975 resultados para Cytogenetic aberrations
Resumo:
The prognostic relevance of additional cytogenetic findings at diagnosis of chronic myeloid leukemia (CML) is unclear. The impact of additional cytogenetic findings at diagnosis on time to complete cytogenetic (CCR) and major molecular remission (MMR) and progression-free (PFS) and overall survival (OS) was analyzed using data from 1151 Philadelphia chromosome-positive (Ph(+)) CML patients randomized to the German CML Study IV. At diagnosis, 1003 of 1151 patients (87%) had standard t(9;22)(q34;q11) only, 69 patients (6.0%) had variant t(v;22), and 79 (6.9%) additional cytogenetic aberrations (ACAs). Of these, 38 patients (3.3%) lacked the Y chromosome (-Y) and 41 patients (3.6%) had ACAs except -Y; 16 of these (1.4%) were major route (second Philadelphia [Ph] chromosome, trisomy 8, isochromosome 17q, or trisomy 19) and 25 minor route (all other) ACAs. After a median observation time of 5.3 years for patients with t(9;22), t(v;22), -Y, minor- and major-route ACAs, the 5-year PFS was 90%, 81%, 88%, 96%, and 50%, and the 5-year OS was 92%, 87%, 91%, 96%, and 53%, respectively. In patients with major-route ACAs, the times to CCR and MMR were longer and PFS and OS were shorter (P < .001) than in patients with standard t(9;22). We conclude that major-route ACAs at diagnosis are associated with a negative impact on survival and signify progression to the accelerated phase and blast crisis.
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We describe a case of retinoblastoma with an atypical presentation and previously unreported cytogenetic aberrations. A 19-month-old girl with left intraocular retinoblastoma was treated with enucleation and chemotherapy. The disease showed aggressive evolution within a short period between diagnosis and relapse. Eight months after diagnosis, a new large tumor was present in the orbit of the right eye, with diffuse bone pain, pancytopenia and diffuse infiltration into the bone marrow and the central nervous system. The child did not respond to treatment and died. Cytogenetic studies made with G-banding, FISH and SKY analysis showed chromosomal aberrations commonly associated with retinoblastoma, including del(13q), i(6+1, and monosomy 16, along with others that had not been reported previously, including dup(5q), dic(15;22) and add(14q). The new chromosomal aberrations may be related to the aggressiveness of the disease in this case.
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The prognostic relevance of additional cytogenetic findings at diagnosis of chronic myeloid leukemia (CML) is unclear. The impact of additional cytogenetic findings at diagnosis on time to complete cytogenetic (CCR) and major molecular remission (MMR) and progression-free (PFS) and overall survival (OS) was analyzed using data from 1151 Philadelphia chromosome-positive (Ph(+)) CML patients randomized to the German CML Study IV. At diagnosis, 1003 of 1151 patients (87%) had standard t(9;22)(q34;q11) only, 69 patients (6.0%) had variant t(v;22), and 79 (6.9%) additional cytogenetic aberrations (ACAs). Of these, 38 patients (3.3%) lacked the Y chromosome (-Y) and 41 patients (3.6%) had ACAs except -Y; 16 of these (1.4%) were major route (second Philadelphia [Ph] chromosome, trisomy 8, isochromosome 17q, or trisomy 19) and 25 minor route (all other) ACAs. After a median observation time of 5.3 years for patients with t(9;22), t(v;22), -Y, minor- and major-route ACAs, the 5-year PFS was 90%, 81%, 88%, 96%, and 50%, and the 5-year OS was 92%, 87%, 91%, 96%, and 53%, respectively. In patients with major-route ACAs, the times to CCR and MMR were longer and PFS and OS were shorter (P < .001) than in patients with standard t(9;22). We conclude that major-route ACAs at diagnosis are associated with a negative impact on survival and signify progression to the accelerated phase and blast crisis.
