Biomedical subjects

Antonio Llombart-Bosch

Publications and source records attributed to Antonio Llombart-Bosch.

At least 19 recordsLinked to original sources

PubMed2007

Evaluation of genetic stability of the SYT gene rearrangement by break-apart FISH in primary and xenotransplanted synovial sarcomas.

Synovial sarcomas (SS) are infrequent and morphologically heterogeneous soft tissue sarcomas. The t(X;18)(p11.2;q11.2), which results in fusion of the SYT gene at 18q11 with the SSX1, SSX2, or (rarely) SSX4 gene is a primary genetic event in 90% of SS. To determine whether the t(X;18) present in the original tumor is maintained in its passages, a dual-color break-apart FISH assay for SYT gene disruption was performed in two tissue microarrays (TMA) comprising eight molecularly confirmed primary SSs and their xenografts, which were followed for several generations. A simplified scoring system was applied to the FISH results of the primary and xenotransplanted SS to classify the FISH data into distinct groups. SYT disruption was identified in all eight primary SS and in all their passages without any significant differences among them, despite wide variations in xenotransplantation time between the primary tumors and their xenografts. The TMA-based FISH assay demonstrated genetic stability related to SYT gene rearrangement in primary and xenografted SS.

Animals↗

PubMed2006

Tissue microarray profiling of primary and xenotransplanted synovial sarcomas demonstrates the immunophenotypic similarities existing between SYT-SSX fusion gene confirmed, biphasic, and monophasic fibrous variants.

This paper discusses the diversity of synovial sarcomas (SSs) [biphasic (BSS), monophasic fibrous (MFSS), and poorly differentiated (PDSS)] and tissue microarray (TMA) evaluation of the immunophenotypic and histological progression of SSs in nude mice using three TMAs comprising 11 primary SSs (8 MFSSs, 2 BSSs, and 1 PDSS) and their xenografts. BSS and MFSS progressively transformed to a similar undifferentiated phenotype with loss of glandular component in the xenografts. Epidermal growth factor receptor and SALL2 were expressed in primary tumors and xenografts. Enhanced bcl-2 and bax expression were noted in xenografts. Ki-67 overexpression in xenografts correlated with high mitotic index. Epithelial membrane antigen (EMA) and cytokeratin AE1/AE3 were detected in all original and xenografted SSs. Hierarchical clustering differentiated original MFSS and BSS, but their xenografts clustered together due to similar immunoexpression profile. Our study demonstrates definite phenotypic variability of BSS and MFSS in the xenografts. Differences in immunoexpression for various markers existed between primary tumor and xenografts but not between subtypes. Hierarchical clustering grouped TMA immunostaining data and confirmed immunophenotypic variability; however, it failed to reveal any immunophenotypic differences between SYT-SSX1 and SYT-SSX2 type tumors. Nonetheless, reverse-transcriptase-polymerase chain reaction detected SYT-SSX transcripts in all primary SSs and their xenografts, thereby demonstrating their genetic stability.

Animals↗

PubMed2006

Prognostic value of the International Neuroblastoma Pathology Classification in Neuroblastoma (Schwannian stroma-poor) and comparison with other prognostic factors: a study of 182 cases from the Spanish Neuroblastoma Registry.

