Universal screening to identify Lynch syndrome: two years of experience in a Northern Italian Center.

Lynch syndrome is caused by germline mutations of genes affecting the mismatch repair proteins MLH1, MSH2, MSH6 or PMS2. Identification of Lynch syndrome patients using germline molecular testing in colorectal cancer (CRC) affected patients and in their healthy relatives is a cost-effective model of cancer prevention. Several studies demonstrate that universal tumor testing using immunohistochemical (IHC) analysis of CRC samples is the most efficient approach to identifying patients affected by Lynch syndrome. We studied a cohort of 352 consecutive CRCs for MSH2, MLH1, MSH6 and PMS2 protein expression using universal IHC screening. IHC mismatch repair (MMR) defects were identified in 70 out of 352 cases (19.8%) including six CRCs MSH2/MSH6 defective, two CRCs, respectively, MSH6 and PMS2 defective, 58 CRCs MLH1/PMS2 defective and four CRCs showing atypical MMR pattern. MLH1 promoter methylation and V600E BRAF mutation analysis were investigated on 61 CRCs. Cancer genetic counseling was offered to all 68 patients affected by MMR defective CRCs and 25 patients opted in to this service (36.8% compliance). Pathogenetic variants of MSH2 genes were identified in two cases (55 and 79 years old). Universal screening based on an IHC approach showed a Lynch syndrome incidence of 1/173. The protocol recommended by regional law improved patient compliance. This study demonstrates that the IHC approach for both MMR deficiency and V600E BRAF mutation detections is the most efficient approach for Lynch syndrome screening in the Italian population.

DNA methylation variations are required for epithelial-to-mesenchymal transition induced by cancer-associated fibroblasts in prostate cancer cells.

Widespread genome hypo-methylation and promoter hyper-methylation of epithelium-specific genes are hallmarks of stable epithelial-to-mesenchymal transition (EMT), which in prostate cancer (PCa) correlates with castration resistance, cancer stem cells generation, chemoresistance and worst prognosis. Exploiting our consolidated 'ex-vivo' system, we show that cancer-associated fibroblasts (CAFs) released factors have pivotal roles in inducing genome methylation changes required for EMT and stemness in EMT-prone PCa cells. By global DNA methylation analysis and RNA-Seq, we provide compelling evidence that conditioned media from CAFs explanted from two unrelated patients with advanced PCa, stimulates concurrent DNA hypo- and hyper-methylation required for EMT and stemness in PC3 and DU145, but not in LN-CaP and its derivative C4-2B, PCa cells. CpG island (CGI) hyper-methylation associates with repression of genes required for epithelial maintenance and invasion antagonism, whereas activation of EMT markers and stemness genes correlate with CGI hypo-methylation. Remarkably, methylation variations and EMT-regulated transcripts almost completely reverse qualitatively and quantitatively during MET. Unsupervised clustering analysis of the PRAD TCGA data set with the differentially expressed (DE) and methylated EMT signature, identified a gene cluster of DE genes defined by a CAF+ and AR- phenotype and worst diagnosis. This gene cluster includes the relevant factors for EMT and stemness, which display DNA methylation variations in regulatory regions inversely correlated to their expression changes, thus strongly sustaining the ex-vivo data. DNMT3A-dependent methylation is essential for silencing epithelial maintenance and EMT counteracting genes, such as CDH1 and GRHL2, that is, the direct repressor of ZEB1, the key transcriptional factor for EMT and stemness. Accordingly, DNMT3A knock-down prevents EMT entry. These results shed light on the mechanisms of establishment and maintenance of coexisting DNA hypo- and hyper-methylation patterns during cancer progression, the generation of EMT and cell stemness in advanced PCa, and may pave the way to new therapeutic implications.

Flexible intramedullary nailing for treatment of proximal humeral and humeral shaft fractures in children: A retrospective series of 118 cases.

