The role of FDG-PET in localization of recurrent lesions of differentiated thyroid cancer (DTC) in patients with asymptomatic hyperthyroglobulinemia in a real clinical practice.

INTRODUCTION: Available methods, including serum thyroglobulin (Tg) measurement and whole-body scan (WBS) performed after radioiodine administration, allow for a precise diagnostics in differentiated thyroid cancer (DTC). However, some asymptomatic patients demonstrate negative WBS despite a high Tg serum concentration. In these subjects, fluorodeoxyglucose-positron emission tomography (FDG-PET) should be considered. The primary aim of our study was to evaluate a diagnostic value of FDG-PET in asymptomatic hyperthyroglobulinemia. The secondary one was to determine a prognostic value of a negative FDG-PET result in DTC patients with elevated Tg level. MATERIAL: One hundred and ten FDG-PET/CT scans were retrospectively analyzed, 85 scans were done under TSH stimulation and 25 on LT4 suppressive therapy. Follow-up ranged between 4 and 9 years. RESULTS: The first FDG-PET/CT detected cancer foci in 49 subjects with a global sensitivity of 45%. When the sensitivity was evaluated with reference to TSH stimulation and suppression, its values were 50 and 28% respectively. In 42 patients, FDG-PET failed to diagnose the reason for elevated Tg level. During further follow-up, in 17 of them, DTC recurrence was detected by other methods (CT, MRI, US). Fourteen subjects with asymptomatic hyperthyroglobulinemia were free of DTC progression for at least 4 years. CONCLUSIONS: FDG-PET in DTC patients with asymptomatic hyperthyroglobulinemia constitutes a valuable diagnostic tool. Negative FDG-PET demonstrated a limited prognostic significance, as only every third patient did not show DTC progression. Moreover, negative FDG-PET does not justify less strict DTC monitoring, because it is related to 40% risk of relapse during the 5-year follow-up.

[L-thyroxine therapy in differentiated thyroid carcinoma: criteria for evaluation of TSH suppression]. / Leczenie L-tyroksyna zróznicowanego raka tarczycy: kryteria supresji wzglednej.

UNLABELLED: Life-time L-thyroxine therapy is obligatory in patients treated for differentiated thyroid carcinoma (DTC) in order to suppress serum TSH. The rationale for that is the TSH stimulation of follicular cells' growth and the presence of TSH receptors on DTC cells. Nevertheless, the exact criteria for TSH suppression in DTC are not specified and are a matter of discussion, stimulated by the recent progress in the evaluation of thyroxine side effects on bone and heart. The aim of the study was the optimalization of the reference range for TSH suppression in DTC patients in order to minimalize the risk of iatrogenic thyrotoxicosis. One hundred and twenty nine patients were randomly chosen among patients treated radically for DTC (116 females and 13 males). Basal and TRH stimulated TSH level, FT4 and FT3 serum level were estimated by microimmunoenzymatic method, while SHBG was estimated by immunofluorimetry. Full suppression (basal TSH < 0.05) was obtained in 64 patients (49%), submaximal suppression (TSH between 0.1 and 0.3 mU/l) was observed in 21 patients (16%). In 29 patients (22%) no suppression was obtained by the applied dose of thyroxine. The risk of iatrogenic hyperthyreosis, as judged by the increase of FT3 or SHBG, was found to be 38% in patients with full suppression and only 5% in patients with submaximal suppression (p < 0.05). CONCLUSION: 1. Suppression of TSH secretion was achieved in 80% of patients with differentiated thyroid carcinoma. The control of TSH level must be controlled every 3 months in 5 first years of therapy. 2. The optimal serum TSH level for L-thyroxine therapy in asymptomatic patients after radical treatment of differentiated thyroid carcinoma ranges between 0.1 to 0.3 mU/L. This range ensures the expected suppression of TSH with only minimal risk of iatrogenic hyperthyreosis.

Is there loss or qualitative changes in the expression of thyroid peroxidase protein in thyroid epithelial cancer?

