Clonal chromosome-aberrations in fibrocystic breast disease-associated with increased risk of cancer

Short-term cultures of 29 samples of fibrocystic breast disease were cytogenetically analyzed. Clonal chromosome aberrations were found in six specimens, whereas the remaining 23 had a normal karyotype. Three of the abnormal samples displayed karyotypic anomalies previously associated with breast cancer, i.e., gain of Iq, trisomy 18 and cytogenetic multiclonality. Furthermore, all cytogenetically aberrant specimens had either proliferative disease without atypia or atypical hyperplasia, features of fibrocystic disease considered risk factors for subsequent breast cancer development. The cytogenetic similarities between breast carcinomas and proliferative fibrocystic breast disease add further support for classifying certain types of fibrocystic disease as a premalignant condition. Whether cytogenetically abnormal fibrocystic lesions are the ones that subsequently progress to cancer remains to be elucidated.

12q amplification defines a subtype of extraskeletal osteosarcoma with good prognosis that is the soft tissue homologue of parosteal osteosarcoma

Extraskeletal osteosarcomas are rare tumors with neoplastic cells synthesizing bone, usually associated with poor prognosis. We present the case of a 40-year-old man with an extraskeletal osteosarcoma that was treated by surgery and adjuvant radiotherapy. Thirteen years after the diagnosis, he remains disease-free, without any recurrences or metastases. Histopathological analysis favored the diagnosis of chondroblastic extraskeletal osteosarcoma grade II. G-banding, comparative genomic hybridization (CGH), and real-time PCR for the MDM2 and CDK4 genes were performed to describe the genetic profile of this tumor and revealed aberrations that are common findings of parosteal osteosarcomas. Ring chromosomes, giant marker chromosomes, and a telomeric association were found with G-banding. CGH revealed that 12q was amplified in the ring and giant markers identified by G-banding. Real-time PCR for MDM2 and CDK4 confirmed the amplification of these genes located in 12q. Our findings suggest that a variant of extraskeletal osteosarcoma, which is genotypically similar to parosteal osteosarcoma, exists and is associated with good prognosis.

Similar cytogenetic findings in two synchronous secondary peripheral chondrosarcomas in a patient with multiple osteochondromas

Secondary peripheral chondrosarcoma is a malignant chondroid tumor arising in a benign precursor, either an osteochondroma or an enchondroma. Multiple osteochondromas syndrome (MO) is an autosomal dominant skeletal disorder associated with bony growths in the form of osteochondromas that occasionally undergo malignant transformation to secondary peripheral chondrosarcomas. We describe the genetic examination of three secondary peripheral chondrosarcomas that had arisen synchronously from osteochondromas in a patient with MO by chromosome banding, high resolution chromosomal comparative genomic hybridization, and mutation analysis of the EXT1 and EXT2 genes. In two of the tumors (the third was not genetically informative), very similar chromosome abnormalities were found, indicating that they must somehow be part of the same neoplastic process in spite of being anatomically distinct.

Forces and moments on posterior teeth generated by incisor intrusion biomechanics

OBJECTIVES

To comparatively evaluate the extrusive forces and torquing moments on the posterior dentition generated during anterior intrusion with different intrusion techniques in the maxillary and mandibular dental arch.

MATERIAL AND METHODS

Seven wire specimens were used for each of the following intrusive arches: Utility arch 0.016 x 0.016' Blue Elgiloy, Utility arch 0.017 x 0.025' TMA and Burstone Intrusion arch 0.017 x 0.025' TMA. The wires were inserted on bracketed dental arches constructed on maxillary Frasaco models, segmented mesially to the maxillary canines. Simulated intrusion from 0.0-3.0 mm was performed on the Orthodontic Measurement and Simulation System (OMSS). The forces and moments were recorded in all three planes of space at 0.1 mm increments and the values at 3.0 mm for all wires were used for all statistical evaluations. The data were analyzed, separately for the forces and moments, by means of two-way analysis of variance (ANOVA) with forces and moments serving as the dependent variables and intrusion technique and jaw (maxilla or mandible) as the independent variable. Post hoc multiple comparisons were performed using the Tukey test at .05 error rate.