BACKGROUND: The aim of this study was to analyze outcomes of treatment and complications in children treated with flexible intramedullary nailing (FIN) due to humeral fracture. HYPOTHESIS: The FIN for treatment of humeral fractures in children would allow an early functional and cast-free follow-up with a quick pain reduction and low complication rate. PATIENTS AND METHODS: From May 2002 until May 2016 case records of all children who underwent fixation with titanium intramedullary nails because of humeral fracture were retrospectively reviewed. The study included 118 patients treated with FIN for proximal humeral or humeral shaft fracture. The average age at the time of trauma was 12 years. Mean follow-up was 77 months. Left hand was affected in 51% of patients. The most common mechanism of injury was fall (n=58), followed by sports injuries, road traffic accidents, pathological fractures, motorbike accidents and bicycle riding. RESULTS: There were no residual valgus/varum deformities. All patients achieved complete radiographic healing at a mean of 7.5 weeks. Nine complications were recorded: 1 humeral shaft fracture in patient with osteogenesis imperfecta, 4 entry site skin irritations, 2 skin infections and 2 radial nerve injuries. There were no cases of delayed union, nonunion or mal-union. After removal of the nails, all patients regained full function and all complications resolved. DISCUSSION: The FIN for humeral fractures is a minimally invasive, simple and well reproducible technique with very low complication rate. CONCLUSION: The FIN for treatment of humeral fractures shows very good functional and cosmetic results. It allows an early functional and cast-free follow-up with a quick pain reduction. LEVEL OF EVIDENCE: Level IV - retrospective study.

Elastic stable intramedullary nailing for pediatric long bone fractures: experience with 175 fractures.

PURPOSE: To demonstrate the effectiveness of intramedullary fixation of displaced long bones shaft fractures in skeletally immature children using the elastic stable intramedullary nails. PATIENTS AND METHODS: The case records of 173 children who underwent fixation with titanium intramedulary nails because of long bones fractures were reviewed. The average age of the patients was 11.7 years, and mean follow-up was 41.3 months. There were 55 humeral, 42 forearm, 42 femoral and 36 tibial fractures. Subjective satisfaction was assessed. RESULTS: All patients achieved complete healing at a mean of 7.5 weeks. Complications were recorded in 11 (6.3%) patients and included: one neuropraxia, six entry site skin irritations, two protrusions of the wires through the skin and two skin infections at the entry site. In a subjective measure of outcome at follow-up, 89% of patients were very satisfied and 11% satisfied; no patients reported their outcome as not satisfied. The implants were removed at a median time of six months from the index operation. CONCLUSION: Elastic Stable Intra-medullary Nailing is the method of choice for the pediatrics patients, because it is minimaly invasive and shows very good functional and cosmetic results. It allows an early functional and cast-free follow-up with a quick pain reduction.

Titanium intramedullary nailing for treatment of simple bone cysts of the long bones in children.

BACKGROUND: Simple or unicameral bone cysts are common benign fluid-filled lesions usually located in the long bones of children before skeletal maturity. Pathological fracture is common, and is often the presenting feature. AIM: The objective of the present study was to evaluate the results of titanium intramedullary nailing for the treatment of unicameral bone cysts with or without a pathological fracture. METHODS: During the period 2001 to 2007, flexible intramedullary nailing for the treatment of a unicameral bone cyst was performed in 18 children. Four of these patients presented with a pathological fracture. The cyst was located in the humerus in 14 patients, in the femur in three, and in the tibia in one. The diagnosis was based on typical radiographs and computed tomography. The mean age of the patients at the time of surgery was 9.4 years, and the mean duration of follow-up was 53 months. Radiographic evaluation was performed, and the cyst was classified as completely healed, healed with residual radiolucency, recurred, or having no response. RESULTS: Mean hospital stay was 24 hours. At one to four weeks postoperatively, all patients were pain free and had full range of motion of adjacent joints. Radiographic signs of cyst healing were present at three months in all patients, and all cysts healed completely. All of the cysts responded to treatment, with no cyst recurrence. No major complications were observed. CONCLUSION: Elastic intramedullary nailing has the twofold benefits of continuous cyst decompression, and early immediate stability to the involved bone segment, which permits early mobilization and return to normal activities.

Pediatric tibial eminence fractures: arthroscopic treatment using K-wire.