There is disagreement concerning the expression of thyroid peroxidase (TPO) in thyroid cancer, some studies finding qualitative as well as quantitative differences compared to normal tissue. To investigate TPO protein expression and its antigenic properties, TPO was captured from a solubilizate of thyroid microsomes by a panel of murine anti-TPO monoclonal antibodies and detected with a panel of anti-human TPO IgGkappa Fab. TPO protein expression in 30 samples of malignant thyroid tissue was compared with TPO from adjacent normal tissues. Virtual absence of TPO expression was observed in 8 cases. In the remaining 22 malignant thyroid tumours the TPO protein level varied considerably from normal to nearly absent when compared to normal thyroid tissue or tissues from patients with Graves' disease (range less than 0.5 to more than 12.5 microg mg(-1) of protein). When expressed TPO displayed similar epitopes, to that of TPO from Graves' disease tissue. The results obtained by the TPO capturing method were confirmed by SDS-PAGE and Western blot analysis with both microsomes and their solubilizates. The present results show that in about two-thirds of differentiated thyroid carcinomas, TPO protein is expressed, albeit to a more variable extent than normal; when present, TPO in malignant tissues is immunologically normal.

[Effects of L-thyroxine suppressive therapy on cardiac mass in patients with differentiated thyroid cancer]. / Wplyw leczenia supresyjnego L-tyroksyna chorych na zróznicowanego raka tarczycy na mase miesnia sercowego.

Patients with differentiated thyroid carcinoma (DTC) receive a life time l-thyroxine therapy in suppressive doses and may exhibit signs of cardiac hypertrophy. The aim of the study was to analyze the left ventricle mass parameters by echocardiography in patients treated with suppressive doses of thyroxine and to relate them to the possible occurrence of cardiac arrhythmias. Ninety four patients aged 19-70 years treated chronically with l-thyroxine were randomly chosen from the population of patients with DTC without concomitant diseases of circulatory system. They were divided into two subgroups according to the length of thyroxine therapy (< 60 months and > or = 60 months). Control group consisted of 41 healthy volunteers, aged 22-73 years. Heart muscle dimensions were measured by echocardiography. Left ventricle mass (LVM) and mass index (LVMI) was calculated. Electrocardiography according to Holter was carried out in 57 patients. The results of echocardiography in the whole group of patients did not differ significantly from the control group, although a tendency towards higher dimensions of the left ventricle was observed. No correlation of hormonal parameters, or thyroxine dose, with LVM or results of Holters ecg was noted. When patients were subdivided into two groups, according to the duration of therapy, significantly higher values of LVM (215 +/- 64 g versus 186 +/- 55; p < 0.05) and LVMI (114 +/- 31 g/m versus 102 +/- 23 g/m; p < 0.05) were observed in patients treated > or = 60 months in comparison to the control group. When results of Holter's ecg in patients with increased LVMI were analyzed, cardiac rhythm disturbances were stated in 50% of them, but most were of minor clinical relevance. Suppressive l-thyroxine therapy does not induce significant left heart hypertrophy during the first 5 years of treatment. Patients treated through a longer period of time should be controlled by echocardiography because of the increasing risk of the left ventricle hypertrophy and arrhythmia.

Estimation of risk of inherited medullary thyroid carcinoma in apparent sporadic patients.

PURPOSE: The study was undertaken to evaluate the frequency of inherited medullary thyroid carcinoma (MTC) among patients with apparent sporadic disease. A stepwise algorithm was used depending on clinical indices and the age of patient at MTC diagnosis. PATIENTS AND METHODS: One hundred sixteen patients with MTC verified by postoperative pathologic examination were subjected to genetic analysis of RET exons 10, 11, 13, 14, and 16 by means of polymerase chain reaction, restriction endonuclease digestion, and DNA sequencing. RESULTS: Among 116 apparent sporadic MTC patients, we identified eleven (9.5%) RET germline mutation carriers. Seven of these (6.0%) were found by routine analysis (exons 10 and 11). The frequency of inherited disease among patients younger than 45 years at diagnosis was 10.2% by analysis of typical mutations in exons 10 and 11. Extended genetic analysis (sequencing of exons 11, 13, 14, and 16) yielded 6.1% additional diagnoses, giving a risk of 16.3% in this age group. One previously unreported mutation in exon 11 affected codon 649 (TCG>TTG, Ser>Leu). In the true sporadic MTC patients younger than 30 years at diagnosis, frequencies of 36% and 4.5% in polymorphic variants L769L and S836S, respectively, were observed. The frequency for L769L was higher than in older patients (P <.05). CONCLUSION: The frequency of inherited disease among apparent sporadic medullary thyroid carcinoma patients is close to 10% in the Polish population of MTC patients. The extended analysis of all known RET proto-oncogene mutation sites is obligatory in patients younger than 45 years at diagnosis, but we also see the need to analyze the impact of rarer mutations in older patients.

