| 1. |
- Harrison, C. J., et al.
(author)
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An international study of intrachromosomal amplification of chromosome 21 (iAMP21) : cytogenetic characterization and outcome
- 2014
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In: Leukemia. - : Springer Science and Business Media LLC. - 0887-6924 .- 1476-5551. ; 28:5, s. 1015-1021
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Journal article (peer-reviewed)abstract
- Intrachromosomal amplification of chromosome 21 (iAMP21) defines a distinct cytogenetic subgroup of childhood B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). To date, fluorescence in situ hybridisation (FISH), with probes specific for the RUNX1 gene, provides the only reliable detection method (five or more RUNX1 signals per cell). Patients with iAMP21 are older (median age 9 years) with a low white cell count. Previously, we demonstrated a high relapse risk when these patients were treated as standard risk. Recent studies have shown improved outcome on intensive therapy. In view of these treatment implications, accurate identification is essential. Here we have studied the cytogenetics and outcome of 530 iAMP21 patients that highlighted the association of specific secondary chromosomal and genetic changes with iAMP21 to assist in diagnosis, including the gain of chromosome X, loss or deletion of chromosome 7, ETV6 and RB1 deletions. These iAMP21 patients when treated as high risk showed the same improved outcome as those in trial-based studies regardless of the backbone chemotherapy regimen given. This study reinforces the importance of intensified treatment to reduce the risk of relapse in iAMP21 patients. This now well-defined patient subgroup should be recognised by World Health Organisation (WHO) as a distinct entity of BCP-ALL.
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| 2. |
- Balgobind, Brian V, et al.
(author)
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Novel prognostic subgroups in childhood 11q23/MLL-rearranged acute myeloid leukemia : results of an international retrospective study.
- 2009
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In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 114:12, s. 2489-2496
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Journal article (peer-reviewed)abstract
- Translocations involving chromosome 11q23 frequently occur in pediatric acute myeloid leukemia (AML) and are associated with poor prognosis. In most cases, the MLL gene is involved, and more than 50 translocation partners have been described. Clinical outcome data of the 11q23-rearranged subgroups are scarce because most 11q23 series are too small for meaningful analysis of subgroups, although some studies suggest that patients with t(9;11)(p22;q23) have a more favorable prognosis. We retrospectively collected outcome data of 756 children with 11q23- or MLL-rearranged AML from 11 collaborative groups to identify differences in outcome based on translocation partners. All karyotypes were centrally reviewed before assigning patients to subgroups. The event-free survival of 11q23/MLL-rearranged pediatric AML at 5 years from diagnosis was 44% (+/- 5%), with large differences across subgroups (11% +/- 5% to 92% +/- 5%). Multivariate analysis identified the following subgroups as independent prognostic predictors: t(1;11)(q21;q23) (hazard ratio [HR] = 0.1, P = .004); t(6;11)(q27;q23) (HR = 2.2, P < .001); t(10;11)(p12;q23) (HR = 1.5, P = .005); and t(10;11)(p11.2;q23) (HR = 2.5, P = .005). We could not confirm the favorable prognosis of the t(9;11)(p22;q23) subgroup. We identified large differences in outcome within 11q23/MLL-rearranged pediatric AML and novel subgroups based on translocation partners that independently predict clinical outcome. Screening for these translocation partners is needed for accurate treatment stratification at diagnosis.
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| 3. |
- Coenen, Eva A, et al.
(author)
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Prognostic significance of additional cytogenetic aberrations in 733 de novo pediatric 11q23/MLL-rearranged AML patients : results of an international study
- 2011
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In: Blood. - : American Society of Hematology. - 0006-4971 .- 1528-0020. ; 117:26, s. 7102-7111
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Journal article (peer-reviewed)abstract
- We previously demonstrated that outcome of pediatric 11q23/MLL-rearranged AML depends on the translocation partner (TP). In this multicenter international study on 733 children with 11q23/MLL-rearranged AML, we further analyzed which additional cytogenetic aberrations (ACA) had prognostic significance. ACAs occurred in 344 (47%) of 733 and were associated with unfavorable outcome (5-year overall survival [OS] 47% vs 62%, P < .001). Trisomy 8, the most frequent specific ACA (n = 130/344, 38%), independently predicted favorable outcome within the ACAs group (OS 61% vs 39%, P = .003; Cox model for OS hazard ratio (HR) 0.54, P = .03), on the basis of reduced relapse rate (26% vs 49%, P < .001). Trisomy 19 (n = 37/344, 11%) independently predicted poor prognosis in ACAs cases, which was partly caused by refractory disease (remission rate 74% vs 89%, P = .04; OS 24% vs 50%, P < .001; HR 1.77, P = .01). Structural ACAs had independent adverse prognostic value for event-free survival (HR 1.36, P = .01). Complex karyotype, defined as ≥ 3 abnormalities, was present in 26% (n = 192/733) and showed worse outcome than those without complex karyotype (OS 45% vs 59%, P = .003) in univariate analysis only. In conclusion, like TP, specific ACAs have independent prognostic significance in pediatric 11q23/MLL-rearranged AML, and the mechanism underlying these prognostic differences should be studied.
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| 4. |
- Hasle, Henrik, et al.
(author)
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Monosomy 7 and deletion 7q in children and adolescents with acute myeloid leukemia : an international retrospective study.