BACKGROUND: Fractures of the tibial intercondylar eminence are observed mostly in children and adolescents, often after minimal trauma. The purpose of this paper is to evaluate the use of K-wire fixation for the arthroscopic treatment of tibial eminence fractures in children. PATIENTS AND METHODS: From January 2002 through January 2009 ten patients were treated arthroscopically because of the intercondylar eminence fracture in a Department of pediatric surgery, University Hospital Split. Arthroscopically controlled reposition was done, and using mobile X-ray two crossed K-wires were introduced percutaneously from the proximal part of the tibia to the fractured intercondylar eminence. Subjective outcome was obtained using IKDC subjective questionnaire. RESULTS: Average hospitalization time was 11 days. Average duration of treatment was 12.5 weeks. Average follow-up was 42 months. Follow-up radiographs showed union in all cases. The mean IKDC subjective score was 96/100. Clinically, all patients exhibited a solid endpoint on the Lachman test. The global IKDC objective score was normal in eight knees and nearly normal in two knees. CONCLUSION: Arthroscopic reduction and fixation by Kirschner wires or a small fragment screw is the best way for treatment intercondylar tibial eminence fractures, in the pediatric population, because is not crossing the epiphyseal plate.

MGMT methylation in diffuse large B-cell lymphoma: validation of quantitative methylation-specific PCR and comparison with MGMT protein expression.

AIMS: (1) To validate a quantitative real time methylation specific PCR assay (MethyLight) for the detection of O6-methylguanine-DNA methyltransferase (MGMT) gene methylation status (MS) in diffuse large B-cell lymphoma (DLBCL). (2) To determine the immunohistochemical (IHC) expression of the MGMT protein and correlate it with MS. Both IHC and MethyLight results were compared with patient's outcome. METHODS: 71 patients with primary nodal DLBCL were studied. MGMT immunoreactivity was detected using a specific monoclonal antibody. The MS of MGMT gene was analysed in 52/71 DLBCL using MethyLight. A selected subset of 40 DLBCL was also analysed using qualitative methylation-specific PCR (MSP). Statistical analysis of overall survival (OS), lymphoma-specific survival (LSS) and progression free survival (PFS) was performed according to IHC and MS results. RESULTS: 19/71 DLBCLs (27%) were MGMT-negative at IHC; all were analysed, together with 33/52 MGMT-positive DLBCLs. MethyLight showed a better performance than MSP. There was a good correlation between the presence of MGMT expression and the unmethylated status; the absence of IHC expression was poorly correlated with the presence of methylation. Better OS, LSS and PFS was found in DLBCLs with MGMT gene methylation. DLBCLs not expressing MGMT at IHC showed a longer PFS. CONCLUSIONS: The quantitative real-time methylation-specific PCR assay for the detection of MGMT gene hypermethylation has been validated for the first time in DLBCL. Immunohistochemistry seems to represent an useful preliminary test to identify unmethylated cases; MS analysis may be performed in non-immunoreactive cases to identify truly methylated DLBCLs, which bear a better prognosis.

Chromosome 6 abnormalities in ovarian surface epithelial tumors of borderline malignancy suggest a genetic continuum in the progression model of ovarian neoplasms.

PURPOSE: We used conventional cytogenetics, molecular cytogenetics, and molecular genetic analyses to study the pattern of allelic loss on chromosome 6q in a cohort of borderline epithelial ovarian tumors. EXPERIMENTAL DESIGN: Fifteen tumor samples were collected from patients undergoing surgery for ovarian tumors. The tumors of borderline malignancy, classified according to the standard criteria, included 4 mucinous and 11 serous tumors. Cytogenetic and molecular cytogenetic (with yeast artificial chromosome clones from 6q26-27) studies were performed on tumor areas contiguous to those used for histological examination ensuring the appropriate sampling. Moreover loss of heterozygosity analysis was performed using PCR amplification of eight microsatellite markers mapping on 6q27 (D6S193, D6S297), 6q26 (D6S305, D6S415, D6S441), 6q21 (D6S287), 6q16 (D6S311), and 6q14 (D6S300). RESULTS: Deletions of this chromosome arm, in particular of 6q24-27, were the most frequent lesions found in this set of tumors. In a tumor with a normal karyotype the only detectable alteration was a deletion of approximately 300 kb within the D6S149-D6S193 interval at band 6q27. This is, to date, the smallest deletion described for borderline tumors. CONCLUSION: Alterations in the above-mentioned interval are a common finding in advanced ovarian carcinomas but also in benign ovarian cysts, implying that some tumors of borderline malignancy may arise from benign tumors and that malignant ones may evolve from tumors of borderline malignancy. Genes located in 6q27 seem to be crucial for this mechanism of early events in ovarian tumorigenesis.

The role of histological investigation in prognostic evaluation of advanced gastric cancer. Analysis of histological structure and molecular changes compared with invasive pattern and stage.

