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.

[Multiple Endocrine Neoplasia I (Wermers Syndrome), Forms of Clinical Manifestation, 5 Case Studies]. / Mnohocetná endokrinní neoplazie I (Wermeruv syndrom) - formy klinické manifestace: 5 kazuistik.

Multiple Endocrine Neoplasia (MEN) is a condition in which several endocrine organs of an individual are affected by adenoma, hyperplasia and less often carcinoma, either simultaneously or at different stages of life. Two existing syndromes, MEN1 and MEN2 (2A, 2B), in literature is also mentioned MEN4, are associated also with other non-endocrine disorders. MEN1 (Wermer syndrome) affects the pituitary, parathyroid, and pancreatic area. 95 % of patients show very early manifestation of hyperparathyroidism, often before 40 years of age. Multiple adenomas gradually involve all four parathyroid glands. The first clinical sign of MEN1 includes recurrent nephrolithiasis. The second most frequent manifestation of MEN1 is pancreatic area (pancreas, stomach and duodenum), again multiple malignancies of varying degree which can metastasize. Most often gastrinomas and insulinomas are involved. Pituitary adenomas occur in about one third of MEN1 patients and tend to be larger and less responsive to treatment. Tumors appearing most often are prolactinomas, tumors producing growth hormone, or afunctional adenomas. The other endocrine tumors include carcinoids and adrenal lesions. In the last year we have registered four MEN1 syndrome patients in our center and one patient has been already followed since 2008. In four out of five patients, nephrolithiasis after 30 years of age was the first clinical symptom, but only one of theses cases resulted in MEN1 diagnosis. In all patients, the clinical symptoms intensified and the diagnosis was established between 36 and 40 years of age. A crutial factor is a cooperation with the urology examination of kidney stones formation in young individuals with nephrolithiasis in order to reveal the potential cases of MEN1 syndrome very early on. Consider the MEN1 genetic diagnostics if recurrent primary hyperparathyroidism or recurrent gastroduodenal ulcer disease appear in patients under 40 years of age.Key words: carcinoid - gastrinoma - hyperparathyroidism - insulinoma - MEN1 - multiple endocrine neoplasia - nefrolithiasis - neuroendocrine tumor - pancreatic area - pituitary gland.

Polymorphisms in selected DNA repair genes and cell cycle regulating genes involved in the risk of papillary thyroid carcinoma.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. In addition to causal somatic mutations in the BRAF gene and RET/PTC rearrangements, the contribution of single nucleotide polymorphisms (SNPs) in low-penetrance genes in the development of PTC has been proposed. METHODS: Four SNPs in the XRCC1 (Arg399Gln, Arg280His, Arg194Trp and T-77C) and one SNP from each of three other genes participating in DNA repair pathways and/or cell cycle regulation (ATM Asp1853Asn, TP53 Arg72Pro, CDKN1B Val109Gly) were selected. The allelic and genotypic distributions of these variants as well as haplotypes of the XRCC1 were examined in 583 individuals comprising well-characterized cohorts of 209 PTC patients and 374 healthy volunteers. Correlations of polymorphism with clinical-pathological data and mutation status were performed. RESULTS: XRCC1 T-77C polymorphism affects the genetic susceptibility for PTC development in men, the specific combination of XRCC1 haplotypes correlates with RET/PTC incidence, CDKN1B Val109Gly significantly influences the risk of developing PTC regardless of gender and in PTC cases, selected genotypes of TP53 Arg72Pro and ATM Asp1853Asn were significantly associated with monitored tumour characteristics. CONCLUSION: It seems that SNPs in studied regulating genes contribute to the development of PTC and modify the tumour behaviour or characteristics.

[Draft of the best medical treatment in patients with low-risk thyroid cancer]. / Návrh optimálního lécebného postupu v lécbe nízkorizikového karcinomu stítné zlázy.

INTRODUCTION: The incidence of well-differentiated low-risk thyroid cancer have increased globally over the last three decades. Thyroid cancer treatment relates to a suitable surgical procedure and the use of adjuvant radio-iodine therapy in selected patients. Evaluation of prognostic factors and risk stratification are critical for determining appropriate treatment. Survival of patients with low-risk thyroid cancer is excellent. Appropriate choice of medical treatment resulted in full recovery in most patients. Relapse risk increases with the size of the primary tumor, along with the findings of the risk factors in men. METHODS AND RESULTS: Our study included a total of 1 980 patients in whom were diagnosed T1a and T1b tumors between the years 2003 to 2012. The population included 1 675 women (84.6 %) of average age of 45.22 years and 305 men (15.4 %) of average age of 50.0 years. The bulk of the file represented papillary carcinomas (1 868; 94.4 %), and smaller group of follicular carcinomas (112; 5.6 %). Patients were divided into four groups according to tumor size. Patients were evaluated according to risk factors: unifocality no other risk factors, multifocality - more bearings in thyroid tumor, metastases in regional lymph nodes, distant metastases or combination of risk factors. Group A: In the monitored set of 678 patients with papillary and follicular microcarcinoma up to 5 mm, during histological input, the findings revealed one bearing (unifocal type of cancer) in 566 patients. Multifocality was found in 112 patients, local nodal metastasis were demonstrated in 24 cases and pulmonary metastasis was discove-red in 1 case. Group B: In this group there were 576 study patients with papillary and follicular microcarcinoma size of 5-10 mm. Histological findings were captured input one bearing carcinoma in 434 patients, 142 patients with multifocality, in 53 cases of local nodal metastasis, and 1 case of bone metastases. Group C: In this group there were 467 study patients with papillary and follicular microcarcinoma size 10-15 mm. The histological initial finding captured unifocal type of cancer in 344 patients, multifocality in 123 patients, in 45 cases local metastases and in 3 cases of pulmonary metastases. Group D: 259 patients were monitored in this group with breast size 16-20 mm. At the initial finding was captured one bearing cancer in 188 patients, multifocality in 71 patients, in 24 cases evidence of local metastases and 2 patients had a case of distant lung metastases. In patients in whom risk factors were found, radioiodine treatment was indicated. This included 744 patients. In this group of patients after a year or more, relapse was observed in 74 patients (9.94 %). In 1 236 patients who did not undergo radioiodine treatment, there was a relapse in 49 patients (3.96 %). CONCLUSION: Based on our analysis, it is necessary to stratify the risk of relapse according to risk factors. In case of missed radioiodine therapy in patients with low-risk cancer without confirmed risk factors, it is also necessary to have regular clinical, laboratory and ultrasound examination. It is important to distinguish patients with risk factors that may contribute to disease recurrence. Only in this way, on one hand we prevent excessive treatment of patients with low-risk thyroid cancer which leads to increased cost of health care, and on the other hand prevent reduced level of care for patients with an increase in relapses.