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N Bown

Publications and source records attributed to N Bown.

At least 37 records · Page 2Linked to original sources
PubMed1999

Jumping translocation at 11q23 with MLL gene rearrangement and interstitial telomeric sequences.

myeloid leukemia of acute myeloid leukemia (AML) M5a showing a jumping translocation with a breakpoint at 11q23. Fluorescence in situ hybridization (FISH) demonstrated triplication of the MLL gene and the presence of interstitial telomeric sequences, supporting the role of repetitive sequences in the mechanism of jumping translocations. Southern blot analysis of the MLL breakpoint cluster region showed the presence of an MLL gene rearrangement. Jumping translocation with MLL gene rearrangement is a previously unreported phenomenon in leukemia cytogenetics.

Aged↗
PubMed1998

Molecular cytogenetic delineation of 17q translocation breakpoints in neuroblastoma cell lines.

It has recently been recognized that unbalanced translocations resulting in the gain of material from 17q are the most common chromosomal changes in neuroblastoma. These rearrangements are associated with established indicators of bad prognosis and poor patient survival. We have used 13 fluorescence in situ hybridization (FISH) probes to map 12 translocation breakpoints on 17q in 10 neuroblastoma cell lines, identifying at least seven different breakpoints, all localized within the proximal half of 17q (268-369 cR, 53-68 cM). These results suggest that the dosage of a gene, or genes, in 17q22-qter is responsible for the clinical effects of 17q gain, rather than the disruption of a specific gene. This region contains two genes, nm23-H1 and NGFR, already implicated in neuroblastoma biology.

Chromosome Breakage↗
PubMed1997

Gain of chromosome arm 17q predicts unfavourable outcome in neuroblastoma patients. U.K. Children's Cancer Study Group and the U.K. Cancer Cytogenetics Group.

Gain of chromosome arm 17q has recently been reported in neuroblastoma tumours. We analysed 17q status in relation to other known prognostic features and clinical outcome in a series of 45 tumours. Chromosome 17 status was detected by cytogenetic analysis, fluorescence in situ hybridisation (FISH) anc comparative genomic hybridisation (CGH) and correlated with other clinical and genetic factors. Survival analysis was calculated by the Kaplan-Meier estimation. Twenty-eight out of 45 tumours showed 17q gain, and this was associated with established indicators of poor prognosis; stage 4 disease (P < 0.001), age above 1 year at diagnosis (P < 0.001), 1p deletion (P < 0.01), MYCN amplification (P = 0.03) and diploidy/tetraploidy (P = 0.04). 17q gain was associated with poor outcome: 3-year survival was 13.5% compared with 100% for tumours without 17q gain (P = 0.0001); and progression-free survival (PFS) was 8.1% after 3 years compared with 83% for 17q normal tumours (P = 0.0001). PFS in 28 MYCN non-amplified patients indicated that 17q status has discriminatory power within this group: PFS 0% for 17q gain (n = 14) versus 100% for normal 17q (n = 14) (P = 0.0001). This study indicates that 17q changes have prognostic significance in neuroblastoma and should be a target for molecular cytogenetic detection at diagnosis.

Adolescent↗
PubMed1997

Comparative genomic hybridization study of primary neuroblastoma tumors. United Kingdom Children's Cancer Study Group.

Neuroblastoma tumors show a complex interaction of genetic abnormalities, among which some are of significant prognostic importance; however, analysis of chromosome changes in this tumor is often unsuccessful. Twenty primary tumors were studied by comparative genomic hybridization (CGH), and abnormalities were found in 19. While these changes included deletions of chromosome arm Ip (45%) and MYCN oncogene amplification (30%), gains of chromosome 17 material were much more frequent (75%). We also found evidence in two cases of a new amplification site at band 2p23.

Adolescent↗
PubMed1997

Promiscuous translocations of chromosome arm 17q in human neuroblastomas.