The relative contribution of tumour histology or molecular changes, compared with invasion pattern or stage, to prognostic assessment of gastric cancer was investigated in a series of 185 advanced (T2 to T4, stage IB to IV) cancers that had undergone intentionally curative surgery at Varese General Hospital. Survival analysis of the histological types considered in commonly used classifications, such as Lauren, Kubo, the World Health Organization (WHO) and related classifications, allowed separation of a small high-grade (Hg, 12 cases) group of adenosquamous, anaplastic and small cell endocrine carcinomas from a large cohesive group (C, 86 glandular or solid cancers) and from another large (87 cases) group of tumours with dissociated cells [29 diffuse (D) and 58 mixed (M) tumours]. Univariate and multivariate analysis showed the independent prognostic value of this C/M+D/Hg classification approach, which proved superior to other classifications and to cell dissociation at the growing front or angio, lympho and neuro-invasion. Expression of sialyl Lewis(c), the DUPAN-2 antigen, proved to be an independent predictor of worse survival among tumours beyond stage I, showing an exclusively or predominantly cohesive structure. Microsatellite instability (MSI) predicted favourable survival in purely cohesive tumours of intermediate (II) stage, especially of solid/medullary and lymphoid stroma/lympho-epithelioma-like structure, among which two distinct tumour subsets were characterised, one MSI-positive and the other Epstein-Barr virus positive. T2NOM0 (stage IB) tumours showed mostly favourable survival independently from histological type, invasive pattern, DUPAN-2 or MSI status. It is concluded that an appropriate histological evaluation, coupled with sialylated glycoproteins histochemistry and, for stage-II tumours, MSI tests may contribute significantly to prognostic assessment of tumours beyond stage I. However, the stage itself, with special reference to lymph-node metastases and invasion level beyond subserosa, remains the most important prognostic clue for gastric cancer.

Frequency of portal and systemic bacteremia in acute appendicitis.

BACKGROUND: Acute appendicitis is the most common condition requiring an emergency abdominal operation in childhood. In the present study, we analyzed the frequency of portal and systemic bacteremia in 42 patients with acute appendicitis and determined the microbial agents responsible for an acute appendicitis and for portal and systemic bacteremia. METHODS: Appendectomies were performed on 50 young patients (5-18 years of age), as well as clinical and bacteriological tests. Six independent samples from each patient isolated from the peripheral vein, superior mesenteric vein, appendix and peritoneum were obtained prior to surgery, during surgery and after surgery for biochemical, immunologic and bacteriologic examination. RESULTS: Pathohistology confirmed the diagnosis of appendicitis in 42 patients, while in the other eight patients there were no obvious pathologic findings, so they served as a control group. Of 50 patients with a clinical appearance of acute appendicitis, in 19 patients (38%) we detected portal bacteremia in the mesenteric vein, while in only three cases (6%) did we find systemic bacteremia detected from the peripheral vein. Furthermore, bacteriologic analysis revealed that Bacteroides spp. and Escherichia coli were the predominant species isolated. CONCLUSIONS: The results presented in this paper suggests that portal bacteremia did not influence peripheral blood reactions. Furthermore, in the present study we have found a positive correlation between the smear and bacteremia of the superior mesenteric vein, but not with the bacteremia of systemic blood.

Expression of acidic fibroblast growth factor (aFGF) and fibroblast growth factor receptor 4 (FGFR4) in breast fibroadenomas.

BACKGROUND/AIM: Fibroadenomas are benign tumours composed of both glandular and fibrous tissue. The mechanisms regulating the growth of these tumours and the relation between the stromal and epithelial cells are poorly understood. Acidic fibroblast growth factor (aFGF) is a well known fibroblast activator, which acts through four specific cell surface receptors, among which, fibroblast growth factor receptor 4 (FGFR4) is highly specific. The aim of this study was to evaluate the distribution of aFGF and FGFR4 in specific cell types of fibroadenomas to understand their possible role in the growth of these breast lesions. METHODS: Formalin fixed and paraffin wax embedded tissues from 15 fibroadenomas and peritumoral normal breasts were investigated for the expression of aFGF and FGFR4 using immunohistochemistry. The presence of aFGF mRNA was also investigated using in situ hybridisation. RESULTS: Immunoreactivity for aFGF and FGFR4 was seen in epithelial cells, but it was lacking in myoepithelial cells of both normal tissues and fibroadenomas. Strong FGFR4 immunoreactivity was found in stromal fibroblasts, which were also weakly positive for aFGF. aFGF mRNA was detected in epithelial cells and in some stromal fibroblasts. CONCLUSIONS: These results suggest a paracrine/autocrine modulation of epithelial and stromal cells of fibroadenomas through an aFGF-FGFR4 interaction. This interaction might regulate various cell functions and the growth of fibroadenomas.