RESULTS

The 0.016 x 0.016' Blue Elgiloy utility arch exerted the highest posterior extrusive forces, 15% higher than the 0.017 x 0.025' TMA utility and 40% higher in comparison with the 0.017 x 0.025' TMA Burstone intrusion arch.The lowest posterior moment in the sagittal plane was generated by the 0.017 x 0.025' TMA Burstone intrusion arch. The 0.016 x 0.016' Blue Elgiloy utility arch exerted 15% higher posterior moments and the 0.017 x 0.025' TMA utility 25% higher. Forces and moments were consistently larger for the mandible compared to the maxilla for the same intrusion technique.

CONCLUSIONS

The upper Burstone 0.017 x 0.025' TMA intrusion arch exerted the lowest forces/moments on posterior teeth. The highest forces were generated by the 0.016 x 0.016-inch Blue Elgiloy utility arch and the highest moments by the lower 0.017 x 0.025-inch TMA utility arch.

Long-term periodontal status of patients with mandibular lingual fixed retention

The purpose of this study was to evaluate the periodontal tissues of patients with mandibular fixed retention for long or short periods of time. A total of 64 individuals were selected for this study using the following inclusion criteria: long-term lingual fixed retention; identical type of lingual fixed retainer bonded with the same materials; no cavities, restorations, or fractures of the mandibular anterior teeth; absence of habits and occlusal interferences; and canine guidance bilaterally. The resultant sample comprised 32 patients (mean age 25 years) who had been in retention for a mean period of 9.65 years (range 9-11 years) and an equal number retained for a period between 3 and 6 months. Plaque, gingival, and calculus indices, probing pocket depth, marginal recession, and bone level at the mandibular six anterior teeth were recorded for both groups. Demographic, clinical, and radiographic data were investigated with conventional descriptive statistics. Comparisons of the different variables between the two participant groups (long- and short-term retention) were carried out using a Mann-Whitney test for indices (plaque, gingival, and calculus), and a Fisher's exact test (two sided) for the remaining variables. No significant difference was found with respect to the plaque and gingival indices and bone level between the two groups. The long-term group presented higher calculus accumulation, greater marginal recession, and increased probing depth (P < 0.05). The results of this study raise the question of the appropriateness of lingual fixed retainers as a standard retention plan for all patients regardless of their attitude to dental hygiene. They also emphasize the importance of individual variability and cautious application of retention protocols after a thorough consideration of issues related to the anatomy of tissues and oral hygiene.

Desmoplastic small round cell tumor of the pleura

Desmoplastic small round cell tumor (DSRCT) is a rare neoplasm with aggressive behavior. Usually it presents as a peritoneal mass, although other cases in various locations have been described. Since less than 10 cases of primary DSRCT in the pleura have been described, it is of interest to report a pediatric case arising from the pleura. The diagnosis was confirmed by molecular detection of the EWS/WT-1 fusion gene product. Multidisciplinary treatment with chemotherapy, radiotherapy, and surgical resection resulted in a progression-free survival time above the median survival, suggesting that this conventional approach could prove effective for this rare and very aggressive malignancy.

Expression of oncofetal RNA-binding protein CRD-BP/IMP1 predicts clinical outcome in colon cancer

The oncofetal CRD-BP/IMP1 RNA binding protein regulates posttranscriptionally a handful of RNA transcripts, implicated in cell adhesion and invadopodia formation and was recently identified as a target of the beta-catenin/Tcf transcription factor that is constitutively activated in colorectal carcinomas (CRCs). The expression of CRD-BP/IMP1 was studied in normal adult intestines and CRCs. In normal mucosa, CRD-BP/IMP1 immunoreactivity was observed in few scattered cells located predominantly at or near the bottom of the crypts, whereas in CRCs the protein was detectable in tumor cells of 50% of the specimens analyzed. CRD-BP/IMP1 mRNA expression was measured by qRT-PCR in 78 CRCs. Thirty-two (41%) of the specimens were negative or had negligible expression, whereas the remaining forty-six (59%) expressed a wide range of CRD-BP/IMP1 mRNA levels. CRD-BP/IMP1 mRNA expression correlated with that of the putative stem/progenitor cell marker Musashi-1 mRNA (p = 0. 035). CRD-BP/IMP1 positive tumors metastasized and/or recurred more frequently (p = 0.001) and its expression defined a group of patients with shorter survival (p = 0.014). Furthermore, in a multivariate analysis CRD-BP/IMP1 expression was found to be an independent predictor of survival (p = 0.015). For stage I & II patients, the differences in metastasis/recurrence and survival rates remained significant (p = 0.001 and 0.033, respectively). These findings indicate that CRD-BP/IMP1 positive tumors exhibit early disease dissemination and unfavorable prognosis.

