Miklós Tanyi

Investigation of β-catenin and E-cadherin expression in dukes B2 stage colorectal cancer with tissue microarray method. Is it a marker of metastatic potential in rectal cancer?

Abstractβ-catenin and E cadherin are both membrane-associated proteins which are essential regulators and providers of cellular adhesion. In the metastatic cascade of malignant tumours, detachment of tumour cells from each other is a very important step. It has been shown in several tumour types, that reduced expression of these proteins is important. The aim of our study was to clarify the expression profile of these proteins, and correlate the findings with the metastasizing potential of early stage colon and rectal cancers. Formalin fixed and paraffin embedded samples from 79 Dukes B2 stage colorectal cancer were examined using a tissue microarray approach. The expression of β-catenin and E-cadherin proteins was determined immunohistochemically. Our findings indicated that there is a tendency for metastatic spread in cases when membranous expression of β-catenin is lost (p = 0.062). Similarly metastases in negative cases developed more rapidly, than in positive ones (p = 0.05). Survival rate was worse in the negative cases. The risk of metastasis in rectal cancer was significantly higher in the β-catenin membranously negative than positive groups (p = 0.024) and in case of β-catenin nuclear expression the risk was also higher (p = 0.047). Reduced E-cadherin expression also correlated with development of metastatic disease, but this association was statistically not significant. The immunohistochemical analysis of 79 cases shows that in Dukes B2 stage colorectal tumours clarification of β-catenin and E-cadherin expression patterns is reliable for predicting the metastatic potential of early stage rectal cancer and hence the method may have relevant implications in the therapeutic management of these cancers.

Two germline alterations in mismatch repair genes found in a HNPCC patient with poor family history

The Bethesda guidelines may offer more useful criteria in patients’ selection for germline mismatch repair gene mutation analysis than guidelines merely based on family background. An early onset double primary colorectal cancer patient with poor family history with MSI-H status was investigated for MLH1 promoter methylation, expression of the MLH1 and MSH2 gene by immunohistochemistry and mutations in the MLH1 and MSH2 genes. The index patient carried two germline alterations, the p.Val716Met in MLH1 and the c.2210+lG>C in MSH2 genes, and both tumors failed to express MLH1 and MSH2 proteins. After subsequent analysis of the whole family of the index patient, the p.Val716Met variant can be defined as a rare polymorphism with the possible contribution of pathogenicity to tumor formation and c.2210+1G>C as a true pathogenic mutation causing an out-of-frame deletion of exon 13.

Detection of internal tandem duplications in the FLT3 gene by different electrophoretic methods

Abstract Background: In acute myeloid leukemia (AML), the internal tandem duplication (ITD) in the juxtamembrane domain of the FLT3 (Fms-like tyrosine kinase 3) gene is one of the most frequent genetic alterations associated with poor prognosis. Methods: A complex evaluation of the analytical properties of the three most frequently used detection methods – PCR followed by agarose (AGE), polyacrylamide (PAGE) or capillary electrophoresis (CE) – was performed on 95 DNA samples obtained from 73 AML patients. Results: All the three methods verified the presence of a mutant allele in 20 samples from 18 patients. AGE and PAGE could detect the presence of 1%–2% mutant allele, while the detection limit of CE was 0.28%. However, acceptable reproducibility (inter-assay CV <25%) of the mutant allele rate determination was only achievable above 1.5% mutant/total allele rate. The reproducibility of the ITD size determination by CE was much better, but the ITD size calculated by PeakScanner or GeneScan analysis was 7% lower as compared to values obtained by DNA sequencing. The presence of multiple ITD was over-estimated by PAGE and AGE due to the formation of heteroduplexes. Conclusions: This study suggests the use of PCR+CE in the diagnostics and the follow-up of AML patients. The data further supports the importance of proper analytical evaluation of home-made molecular biological diagnostic tests.