[Prospective analysis of criteria for interpreting measurements of thyroglobulin serum concentration during conditions of endogenous TSH stimulation in serum of patients with differentiated thyroid carcinoma]. / Prospektywna analiza kryteriów interpretacyjnych oznaczania stezenia tyreoglobuliny w warunkach stymulacji endogennym TSH w surowicy chorych na zróznicowane raki tarczycy.

The aim of this study was the assessment of diagnostic value of thyroglobulin serum measurement in patients with DTC during endogenous TSH stimulation. Thyroglobulin was measured by immunofluorometric method (Delfia-Wallac) in patients after combined surgery and I131 ablation. Predictive values for two threshold levels 10 and 30 ng/ml were compared. At 5 years follow up it has been demonstrated, that Tg values higher than 10 ng/ml were the true signals of DTC relapse only in 46% patients. Tg values higher than 30 ng/ml were associated with disease progression in 65% of patients. Thus, we accept Tg concentration of 30 ng/ml measured during endogenous TSH stimulation as a good cut-off limit for the detection of DTC progression. Reduction of this threshold up to 10 ng/ml is associated with the increased risk of false positive results.

[Comparison of efficacy of various methods of thyroglobulin measurements in differentiated thyroid cancer]. / Porównanie skutecznosci róznych metod oznaczania tyreoglobuliny jako markera zróznicowanego raka tarczycy.

Monitoring patients with differentiated thyroid carcinoma (DTC) by thyroglobulin (Tg) measurements requires selecting optimal methods used for detection of this marker. An increase the thyroglobulin concentration in serum is a predictor of tumor recurrence. All serum thyroglobulin assays can be falsified by presence of Tg autoantibodies, which are present in approximately 20% of DTC patients. The aim of this study was a comparison of the clinical utility of two different methods for determining serum Tg concentration in monitoring patients with DTC during thyroxine treatment. Tg concentration was measured in serum samples of 1530 patients with DTC during replacement thyroid hormone using two methods: fluoroimmunometric assay (IFMA) Wallac Delfia Thyroglobulin and immunoradiometric assay (IRMA) Brahms DYNOtest Tg-S. 1847 values of Tg concentration and recovery test detected between 1992 and 1995 years using IFMA methods and 1187 values of Tg and thyroglobulin autoantibodies concentration measured in 2000 year using IRMA methods were also included. The correlation between Tg values in all patients group wasn't good (r = 0.83; p < 0.05), but when we excluded patients with incorrect recovery test determined by IRMA, the correlation factor was higher (r = 0.94; p < 0.05). The estimation of Tg recovery test obtained in IRMA assay eliminated from monitoring only 3% patients with DTC, when IFMA assay excluded nearly 1/5 patients, whereas the estimation Tg autoantibodies 7% from all patients. The IRMA method is the most resistant to interference and allows to monitor a reliably greater group of patients with DTC during thyroxine treatment.

[Thyroglobulin RT-PCR method for detection of lymph node metastases during the course of differentiated thyroid cancers]. / Metoda RT-PCR dla tyreoglobuliny w wykrywaniu przerzutów nowotworowych do wezlów chlonnych w przebiegu zróznicowanych raków tarczycy.