Greek BRCA1 and BRCA2 mutation spectrum: two BRCA1 mutations account for half the carriers found among high-risk breast/ovarian cancer patients

127 Greek breast/ovarian cancer families were screened for germline BRCA1/2 mutations by dHPLC followed by direct sequencing. Our results indicated 16 and 5 breast/ovarian cancer families bearing deleterious mutations in the BRCA1 and BRCA2 genes, respectively. Two novel BRCA2 germline mutations (G4X and 3783del10) are reported here for the first time. Subsequent compilation of our present findings with previously reported mutation data reveals that in a total of 287 Greek breast/ovarian cancer families, 46 and 13 carry a deleterious mutation in BRCA1 and BRCA2, respectively. It should be noted that two BRCA1 mutations, 5382insC and G1738R, both located in exon 20, account for 46% of the families found to carry a mutation. Based on our mutation analysis results, we propose here a hierarchical, cost-effective BRCA1/2 mutation screening protocol for individuals of Greek ethnic origin. The suggested protocol can impact on the clinical management of breast-ovarian cancer families on a national healthcare system level.

Maxillary incisor torque with conventional and self-ligating brackets: a prospective clinical trial

OBJECTIVES

To test the hypothesis that the engagement mode of wire to bracket affects the buccolingual inclination of maxillary incisors in extraction and non-extraction treatment with self-ligating and conventional brackets.

DESIGN

A randomized clinical trial employing a random distribution of variables among the studied populations.

SETTING AND SAMPLE POPULATION

Private practice of one author. A total of 105 patients followed prospectively, were divided into two groups based on the inclusion of extraction in the treatment planning. These groups were further divided in two subgroups each, one receiving a self-ligating bracket and the other treated with a conventional Edgewise appliance of the same slot size and prescription.

EXPERIMENTAL VARIABLE

Difference in the buccolingual inclination of maxillary incisors before and after treatment with the two appliances across the two treatment groups (extraction and non-extraction).

OUTCOME MEASURE

Angular measurements of the Sella-Nasion and Nasion-A point to maxillary incisor axis.

RESULTS

No difference was found in the mean difference of the two angles measured for the two bracket groups studied.

CONCLUSION

Self-ligating brackets seem to be equally efficient in delivering torque to maxillary incisors relative to conventional brackets in extraction and non-extraction cases.

Chromosome analysis and molecular cytogenetic investigations of an epithelioid hemangioendothelioma

Epithelioid hemangioendothelioma is a rare, well-differentiated endothelial tumor with a wide spectrum of clinical behavior and for which genetic data are extremely limited. We present a case of an epithelioid hemangioendothelioma in a 22-year-old male, which was analyzed with multiple cytogenetic approaches. Conventional cytogenetic analysis detected structural abnormalities of 11q13 and 11q14, rings, and marker chromosomes. Multi-color FISH (mFISH) and high-resolution multi-color banding (mBAND) analyses demonstrated that the aberrations of chromosome 11 were deletions and that the ring and marker chromosomes consisted of 12(q14 approximately q21) material. Comparative genomic hybridization (CGH) analysis revealed gains of 11(q13 approximately q14) and 12(q11 approximately q21), loss of 11(q21 approximately qter), and 2 amplicons at 12(q12 approximately q13) and 12(q14 approximately q21). Our data indicate that a subset of epithelioid hemangioendotheliomas may be characterized by complex rearrangements involving deletions and gains of 11q and 12q amplifications. The present case also shows that, in order to describe and understand such complex chromosome aberrations, chromosome analysis must be complemented with several molecular cytogenetic techniques.

