attention has been paid to the treatment of thyroid cancer, and this tradition continues till this time. The article reviews the main directions of development of this department since the very beginning to present.

The risk of medullary thyroid carcinoma in patients with Hirschsprung's disease

Hirschsprung's disease (HD) can be associated with the development of neuroendocrine tumours such as medullary thyroid carcinoma (MTC). The RET proto-oncogene is the major gene responsible for both HD and MTC. Mutations in exon 10 (codons 609, 611, 618, 620) were found in patients with co-occurrence of HD and MTC. The aim of the study was to screen the MTC risk in patients with HD. The prospective and retrospective genetic analyses comprised 56 HD patients (41 males, 15 females, aged 0-47). The prospective subgroup of patients consisted of 34 patients (25 boys, 9 girls) operated on between June 2003 and December 2005. The retrospective subgroup comprised 22 patients (16 boys, 6 girls) of 194 patients who were operated on between December 1979 and May 2003, non-systematically chosen preferably for total colonic aganglionosis (TCA). DNAs were isolated from blood and resected segments of aganglionic bowel. The HD patients and nine available family members (2 HD) were tested for RET mutations in exons 10, 11, 13, 14, 15 and 16. Direct double-stranded fluorescent sequencing revealed typical germline heterozygous MTC risk RET mutations in 3/56 (5.4%) female HD patients: Cys609Tyr, Cys620Arg (both exon 10) and Tyr791Phe (exon 13). Two of these patients had TCA and one patient had classical type of HD. One TCA patient developed clinical stage of MTC and underwent total thyroidectomy (TTE). The other two RET positive HD patients (aged 7 and 25 years) are screened for calcitonin level and they are without TTE till now. Two family members (mothers of TCA patients) with detected RET mutation underwent prophylactic TTE with MTC finding. Results showed the benefit of systematic RET mutation screening in HD patients in order to identify the risk of MTC in preclinical stage of the disease in patients with HD and their family members. We recommend to investigate not only exon 10 but also exon 13.

[Thyroid carcinomas and Hirschsprung's disease--10-year experience with molecular genetic testing of the RET proto-oncogene]

In the last ten years, research has confirmed the role of the RET proto-oncogene in the pathogenesis of thyroid cancer such as medullary thyroid carcinoma (MTC) and papillary thyroid carcinoma (PTC), multiple endocrine neoplasia type 2 (MEN 2) and Hirschsprung's disease that can be associated with MTC or MEN 2. Through the use of molecular genetic testing, we are able to detect gene mutations and the course the disease might take can be predicted, thus enabling us to cure mutation carriers among the high-risk patients can at a very early, clinically asymptomatic stage of the disease; prophylactic total thyreoidectomy in said patients is recommended. At this juncture, there is extensive on-going research on the physiological role played by the RET proto-oncogene on the normal proliferation, differentiation and survival of the cell. Thanks to the new findings there are now possibilities of the theurapeutic use of gene therapy on an RET signaling cascade level in near future.

[Radionuclide screening in endocrinology]

The study provides an overview of current possibilities for use of nuclear medicine methods in endocrine diagnostics and therapy. Somatostatin receptor analogue is applied to the hypothalamus-hypophysis system, analogue medium to is used, in thyroid diagnostics, besides the determined tumour markers, tenchecium-labelled MIBI radioiodine 131 is used to determine and monitor carcinomas. Recently, rhTSH before starting thyroid carcinoma treatment is used. Neuroendocrinology tumours are suspected through 123I-MIBG; when scintigraphy is positive, therapeutic 131I-MIBG can be administrated. In diagnostics of the pituitary gland, two-step scintigraphy of MIBI is preferably used rather than subtraction methods. In patients with late or not significantly differenciated malignant tumours, positrone emission tomography is of benefit.