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In childhood-onset acute myeloid leukaemia (AML) the clinical value of karyotypic aberrations is now acknowledged, although there is still debate concerning the prognostic significance of some events. To add to this knowledge, cytogenetic analysis was performed on a consecutive series of 84 childhood AML patients diagnosed in Switzerland. A result was obtained for all patients, with 69 (82%) showing a clonal karyotypic aberration. In the remaining 15 (18%), no karyotypic aberration was seen by either conventional or fluorescence in situ hybridisation analyses. The most frequent aberrations observed were t(11q23) (19% of all patients), t(8;21) (12%) and +8 (11%). Except for cytogenetics, no clinical parameter was shown to be significantly associated with outcome. The analysis of individual cytogenetic subgroups demonstrated that aberrations involving chromosome 16q were the strongest predictor of a good prognosis, while +8 and complex karyotypes represented the strongest predictors of a poor prognosis. It was also noteworthy that patients with the rare aberrations of del(11q) (n = 4) and t(16;21)(p11;q22) (n = 3) had a poor outcome. The results support the importance of cytogenetic analysis in childhood AML, but show that further work is required in the classification of the poor prognosis aberrations.
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Polymorphisms of the p53 gene, which participates in DNA repair, can affect the functioning of the p53 protein. The Arg and Pro variants in p53 codon 72 were shown to have different regulation properties of p53-dependent DNA repair target genes that can affect various levels of cytogenetic aberrations in chronic hepatitis B patients. The present study aimed to examine the frequency of chromosomal aberrations and the mitotic index in patients with chronic hepatitis B and their possible association with p53 gene exon 4 codon 72 Arg72Pro (Ex4+119 G>C; rs1042522) polymorphism. Fifty-eight patients with chronic hepatitis B and 30 healthy individuals were genotyped in terms of the p53 gene codon 72 Arg72Pro polymorphism by PCR-RFLP. A 72-h cell culture was performed on the same individuals and evaluated in terms of chromosomal aberrations and mitotic index. A high frequency of chromosomal aberrations and low mitotic index were detected in the patient group compared to the control group. A higher frequency of chromosomal aberrations was detected in both the patient and the control groups with a homozygous proline genotype (13 patients, 3 control subjects) compared to patients and controls with other genotypes [Arg/Pro (38 patients, 20 control subjects) and Arg/Arg (7 patients, 7 control subjects)]. We observed an increased frequency of cytogenetic aberrations in patients with chronic hepatitis B. In addition, a higher frequency of cytogenetic aberrations was observed in p53 variants having the homozygous proline genotype compared to variants having other genotypes both in patients and healthy individuals.
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Genetic abnormalities are critical prognostic factors for patients diagnosed with multiple myeloma (MM). This retrospective, multicenter study aimed to contribute with the genetic and clinical characterization of MM patients in a country with continental dimensions such as Brazil. Genetic abnormalities were assessed by cIg-fluorescent in situ hybridization (cIg-FISH) in a series of 152 MM patients (median age 55 years, 58.5% men). Overall, genetic abnormalities were detected in 52.7% (80/152) of patients. A 14q32 rearrangement was detected in 33.5% (n=51), including t(11;14), t(4;14) and t(14;16) in 18.4, 14.1, and 1% of cases, respectively. del(13q) was identified in 42.7% (n=65) of patients, of whom 49.2% (32/65) presented a concomitant 14q32 rearrangement. del(17p) had a frequency of 5.2% (n=8). del(13q) was associated with high plasma cell burden (≥50%, P=0.02), and del(17p) with advanced ISS stages (P=0.05) and extramedullary disease (P=0.03). t(4;14) was associated with advanced Durie-Salmon stages (P=0.008), renal insufficiency (P=0.01) and was more common in patients over 60 years old. This study reports similar frequencies of genetic abnormalities to most series worldwide, whereas the t(14;16) and del(17p), two high risk factors for newly diagnosed patients, exhibited lower frequencies. Our results expand the knowledge on the molecular features of MM in Brazil, a country where innovative therapies that could overcome a poor prognosis for some genetic abnormalities are not always available.