In addition to clinical and biological factors, further valuable prognostic information in neuroblastoma (Schwannian stroma-poor) (NB) patients is provided by the histopathologic analysis and the application of the International Neuroblastoma Pathology Classification (INPC) system. The objective of this study was to assess the prognostic impact of the INPC classification in a series of NB (Schwannian stroma-poor) and its relation with other prognostic factors. One hundred eighty-two cases of NB were collected from the files of the Spanish Neuroblastoma Registry. Slides were reviewed, and NB cases were grouped into favorable and unfavorable categories according to INPC criteria, taking into account morphological features (mitosis-karyorrhexis index, histological subtype) and patient's age at diagnosis. Other pathological [presence of calcifications, tissular components, and number of mitotic cells per 10 high-power field (HPF)], immunohistochemical (P-glycoprotein and Ki-67 protein expression) and genetic (MYCN amplification and chromosome 1p deletion) features were also studied. Statistical analyses of overall survival with Kaplan-Meier curves and a multivariate study using Cox regression were performed (40.3% of NBs were considered favorable and 59.7% unfavorable). Unfavorable NB showed a mean survival time of 57 months compared with 89 months in favorable cases. Advanced stage, more than ten mitoses per 10 HPF, Ki-67 expression in more than 30% of tumor cells, MYCN oncogene amplification and chromosome 1p deletion were observed more frequently in unfavorable NB. The Cox regression analysis demonstrated that clinical stage (International Neuroblastoma Staging System stage 4) and histological subtype (undifferentiated NB) were the most important factors that influence the overall survival (p<0.001). INPC classification results are major prognostic indicators in NB and should be considered in the therapeutic stratification of NB patients.

Child↗

PubMed2006

HER2 amplification in recurrent breast cancer following breast-conserving therapy correlates with distant metastasis and poor survival.

The authors analyzed the HER2 status in early-stage nonrecurrent and recurrent breast cancer groups following breast-conserving treatment. Retrospective analyses of a group of 36 invasive early breast cancer (IBC) patients who developed a local recurrence as a first event and of a random control group of 69 IBC patients were made. HER2 status was assessed by the HercepTest and fluorescence in situ hybridization. The Kaplan-Meier proportional log-rank test was used to study the impact of the biological factors on the metastasis-free interval (MFI) and the overall survival (OS). The Cox proportional hazards model, using stepwise selection was performed to identify the independent predictors of poor outcome. The median time of follow-up was 156 months (range: 22-230) for the nonrecurrent group of patients and 119 months (range: 36-228) for the recurrent group. No significant differences between either group were observed in terms of either patient or tumor characteristics, or of HER2 expression. However, a higher proportion of HER2 amplified cases were found in the recurrent group, in contrast to a higher proportion of hormonal receptor positive cases in the nonrecurrent group. After univariate and multivariate analyses, HER2 amplification was found to be an independent predictive factor for distant metastasis (HR = 10.75; p = 0.00008) and for survival (HR = 4.22; p = 0.004). In conclusion, HER2 amplification constitutes an independent poor prognostic factor for the MFI and OS in patients with recurrent breast cancer. The clinical implications are discussed.

Adult↗

PubMed2006

Molecular and immunohistochemical analysis of the prognostic value of cell-cycle regulators in urothelial neoplasms of the bladder.

OBJECTIVE: To evaluate the prognostic and predictive value of molecular and immunohistochemical markers related to cell-cycle control in terms of recurrence, progression, and survival in urothelial neoplasms of the bladder (UNB). PATIENTS AND METHODS: Clinical and pathological findings of 84 patients with UNB were assessed. Homozygous deletion (HD) and promoter methylation of p14ARF, p15INK4B, p16INK4A, loss of heterozygosity of the locus 9p21, p53 mutations, and immunohistochemical expression of p53, p16, p14, p21, p27, pRb, Ki67, MDM2, and cyclin D1 proteins were evaluated in relation to overall survival (OS), recurrence-free survival (RFS), and progression-free survival (PFS). RESULTS: In the univariate analysis, RFS was shorter in cases with p14ARF (p=0.006), p15INK4B (p=0.003), p16INK4A (p=0.03) HD, low p14 immunoreactivity index (IRI) (p=0.01) and high Ki67 IRI (p=0.04); HD of the 9p21 locus genes and p14 IRI remained as independent prognostic factors for early UNB recurrence (p=0.006) whereas tumour stage (p=0.00001) and cyclin D1 IRI (p=0.049) were related to worse PFS in the multivariate analysis. In the univariate analysis, IRI for Ki67 (p=0.002), cyclin D1 (p=0.06), p53 (p=0.00008), p16 (p=0.02), p27 (p=0.0005) MDM2 (p=0.01) and p53 mutations (p=0.03) were related to poor OS, and only the Ki67 IRI retained their independent value in the multivariate analysis. CONCLUSION: 9p21 HD and p14 IRI constitute independent predictive factors for UNB recurrence and cyclin D1 IRI and tumour stage for progression. In addition, Ki67 IRI and tumour stage are independent prognostic factors for overall survival in UNB.