Deletions of chromosome arm 1p and amplification of the MYCN oncogene are well-recognized genetic changes in neuroblastoma cells. Technical difficulties in cytogenetic analysis of this tumour have hampered the recognition of other recurring abnormalities, but recent use of molecular cytogenetic techniques has indicated significant involvement of chromosome arm 17q. In primary tumours and in cell lines, a recurrent unbalanced translocation t(1p;17q) has been identified by fluorescence in situ hybridization. We confirm the occurrence of this translocation in primary tumours and, in addition, we describe seven new structural rearrangements all of which result in gain of 17q in tumour cells. These rearrangements involved chromosome arms 9p, 10q, 11p, 14q, and 16q. Triplication of the 17q arm was seen in one case. The 17q breakpoint was most commonly q21. All these 17q changes were found in near-diploid tumours. We have also reviewed the literature for neuroblastoma karyotypes involving 17q abnormalities; taken in conjunction with our findings this indicates a remarkable promiscuity of translocation partners, with more than 20 different chromosome regions involved in 17q translocations.

Bone Marrow Neoplasms↗
PubMed1995

Solid alveolar rhabdomyosarcoma with a t(2;13).

We report a child with a progressive "solid alveolar rhabdomyosarcoma" in whom analysis of tumor cells revealed a t(2;13) translocation characteristic of the classical alveolar subtype. Both subtypes of alveolar rhabdomyosarcoma are associated with a poor response to treatment and the occurrence of this translocation in both is suggestive of a common biologic origin.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

De novo acute myeloid leukaemia in patients over 55-years-old: a population-based study of incidence, treatment and outcome. Northern Region Haematology Group.

A 4-year prospective study of de novo acute myeloid leukaemia in patients aged 56 years and over was undertaken in the Northern Region of England (population 3.09 million). The study was conducted to assess the incidence and outcome of treatment in all elderly patients diagnosed between January 1, 1988 and December 31, 1991. Two hundred cases de novo AML were confirmed, giving an incidence of 6.05/10(5) per annum (age specific population) (95% Cl, 5.2-6.9). Acute promyelocytic leukaemia was rare. Erythroleukaemia, monocytic leukaemia and AML with trilineage myelodysplasia were more common than in younger patients. Karyotypic abnormalities classically associated with response to therapy were present in only six of 91 patients where cytogenetic data was available. Treatment was at the discretion of the physician in charge: if given, specific treatment was recorded and clinical outcome assessed. Only 84 (42%) of patients received treatment with curative intent. Forty-four of 84 achieved a complete remission, usually of brief duration. A normal karyotype in leukaemic cells was associated with a survival advantage in this group (p < 0.05). Actuarial overall survival at 4 years for the entire group was 2.5%. Even with aggressive treatment, the outcome is poor. The pattern of disease and its lack of response to conventional treatment would support the hypothesis that AML in the elderly may differ biologically from that observed in younger patients. Karyotyping appears to predict those patients likely to benefit from intensive therapy and decisions about management in otherwise fit patients should, if possible, be delayed until a result is obtained. Every effort should be made to give such patients optimal treatment. However, most patients are unsuitable for aggressive treatment and, since long-term survival is rare, cure should not be offered as an inducement to accept such treatment and improving quality of life outside hospital should be the aim of treatment in this group.

Acute Disease↗
PubMed1995

Evaluation of the impact of allogenic transplant in first remission on an unselected population of patients with acute myeloid leukaemia aged 15-55 years. The Northern Regional Haematology Group.