Children war casualties during the 1991-1995 wars in Croatia and Bosnia and Herzegovina.

AIM: To analyze clinical course of war-related injuries in children treated at the Split University Hospital during the wars in Croatia (1991-1995) and Bosnia and Herzegovina (1992-1995). METHODS: Medical records of 94 treated children were analyzed. The severity of wounds was scored according to the Abbreviated Injury Scale (AIS) and Injury Severity Score (ISS) evaluation systems. RESULTS: Most children were wounded during shelling/bombing (n = 28, 10 boys and 18 girls) and by left over explosive devices (n = 26). Children injured by left over explosive devices were predominantly boys (23/26 children), aged 10 to 16 years (19/26 children). Extremities were the most frequently wounded body regions (43% of all wounded regions). The wounds to the head/neck (median AIS = 5.0, range 1-6) and abdomen (median AIS = 4.5, range 3-5) were the most severe. Abdominal wounds required surgical procedures (p < 0.001) and antibiotic treatment (p < 0.05) most frequently, as well as patients with greater AIS and ISS scores (p < 0.05). According to the treatment outcome, more patients wounded to the abdomen and extremities showed improvement than no change or complete recovery (p < .05). Permanent disability remained in 37 (39.4%) children and three (3.3%) children died. CONCLUSION: Boys in upper elementary grades and high school were at greater risk of being wounded by fragments of left over explosive devices than younger boys or girls. The most severe wounds were to the head/neck and the abdomen and inflicted during the shelling or bombing. This should be taken into account in organization of surgical care for the children with war-related injuries.

Immunohistochemical pattern of hMSH2/hMLH1 in familial and sporadic colorectal, gastric, endometrial and ovarian carcinomas with instability in microsatellite sequences.

Alterations of DNA mismatch repair (MMR) genes are involved in carcinogenesis of sporadic and inherited human cancers characterised by instability of DNA microsatellite sequences (MSI). MSI tumours are usually identified using molecular analysis. In the present investigation, hMLH1 and hMSH2 immunohistochemistry was tested in order to evaluate the utility of this method in predicting MMR deficiency. Colorectal (72), gastric (68), endometrial (44) and ovarian (17) carcinomas were independently evaluated for familial history, histological type of tumour, MSI status and immunohistochemical results. Loss of expression of either hMLH1 or hMSH2 was observed in 51 of 55 (92.8%) MSI tumours, while 145 of 146 microsatellite stable (MSS) tumours expressed both the hMLH1 and hMSH2 gene products. Independently of tumour site, an overall agreement between immunohistochemical and molecular results was observed in 15 hereditary non-polyposis colorectal cancer-related tumours. Among sporadic tumours, only 2 of 60 colorectal and 2 of 66 gastric carcinomas, displaying MSI, expressed both hMLH1 and hMSH2 gene products. All 39 endometrial and 16 ovarian tumours presented a concordant molecular and immunohistochemical profile. These data show that immunohistochemistry is an accurate and rapid method to predict the presence of defective DNA MMR genes and to identify both sporadic and familial MSI tumours.

Molecular definition of Xq common-deleted region in patients affected by premature ovarian failure.