Double germline mutations in the RET Proto-oncogene in MEN 2A and MEN 2B kindreds

Medullary thyroid carcinoma (MTC) is a rare form of thyroid cancer representing about 10% of all thyroid malignancies. It occurs mostly as a sporadic tumor or in association with autosomal dominant inherited cancer syndromes--multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in exons 8, 10, 11, 13, 14, 15 and 16 of the RET proto-oncogene are found in most of the familial cases. There are only a few published data reporting multiple germline mutations in the RET proto-oncogene. We have detected double germline mutations in 2 different exons on the same RET allele in two MEN 2 families. In the MEN 2A family, double germline mutation in exons 10 (Cys620Phe) and 13 (Tyr791Phe) was detected. In the MEN 2B family, beside the classical germline mutation in exon 16 (Met918Thr) a second germline mutation in exon 13 (Tyr791Phe) was found. This study revealed that MEN 2 syndromes can also be caused by double germline mutations in the RET proto-oncogene and these families can be added to small worldwide cohort of families with multiple germline mutations.

New multiple somatic mutations in the RET proto-oncogene associated with a sporadic medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) occurs mostly as a sporadic tumor or in connection with inherited cancer syndromes-multiple endocrine neoplasia (MEN) types 2A and 2B and familial MTC. Germline mutations in the RET proto-oncogene are found in most of the familial cases. Somatic mutations in the RET proto-oncogene are detected in 23%-69% of patients with sporadic MTC. The most frequent somatic mutation is Met918Thr in exon 16 and only a small percentage of mutations in other RET exons have been observed. In a very few cases double mutations were found. Genetic screening for somatic mutations in RET exons 10, 11, 13, 14, 15, and 16 in Czech patients with sporadic MTC was carried out by DNA sequencing. This study presents a new triplesomatic mutation Gly911Asp, Met918Thr, and Glu921Lys in exon 16 of the RET proto-oncogene detected in an 18-year-old Czech male patient. In the second case, a new double-somatic mutation Val591Ile in exon 10 with a concomitant somatic mutation Met918Thr in exon 16 was found in a 77-year-old Czech female patient. These both newly described somatic multiple mutations were revealed in a hemizygous status, the loss of heterozygosity in tumor tissues in comparison with germline DNA was confirmed.

[The volumes of the thyroid gland in adults aged 18-65 years in the Czech Republic--determination of the norms]

OBJECTIVE

In the areas with moderate iodine deficit the sonographic examination of thyroid gland is a precious method of precise determination of its volume. The objective of the work was the sonographic examination of males and females aged 18-65 years and to determine the norms of the volumes of thyroid gland.

METHODS AND RESULTS

In total, by random sampling, there were sonographically examined 3 416 adults in 11 areas of the Czech Republic; there was chosen a set of 971 females and 681 males whose iodinuria level in first morning urine sample was equal or higher than 100 microg/l. This set was divided according to sex and into the age categories in 5-year interval. The measurement of 3 dimensions of the thyroid gland was determined by Medison-Kretz SA 600 sonographic device with the use of 7.5 MHz linear probe for the depth and width measurement and 3.5 MHz probe was used for the lengths measurement. The volume was determined for each lobe individually using Brunn's formula: V (ml) = 0.479 x length x depth x width. Our results imply the age-related increase of the volume of thyroid gland at both sexes (F-ratio = 1.99, p < 0.0001). At men and women the volume of thyroid gland fluently increases to the 30th year equally, from 30 years to 55 years it increases more rapidly in men while in women there is observed a moderate plateau. Further increase of the volume of thyroid gland is equally fluent from the age of 55 years.

CONCLUSION

We managed to determine first own norms of the volumes of thyroid gland for men and women aged 18-65 years in the Czech Republic in five-year age categories. In terms of practical use we recommend 90th percentile as a limit for the evaluation of upper limit of thyroid gland and the 10th percentile for the evaluation of lower limit of the volume of thyroid gland.