Biomarkers, Tumor↗

PubMed2006

Extracellular matrix alterations in conventional renal cell carcinomas by tissue microarray profiling influenced by the persistent, long-term, low-dose ionizing radiation exposure in humans.

The present study was carried out in order to examine molecular alterations of extracellular matrix (ECM), associated with cell-cell communication in conventional (clear-cell) renal cell carcinomas (cRCCs) influenced by persistent long-term, low-dose ionizing radiation (IR) exposure to patients living more than 19 years after the Chernobyl accident in Cesium 137 (137Cs)-contaminated areas of Ukraine. The ECM major components such as fibronectin, laminin, E-cadherin/beta-catenin complexes and p53 tumor suppressor gene protein, and transforming growth factor beta 1 (TGF-beta1) were immunohistochemically (IHC) evaluated in cRCCs from 59 Ukrainian patients, which represented 18 patients living in non-contaminated areas and 41 patients from 137Cs-contaminated areas. In contrast, a control group of 19 Spanish patients with analogue tumors were also investigated. For IHC evaluation, a tissue microarray technique was used. Decrease or loss and abnormal distribution of fibronectin, laminin, E-cadherin/beta-catenin complexes accompanied by elevated levels of p53 and TGF-beta1 were detected in the Ukrainian cRCCs from 137Cs-contaminated areas with statistically significant differences. Thus, our study suggests that chronic long-term, low-dose IR exposure might result in global remodeling of ECM components of the cRCCs with disruption in peri-epithelial stroma and epithelial basement membranes.

Adolescent↗

PubMed2006

[Analysis of the COL1A1-PDGFB fusion gene in a case of dermatofibrosarcoma protuberans with a fibrosarcoma component].

Dermatofibrosarcoma protuberans (DFSP) is an infrequent tumor of intermediate malignancy, with little tendency to develop metastases but with a high rate of local recurrence. Cytogenetically, DFSP is characterized by a reciprocal translocation, t(17;22)(q22;q13), which is a conditioning factor in the fusion of the collagen type I alpha I gene (COL1A1) in chromosome 17q with the platelet-derived growth factor beta chain gene (PDGFB) in chromosome 22q. The fusion of these genes is variable, involving one of the 51 exons of the COL1A1 gene and exon 2 of the PDGFB gene. We present the case of a 37-year-old woman with a tumor on the arm whose histology showed a neoplastic infiltration of the subcutaneous cellular tissue made up of fusiform cells with an elongated nucleus in a storiform pattern and other more pleomorphic cells in a herringbone pattern, compatible with DFSP with a fibrosarcoma component. The molecular biology study with RT-PCR analysis of paraffin-embedded material and later sequencing showed a new fusion of exon 19 of the COL1A1 gene and exon 2 of PDGFB, supporting a diagnosis of DFSP. A study of the COL1A1-PDGFB fusion products is useful in cases where histology and immunohistochemistry are insufficient for the differential diagnosis of DFSP versus other sarcomas. It also justifies the use of new avenues of treatment with tyrosine kinase inhibitors.

Adult↗

PubMed2006

GIST: particular aspects related to cell cultures, xenografts, and cytogenetics.

In less than half a decade, gastrointestinal stromal tumors (GIST) have emerged from historical anonymity to become a model of kinase-targeted therapies. Approximately 80% to 85% of GISTs harbor activating mutations of the KIT or PDGFRA tyrosine kinase genes, and such mutations have predictive and prognostic value. In this regard, the in vitro and in vivo models have provided valuable tools for understanding the molecular pathology of this interesting neoplasm. This review charts particular aspects in the field of cell cultures and tumor xenografts in nude mice in GIST and their implication in the establishment of appropriate models for discovering and testing therapy. The cytogenetic features of these tumors are also discussed. Classic karyotyping, loss of heterozygosity, fluorescent in situ hybridization, comparative genomic hybridization (CGH), and CGH-array analyses have shown that chromosomal numerical abnormalities and loss of genetic material at chromosomes 1p, 9p, 14q, and 22q are significantly associated with GIST malignancy and response to treatment. Furthermore, these regions constitute "hot" areas for finding candidate genes involved in the pathogenesis of GISTs. A deeper knowledge of these genetic aspects of GIST will provide a better understanding of this neoplasm that could translate into clinical practice.