A new mutation in Muir-Torre syndrome associated with familiar transmission of different gastrointestinal adenocarcinomas

Hereditary Nonpolyposis Colorectal Carcinoma (HNPCC) is the most frequent inherited disease which can lead to the development of tumors in the colon and other locations. Its genetic basis is related to the germline mutation of the Mismatch Repair (MMR) genes. Muir-Torre syndrome is considered one of the subtypes of this disease, in which the HNPCC tumor spectrum is frequently associated with sebaceous carcinoma of the skin or keratoacanthoma. A 57 years old male patient is presented with a mucinous carcinoma of the caecum and an adenocarcinoma of the pancreas head. A malignant sebaceous carcinoma was removed from his left neck area. His family history was significant for two cases of colon carcinoma, two cases of stomach cancer and a case of metacron endometrial and skin tumor as well. Both the colon carcinoma and the skin tumor proved to be microsatellite unstable. An Arg>Pro switch missense mutation was found in codon 265 of the hMLH1 gene. This error was found in 4 other members of his family. The detected genetic alteration was considered pathogenic and was not published yet in English literature. The significance of this particular case is the rare tumor association in a patient with Muir-Torre syndrome (MTS). In cases of sebaceous skin lesions, evaluation of family history is of utmost importance in the early detection of HNPCC and in the follow up care of family members with the particular mutation.

Difficulties in recognizing families with Hereditary Non-polyposis Colorectal Carcinoma. Presentation of 4 families with proven mutation

INTRODUCTION Hereditary Non-polyposis Colorectal Carcinoma is the most frequent genetic disease leading to colon and other malignancies. Recognizing the condition requires extensive family history going back several generations focusing particularly on the types of tumors occurring in the family at different age groups. METHODS In families who met the Amsterdam and Bethesda Criteria, the removed tumor tissue was first examined by immunohistochemistry and microsatellite instability analysis. Subsequently DNA sequencing was performed to detect an underlying Mismatch Repair Gene mutation and multiple ligation dependent probe amplification was applied for recognizing large deletions in Mismatch Repair Genes. RESULTS In the investigated families 3 pathogen mutations, 1 large deletion and 2 cases of polymorphism were found. There is considerable difference between the families in terms of the types of malignancies and the age in which those appeared. CONCLUSION Recognizing families with Hereditary Non-polyposis Colorectal Carcinoma presents great difficulties because of the variety of phenotypes in presentation. Special attention should be paid to small families and those who present with cancer of other than colon origin. Practicing physicians should be made aware of the fact that this disease may have atypical presentations. Follow up of families who have already been screened may be difficult for social, economical or religious reasons.

Correlations between clinicopathological parameters and molecular signatures of primary tumors for patients with stage T3n0 colorectal adenocarcinomas: a single center retrospective study on 100 cases.

BACKGROUND/AIMS To examine the clinical and protein expression characteristics of tumor tissues for prediction of prognosis in colorectal cancer (CRC). METHODOLOGY We retrospectively analyzed the clinicopathological data of patients with stage T3N0 CRC, operated between 1997-2003 and the surgical materials for the relation between disease prognosis and p53, p21, p16, β-catenin, E-cadherin, EGFR, hMLH1, hMSH2 and TS protein expressions. RESULTS A significantly shorter 3-year disease free survival was observed in patients under the age of 50. The worst 5-year overall survival (OS) observed for patients over 70. Tumor localization and number of processed lymph nodes significantly affected prognosis. The EGFR, hMSH2 and TS expressions and the 5-fluorouracyl treatment were not found to be of prognostic value; p53 and p21 positivity had significantly worse survival. When β-catenin membrane expression disappeared on tumor cells, the 5-year OS rate decreased and time to metastasis shortened significantly. Membrane β-catenin expression, processed lymph nodes number and age were detected as independent prognostic markers. CONCLUSIONS These results suggest that the evaluation of a clinicopathological profile, based on age, tumor localization, number of examined lymph nodes, p53, p21 and E-cadherin β-catenin expression appears to be useful in identifying high risk patients.

Ki-67 – new faces of an old player

The Ki-67 protein was isolated twenty-five years ago and has become the first histological marker of proliferating cells until now. This molecule with a unique structure possesses such fundamental biological functions that are essential for normal cell proliferation. Since the Ki-67 protein is present in every dividing cell (G1, S, G2/M phase) but is absent from the resting cells (G0 phase) it is very much suitable for identifying the proliferating fraction of cells. Thus, it provides essential information concerning the malignancy of a tumor and about the prediction of response to a certain therapy. Based on its important role in cell proliferation, the Ki-67 protein might also play a role in tumor genesis. In their present work the authors discuss the history and the properties of Ki-67, its role in cell cycle regulation and its prognostic importance in different malignant disorders.

