Jan Włoch

Gene Expression Profile of Papillary Thyroid Cancer: Sources of Variability and Diagnostic Implications

The study looked for an optimal set of genes differentiating between papillary thyroid cancer (PTC) and normal thyroid tissue and assessed the sources of variability in gene expression profiles. The analysis was done by oligonucleotide microarrays (GeneChip HG-U133A) in 50 tissue samples taken intraoperatively from 33 patients (23 PTC patients and 10 patients with other thyroid disease). In the initial group of 16 PTC and 16 normal samples, we assessed the sources of variability in the gene expression profile by singular value decomposition which specified three major patterns of variability. The first and the most distinct mode grouped transcripts differentiating between tumor and normal tissues. Two consecutive modes contained a large proportion of immunity-related genes. To generate a multigene classifier for tumor-normal difference, we used support vector machines-based technique (recursive feature replacement). It included the following 19 genes: DPP4, GJB3, ST14, SERPINA1, LRP4, MET, EVA1, SPUVE, LGALS3, HBB, MKRN2, MRC2, IGSF1, KIAA0830, RXRG, P4HA2, CDH3, IL13RA1, and MTMR4, and correctly discriminated 17 of 18 additional PTC/normal thyroid samples and all 16 samples published in a previous microarray study. Selected novel genes (LRP4, EVA1, TMPRSS4, QPCT, and SLC34A2) were confirmed by Q-PCR. Our results prove that the gene expression signal of PTC is easily detectable even when cancer cells do not prevail over tumor stroma. We indicate and separate the confounding variability related to the immune response. Finally, we propose a potent molecular classifier able to discriminate between PTC and nonmalignant thyroid in more than 90% of investigated samples.

Total Thyroidectomy and Adjuvant Radioiodine Treatment Independently Decrease Locoregional Recurrence Risk in Childhood and Adolescent Differentiated Thyroid Cancer

We sought to assess whether extensive surgical treatment, postsurgical radioiodine therapy, or both decrease the risk of locoregional recurrence (LR) after curative primary treatment in children and adolescents diagnosed with differentiated thyroid cancer (DTC) at age ≤18 y. Methods: To determine the incidence of and identify predictive factors for thyroid bed recurrence (TBR) or lymph node recurrence (NR), we performed a chart review and retrospective multivariate Cox regression analysis on 235 patients with DTC diagnosed at age ≤18 y and managed with curative intent at our tertiary referral center from 1973 to 2002; 40 of these patients had distant metastases at diagnosis. We also determined overall and recurrence-free survival and generated curves for these variables using Kaplan–Meier and Cox univariate analysis. Results: During a median follow-up of 82 mo (range, 5–402 mo), no DTC-related deaths occurred, 203 (86%) children remained recurrence-free, and 32 (14%) children had LR, including TBR in 9 (28% of LR), NR in 20 (63% of LR), and both in 3 (9% of LR). Among patients treated with radical intent and showing no distant metastases, the most recent thyroglobulin level was <1 ng/mL in all but 4% of cases. The median time from the first surgery to LR was 37 mo (range, 9–280 mo). In multivariate analysis, significant risk factors for TBR were less than total thyroidectomy and lack of postsurgical radioiodine treatment (respective risk increases of 9.5 [P = 0.04] and 11 times [P = 0.03]). For NR, classic papillary histology, incomplete primary lymph node management (i.e., lack of modified lymphadenectomy of affected lymph nodes or lack of confirmation of disease-free nodes by intraoperative staging), and absence of adjuvant radioiodine therapy were independent significant predictive factors that increased the recurrence risk by 1.9 (P = 0.02), 3.3 (P = 0.02), and 3.2 (P = 0.02) times, respectively. Age or sex did not correlate with LR risk. Conclusion: In DTC patients ≤18 y of age, extensive initial therapy—consisting of total thyroidectomy combined with modified lymphadenectomy performed in case of lymph node metastases and followed by radioiodine therapy—is associated with a substantial decrease of DTC LR risk.