UNLABELLED: In patients with a suspicion of recurrence of differentiated thyroid cancer with metastases to lymph nodes, detection of thyroglobulin (Tg) mRNA in fine needle biopsy material may support the interpretation of classic cytological examination in cases where it fails to detect lymph node involvement early enough. AIM: Prospective study of thyroglobulin mRNA detection in neck lymph nodes in patients with suspected differentiated thyroid cancer (DTC) metastases. MATERIAL: 70 nodes from 60 patients with suspected DTC recurrence were investigated. Patients with suspicion of lymph node metastases of other types of cancer were included as a control group. Thyroglobulin RT-PCR was conducted in residual material left after preparation of cytological smears from fine needle biopsy specimens. Primers spanning exons 3-5 were used with 39 cycles of PCR. RNA isolation control and cDNA amplification were carried out using GADPH starters. RESULTS: Classical cytology confirmed nodal involvement in 22 of DTC patients, RT-PCR Tg was positive in 20 of them (91%). Among 48 patients with a suspicion of DTC recurrence and negative cytology, Tg mRNA was found twice. One positive RT-PCR result was confirmed by repeated cytology conducted 4-6 months later and followed by surgery. No positive result of RT-PCR was obtained with other head and neck malignancies. The overall specificity was estimated with 98%. CONCLUSIONS: RT-PCR Tg shows sufficient specificity to be applied in further studies estimating its usefulness in fine needle biopsy for early detection of lymph node metastases in differentiated thyroid cancer.

[Consequences of clinical genetic analysis of RET proto-oncogene]. / Konsekwencje kliniczne analizy genetycznej protoonkogenu RET.

Preliminary results of treatment of inherited medullary thyroid carcinoma, diagnosed primarily with genetic analysis of mutation of protooncogene RET are presented. Among 16 carriers of mutation identical with mutation diagnosed earlier in proband, there were 4 patients with clinically obvious medullary thyroid carcinoma and 12 asymptomatic carriers. In all patients, in whom calcitonin level was increased preoperatively, its normalization was obtained. The paper summarizes these aspects of cooperation between geneticians and physicians in which diagnostic results influence clinical decisions (indication and time of thyroid and lymph nodes surgery and it's spectrum, range of diagnostic procedures towards pheochromocytoma and parathyroid hyperplasia in relation to the found mutation).

[Proto-oncogene RET somatic mutations in medullary thyroid carcinoma]. / Mutacje somatyczne protoonkogenu RET w raku rdzeniastym tarczycy.

UNLABELLED: Somatic mutations of the RET protooncogene are present in 23-68% cases of sporadic medullary thyroid carcinoma (MTC). The aim of the study was to introduce the RET somatic mutations analysis in tumor tissue as well as to evaluate their types and frequencies in postoperative specimens of MTC patients treated in the Center of Oncology in Gliwice. MATERIAL: 14 tumor tissues obtained from sporadic MTC patients and two control groups--six and four specimens from patients with MEN 2A and MEN 2B syndrome respectively. METHODS: Tumor tissue DNA isolation followed by PCR amplification of RET exons 10, 11, 13, 14, 16 and automated, fluorescent sequencing of PCR products. We identified somatic mutation ATG > ACG in codon 918, exon 16 in 7 of 14 (50%) of analyzed sporadic MTC cases. We also found one deletion/insertion mutation in RET exon 11 that encompasses cysteine codon 634 and has not been published so far. The types and frequencies of found RET gene mutations were similar to previously reported. The analysis of RET somatic mutations supports the differentiation between the sporadic and inherited MTC. The presence of somatic mutation and its simultaneous absence in the germline proves sporadic type of cancer.

[Results of treating medullary thyroid carcinoma: the differences between sporadic and inherited forms]. / Wyniki leczenia raka rdzeniastego tarczycy: róznice pomiedzy postaciami sporadyczna i dziedziczna.

Medullary thyroid carcinoma (MTC) can be divided into two subgroups: sporadic or inherited. Hereditary form of MTC is often believed to be form with better prognosis than sporadic one. In this study the differences in MTC prognosis in Polish population of patients was analyzed. The group of 169 patients with MTC was examined. Hereditary cancer was stated in 48 (28%) patients. The median age of disease onset was 41 years (from 7 to 71 years). Genetic examination of RET protooncogene was performed in all patients. The calcitonin and CEA serum level analysis and radiological and radioisotopic examinations were used for monitoring of the disease course. Nineteen cases of MEN 2A syndrome, 11 cases of MEN 2B one and 18 cases of non classified familial MTC were recognized among patients with inherited MTC. Significantly lower age of disease onset in inherited MTC than in sporadic one was observed (27 years vs. 43.7 years, p < 0.001). Local or nodal recurrence was observed in 22 (13%) patients, distant metastases were stated in 21 (12%) patients. Basal or stimulated serum calcitonin level was increased in 85 (50%) patients. No significant differences between sporadic and inherited disease were observed. Eight patients died during observation, including 3 patients with sporadic MTC and 5 patients with inherited MTC. The updated 10-year survival rate was 97% in patients with sporadic MTC; in hereditary MTC it was about 20% worse. The complications related to the presence of adrenal tumors were the main reason for death in MEN2 and no significant differences in the course of MTC itself were observed.