Animals↗

PubMed2006

p16INK4A (CDKN2A) gene deletion is a frequent genetic event in synovial sarcomas.

We assessed the frequency of genomic deletion of p16INK4A (CDKN2A) in synovial sarcomas (SSs) and its possible association with immunoexpression of p16 and cyclin D1 and the Ki-67 proliferation index using dual-color fluorescence in situ hybridization (FISH) on tissue microarray sections of 41 histologically and molecularly confirmed SSs. A heterozygous p16INK4A gene deletion was identified in 28 (74%) of 38 cases, with 25 (89%) of them showing abnormal p16 protein expression (20 negative and 5 heterogeneous). Of 25 cases, 19 (76%) exhibiting increased cyclin D1expression also demonstrated heterozygous p16INK4A deletion. No significant association was observed between p16INK4A deletion and Ki-67 proliferation index, tumor grade, or histologic subtype. Our results demonstrate that p16INK4A (CDKN2A) gene deletion is a frequent genetic event in SS.

Biomarkers, Tumor↗

PubMed2005

Deletions affecting codons 557-558 of the c-KIT gene indicate a poor prognosis in patients with completely resected gastrointestinal stromal tumors: a study by the Spanish Group for Sarcoma Research (GEIS).

PURPOSE: To explore the prognostic value of mutations in c-KIT and PDGFR-alpha genes with respect to relapse-free survival (RFS) in patients with gastrointestinal stromal tumors (GIST). We have investigated the prognostic relevance of the type and position of the mutations, in addition to other clinicopathologic factors, in a large series of patients with GIST. METHODS: For this study, 162 patients were selected according to the following criteria: completely resected tumors with negative margins attended between 1994 and 2001; no metastasis at diagnosis; tumor larger than 2 cm, c-KIT-positive immunostaining; and no other primary tumors. RESULTS: The median follow-up was 42 months for patients free of recurrence. Mutations were detected in 96 tumors (60%): 82 cases involving c-KIT and 14 cases involving PDFGR-alpha. Univariate analysis demonstrated the following as poor prognostic factors for RFS: tumors larger than 10 cm (P < .0001); mitotic count higher than 10 mitoses per 50 high-power fields (P < .0001); high risk index (P < .0001); intestinal GIST location (P = .0041); high cellularity (P < .0001); tumor necrosis (P < .0001); deletions affecting exon 11 (P = .0007); and deletions affecting codons 557 to 558 (P < .0001). After the multivariate analysis, only the high risk index (relative risk [RR], 12.36), high cellularity (RR, 3.97), and deletions affecting codons 557 to 558 of c-KIT (RR, 2.57) corresponded to independent prognostic factors for RFS in GIST patients. CONCLUSION: Deletions affecting codons 557 to 558 are relevant for the prognosis of RFS in GIST patients. This critical genetic alteration should be considered to be a new prognostic stratification variable for randomized trials exploring imatinib mesylate in the adjuvant setting in GIST patients.

Adult↗

PubMed2005

Mutational analysis of the c-KIT AND PDGFRalpha in a series of molecularly well-characterized synovial sarcomas.