Occurrence of bladder metastasis 10 years after surgical removal of a primary gastric cancer: A case report and review of the literature

IntroductionSecondary bladder neoplasms are uncommon and they represent only 2% of all malignant bladder tumors.Case presentationThe authors present a case of a 59-year-old Caucasian man with a primary gastric adenocarcinoma that had been surgically removed 10 years before he developed bladder metastasis. He presented with low abdominal pain after 10 years without any symptoms. Cystoscopy and an abdominal computed tomography scan showed a bladder tumor. A transurethral resection of the bladder tumor was performed. A histological examination revealed an adenocarcinoma, which turned out to be a metastasis of the primary gastric tumor. One year later, abdominal surgery revealed peritoneal metastases.ConclusionThis is the first known case in Europe where bladder metastasis occurred 10 years after surgical removal of a primary gastric neoplasm. There are only four cases in the literature where metastases of the peritoneum developed 11 years after surgical removal of a primary gastric tumor.

Q48P mutation in the hMLH1 gene associated with Lynch syndrome in three Hungarian families

Lynch syndrome (Hereditary nonpolyposis colorectal cancer, HNPCC) is an inherited disease with variable phenotype causing the development of colon cancer and other malignancies. The basis of the disease is believed to be the mismatch repair gene mutations. Genetic screening has been performed among the patients who have undergone surgery for colon cancer at the University of Debrecen, Department of Surgery. Tumor samples of the screened patients were submitted to immunohistochemistry on hMLH1, hMSH2 and hMSH6 genes, microsatellite instability testing, followed by sequencing and multiple ligation dependent probe amplification. Three families were identified with the missense mutation c.143A>C (p.Q48P) of hMLH1 gene. In one of the families a segregation analysis of this particular variant was also accomplished. The segregation analysis revealed a clear correlation between the tumor cases and the occurrence of this mutation. However, none of the analyzed 100 healthy controls demonstrated the same aberration. There is only one published evidence in the literature about the presence of this rare variant in any population. The Gln to Pro switch in the ATPase domain, a conservative region of the hMLH1 gene, creates significant changes in the protein structure. These results indicate that this mutation is the abnormality responsible for the patients’ phenotype and it is feasible that this particular aberration occurs more frequently among Hungarian Lynch syndrome patients.

A hereditaer nonpolyposus colorectalis carcinoma szindrómás betegek szűrésének és szoros utánkövetésének fontossága egy családfa bemutatása kapcsán

INTRODUCTION Hereditary nonpolyposis colorectal carcinoma (HNPCC) is an autosomal dominant disease, which shows familial clustering. AIM We would like to emphasize the importance of monitoring the HNPCC syndrome patients by presenting a case of a proven MMR gene mutation carrier and her family tree encompassing 10 years. MATERIALS AND METHOD To screen a suspected HNPCC Hungarian family member we are taking thorough family histories. If the diagnosis of HNPCC was further supported by immunohistology and the microsatellite status, sequencing of the MMR genes was carried out. RESULTS A novel mutation in exon 6 of the hMSH2 gene leading to the deletion of two nucleotide pairs [c.969-970delTC] was detected in our patient. During the 10-year follow-up period of our patient new HNPCC-associated tumors have developed in several family members. Conslusion: Close surveillance of the patient and its family members at risk was effective, although it requires compliance from the subjects. Orv Hetil. 2017; 158(30): 1182-1187.Absztrakt: Bevezetes: A hereditaer nonpolyposus colorectalis carcinomara jellemző mutaciok (HNPCC) autoszomalis dominans oroklődesmenetet mutatnak. Leginkabb vastagbeldaganatok kialakulasaert felelősek. Celkitűzes: A HNPCC-szindromas betegek szűresenek es kovetesenek fontossagat szeretnenk hangsulyozni egy igazolt MMR-gen-mutaciot hordozo betegunk jelenlegi es 10 evvel korabbi csaladfajanak osszehasonlitasaval. Betegek es modszer: Hazankban előfordulo, HNPCC-re gyanus csaladok kiszűrese erdekeben alapos csaladi anamnezist veszunk fel. Amennyiben az immunhisztokemiai es mikroszatellitainstabilitas-vizsgalatok HNPCC-szindromara utalnak, elvegezzuk az MMR-genek szekvenalasat. Eredmenyek: Betegunknel egy, a hMSH2-gen 6. exon ket bazispart erintő deletioja (c.969–970delTC) igazolodott. Tizeves utankovetes soran betegunknel es rokonainal ujabb, a HNPCC-re jellemző tumorok jelentek meg. Kovetkeztetes: A veszelyeztetett csaladtagok kovetese soran a szekunder prevencio a jol egyuttműkodő betegeknel hatekony volt. ...