High-resolution cytogenetic analysis of a large number of women with premature ovarian failure (POF) identified six patients carrying different Xq chromosome rearrangements. The patients (one familial and five sporadic cases) were negative for Turner's stigmata and experienced a variable onset of menopause. Microsatellite analysis and fluorescent in situ hybridization (FISH) were used to define the origin and precise extension of the Xq anomalies. All of the patients had a Xq chromosome deletion as the common chromosomal abnormality, which was the only event in three cases and was associated with partial Xp or 9p trisomies in the remaining three. Two of the Xq chromosome deletions were terminal with breakpoints at Xq26.2 and Xq21.2, and one interstitial with breakpoints at Xq23 and Xq28. In all three cases, the del(X)s retained Xp and Xq specific telomeric sequences. One patient carries a psu dic(X) with the deletion at Xq22.2 or Xq22.3; the other two [carrying (X;X) and (X;9) unbalanced translocations, respectively] showed terminal deletions with the breakpoint at Xq22 within the DIAPH2 gene. Furthermore, the rearranged X chromosomes were almost totally inactivated, and the extent of the Xq deletions did not correlate with the timing of POF. In agreement with previous results, these findings suggest that the deletion of a restricted Xq region may be responsible for the POF phenotype. Our analysis indicates that this region extends from approximately Xq26.2 (between markers DXS8074 and HIGMI) to Xq28 (between markers DXS 1113 and ALD) and covers approximately 22 Mb of DNA. These data may provide a starting point for the identification of the gene(s) responsible for ovarian development and folliculogenesis.

A large 6q deletion is a common cytogenetic alteration in fibroadenomas, pre-malignant lesions, and carcinomas of the breast.

To assess whether early breast lesions are the precursors of invasive carcinomas, three classes of breast lesions, namely benign tumors (including fibroadenomas), putative premalignant lesions (including cases of atypical hyperplasia), and invasive carcinomas, were compared at the cytogenetic and molecular cytogenetic levels. Genetic relatedness was clearly demonstrated by the sharing of several anomalies, among which 6q deletions outnumbered all of the other alterations detected. Indeed, deletions of the long arm of chromosome 6, most likely occurring in epithelial cells, were present in 83.9% of benign breast tumors, 64% of putative premalignant lesions, and 77.4% of analyzable carcinomas. Furthermore, the interval between 6q24 and qter appeared to be the common region of deletion in all three classes of breast lesions, whereas the minimal common region of deletion was 6q27-qter. Interestingly, the latter region was reported previously to be deleted in benign ovarian tumors and recently found to harbor a gene (SEN6) that is important for SV40-mediated immortalization of human cells.

CHK1 frameshift mutations in genetically unstable colorectal and endometrial cancers.

The protein encoded by the CHK1 gene plays an important role in the G2 checkpoint in mammalian cells. In its coding region it presents a sequence of nine consecutive adenines that are a potential site of mutations in tumors with microsatellite instability (MSI). We analyzed the presence of frameshift mutations in the CHK1 gene in human colon and endometrial cancer samples. In the same cancer samples genes known to be altered in these tumors (BAX, TGFBRII, and IGFIIR) were also analyzed. CHK1 frameshfit mutations were found in 1 out 10 colon cancers and 2 out of 7 endometrial cancers showing MSI. CHK1 alterations were associated with the presence of a high degree of MSI. No alterations were found in patients with tumors showing low frequency or lacking instability (microsatellite stable). The same was true for the other four genes analyzed. The insertion or deletion of one A in the poly A tract resulted in a truncated protein. Alterations of the CHK1 gene could represent an alternative way of cancer cells to escape from cell cycle control. Genes Chromosomes Cancer 26:176-180, 1999.

Microsatellite instability in gastric MALT lymphomas and other associated neoplasms.

BACKGROUND: Microsatellite instability (MSI), caused by a reduced efficacy of the DNA mismatch repair (MMR) machinery, represents a type of genomic instability frequently detected in HNPCC spectrum cancers and in a subset of sporadic carcinomas. The involvement of MSI in the pathogenesis of gastric lymphoma of mucosa-associated lymphoid tissue (MALT) has never been conclusively investigated. In this study, we tested the presence of MSI in tumor samples of patients harboring both MALT lymphomas and other types of malignancies. MATERIALS AND METHODS: We examined 10 microsatellite loci (D3S11, D3S1261, D3S1265, D6S262, D6S193, BAT-26, BAT-25, D17S250, APC, D2S123) out of a total of 34 primary tumors from 14 patients with MALT lymphomas and one or more additional neoplasms. The patients' MSI results were also tested for an association with a positive family history of cancer. RESULTS: MSI, defined by the presence of microsatellite alterations in more than 40% of the examined loci, was scored negative in all tumors studied, and pedigree analysis failed to identify any condition of familial cancer among the patients examined. CONCLUSIONS: The present study suggests that defects in DNA mismatch repair do not contribute significantly to the molecular pathogenesis of MALT lymphomas and associated neoplasms.