High frequency of recurrent mutations in BRCA1 and BRCA2 genes in Polish families with breast and ovarian cancer

Germ‐line mutations in BRCA1 and BRCA2 genes result in a significantly increased risk of breast and ovarian cancer. Other genes involved in an increased predisposition to breast cancer include the TP53 gene, mutated in Li‐Fraumeni syndrome. To estimate the frequency of germ‐line mutations in these three genes in Upper Silesia, we have analyzed 47 breast/ovarian cancer families from that region. We found five different disease predisposing mutations in 17 (36%) families. Twelve families (25.5%) carried known BRCA1 mutations (5382insC and C61G), four families (8.5%) carried novel BRCA2 mutations (9631delC and 6886delGAAAA), and one family (2%) harbored novel mutation 1095del8 in the TP53 gene, which is the largest germline deletion in coding sequence of this gene identified thus far. The 5382insC mutation in BRCA1 was found in 11 families and the 9631delC mutation in BRCA2 occurred in three families. These two mutations taken together contribute to 82% of all mutations found in this study, and 30% of the families investigated harbor one of these mutations. The very high frequency of common mutations observed in these families can only be compared to that reported for Ashkenazi Jewish, Icelandic, and Russian high‐risk families. This frequency, however, may not be representative for the entire Polish population. The observed distribution of mutations will favor routine pre‐screening of predisposed families using a simple and cost‐effective test. Hum Mutat 16:482–490, 2000.

Pheochromocytoma in rats with multiple endocrine neoplasia (MENX) shares gene expression patterns with human pheochromocytoma

Pheochromocytomas are rare neoplasias of neural crest origin arising from chromaffin cells of the adrenal medulla and sympathetic ganglia (extra-adrenal pheochromocytoma). Pheochromocytoma that develop in rats homozygous for a loss-of-function mutation in p27Kip1 (MENX syndrome) show a clear progression from hyperplasia to tumor, offering the possibility to gain insight into tumor pathobiology. We compared the gene-expression signatures of both adrenomedullary hyperplasia and pheochromocytoma with normal rat adrenal medulla. Hyperplasia and tumor show very similar transcriptome profiles, indicating early determination of the tumorigenic signature. Overrepresentation of developmentally regulated neural genes was a feature of the rat lesions. Quantitative RT-PCR validated the up-regulation of 11 genes, including some involved in neural development: Cdkn2a, Cdkn2c, Neurod1, Gal, Bmp7, and Phox2a. Overexpression of these genes precedes histological changes in affected adrenal glands. Their presence at early stages of tumorigenesis indicates they are not acquired during progression and may be a result of the lack of functional p27Kip1. Adrenal and extra-adrenal pheochromocytoma development clearly follows diverged molecular pathways in MENX rats. To correlate these findings to human pheochromocytoma, we studied nine genes overexpressed in the rat lesions in 46 sporadic and familial human pheochromocytomas. The expression of GAL, DGKH, BMP7, PHOX2A, L1CAM, TCTE1, EBF3, SOX4, and HASH1 was up-regulated, although with different frequencies. Immunohistochemical staining detected high L1CAM expression selectively in 27 human pheochromocytomas but not in 140 nonchromaffin neuroendocrine tumors. These studies reveal clues to the molecular pathways involved in rat and human pheochromocytoma and identify previously unexplored biomarkers for clinical use.

The prognostic value of tumor markers doubling times in medullary thyroid carcinoma - preliminary report.

IntroductionCalcitonin (Ct) and carcinoembrional antigen (CEA) are widely used as tumor markers for the post-operative follow-up of patients with medullary thyroid carcinoma (MTC).In patients with elevated serum Ct and CEA their dynamics can be described by calculating the doubling time (DT) - the time, they need to double the serum concentration. Previous reports concluded that the Ct and CEA DT have prognostic value in MTC patients.Patients and methodsWe retrospectively analyzed data of 70 MTC patients with elevated serum Ct or CEA. In total, doubling times were calculated and the DT of the less favorable marker was used to stratify the patients into the low- and high-risk group with the cut-off value of 2 years. The survival analysis was performed using Cox proportional hazard method.ResultsThe doubling time < = 2 years of the less-favorable marker had significant prognostic impact for recurrence-free survival, HR = 2.61 (1.43-4.71) and overall survival, HR = 8.99 (3.51-23.04).ConclusionsThe calcitonin and carcinembrional antigen doubling times of less than two years are negative prognostic factors for MTC recurrence-free and total survival in patients with persistent or recurrent disease. They may be used as predictive factors for more intensive search of disease localization in asymptomatic hypercalcitoninemia and for therapy choice in symptomatic disease.

Timing and criteria for prophylactic thyroidectomy in asymptomatic RET carriers – the role of Ct serum level