Intratumor genomic heterogeneity in breast cancer with clonal divergence between primary carcinomas and lymph node metastases

Conflicting theories of epithelial carcinogenesis disagree on the clonal composition of primary tumors and on the time at which metastases occur. In order to study the spatial distribution of disparate clonal populations within breast carcinomas and the extent of the genetic relationship between primary tumors and regional metastases, we have analyzed by comparative genomic hybridization 122 tissue samples from altogether 60 breast cancer patients, including 34 tumor samples obtained from different quadrants of 9 breast carcinomas, as well as paired primary-metastatic samples from 12 patients. The median intratumor genetic heterogeneity score (HS) was 17.4% and unsupervised hierarchical clustering analysis comparing the genetic features to those of an independent series of 41 breast carcinomas confirmed intratumor clonal divergence in a high proportion of cases. The median HS between paired primary breast tumors and lymph node metastases was 33.3%, but the number of genomic imbalances did not differ significantly. Clustering analysis confirmed extensive clonal divergence between primary carcinomas and lymph node metastases in several cases. In the independent series of 41 breast carcinomas, the number of genomic imbalances in primary tumors was significantly higher in patients presenting lymph node metastases (median = 15.5) than in the group with no evidence of disease spreading at diagnosis (median = 5.0). We conclude that primary breast carcinomas may be composed of several genetically heterogeneous and spatially separated cell populations and that paired primary breast tumors and lymph node metastases often present divergent clonal evolution, indicating that metastases may occur relatively early during breast carcinogenesis.

TP53 mutations are associated with a particular pattern of genomic imbalances in breast carcinomas

TP53 mutations play an important role in the development of several cancers and are present in 20-40% of all breast carcinomas, contributing to increased genomic instability. In order to address the relationship of mutated TP53 to genomic complexity, the present study analysed 61 breast carcinomas for TP53 mutations and compared mutation status with the pattern of genomic imbalances as assessed by comparative genomic hybridization (CGH). Twenty per cent of the present series of breast carcinomas harboured TP53 mutations. An increasing number of abnormalities, as identified by CGH (higher genomic complexity), correlated significantly with mutant TP53. Among the chromosome arms most commonly altered (in more than 20% of the tumours), loss of 8p and gain of 8q were associated with TP53 mutations, whereas loss of 16q was associated with wild-type TP53. By performing supervised hierarchical clustering analysis of the CGH data, a cluster of chromosome imbalances was observed that showed differences between wild-type and mutant TP53 cases. Among these, loss of chromosome arm 5q revealed the strongest correlation with altered TP53. To investigate further the most commonly deleted region of 5q, gene expression patterns from two publicly available microarray data sets of breast carcinomas were evaluated statistically. The expression data sets identified potential target genes, including genes involved in ubiquitination and the known TP53 target CSPG2. The genomic complexity of breast carcinomas as assessed by CGH is associated with TP53 mutation status; breast cancers with TP53 mutations display more complex genomes than do those with wild-type TP53. The pattern of genomic imbalances associated with mutant TP53 is non-random, with loss of chromosome arm 5q being particularly closely associated with TP53 mutations.

Cytogenetic manifestations of multiple myeloma heterogeneity

To investigate the genetic basis of the great heterogeneity observed in the clinical behavior of multiple myeloma (MM), a combined approach of G-banding, interphase fluorescence in situ hybridization (FISH), and multicolor FISH (M-FISH) was employed to analyze 70 samples from 53 patients with MM. G-banding revealed abnormal karyotypes in 77% of the cases. The origin of 31 chromosome markers was identified or revised by M-FISH. Combined metaphase karyotypic data and interphase FISH findings, using the immunoglobulin heavy-chain (IGH), IGH/cyclin D1 gene (CCND1), and D13S319 probes, revealed chromosome abnormalities in all evaluated patients and marked inter- and intratumor cytogenetic heterogeneity in the investigated MM samples. Cytogenetically unrelated clones were detected in 26% of the cases, mostly MM evaluated at diagnosis, whereas cytogenetic clonal evolution, manifested as related clones in 20% of the cases, was associated with disease progression. Among the 14q32 rearrangements, present in 66% of the cases, at least three cytogenetic subsets could be identified: one with t(11;14), usually without 13q14 deletion; another with other IGH changes, often 13q14 deletion, and hypodiploid modal chromosome number; and a third without changes in 14q32 but with abnormalities of chromosome 17. The correlation found between cytogenetic and clinicopathologic characteristics provided support for the concept that general genomic features in conjunction with specific chromosome rearrangements define the malignant phenotype in the various subsets of MM.