BRCA1 and BRCA2 genes: role in hereditary breast and ovarian cancer in Italy.

The heritable defects of BRCA1 and BRCA2 genes have been shown to predispose to breast and ovarian cancers. In a previous report, we analyzed 46 Italian families with breast and/or ovarian cancer for BRCA1 mutations. In the present study, those families and 11 others were screened for BRCA2 mutations; the newly enrolled families were also analyzed for the BRCA1 gene. The coding region and splice boundaries of BRCA2 and BRCA1 genes were assessed by the protein-truncation test and single-strand conformational polymorphism. A total of 20 different mutations were found in 21 families (37%). A total of 9 families (16%) showed mutations in the BRCA1 gene, including the one new mutation identified in this study (5382insC), and 12 families (21%) presented mutations in the BRCA2 gene. BRCA2-mutated families presented breast and ovarian cancers or breast cancers only, whereas most BRCA1-mutated families presented ovarian cancer alone or in association with breast cancer. All the BRCA2 mutations led to a truncated protein: 6 were frameshift mutations, 4 were non-sense mutations and 2 involved the intronic invariant region leading to splice variants. Therefore, in the Italian population, the cumulative proportion of BRCA1 and BRCA2 mutations was within the range observed in other studies (37%), with higher involvement of BRCA2 than of BRCA1. Many families in which no mutations were found presented a very high incidence of breast and/or ovarian cancer. Among the 36 BRCA1 and BRCA2 wild-type families, 24 presented at least 4 cancer cases, indicating the existence of other important predisposing genes.

Microsatellite instability in endometrial cancer: relation to histological subtypes.

Fifty-one endometrial cancers were analyzed with regard to whether or how microsatellite instability (MI) was associated with the development of different types of endometrial malignant neoplasms. We investigated 6 loci previously reported as informative for colorectal cancer and a group of 8 loci located on 6q. Replication error (RER+) phenotype was detected in 10 of 51 (19.6%) endometrial cancers (ECs), all but one of which showed endometrioid differentiation. On the contrary, the RER+ phenotype was not detected in serous carcinomas and malignant mixed Müllerian tumors. MI was present in both early and advanced stage ECs. No correlation was found between age, grade, stage, familial pattern, mitotic index, and the RER+ phenotype of ECs. Only 1 of 8 endometrial carcinomas showing MI was associated with mutant p53 expression, while the majority of RER+ tumors were positive for estrogen and progesterone receptors. Our findings suggest that MI plays an early role in endometrial tumorigenesis and is significantly correlated with adenocarcinomas showing endometrioid features (EAs). The frequent involvement of the telomeric region of chromosome 6 in the MI of EA is an indication that this region may be crucial in the process of EA tumorigenesis.

The value of microsatellite instability in the detection of HNPCC families and of sporadic colorectal cancers with special biological features: an investigation on a series of 100 consecutive cases.

BACKGROUND: Microsatellite instability (MI) is a biological characteristic of most tumors involved in hereditary non-polyposis colorectal cancer (HNPCC). This disease appears to be caused by germline mutations in mismatch repair (MMR) genes, which are responsible for repairing single base-pair mismatches. At least five human genes participate in MMR. MI also occurs in 10%-15% of sporadic colorectal cancers. Because MI detection has been suggested as an alternative diagnostic tool for identification of HNPCC families, in this study we analyzed the MI pattern in 100 consecutive colorectal carcinomas in order to correlate them with the clinicopathologic features and family histories of the patients. PATIENTS AND METHODS: A series of 100 colorectal cancers was evaluated for MI with 10 polymerase chain reaction primer sets. Instability results were compared with family history and other clinical and biological characteristics. RESULTS: MI was detected in 36 of 100 cancers, 27 of which showed low instability and nine a high instability. The low- and high-instability cases showed similar clinicopathological characteristics, and significantly positive associations were observed between MI and mucinous histological type (P = 0.0001) and MI and peritumoral lymphocytic infiltration (P = 0.01). A single HNPCC family was identified in the high-grade MI group, while two families belonged to the MI-negative group. CONCLUSIONS: Our data suggest that MI screening is probably not an efficient strategy for identifying HNPCC cases. MI does, however, appear capable of defining a category of colorectal cancers with favourable prognostic features and should be investigated at least in all cases of mucinous adenocarcinomas.