Resumo:
Purpose: Genetic biomarkers of head and neck tumors could be useful for distinguishing among patients with similar clinical and histopathologic characteristics but having differential probabilities of survival. The purpose of this study was to investigate chromosomal alterations in head and neck carcinomas and to correlate the results with clinical and epidentiologic variables.Experimental Design: Cytogenetic analysis of short-term cultures from 64 primary untreated head and neck squamous cell carcinomas was used to determine the overall pattern of chromosome aberrations. A representative subset of tumors was analyzed in detail by spectral karyotyping and/or confirmatory fluorescence in situ hybridization analysis.Results: Recurrent losses of chromosomes Y (26 cases) and 19 (14 cases), and gains of chromosomes 22 (23 cases), 8 and 20 (11 cases each) were observed. The most frequent structural aberration was del(22)(q13.1) followed by rearrangements involving 6q and 12p. The presence of specific cytogenetic aberrations was found to correlate significantly with an unfavorable outcome. There was a significant association between survival and gains in chromosomes 10 (P = 0.008) and 20 (P = 0.002) and losses of chromosomes 15 (P = 0.005) and 22 (P = 0.021). Univariate analysis indicated that acquisition of monosomy 17 was a significant (P = 0.0012) factor for patients with a previous family history of cancer.Conclusions: the significant associations found in this study emphasize that alterations of distinct regions of the genome may be genetic biomarkers for a poor prognosis. Losses of chromosomes 17 and 22 can be associated with a family history of cancer.
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Introduction: Acquired genetic instability in chronic myeloid leukemia (CML) as a consequence of the translocation t(9;22)(q34;q11) and the resulting BCR-ABL fusion causes the continuous acquisition of additional chromosomal aberrations and mutations and thereby progression to accelerated phase (AP) and blast crisis (BC). At least 10% of patients in chronic phase (CP) CML show additional alterations at diagnosis. This proportion rises during the course of the disease up to 80% in BC. Acquisition of chromosomal changes during treatment is considered as a poor prognostic indicator, whereas the impact of chromosomal aberrations at diagnosis depends on their type. Patients with major route additional chromosomal alterations (major ACA: +8, i(17)(q10), +19, +der(22)t(9;22)(q34;q11) have a worse outcome whereas patients with minor route ACA show no difference in overall survival (OS) and progression-free survival (PFS) compared to patients with the standard translocation, a variant translocation or the loss of the Y chromosome (Fabarius et al., Blood 2011). However, the impact of balanced vs. unbalanced (gains or losses of chromosomes or chromosomal material) karyotypes at diagnosis on prognosis of CML is not clear yet. Patients and methods: Clinical and cytogenetic data of 1346 evaluable out of 1544 patients with Philadelphia and BCR-ABL positive CP CML randomized until December 2011 to the German CML-Study IV, a randomized 5-arm trial to optimize imatinib therapy by combination, or dose escalation and stem cell transplantation were investigated. There were 540 females (40%) and 806 males (60%). Median age was 53 years (range, 16-88). The impact of additional cytogenetic aberrations in combination with an unbalanced or balanced karyotype at diagnosis on time to complete cytogenetic and major molecular remission (CCR, MMR), PFS and OS was investigated. Results: At diagnosis 1174/1346 patients (87%) had the standard t(9;22)(q34;q11) only and 75 patients (6%) had a variant t(v;22). In 64 of 75 patients with t(v;22), only one further chromosome was involved in the translocation; In 8 patients two, in 2 patients three, and in one patient four further chromosomes were involved. Ninety seven patients (7%) had additional cytogenetic aberrations. Of these, 44 patients (3%) lacked the Y chromosome (-Y) and 53 patients (4%) had major or minor ACA. Thirty six of the 53 patients (2.7%) had an unbalanced karyotype (including all patients with major route ACA and patients with other unbalanced alterations like -X, del(1)(q21), del(5)(q11q14), +10, t(15;17)(p10;p10), -21), and 17 (1.3%) a balanced karyotype with reciprocal translocations [e.g. t(1;21); t(2;16); t(3;12); t(4;6); t(5;8); t(15;20)]. After a median observation time of 5.6 years for patients with t(9;22), t(v;22), -Y, balanced and unbalanced karyotype with ACA median times to CCR were 1.05, 1.05, 1.03, 2.58 and 1.51 years, to MMR 1.31, 1.51, 1.65, 2.97 and 2.07 years. Time to CCR and MMR was longer in patients with balanced karyotypes (data statistically not significant). 5-year PFS was 89%, 78%, 87%, 94% and 69% and 5-year OS 91%, 87%, 89%, 100% and 73%, respectively. In CML patients with unbalanced karyotype PFS (p<0.001) and OS (p<0.001) were shorter than in patients with standard translocation (or balanced karyotype; p<0.04 and p<0.07, respectively). Conclusion: We conclude that the prognostic impact of additional cytogenetic alterations at diagnosis of CML is heterogeneous and consideration of their types may be important. Not only patients with major route ACA at diagnosis of CML but also patients with unbalanced karyotypes identify a group of patients with shorter PFS and OS as compared to all other patients. Therefore, different therapeutic options such as intensive therapy with the most potent tyrosine kinase inhibitors or stem cell transplantation are required.