Insulin sensitivity and counter-regulatory hormones in hypothyroidism and during thyroid hormone replacement therapy

We examined insulin sensitivity and secretion, together with the levels of selected glucoregulatory hormones, in 15 female patients with severe hypothyroidism (H) and during subsequent thyroid hormone replacement therapy (HRT) using the euglycaemic hyperinsulinaemic clamp technique. Insulin action, as evaluated by glucose disposal, the insulin sensitivity index, and fasting post-hepatic insulin delivery rate were established. The basal levels of insulin, C-peptide and counter-regulatory hormones were measured in basal condition. In H, glucose disposal (p<0.01), the insulin sensitivity index (p<0.01) and post-hepatic insulin delivery rate (p<0.05) were significantly lower than during HRT. No significant changes in the levels of fasting insulin and C-peptide were observed. The levels of counter-regulatory hormones in patients with H were significantly higher than during HRT (glucagon, p<0.05; epinephrine, p<0.01; cortisol, p<0.05; growth hormone, p<0.05). In H, an inverse correlation between insulin sensitivity and insulin secretion was observed (p<0.05). Cortisol was the most important factor affecting the variability of insulin sensitivity values, regardless of thyroid function (p=0.0012). In conclusion, H altered both insulin sensitivity and the levels of selected counter-regulatory hormones. The situation was restored by HRT, as manifested not only by normalisation of insulin sensitivity, secretion and levels of glucoregulatory hormones, but also by improvement of their relationships.

Exon 5 of the RET proto-oncogene: a newly detected risk exon for familial medullary thyroid carcinoma, a novel germ-line mutation Gly321Arg

Familial medullary thyroid carcinoma (FMTC) is an autosomal dominant inherited disease, characterized by germ-line mutations in the RET proto-oncogene, mainly in exons 10 and 11, but also in exons 13, 14 and 15. Recently, mutations in exons 8 and 16 associated with FMTC were also described. In the herein presented study, single strand conformation polymorphism (SSCP) method for rapid screening of mutations in the RET proto-oncogene and fluorescent sequencing method were used. In one Czech family with FMTC, we have identified a novel missense point mutation of the RET proto-oncogene in exon 5, that results in substitution of arginine by glycine at codon 321 in the cadherin-like domain of ret protein. It seems that this mutation causes FMTC as no other mutation was found in the classical risk exons (10, 11, 13, 14, 15 and 16) of the RET proto-oncogene. The mutation cosegregates with medullary thyroid carcinoma (MTC) or C cell hyperplasia (CCH) in two patients; two other family members are mutation carriers without clinical signs of MTC so far. To improve the diagnosis of FMTC, analysis of exon 5 of the RET proto-oncogene should be considered in families with no identified classical RET mutations.

Block copolymer adsorption from a homopolymer melt to an amine-terminated surface

Using neutron reflectometry, the adsorption of diblock copolymers from a neutral polystyrene (PS) matrix is studied as a function of substrate type and non-adsorbing block degree of polymerization. The block copolymer is poly(deutero styrene)-block-poly(methyl methacrylate) and the substrates are silicon oxide, SiO(x), and SiO(x) functionalized with (3-aminopropyl)triethoxysilane (APTES). We have determined the equilibrium volume fraction-depth profiles for such films, and compared them with volume fraction profiles generated by self-consistent mean-field (SCMF) theory and find good agreement between the experimental and theoretical data. SCMF calculations show that the segmental interaction energy between PS matrix chains and APTES is two orders of magnitude stronger than that between PS and SiO(x).

A novel Czech kindred with familial medullary thyroid carcinoma and Hirschsprung's disease

PURPOSE

The RET proto-oncogene is involved in neural crest disorders. Activating germline mutations in the RET proto-oncogene cause the development of familial medullary thyroid carcinoma (FMTC) or medullary thyroid carcinoma (MTC) as a part of multiple endocrine neoplasia type 2 (MEN2) syndrome. Inactivating germline mutations in the RET proto-oncogene are detected in Hirschsprung's disease (HSCR). Only in a very small number of families are these 2 diseases expressed together.

METHODS

This study presents a novel Czech kindred with FMTC-HSCR phenotype. Two family members (mother and daughter) were tested for RET germline mutations in exons 10, 11, 13, 14, 15, and 16.

RESULTS

Direct fluorescent sequencing of genomic DNA revealed a heterozygous mutation in the RET proto-oncogene in exon 10 at codon C609Y in both persons tested. This family was reclassified, thanks to genetic screening from the apparently sporadic MTC-HSCR to FMTC-HSCR.