[Rearrangement of the RET gene in papillary thyroid carcinoma]. / Rearanzacje genu RET w raku brodawkowatym tarczycy.

The RET/PTC oncogenes, activated forms of the RET protooncogene, almost exclusively found in papillary thyroid carcinoma (PTC). What is more, the targeted expression of RET/PTC in mice leads to the development of thyroid tumors very similar to human PTCs. In all RET/PTC types the RET tyrosine kinase domain is fused to the N-terminus of ubiquitously expressed genes that is capable of ligand-independent dimerization. The majority of RET/PTC identified consists of two types which results from the inversion of chromosome 10: RET/PTC1 and RET/PTC3. The prevalence of RET/PTC in papillary thyroid carcinomas of thyroid varies widely from a few to about 80% with the highest frequency in tumors arising in children after ionizing radiation. In Polish population the frequency of RET rearrangements in papillary cancers is 27%, although, it was reported to be twice higher in young patients (50% in patients younger than 21 at operation). Correlation with clinical outcome as well as prognostic value of RET/PTC is controversial. Some authors suggest that it predicts metastases, others found rearranged RET in more favourable, slow growing tumors. RET/PTC3 seems to be associated with solid/follicular variant PTC and short latency period (it is found more frequently in children) whereas RET/PTC1--with classic PTC variant and long latency.

The genetic background of medullary thyroid carcinoma in young patients.

The study was undertaken to evaluate the frequency of RET polymorphisms at codons 769 and 836 in young medullary thyroid carcinoma (MTC) patients in whom the presence of a known germline mutation has been excluded. 40 patients aged 10-29 were subjected to genetic analysis of RET exons 10, 11, 13, 14 and 16 and compared to 140 older patients. The hereditary component occurred to be very high in young MTC patients: 57% carry the germline mutation, other 28% exhibit at least one rare polymorphic variant of RET. The observed allelic frequencies were 38% for polymorphic variant L769CTG and 6% for variant S836AGT. The results were significantly higher than those obtained in the group of older patients: 20% and 1% for L769CTG and S836AGT, respectively. Our results speak in favour that the polymorphism in RET codon 769 and 836 may also be a factor predisposing to the development of MTC in young age.

Association of polymorphism of LTalpha and TNF genes with Graves' disease.

Graves' disease (GD) is an autoimmune disease, which develops on the basis of an interaction between genetic, environmental and endogenous factors. GD is associated with some HLA genes. Closely linked with them are TNF genes (TNF and LTalpha). Their role in the pathogenesis of GD is still unclear. Two functional polymorphisms within TNF genes include a substitution of G with A in intron I of LTalpha gene and the same one at position -308 in the TNF gene promoter. We carried out a case-control study for the analysis of the contribution of TNF genes to GD in Polish patients. 156 patients with GD diagnosed by clinical data were investigated and compared to 80 healthy persons with negative familial anamnesis. Both TNF and LTalpha were analysed by PCR/Nco I RFLP. The allelic frequency of the rarer TNF2 (A) allele, was 24.7% in GD patients, significantly higher than in healthy persons (9.3%; p<0.0001). The OR was 4.38 for this allele. The frequency of heterozygotes was 41.8% in GD, as compared to 13.6% in the control group. The allelic frequency of the rarer LTB*1 (G) allele was also significantly increased: from 21.9% in the control group to 37.2% in GD patients (p<0.01; OR 2.81). The frequency of heterozygotes was 48.7% in GD, and 28.8% in the control group. The results indicate that TNF genes may contribute to GD in the Polish population.