Resumo:
Karyotype analysis of acute lymphoblastic leukemia (ALL) at diagnosis has provided valuable prognostic markers for treatment stratification. However, reports of cytogenetic studies of relapsed ALL samples are limited. We compared the karyotypes from 436 nonselected B-cell precursor ALL patients at initial diagnosis and of 76 patients at first relapse. We noticed a relative increase of karyotypes that did not fall into the classic ALL cytogenetic subgroups (high hyperdiploidy, t(12;21), t(9;22), 11q23, t(1;19), <45 chromosomes) in a group of 29 patients at relapse (38%) compared to 130 patients at presentation (30%). Non-classical cytogenetic aberrations in these 29 patients were mostly found on chromosomes 1, 2, 7, 9, 13, 14, and 17. We also describe six rare reciprocal translocations, three of which involved 14q32. The most frequent abnormalities were found in 9p (12/29 cases) and were associated with a marked decrease in the duration of the second remission, but not of the probability of 10-year event-free survival after relapse treatment. From 29 patients with non-classical cytogenetic aberrations, only 8 (28%) had been stratified to a high risk-arm on the first treatment protocol, suggesting that this subgroup might benefit from the identification of new prognostic markers in future studies.
Resumo:
Major route additional cytogenetic aberrations (ACA) at diagnosis of chronic myeloid leukaemia (CML) indicate an increased risk of progression and shorter survival. Since major route ACA are almost always unbalanced, it is unclear whether other unbalanced ACA at diagnosis also confer an unfavourable prognosis. On the basis of 1348 Philadelphia chromosome-positive chronic phase patients of the randomized CML study IV, we examined the impact of unbalanced minor route ACA at diagnosis versus major route ACA on prognosis. At diagnosis, 1175 patients (87.2 %) had a translocation t(9;22)(q34;q11) and 74 (5.5 %) a variant translocation t(v;22) only, while a loss of the Y chromosome (-Y) was present in addition in 44 (3.3 %), balanced or unbalanced minor route ACA each in 17 (1.3 %) and major route ACA in 21 (1.6 %) cases. Patients with unbalanced minor route ACA had no significantly different cumulative incidences of complete cytogenetic remission or major molecular remission and no significantly different progression-free survival (PFS) or overall survival (OS) than patients with t(9;22), t(v;22), -Y and balanced minor route karyotypes. In contrast, patients with major route ACA had a shorter OS and PFS than all other groups (all pairwise comparisons to each of the other groups: p ≤ 0.015). Five-year survival probabilities were for t(9;22) 91.4 % (95 % CI 89.5-93.1), t(v; 22) 87 % (77.2-94.3), -Y 89.0 % (76.7-97.0), balanced 100 %, unbalanced minor route 92.3 % (72.4-100) and major route 52.2 % (28.2-75.5). We conclude that only major route, but not balanced or unbalanced minor route ACA at diagnosis, has a negative impact on prognosis of CML.