CONCLUSION

The germline mutation was detected because of the systematic genetic screening of the RET proto-oncogene, which is useful for genetic counseling of potential risk of HSCR and MTC in other family members. This family could be added to the small worldwide cohort of families with MEN2A/FMTC-HSCR.

Screening of six risk exons of the RET proto-oncogene in families with medullary thyroid carcinoma in the Czech Republic

Medullary thyroid carcinoma (MTC) occurs as a sporadic form (75%) or as an autosomal dominant inherited familial disorder (25%) called familial MTC (FMTC) or as multiple endocrine neoplasia type 2 (MEN2) syndromes. Germ-line mutations in the rearranged during transfection (RET) proto-oncogene in exons 10, 11, 13, 14, 15 and 16 are known to be a cause of most of the familial forms. In this paper we report molecular genetic testing of 106 families with MTC (358 tested persons) from the Czech Republic in which we directly sequenced these six exons of the RET proto-oncogene. We detected germ-line mutations in 100% of MEN2B families (4/4 families), 90% of MEN2A families (9/10), 40% of FMTC families (4/10) and 7% of apparently sporadic MTC (6/82). Eleven different germ-line mutations were revealed. MEN2B was associated with mutation Met918 Thr in exon 16. In one MEN2B family beside this mutation the Tyr791 Phe was also found, which has not yet been reported. MEN2A was restricted to different mutations in exon 11 (codon 634). In FMTC and 'sporadic' MTC families the mutations in exons 10, 11, 13 and 14 were detected. The genotype/phenotype correlations are given. Genetic testing revealed germ-line mutations in 23 index patients, 24 family members and excluded them in 53 relatives.

Thyroid surgery in children and adolescents

Authors present 114 children and adolescents of the total 3865 patients that underwent surgery on the Department of Otorhinolaryngology and Head and Neck Surgery, 1st Faculty of Medicine, Charles University, Prague, Department of Otorhinolaryngology of IPVZ, Prague because of a thyroid disease in years 1991-2000. The male/female ratio in the group was 1:6.5, 16 (13.9%) males and 99 (86.1%) females. For non-malignant disease, the male/female ratio was 1:6.5 and for malignant disease, it was 1:5.4. Thyroid surgery was indicated for non-malignant disease in 82 (71.9%) cases--11 males and 71 females. Most frequently it was indicated because of Graves-Basedow and Hashimoto toxicosis--in 39 children (34.2%), in 5 children (4.4%) for toxic adenoma. Because of the polynodular goiter surgery was indicated in 13 cases (11.4%), in 22 cases (19.3%) for mononodular goiter. Three girls (2.6%) were recommended for surgery because of Hashimoto thyreoiditis and for mechanic syndrome in diffuse goiter one girl (0.9%). Malignant tumor was found in 32 children (28.1%)--5 males and 27 females. Most frequent histological type was papillary cancer--in 25 cases (21.9%). Follicular cancer was diagnosed in four cases (3.5%) and medullar cancer in three cases (2.6%). TNM classification in children and adults is summarized in Table 1. Surgery was carried out in two children with distant metastases (lung localization). In both children the pre-disease stage lasted more than 12 months. The first manifestation of the disease was a finding of enlarged and palpable nodes on the neck. The authors summarize indications for surgery of thyroid diseases in children and adolescents. A treatment of the thyroid gland is a teamwork. Indication for surgery is carried out by a pediatric endocrinologist in cooperation with a surgeon specialized in thyroid surgery. The possible identification of the recurrent laryngeal nerve by a surgery microscope is an unquestionable advance. Children and adults should be centralized into health-care centers capable not only of surgery, but also of endocrinology care. In children with a malignant disease there is a need for cooperation with a pediatric oncologist and a following oncological treatment on a nuclear medicine department. The authors summarize the information about today's thyroid surgery care possibilities for children and adolescents. They point out the differences in indications and the decision about extent of surgery in children and adolescents.