- 2007
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In: Blood. - 0006-4971. ; 109:11, s. 4641-7
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Journal article (peer-reviewed)abstract
- Monosomy 7 (-7) and deletion 7q \del(7q)] are rare in childhood acute myeloid leukemia (AML). We retrospectively collected data on 258 children with AML or refractory anemia with excess blasts in transformation (RAEB-T) and -7 or del(7q) with or without other cytogenetic aberrations \+/- other]. Karyotypes included -7 (n = 90), -7 other (n = 82), del(7q) (n = 21), and del(7q) other (n = 65). Complete remission (CR) was achieved in fewer patients with -7 +/- other compared with del(7q) +/- other (61% versus 89%, P < .001). Overall, the 5-year survival rate was 39% (SE, 3%). Survival was superior in del(7q) +/- other compared with -7 +/- other (51% versus 30%, P < .01). Cytogenetic aberrations considered favorable in AML \t(8;21)(q22;q22), inv(16)(p13q22), t(15;17)(q22;q21), t(9;11)(p22;q23)] (n = 24) were strongly associated with del(7q) and a higher 5-year survival rate compared with del(7q) without favorable cytogenetics (75% versus 46%, P = .03). Patients with -7 and inv(3),-5/del(5q), or + 21 had a 5-year survival rate of 5%. Stem cell transplantation analyzed as a time-dependent variable had no impact on overall survival. However, patients not achieving CR had a 31% survival rate after stem cell transplantation. Childhood AML with chromosome 7 aberrations represents a heterogeneous group of disorders with additional cytogenetic aberrations having a major prognostic impact which should be reflected in future risk-group stratification.
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| 5. |
- Sandahl, Julie Damgaard, et al.
(author)
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t(6;9)(p22; q34)/DEK-NUP214-rearranged pediatric myeloid leukemia : an international study of 62 patients
- 2014
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In: Haematologica. - : Ferrata Storti Foundation (Haematologica). - 0390-6078 .- 1592-8721. ; 99:5, s. 865-872
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Journal article (peer-reviewed)abstract
- Acute myeloid leukemia with t(6; 9)(p22; q34) is listed as a distinct entity in the 2008 World Health Organization classification, but little is known about the clinical implications of t(6; 9)-positive myeloid leukemia in children. This international multicenter study presents the clinical and genetic characteristics of 62 pediatric patients with t(6; 9)/DEKNUP214-rearranged myeloid leukemia; 54 diagnosed as having acute myeloid leukemia, representing <1% of all childhood acute myeloid leukemia, and eight as having myelodysplastic syndrome. The t(6; 9)/DEK-NUP214 was associated with relatively late onset (median age 10.4 years), male predominance (sex ratio 1.7), French-American-British M2 classification (54%), myelodysplasia (100%), and FLT3-ITD (42%). Outcome was substantially better than previously reported with a 5-year event-free survival of 32%, 5-year overall survival of 53%, and a 5-year cumulative incidence of relapse of 57%. Hematopoietic stem cell transplantation in first complete remission improved the 5-year event-free survival compared with chemotherapy alone (68% versus 18%; P<0.01) but not the overall survival (68% versus 54%; P=0.48). The presence of FLT3-ITD had a non-significant negative effect on 5-year overall survival compared with non-mutated cases (22% versus 62%; P=0.13). Gene expression profiling showed a unique signature characterized by significantly higher expression of EYA3, SESN1, PRDM2/RIZ, and HIST2H4 genes. In conclusion, t(6; 9)/DEK-NUP214 represents a unique subtype of acute myeloid leukemia with a high risk of relapse, high frequency of FLT3-ITD, and a specific gene expression signature.
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| 6. |
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| 7. |
- Moorman, AV, et al.
(author)
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No prognostic effect of additional chromosomal abnormalities in children with acute lymphoblastic leukemia and 11q23 abnormalities
- 2005
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In: Leukemia. - London : Nature Publishing Group. - 0887-6924 .- 1476-5551. ; 19:4, s. 557-563
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Journal article (peer-reviewed)abstract
- This study characterized the additional chromosomal abnormalities (ACA) associated with 11q23 rearrangements in 450 infants and children with acute lymphoblastic leukemia ( ALL) and examined the impact of these ACA on survival. Overall, 213 (47%) cases had ACA but the incidence varied according to patient age and 11q23 subgroup. Infants and patients with t(4; 11)(q21; q23) had the lowest incidence of ACA (50/182 (27%) and 57/216 (26%) respectively), whereas patients with del( 11)( q23) had the highest incidence (66/93 (71%)). Del( 11)( q23) abnormalities were heterogeneous and occasionally secondary to t( 9; 22)(q34; q11.2). Thus, patients with del( 11)( q23) comprised a separate biological entity, which was clearly distinct from those with an 11q23 translocation. The most frequent specific ACA were trisomy X ( n = 38), abnormal 12p ( n = 32), abnormal 9p ( n = 28) and del( 6q) ( n = 19). The presence of ACA did not change the 5 year event-free survival estimates among children (56% (95% CI 46 - 65%) vs 62% (54 - 69%)) or infants (22% ( 15 - 29%) vs 18% ( 9 - 29%)), nor when the different 11q23 subgroups were analyzed separately. This study has conclusively demonstrated that there is no prognostic effect of secondary chromosomal changes in association with 11q23 abnormalities in childhood ALL. However, characterization of these ACA is important to determine their potential role in initiation of MLL driven leukemogenesis.
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