The aim of this study was to collect prospectively unselected, population-based data on young adults with acute myeloid leukaemia (AML) over a 9-year period and to evaluate the impact on survival of the introduction of allogeneic transplantation performed in first remission. The population within the Northern Region of England is 3.09 million. During the study period a total of 149 de novo patients between 15 and 55 years old presented. The incidence of AML was 0.79 per 10(5) (age-specific population) in the 15-24-year-old group, 0.85 per 10(5) in the group 25-39 years old and 1.35 per 10(5) in the 40-55-year-old group. Remission induction success varied with age (74% for patients < 40 years and 58% for patients 40-55 years). In the 15-40 year old group 28 patients had an HLA-matched donor, 22 patients had a transplant (one syngeneic) and 24 patients in the 15-40-year-old group in remission at 6 months did not have a transplant. The allogeneic group < 40 years old had an event-free survival (EFS) at 4 years of 62%, whereas patients of the same age who received chemotherapy alone had an EFS at 4 years of 24%. A small heterogeneous group of 14 patients who had intensification with autotransplant are not included in this analysis. The population study approach demonstrates the difficulties of introducing uniform treatment strategy in this disease group. The study confirms the view that allogeneic transplant in first remission in the 15-40-year-old group is the treatment of choice. Unfortunately the overall impact of transplant on the population is not great since only 22 of 149 patients (14%) were able to receive an allograft in first remission.

Adolescent↗
PubMed1994

Molecular heterogeneity of variant Philadelphia translocations in childhood acute lymphoblastic leukaemia.

In acute lymphoblastic leukemia (ALL), it is unclear whether variant Philadelphia (Ph) translocations have the same molecular and clinical implications as the classical translocation. Two children with Ph+ ALL with variant translocations are described. One, in whom cytogenetic remission was not achieved, had evidence of translocation of c-abl to chromosome 22, rearrangement of minor breakpoint cluster region (mBCR) and expression of hybrid bcr/abl transcripts. In the other case, no gene rearrangement was found and complete remission was achieved. Variant Ph translocations in childhood ALL are heterogeneous at the molecular level. Molecular studies coupled with observations of clinical outcome are needed in larger numbers of such children to determine whether poor clinical response correlates with bcr/abl involvement and to allow planning of appropriate therapeutic strategies.

Child↗
PubMed1992

Acute lymphoblastic leukemia in patients aged 60 years and over: a population-based study of incidence and outcome.

Data on all patients aged 60 or older in whom a diagnosis of acute lymphoblastic leukemia (ALL) was made in the Northern Health Region of the United Kingdom, over a period of 8 1/2 years, were studied to determine the incidence and range of biological subtypes, and the outcome of a variety of therapeutic approaches. Forty-nine cases were diagnosed (31% of all adult ALL), giving an incidence of 0.9 per 100,000 age-specific population (ASP). Immunophenotyping was performed in 41 patients. Eighteen had common, two T-ALL, 10 null, and 7 B-ALL. Four were biphenotypic with both lymphoid and myeloid markers. One patient refused treatment and four were considered too frail for chemotherapy. Twenty-two were treated palliatively. Aggressive "curative" treatment was planned for 22, but three died before it started. The actuarial survival for the whole group was 4%. The median survival of the palliatively treated group was 1 month, compared with 3 months for those given aggressive treatment. Only two patients (aged 74 and 67) survived more than 2 years in complete remission (CR), both having been treated aggressively. We conclude that the prognosis for those over 60 years of age is extremely poor, but that for a small number of patients a useful prolongation of good quality life may be achieved. Age should not, by itself, be a bar to treatment intended to induce remission. Patients and their relatives should be made aware of the overall poor prognosis and advised of the therapeutic goals when decisions regarding management are being made.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1992

Chronic myelomonocytic leukemia with t(13;14) in a child.

Bone marrow cells from a child with chronic myelomonocytic leukemia showed an acquired, non-Robertsonian translocation between chromosomes 13 and 14, t(13;14)(q12.?2;q32.?3). This rearrangement has not previously been reported in childhood myeloproliferative or myelodysplastic disorders.

Child↗
PubMed1992

Philadelphia positive acute leukaemia with minor breakpoint cluster rearrangement may be a stem cell disease.