Resumo:
Die akute myeloische Leukämie (AML) stellt ein äußerst heterogenes hämatologisches Krankheitsbild dar, welches durch die unkontrollierte Proliferation unausdifferenzierter und gleichzeitig nicht-funktioneller hämatopoetischer Zellen gekennzeichnet ist. Sowohl die unterschiedliche Zellherkunft, als auch zytogenetische Aberrationen und molekulargenetische Mutationen sorgen für eine große Diversität der Erkrankung. In der Therapie kommen Chemotherapeutika zum Einsatz, welche die Leukämie in eine komplette Remission bringen sollen. Der einzige kurative Ansatz besteht aus der allogenen hämatopoetischen Stammzelltransplantation. Abgesehen von den gewünschten kurativen Effekten, induzieren die im Transplantat befindlichen Spender-T-Lymphozyten ebenfalls die Transplantat-gegen-Wirt Erkrankung – eine Hauptursache von Mortalität und Morbidität nach erfolgter allogener hämatopoetischer Stammzelltransplantation. Da bei vielen Patienten aufgrund ihres Alters und ihrer Begleiterkrankungen eine Transplantation nicht tolerieren und da viele akuten myeloischen Leukämien trotz Chemotherapie progredient sind, schlägt die Therapie fehl und es gibt keine Chance auf Heilung. rnZur Erforschung der pathologischen Prozesse der akuten myeloischen Leukämie sowie für die Entwicklung neuer Therapiekonzepte bedarf es stabiler Tiermodelle, die die maligne Erkrankung des Menschen darstellen können. Ziel der vorliegenden Arbeit war die Untersuchung des Engraftments humaner primärer akuter myeloischer Leukämien in immuninkompetenten NSG-Mäusen. Die Untersuchungen zeigten, dass lediglich 61,5% der getesteten Leukämien in den Versuchstieren nach der Xenotransplantation nachgewiesen werden konnten. Die Gründe hierfür sind noch nicht ausreichend geklärt, beinhalten jedoch vermutlich Elemente des Homings, des Überlebens der Zelle in der fremden murinen Knochenmarknische, der Abwesenheit spezifischer humaner Wachstumsfaktoren, sowie intrinsische Unterschiede unter den verschiedenen Leukämieproben. Leukämien, die mit einer schlechten Prognose beim Patienten verbunden sind, wachsen in den Tieren stärker an. In den Versuchen konnte gezeigt werden, dass Leukämien mit einer Längenmutation des FLT3-Rezeptors eher häufiger in den NSG-Mäusen anwachsen, als wenn diese Mutation fehlt. Die Analyse der erstellten Wachstumskinetiken zweier Leukämien ergab, dass die Höhe des Engraftments in den einzelnen Organen sowohl von der transplantierten Zellmenge, als auch von der Höhe der angesetzten Versuchszeit abhängt. Zudem wurde ein Wachstum humaner T-Lymphozyten in den xenotransplantierten Mäusen beobachtet, welches sowohl mit einem höheren Engraftment der Leukämie in der Maus verbunden war, als auch mit einer höheren Tiersterblichkeit vergesellschaftet war.rnZum Verhindern dieses Wachstums wurden zwei unterschiedliche Methoden angewendet und miteinander verglichen. Dabei erzielten sowohl die medikamentöse Behandlung der Tiere mit dem Calcineurininhibitor Cyclosporin A, als auch die CD3-Depletion der Leukämie vor der Transplantation ein T-Zell-freies Wachstum in den Mäusen, letzteres erwies sich jedoch als das schonendere Verfahren. In den T-Zell-freien Tieren konnte bei dem Großteil der Tiere kein Engraftment im Knochenmark festgestellt werden, was auf einen positiven Einfluss der humanen T-Lymphozyten beim Vorgang des Engraftments schließen lässt.rn
Resumo:
Karyotype analysis of acute lymphoblastic leukemia (ALL) at diagnosis has provided valuable prognostic markers for treatment stratification. However, reports of cytogenetic studies of relapsed ALL samples are limited. We compared the karyotypes from 436 nonselected B-cell precursor ALL patients at initial diagnosis and of 76 patients at first relapse. We noticed a relative increase of karyotypes that did not fall into the classic ALL cytogenetic subgroups (high hyperdiploidy, t(12;21), t(9;22), 11q23, t(1;19), <45 chromosomes) in a group of 29 patients at relapse (38%) compared to 130 patients at presentation (30%). Non-classical cytogenetic aberrations in these 29 patients were mostly found on chromosomes 1, 2, 7, 9, 13, 14, and 17. We also describe six rare reciprocal translocations, three of which involved 14q32. The most frequent abnormalities were found in 9p (12/29 cases) and were associated with a marked decrease in the duration of the second remission, but not of the probability of 10-year event-free survival after relapse treatment. From 29 patients with non-classical cytogenetic aberrations, only 8 (28%) had been stratified to a high risk-arm on the first treatment protocol, suggesting that this subgroup might benefit from the identification of new prognostic markers in future studies.