The c-KIT and the platelet-derived growth factor receptor alpha (PDGFRalpha) have been shown to be important for tumor growth and progression in several soft-tissue sarcomas, including synovial sarcomas (SSs). It has been suggested that these c-KIT-positive cases might benefit from a tyrosine kinase inhibitor therapy. In this study, we analyze a series of SSs to investigate the presence of c-KIT and PDGFRalpha mutations with the aim of selecting those for a more adequate and appropriate therapy. We analyzed fresh-frozen tissues from 12 SSs (8 primary tumors and 4 nude mice xenotransplants from primary tumors). RNA was extracted to identify the presence of the SYT-SSX gene fusion to confirm the SS diagnosis. Mutational analysis of exons 9, 11, 13, and 17 of c-KIT and exons 12 and 18 of PDGFRalpha was performed by direct sequencing. Immunohistochemical analysis of c-KIT, PDGFRalpha, and p-PDGFRalpha was also performed. All analyzed cases showed the presence of SYT-SSX gene fusion transcripts confirming the diagnosis of SS, 10 carried the SYT-SSX1 fusion, and 2 the SYT-SSX2. Immunohistochemical analysis showed expression of c-KIT in 3 cases in which no molecular alterations were detected. For the PDGFRalpha, we observed an in-frame deletion of codons 554 and 555 in a case which also showed a strong immunopositivity for the phosphorylated form of PDGFRalpha. PDGFRalpha expression was observed in 8 cases. We suggest that a more exhaustive mutational analysis of the c-KIT and PDGFRalpha genes should be performed to ascertain which cases would really benefit from a tyrosine kinase inhibitor therapy in SS.

Adolescent↗

PubMed2004

Anaplastic carcinoma of the thyroid with rhabdomyosarcomatous differentiation: a report of two cases.

Anaplastic carcinoma of the thyroid gland (ACT) is a highly malignant tumor that is almost invariably associated with a fatal outcome. It demonstrates a variety of peculiar histological features, with squamoid, giant cell and spindle cell growth patterns. The spindle cell variant of ACT is usually indistinguishable from a true sarcoma and it can simulate fibrosarcoma, malignant fibrous histiocytoma (MFH), hemangiopericytoma and angiosarcoma or rhabdomyosarcoma. Although a rhabdomyosarcomatous appearance has sometimes been mentioned in the literature, true skeletal muscle differentiation has never been consistently proved. We report two cases of ACT with rhabdomyosarcomatous differentiation, as demonstrated by means of immunohistochemistry and electron microscopy. Both cases disclosed a very similar histological appearance, with a main population of small, pleomorphic, round-to-oval cells arranged in a storiform pattern, admixed with scattered pleomorphic giant cells, an image similar to that of the usual type of MFH. Stains for epithelial markers showed only few, scattered, weakly positive cells. Thyroglobulin and calcitonin were negative in tumor cells in both cases. On the contrary, positivity to vimentin was strong and generalized. Immunomarkers of muscular differentiation showed a consistent positivity. At the ultrastructural level, the cells disclosed the same spindle and pleomorphic morphology, with large, bizarre nuclei and cytoplasm with abundant mitochondria, rough endoplasmic reticulum, secretory granules and lipid droplets. There were also cells with wide cytoplasm filled with filamentous material, either of actin or myosin, as well as Z-band material. In conclusion, the cases reported here show a clear-cut rhabdomyosarcomatous differentiation of ACT, confirmed both immunohistochemically and ultrastructurally, a feature not previously reported in the literature. These findings may contribute to the broadening of the differentiation spectrum of this unusual neoplasm.

Carcinoma↗

PubMed2004

The INK4a /ARF locus: role in cell cycle control for renal cell epithelial tumor growth after the Chernobyl accident.

Previous studies have shown that during the period subsequent to the Chernobyl accident, increases in morbidity, aggressivity and proliferative activity of renal-cell carcinomas (RCCs) in Ukrainian patients were recognized. The present paper describes the molecular alterations of those tumor suppressor genes located on chromosome 9p21 ( INK4a/ARF locus and p15(INK4B)) in 26 primary renal-cell epithelial tumors from patients with different degrees of radiation exposure after the Chernobyl accident in Ukraine. Radiometric measurement of Cesium 137 ((137)Cs) was conducted with 1-day urine from all patients before surgery. Our results demonstrate that RCCs from patients living in the radio-contaminated areas showed aberrant hypermethylation of p14(ARF) and p16(INK4A) genes, associated with increased p38MAPK, p14(ARF), mdm2, cyclinD1 and Ki67 protein expression levels. Present findings show the possibility that chronic long-term low-dose radiation activates the INK4a/ARF locus, targeted by activation of the p38MAPK cascade. These actions could lead to disruptions and loss of cell cycle checkpoints and, thereby, to cellular transformation.