Metaphase and interphase cytogenetics in fibroadenomas of the breast

Short-term cultures of fifty-two samples of fibroadenomas were cytogenetically analyzed. Thirty-three of the successfully karyotyped fibroadenomas were further investigated for the presence of amplifications in the CCND1, c-MYC and HER/2-neu genes by means of FISH analysis. Compared to carcinomas, fibroadenomas seem to have less complex cytogenetic rearrangements and limited alterations on HER-2/neu, CCND1 and c-MYC loci. A cytogenetic subgroup of fibroadenomas with hyperdiploid karyotypes and only numerical changes was observed. Amplification of CCND1 seems to play a more substantial role in benign tumor progression. These findings confirm that fibroadenomas do have genetic alterations and support the hypothesis that a fibroadenoma subset displays changes also found in carcinomas, thus indicating that patients belonging to this group might have an increased risk for subsequent breast cancer.

Assessment of clonal relationships in ipsilateral and bilateral multiple breast carcinomas by comparative genomic hybridisation and hierarchical clustering analysis

The issue of whether multiple, ipsilateral or bilateral, breast carcinomas represent multiple primary tumours or dissemination of a single carcinomatous process has been difficult to resolve, especially for individual patients. We have addressed the problem by comparative genomic hybridisation analysis of 26 tumours from 12 breast cancer patients with multiple ipsilateral and/or bilateral carcinoma lesions. Genomic imbalances were detected in 25 of the 26 (96%) tumours. Using the genomic imbalances detected in these 26 lesions as well as those previously found by us in an independent series of 35 unifocal breast carcinomas, we compared a probabilistic model for likelihood of independence with unsupervised hierarchical clustering methodologies to determine the clonal relatedness of multiple tumours in breast cancer patients. We conclude that CGH analysis of multiple breast carcinomas followed by unsupervised hierarchical clustering of the genomic imbalances is more reliable than previous criteria to determine the tumours’ clonal relationship in individual patients, that most ipsilateral breast carcinomas arise through intramammary spreading of a single breast cancer, and that most patients with bilateral breast carcinomas have two different diseases.

Characterization of a novel large deletion and single point mutations in the BRCA1 gene in a Greek cohort of families with suspected hereditary breast cancer

BACKGROUND

Germline mutations in BRCA1 and BRCA2 predispose to breast and ovarian cancer. A multitude of mutations have been described and are found to be scattered throughout these two large genes. We describe analysis of BRCA1 in 25 individuals from 18 families from a Greek cohort.

METHODS

The approach used is based on dHPLC mutation screening of the BRCA1 gene, followed by sequencing of fragments suspected to carry a mutation including intron--exon boundaries. In patients with a strong family history but for whom no mutations were detected, analysis was extended to exons 10 and 11 of the BRCA2 gene, followed by MLPA analysis for screening for large genomic rearrangements.

RESULTS

A pathogenic mutation in BRCA1 was identified in 5/18 (27.7 %) families, where four distinct mutations have been observed. Single base putative pathogenic mutations were identified by dHPLC and confirmed by sequence analysis in 4 families: 5382insC (in two families), G1738R, and 5586G > A (in one family each). In addition, 18 unclassified variants and silent polymorphisms were detected including a novel silent polymorphism in exon 11 of the BRCA1 gene. Finally, MLPA revealed deletion of exon 20 of the BRCA1 gene in one family, a deletion that encompasses 3.2 kb of the gene starting 21 bases into exon 20 and extending 3.2 kb into intron 20 and leads to skipping of the entire exon 20. The 3' breakpoint lies within an AluSp repeat but there are no recognizable repeat motifs at the 5' breakpoint implicating a mechanism different to Alu-mediated recombination, responsible for the majority of rearrangements in the BRCA1 gene.

CONCLUSIONS

We conclude that a combination of techniques capable of detecting both single base mutations and small insertions/deletions and large genomic rearrangements is necessary in order to accurately analyze the BRCA1 gene in patients at high risk of carrying a germline mutation as determined by their family history. Furthermore, our results suggest that in those families with strong evidence of linkage to the BRCA1 locus in whom no point mutation has been identified re-examination should be carried out searching specifically for genomic rearrangements.