Resumo:
Unbalanced (major route) additional cytogenetic aberrations (ACA) at diagnosis of chronic myeloid leukemia (CML) indicate an increased risk of progression and shorter survival. Moreover, newly arising ACA under imatinib treatment and clonal evolution are considered features of acceleration and define failure of therapy according to the European LeukemiaNet (ELN) recommendations. On the basis of 1151 Philadelphia chromosome positive chronic phase patients of the randomized CML-study IV, we examined the incidence of newly arising ACA under imatinib treatment with regard to the p210BCR-ABL breakpoint variants b2a2 and b3a2. We found a preferential acquisition of unbalanced ACA in patients with b3a2 vs. b2a2 fusion type (ratio: 6.3 vs. 1.6, p = 0.0246) concurring with a faster progress to blast crisis for b3a2 patients (p = 0.0124). ESPL1/Separase, a cysteine endopeptidase, is a key player in chromosomal segregation during mitosis. Separase overexpression and/or hyperactivity has been reported from a wide range of cancers and cause defective mitotic spindles, chromosome missegregation and aneuploidy. We investigated the influence of p210BCR-ABL breakpoint variants and imatinib treatment on expression and proteolytic activity of Separase as measured with a specific fluorogenic assay on CML cell lines (b2a2: KCL-22, BV-173; b3a2: K562, LAMA-84). Despite a drop in Separase protein levels an up to 5.4-fold increase of Separase activity under imatinib treatment was observed exclusively in b3a2 but not in b2a2 cell lines. Mimicking the influence of imatinib on BV-173 and LAMA-84 cells by ESPL1 silencing stimulated Separase proteolytic activity in both b3a2 and b2a2 cell lines. Our data suggest the existence of a fusion type-related feedback mechanism that posttranslationally stimulates Separase proteolytic activity after therapy-induced decreases in Separase protein levels. This could render b3a2 CML cells more prone to aneuploidy and clonal evolution than b2a2 progenitors and may therefore explain the cytogenetic results of CML patients.
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Epithelioid sarcoma is a rare, aggressive soft tissue tumor of unknown histogenesis showing predominantly epithelioid cytomorphology. We conducted a conventional and molecular cytogenetic study of a 27-year-old male with epithelioid sarcoma with angiomatoid features. Cytogenetic analysis of epithelioid sarcoma metaphase spreads by GTG-banding revealed a diploid chromosome complement with structural and numerical aberrations. Comparative genomic hybridization analysis demonstrated the amplification of 3p24 similar to pter, 4p15.2-p16 and 18q23, while chromosome losses involved 3p13-p14, 3q24-q26.1, 9q21, and 11q21. Fluorescence in situ hybridization assessment showed normal hybridization patterns for the C-MYC and CCND1 loci; CCND1 RNA overexpression was detected by real-time polymerase chain reaction analysis. Genetic evaluation of this rare condition may be useful in determining if epithelioid sarcoma is associated with a distinct genetic background.
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Contemporary anticancer therapies have largely improved the outcome for children with cancer, especially for Acute Lymphoblastic Leukemia (ALL). Actually, between 78% and 85% of patients achieve complete remission and are alive after 5 years of therapy completion. However, as cure rates increase, new concerns about the late effects of genotoxic treatment emerge, being the risk of developing secondary neoplasias, the most serious life-threatening rising problem. In the present paper, we describe and review the cytogenetic findings in peripheral lymphocytes from ALL survivors, and discuss aspects associated to the occurrence of increased chromosome rearrangements in this growing cohort.