Adult↗

PubMed2004

Association of loss of 1p and alterations of chromosome 14 in meningioma progression.

Meningiomas are usually benign tumors; however, they can recur after surgical resection and occasionally show histologic progression to a higher grade II and III malignancy. The second most frequently reported genetic abnormality after 22q loss is deletion of 1p, although alterations in 9q, 10q, and 14q are also implicated in meningioma progression. Fourteen tumors comprising six benign, four atypical, and four malignant meningiomas were examined by means of cytogenetic and fluorescence in situ hybridization analysis. All tumors showed losses in different regions of 1p, with 1p11, 1p13, 1p21, 1p22, 1p32, and 1q21 breakpoints; eight tumors also presented alterations of chromosome 14. Five of the six cases with deletions on 1p and normal chromosome 14 were grade I, and two were recurrent. All but one of the eight cases with simultaneous 1p deletion and alterations of chromosome 14 were grade II (3 cases) and grade III (4 cases); all the grade III cases were recurrent. These results support the possible association between changes in 1p and chromosome 14 with the evolution of aggressive meningiomas through tumor progression.

Adult↗

PubMed2004

Age, sex and co-exposure to N-ethyl-N-nitrosourea influence mutations in the Alu repeat sequences in diethylstilbestrol-induced kidney tumors in Syrian hamsters.

We report, for the first time, mutations in the Alu repeat regions in the genome of kidney tumors induced by diethylstilbestrol in Syrian hamsters. Among the 66 loci amplified by 11 random primers, 28 loci exhibited insertions, deletions or losses or gains in intensity in the genome of kidney tumor tissues compared with normal kidney tissues from age-matched hamsters. Higher numbers of mutated Alu loci were observed in the tumors of old hamsters compared with young hamsters. In N-ethyl-N-nitrosourea- and diethylstilbestrol-treated hamsters deletion of a 0.59 kb locus amplified with primer OPC03 was observed in most of the female hamsters, but not in male hamsters. An insertion mutation of a 0.498 kb locus amplified with primer OPC03 was observed in 12 of 36 diethylstilbestrol-induced kidney tumors. The cloning and sequencing of the 0.498 kb locus amplified with primer OPC03 revealed that it had significant sequence similarity to the mouse RIKEN cDNA clone. These findings indicate that age, sex and co-exposure to N-ethyl-N-nitrosourea influence mutations in the Alu repeat sequences in the genome of diethylstilbestrol-induced kidney tumors in Syrian hamsters. Structural alterations in Alu repeats in critical target genes may be involved in diethylstilbestrol-induced carcinogenesis.

Age Factors↗

PubMed2004

Deregulation of the G1 to S-phase cell cycle checkpoint is involved in the pathogenesis of human osteosarcoma.

Osteosarcoma (OS) displays complex karyotypes with numerical changes as well as structural abnormalities suggesting that several oncogenes and tumor suppressor genes may be implicated in the biology of OS. The aim of our study was to investigate the possible implication of the molecular alterations of the G1 to S-phase checkpoint genes in the pathogenesis of OS. We analyzed samples from 29 patients and found molecular alterations of the RB and TP53 genes in 6 (21%) and 3 (10%) cases, respectively. Homozygous deletion of the INK4A/ARF locus and methylation of INK4A was detected in 3 (10%) and 2 (7%) cases, respectively. CDK4 and MDM2 co-amplification was observed in 1 case (3%). Cyclin D3 is differentially expressed in a greater proportion than D1- and D2-type cyclins. Cytogenetically, all cases had complex karyotypes being especially significant the losses of the chromosomes 4, 13, and 17. As a whole, 11 of 29 (38%) analyzed OS presented alterations in some of the analyzed G1 to S-phase checkpoint genes. These alterations were more frequently present in adults (P = 0.032). All patients with genetic alterations in the G1/S-phase checkpoint died during their clinical follow-up, whereas more than 53% of the remaining cases were alive in this period (P = 0.007). Hence, in the pathogenesis of human OS, deregulation of the G1/S checkpoint genes, especially RB, TP53, and INK4/ARF locus, plays an important role and defines a subgroup of patients with a poor outcome.