Changes of noradrenergic activity and lipolysis in the subcutaneous abdominal adipose tissue of hypo- and hyperthyroid patients: an in vivo microdialysis study

Thyroid function plays an important role in the regulation of overall metabolic rate and lipid metabolism. However, it is uncertain whether thyroid hormones directly affect lipolysis in adipose tissue and to what extent those changes contribute to overall metabolic phenotype. Our study was designed, using the microdialysis technique, to determine basal and isoprenaline-stimulated local lipolysis and to determine local concentrations of lipolysis-regulating catecholamines in abdominal subcutaneous adipose tissue in 12 patients with hypothyroidism, 6 patients with hyperthyroidism, and 12 healthy control subjects. Plasma norepinephrine (NE) concentrations in hypothyroid subjects were significantly higher than in the control and hyperthyroid groups. In contrast, systemic, adipose NE levels in hypothyroid patients were decreased relative to controls. Hyperthyroidism, on the other hand, resulted in four-fold higher adipose NE levels. Basal lipolysis measured by glycerol concentrations in adipose tissue was significantly attenuated in hypothyroid patients and markedly increased in hyperthyroid patients in comparison with the control group. In addition to differences in basal lipolysis, hypothyroidism resulted in attenuated, and hyperthyroidism in enhanced, lipolytic response to local stimulation with beta(1,2)-adrenergic agonist isoprenaline. These results demonstrate that lipolysis in abdominal subcutaneous adipose tissue is strongly modulated by thyroid function. We suggest that thyroid hormones regulate lipolysis primarily by affecting local NE concentration and/or adrenergic postreceptor signaling.

Detection of the sentinel node in breast carcinoma using method of a single subcutaneous injection of radiopharmaceutical

The objective of this work is retrospective evaluation of results of the intraoperative detection of sentinel node in breast carcinoma after a single subcutaneous injection of radiopharmaceutical (RF) within a two-day protocol. From May/2001 to June/2002, lymphoscintigraphy of the sentinel node (SN) and its subsequent radioguided intraoperative detection (RGS) was performed in 43 women having stage T1-T2, N0 breast carcinoma. The static scans in the anterior and relevant lateral projections were performed using a gamma camera at approximately 30-minute intervals after the subcutaneous administration of 15 MBq 99mTc Senti-Scint, until the SN was displayed. The localization of the SN was marked on the overlying skin with a water-resistant permanent marker in 1-2 projections. RGS was accessed within 18-24 hours after the injection of the RF and all patients underwent an axillary dissection. The SN was detected in all patients, and in all cases was localized in the ipsilateral axilla. In 26 patients (60%), no metastatic process was found either in the SN or in any other axillary node. However, in one node, deposits of the carcinoma were detected in surrounding fatty tissue with propagation along the vessels and nerve. In 16 patients (37%), metastases in the SN were proved, in 7 cases (16%), a metastatic process was proved at the same time even in further lymph nodes. A number of false negative findings (5.8%) is consistent with the literature data. The method fails in the detection of intramammary localized SNs.

[Genetic causes of the thyroid carcinomas]

Thyroid carcinomas represent only 1% of all human malignancies, but more than 90% of endocrine tumors. It can be histologically divided into papillary, follicular, anaplastic or medullary thyroid carcinomas. Here we report the genetic causes of the development of these tumors. For papillary thyroid carcinoma formation of fused genes of tyrosine kinases (RET proto-oncogene, NTRK1 proto-oncogene and met proto-oncogene) with other genes is typical. They can activate these kinases and induce mutation in BRAF gene. The presence of PAX8/PPARgamma fused gene and ras mutations are important in the development of follicular thyroid carcinoma. Anaplastic thyroid carcinoma derives from the dedifferentiation of papillary and follicular carcinomas as a consequence of mutation or loss of heterozygozity in p53 gene. Medullary thyroid carcinoma comes from parafollicular C-cells, where point somatic and germ-line mutations (in familial form of medullary thyroid carcinoma or in multiple endocrine neoplasia type 2) in the RET proto-oncogene determine its development. Identification of these specific genetic alternations for each type of carcinoma can contribute to precision of the diagnosis, explanation of the origin of carcinomas, establishment of prognosis of the disease or in future as a tool for the target gene therapy.