Authors summarize in this brief review results of European discussion, held on ETA-CRN Meeting in Lisbon, 2009, on the American Thyroid Association Medullary Thyroid Cancer (MTC) Guidelines published in the same year and focus on the timing of prophylactic thyroidectomy. ATA 2009 guidelines classified RET protooncogene mutation carriers into 4 levels: A, B, C, D. ATA for prophylactic thyroidectomy were generally independent of the serum calcitonin (Ct) concentration but based on a priori risk levels. This was well accepted as the important novelty was to delineate risk level specially for RET 634 mutation (level C). In the ATA Guidelines total prophylactic thyroidectomy below age 5 years was recommended in RET 634 mutation carriers regardless of Ct status. However, some European experts favored to base the decision not only on the results of DNA testing but also on the going Ct level. The European discussion reflected divergent opinions and indicated the need of publication of European experience instead of arbitrary opinions. It was stressed that patients carrying the same RET mutation present heterogenic progression to the clinically overt medullary thyroid cancer, even in the same family. Thus, in summary, the ATA MTC guidelines constituted a positive stimulus to publish further evidence for Ct-guided pre-emptive thyroidectomy for RET gene mutation carriers and the conclusion is drawn on the basis of experience expressed in Lisbon and published later evidence that the integrated algorithm based on age - Ct - type of RET mutation should be considered in the decision of pre-emptive thyroidectomy.

Prognostic value of lymph node metastases of differentiated thyroid cancer (DTC) according to the local advancement and range of surgical excision

In differentiated thyroid carcinoma (DTC) with primary tumor smaller than 1 cm, the routine central lymph node (LN) dissection is questioned, due to increased risk of post-surgery complications and lack of confirmed benefit.AimThe analysis of prognostic significance of LN metastases, in DTC patients to verify the potential role of central neck lymphadenectomy on disease staging.Materials and methodsThe group of 195 DTC patients, primarily operated between 2004 and 2005, was retrospectively analyzed. 184 patients after radical operation, with no distant metastases diagnosed before surgery, were included into analysis. LN metastases were observed in 55 of cases (28%). In 124 cases only dissection of central LN compartment was performed, in 36 patients also uni- or bilateral modified cervical lymphadectomy was carried out. In 24 patients with tumor limited to the thyroid gland without suspicious lymph nodes, the routine central lymph node dissection was not done.ResultsMedian follow-up was 4 years. The 5-year overall and disease free survival standardized ratio were 100% and 95% respectively. The risk of LN metastases increased with the more locally advanced cancer. In the group of 124 patients, in whom only central LN dissection was performed, LN metastases were diagnosed in 15 cases (12%). No significant relation between multifocality and frequency of central and/or lateral LN metastases was noticed. Significant correlation between N feature and extrathyroidal invasion was observed (p = 0,0003). The presence of LN metastases was related to worsening of disease free survival from 99 to 90%. During the follow-up recurrence occurred in 6 (3%) cases. In 24 patients in whom only total thyroidectomy was done, no local or distant recurrence was observed. The assessment of early postoperative complications (hypoparathyroidism, paresis of vocal cords) indicated that the frequency of early calcium balance disturbances was significantly lower in patients in whom central LN dissection was not performed (p = 0,04)ConclusionsOur result indicate that in the early diagnosis of thyroid cancer, the occurrence of LN DTC metastases is rarer and was observed only in 12% of elective dissections of central LN node compartment, if no lateral dissection was indicated due to the lack of clinical suspicion. In DTC patients with tumor diameter <1 cm and no sonographical or inraoperative suspicion on LN involvement, routine central lymphadenectomy may be not obligatory.

Diagnostics and treatment of differentiated thyroid carcinoma in children - Guidelines of Polish National Societies.

1Department of Paediatric Endocrinology and Rheumatology, Poznan University of Medical Sciences, Poznan, Poland 2Department of Nuclear Medicine and Endocrine Oncology, Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, Gliwice, Poland. 3Department of Paediatrics and Paediatric Endocrinology, School of Medicine in Katowice, Medical University of Silesia, Katowice, Poland 4Department of Oncological and Reconstructive Surgery, Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, Gliwice, Poland 5Department of Oncological Endocrinology and Nuclear Medicine, Centre of Oncology – Maria Sklodowska-Curie Memorial Institute, Warsaw, Poland 6Department of Tumour Pathology, Maria Sklodowska-Curie Memorial Cancer Centre and Institute of Oncology, Gliwice Branch, Gliwice, Poland 7Department of Paediatrics and Endocrinology, Medical University, Warsaw, Poland 8Department of General and Oncological Surgery, Medical University of Lodz, Lodz, Poland 9Private practice, Katowice, Poland 10Department of Paediatric Surgery and Urology, Wroclaw Medical University, Wroclaw, Poland 11Department of Morphometry of Endocrine Glands, Chair of Endocrinology, Medical University of Lodz, Lodz, Poland 12Department of Dental Pathology, Medical University of Lodz, Lodz, Poland 13Department of Tumour Pathology, Poznan University of Medical Sciences, Poznan, Poland 14Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences, Poznan, Poland 15Department of Endocrinology and Metabolic Diseases, Polish Mother’s Memorial Hospital-Research Institute, Medical University of Lodz, Lodz, Poland