The biology of Philadelphia chromosome positive (Ph+) acute lymphoblastic leukaemia (ALL) is the subject of much interest. We present a case of Ph+ ALL with a minor breakpoint cluster (mBCR) rearrangement who subsequently relapsed with Ph+ mBCR+ acute myeloid leukaemia and later with Ph+ mBCR+ acute stem cell leukaemia. This case provides further evidence that Ph+ ALL with a mBCR rearrangement may arise from a pluripotent stem cell with similar potential to that of chronic granulocytic leukaemia to undergo blastic crises with differing lineage characteristics.

Acute Disease↗
PubMed1992

Alveolar rhabdomyosarcoma infiltrating bone marrow at presentation: the value to diagnosis of bone marrow trephine biopsy specimens.

AIMS: To describe the histological appearances of bone marrow infiltrated with rhabdomyosarcoma at presentation and to determine their value in establishing the diagnosis. METHODS: Patients presenting over seven years in the northern health region of England with rhabdomyosarcoma were studied. Bone marrow aspirates and trephine biopsy specimens taken at presentation were examined. RESULTS: Seven of 32 patients with rhabdomyosarcoma had bone marrow infiltration, resulting in marrow failure in all cases, at diagnosis. The diagnosis was established in these seven by the typical cytological appearances and immunophenotype of the infiltrating cells (all seven patients) and cytogenetic abnormalities (three patients). Histological examination of the bone marrow showed a pseudoalveolar pattern with fibrous septal bands, enlarged vascular channels, and lack of cohesion of the tumour cells within the subdivided aggregates in all seven. In four cases multinucleate giant cells, often with peripherally sited nuclei, were found. CONCLUSIONS: These histological features of infiltrated marrow are so characteristic that the diagnosis of alveolar rhabdomyosarcoma can be made, or at least suspected, in many cases even without recourse to technically difficult and expensive further investigations. Bone marrow biopsy should be a routine part of the investigation of patients with bone marrow failure and will be of particular value in the diagnosis of those with disseminated alveolar rhabdomyosarcoma.

Adolescent↗
PubMed1991

Secondary acute lymphoblastic leukaemia with 4:11 translocation following treatment for Hodgkin's disease: case report and review of the literature.

It is apparent that treatment of Hodgkin's disease can be complicated by the development of secondary leukaemia. Most such leukaemias are of the non-lymphocytic type. We describe here a patient treated for Hodgkin's disease with chemo- and radiotherapy who developed secondary acute lymphoblastic leukaemia with a non-random chromosomal abnormality t(4;11). The frequency of such cases is assessed by a literature review and evidence for their pluripotent cell origin is discussed.

Adult↗
PubMed1988

Cytogenetic investigations of solid tumours of children.

The association of non-random chromosome abnormalities with solid tumours of childhood may improve accuracy of diagnosis and prognosis and lead to a better understanding of their biology. In a pilot study in the Northern region of England fresh tumour biopsy specimens were obtained from 39 to 72 consecutive solid tumours in children who presented over a period of 21 months. Cytogenetic analysis was possible in 33 and clonal chromosomal abnormalities were detected in nine. In addition, seven of 10 tumours investigated after treatment were abnormal. Ten of these 16 abnormal karyotypes have not previously been described. This pilot study has shown that a concerted investigation of tumour cytogenetics is possible. A multicentre study is essential if our knowledge of basic tumour cytogenetics is to progress.

Biopsy↗
PubMed1987

Cytogenic investigations in the assessment of response to treatment in neuroblastoma.

In a patient with stage IV disseminated neuroblastoma treated by chemotherapy extensive cytogenetic investigations were performed on the residual primary tumour and bone marrow immediately before myeloablative treatment and autologous marrow rescue. Two abnormal clones both showing lp+, a characteristic abnormality of neuroblastoma, were detected in cells from the residual primary tumour, providing direct evidence of persisting viable tumour. Such investigations should be a routine part of the assessment of response to treatment in patients with neuroblastoma, and could be extended to others in whom "second look" surgery is performed.

Adrenal Gland Neoplasms↗