Influence of neurotransmitters on sexual differentiation of brain structure and function.

Newborn rats received daily subcutaneous treatment with compounds which influence serotoninergic, cholinergic, alpha-adrenergic and beta-adrenergic activity. In adulthood luteinizing hormone (LH) secretion pattern, female sexual behavior, and the volume of the sexually dimorphic nucleus of the preoptic are (SDN-POA) were determined. Postnatal administration of l-tryptophan increased the volume of the SDN-POA significantly when given alone or when given simultaneously with testosterone propionate (TP). Para-chlorophenyl-alanine (pCPA) also increased SDN-POA volume, but did not potentiate the stimulating influence of TP. Clonidine had no effect per se on SDN-POA development, but it significantly potentiated the effect of TP in females. Salbutamol increased SDN-POA volume in females and in males. Postnatal treatment of female rats with the alpha-adrenergic receptor antagonists prazosine and yohimbine or with the nicotin receptor antagonist mecamylamine had permanent potentiating effects on the pattern of LH secretion, whereas postnatal treatment with beta-adrenergic compounds reduced the LH-release response to gonadal steroids in adulthood. Postnatal treatment with clonidin or l-tryptophane inhibited differentiation of the capacity for lordosis behavior. Beta-receptor agonists postnatally had a potentiating effect on the capacity for lordosis behavior in female and male rats. Cholinergic stimulation postnatally inhibited differentiation of the capacity for lordosis behavior in female rats, but prevented the inhibitory effect of postnatal androgenization. There was no correlation between SDN-POA volume and any of the two functional parameters.

Postnatal treatment of rats with the beta 2-adrenergic agonist salbutamol influences the volume of the sexually dimorphic nucleus in the preoptic area.

Sexual differentiation of the brain seems to be influenced by postnatal interaction of gonadal steroids with neurotransmitter systems, in particular the adrenergic system. Stimulation or inhibition of adrenergic receptors during early postnatal development had previously been shown to influence steroid-induced sexual differentiation of rat brain function. In the present study newborn male and female rats were treated daily for 5 days with salbutamol, a specific beta 2-receptor agonist, or with alprenolol, a beta-receptor antagonist and the volume of the sexually dimorphic nucleus of the preoptic area (SDN-POA) was examined in adulthood. This nucleus, one of the most striking sex differences in brain anatomy, is several-fold larger in male than in female rats. Postnatal treatment with salbutamol increased SDN-POA volume in female and in male rats. The effect was particularly striking in males, because any previous pre- and/or postnatal treatment of male rats with large amounts of gonadal steroids had been unable to increase the volume of the SDN-POA above normal. The beta-receptor antagonist alprenolol had no effect on SDN-POA differentiation. The results indicate that beta 2-adrenergic stimulation influences development and differentiation of the SDN-POA.

Postnatal treatment of rats with beta-adrenergic agonists or antagonists influences differentiation of sexual brain functions.

Sexual differentiation of the brain seems to be influenced by postnatal interaction of gonadal steroids with neurotransmitter systems, in particular the adrenergic system. Stimulation or inhibition of alpha-adrenergic receptors during early postnatal development had previously been shown to influence steroid-induced sexual differentiation of brain functions. In the present study newborn male and female rats were treated either with salbutamol, a selective beta 2-adrenergic receptor agonist, isoprenaline, a general beta-adrenergic receptor agonist, or with alprenolol, a general beta-adrenergic receptor antagonist. In adulthood the female animals were ovariectomized and were tested for the capacity to show an LH-surge response and female sexual behaviour after priming with estradiol benzoate (EB) and progesterone (P). Male animals were tested for expression of male sexual behavior and, after gonadectomy and priming with EB + P, for the capacity to show female lordosis behavior. In summary, our results suggest that activation or inhibition of beta-adrenergic receptors during postnatal development permanently impairs the responsiveness of the center for cyclic gonadotropin release to gonadal steroids in female rats and impairs the expression of ejaculatory behavior in male rats. A slight stimulatory effect on the expression of female lordosis behavior was observed in male and female rats after postnatal activation of beta-adrenergic receptors.