Adolescent↗

PubMed2004

Prognostic value of morphometry in low grade papillary urothelial bladder neoplasms.

OBJECTIVE: To analyze the prognostic value of morphometry in low grade papillary urothelial bladder neoplasms (LGPUBNs). STUDY DESIGN: The primary (most common) and secondary (second most common) histologic grades were considered in accordance with the 1998 World Health Organization/International Society of Urological Pathology and the 1999 World Health Organization classifications. With the primary grade, 54 cases were papillary urothelial neoplasms of low malignant potential (PUNLMPs) and 66 low grade papillary urothelial carcinomas (LGPUCs), whereas the secondary grade consisted of 45 PUNLMPs and 75 LGPUCs. To assess the proliferative index, an immunohistochemical study was performed. Regarding nuclear morphometry, an image analysis system on Feulgen-stained sections was utilized in different tumor zones (Zs): Z 1, 100-150 cells from the outer layers of the papillae; Z 2, 100-150 cells from the inner layers; and Z 3, 10 largest nuclei. In univariate studies, a t test, and Mann-Whitney U test and Kaplan-Meier curves were applied, whereas a Cox regression model was used for multivariate study of the variables: size, multiplicity, maximum Ki-67 index, mean nuclear area (MNA) and SD, mean nuclear perimeter and SD, and roundness factor. RESULTS: All 120 cases were followed for a mean of 76.6 months (range, 36-168). In univariate studies, many variables showed a significant correlation (p < 0.05) with recurrence prediction, relapse-free interval and histologic grade regardless of adjuvant therapy. Otherwise, only the MNA of the 10 largest nuclei (threshold, 52 microm2) and the maximum proliferative index (threshold, 7.9%) appeared as independent prognostic markers in the multivariate study. CONCLUSION: In LGPUBNs, the independent prognostic value of MNA of the 10 largest nuclei as well as the maximum proliferative index indicates the importance of histologic grade assessment based on the secondary (second most common) grade.

Aged↗

PubMed2003

Cytogenetic and molecular findings related to rhabdomyosarcoma. An analysis of seven cases.

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in childhood. Histologically, it is subdivided histologically into two main subtypes: alveolar (ARMS) and embryonal (ERMS). ARMS is characterized by t(2;13)(q35;q14) or its variant t(1;13)(p36;q14), which fuse PAX3 and PAX7, respectively, with FKHR to produce chimeric genes. ERMS is frequently associated with loss of heterozygosity of 11p15.5. We investigated seven RMS (three ARMS and four ERMS) by means of cytogenetic, fluorescence in situ hybridization, and molecular analyses, including the study of the main genes implicated in the G1- to S-phase cell cycle transition, and correlated these studies with pathologic findings and clinical outcome. All tumors showed clonal, numerical, and structural chromosomal abnormalities. Two ARMS had the t(2;13)(q35;q14) and the third a PAX7/FKHR fusion, a cryptic t(1;13)(p36;q14), undetected by cytogenetic techniques, but revealed by reverse transcriptase polymerase chain reaction. One ERMS showed a der(11)t(3;11)(p21;p15) as a sole structural anomaly. Gene amplification was seen in four tumors, as double minutes or in the form of homogeneously staining regions. Overexpression of MYCN oncogene was found in two ARMS; N-myc DNA probe detected oncogene amplification located on the double minutes of these cases. Analysis of the regulatory genes responsible for G1- to S-phase transition showed a homozygous deletion of the 9p21 locus genes in a spindle-cell ERMS.

Child↗