• Acute myeloid leukemia (AML) with t(7;12)(q36;p13) is associated with infancy and trisomy 19: Data from Nordic Society for Pediatric Hematology and Oncology (NOPHO-AML) and review of the literature

      Espersen, Anne Dorte Lerche; Noren-Nyström, Ulrika; Abrahamsson, Jonas; Ha, Shau-Yin; Pronk, Cornelis Jan; Jahnukainen, Kirsi; Jónsson, Ólafur G.; Lausen, Birgitte; Palle, Josefine; Zeller, Bernward; et al. (Wiley, 2018-07)
      The t(7;12)(q36;p13) (MNX1/ETV6) is not included in the WHO classification but has been described in up to 30% of acute myeloid leukemia (AML) in children <2 years and associated with a poor prognosis. We present the clinical and cytogenetics characteristics of AML cases with t(7;12)(p36;p13). A literature review identified 35 patients with this translocation, published between 2000 and 2015. Outcome data were available in 22 cases. The NOPHO-AML (Nordic Society for Pediatric Hematology and Oncology) database contained 651 patients with AML from 1993 to 2014 and seven (1.1%) had the translocation. The t(7;12) was only present in patients <2 years of age (median age 6 months) but none was diagnosed as newborn. These patients constituted 4.3% of the patients <2 years of age. There was a strong association with trisomy 19 (literature: 86%, NOPHO: 100%) and +8 (literature: 19%, NOPHO: 14%). Seventeen of 22 patients from the literature with t(7;12) and four of seven patients from the NOPHO database suffered from relapse. The patients with t(7;12) had a 3-year event free survival of 24% (literature) vs. 43% (NOPHO) and a 3-year overall survival of 42% (literature) vs. 100% (NOPHO). None of the NOPHO patients was treated with hematopoietic stem cell transplantation (HSCT) in first complete remission. Relapse was frequent but the salvage rate using HSCT was high. We conclude that t(7;12)(q36;13) is a unique subgroup of childhood AML with presentation before 2 years of age with most cases being associated with +19.
    • The applicability of the WHO classification in paediatric AML. A NOPHO-AML study.

      Sandahl, Julie D; Kjeldsen, Eigil; Abrahamsson, Jonas; Ha, Shau-Yin; Heldrup, Jesper; Jahnukainen, Kirsi; Jónsson, Ólafur G; Lausen, Birgitte; Palle, Josefine; Zeller, Bernward; et al. (Wiley-Blackwell, 2015-06)
      The World Health Organization (WHO) classification of myeloid leukaemia was revised in 2008. It incorporates newly recognized entities and emphasizes the pivotal role of cytogenetic abnormalities. The aim of this study was to evaluate the usability of the WHO classification when applied to a large population-based paediatric acute myeloid leukaemia (AML) cohort. We included children diagnosed with de novo AML, 0-18 years of age from the Nordic countries and Hong Kong from 1993 to 2012. Data were retrieved from the Nordic Society for Paediatric Haematology and Oncology AML database and patients classified according to the WHO 2008 classification. A successful karyotype was available in 97% of the cases. AML with recurrent genetic abnormalities were present in 262 (41%) and 94 (15%) were classified as AML with myelodysplasia-related changes (AML-MDS). WHO classifies patients with monosomy 7 and del(7q) into one group. We found that -7 (n = 14) had significantly poorer outcome than del(7q) (n = 11); 5-year event-free survival 26% vs. 67%, (P = 0·02), and 5-year overall survival 51% vs. 90%, (P = 0·04). The largest group was the highly heterogeneous AML not otherwise specified (NOS) (n = 280) (44%). In conclusion, the WHO classification allocated 15% to AML-MDS, 44% to NOS and grouped together entities with clearly different outcome, therefore limiting the applicability of the current WHO classification in children with AML.
    • Associations between neutrophil recovery time, infections and relapse in pediatric acute myeloid leukemia

      Løhmann, Ditte J. A.; Asdahl, Peter H.; Abrahamsson, Jonas; Ha, Shau-Yin; Jónsson, Ólafur G.; Kaspers, Gertjan J. L.; Koskenvuo, Minna; Lausen, Birgitte; De Moerloose, Barbara; Palle, Josefine; et al. (Wiley, 2018-09)
      BACKGROUND: Children with acute myeloid leukemia (AML) treated similarly show different toxicity and leukemic responses. We investigated associations between neutrophil recovery time after the first induction course, infection and relapse in children treated according to NOPHO-AML 2004 and DB AML-01. PROCEDURE: Newly diagnosed patients with AML with bone marrow blast <5% between day 15 after the start of the treatment and the start of second induction course, and in complete remission after the second induction course were included (n = 279). Neutrophil recovery time was defined as the time from the start of the course to the last day with absolute neutrophil count <0.5 × 109 /l. Linear and Cox regressions were used to investigate associations. RESULTS: Neutrophil recovery time after the first induction course was positively associated with neutrophil recovery time after the remaining courses, and longer neutrophil recovery time (≥25 days) was associated with increased risk of grade 3-4 infections (hazard ratio 1.4, 95% confidence interval [CI], 1.1-1.8). Longer neutrophil recovery time after the first induction (>30 days) was associated with the increased risk of relapse (5-year cumulative incidence: 48% vs. 42%, hazard ratio 1.7, 95% CI, 1.1-2.6) for cases not treated with hematopoietic stem cell transplantation in first complete remission. CONCLUSION: Longer neutrophil recovery time after the first induction course was associated with grade 3-4 infections and relapse. If confirmed, this knowledge could be incorporated into risk stratification strategies in pediatric AML.
    • Associations between pretherapeutic body mass index, outcome, and cytogenetic abnormalities in pediatric acute myeloid leukemia.

      Løhmann, Ditte J A; Asdahl, Peter H; Abrahamsson, Jonas; Ha, Shau-Yin; Jónsson, Ólafur G; Kaspers, Gertjan J L; Koskenvuo, Minna; Lausen, Birgitte; De Moerloose, Barbara; Palle, Josefine; et al. (Wiley, 2019-09-18)
      BACKGROUND: Associations between body mass index (BMI), outcome, and leukemia-related factors in children with acute myeloid leukemia (AML) remain unclear. We investigated associations between pretherapeutic BMI, cytogenetic abnormalities, and outcome in a large multinational cohort of children with AML. METHODS: We included patients, age 2-17 years, diagnosed with de novo AML from the five Nordic countries (2004-2016), Hong Kong (2007-2016), the Netherlands and Belgium (2010-2016), and Canada and USA (1995-2012). BMI standard deviations score for age and sex was calculated and categorized according to the World Health Organization. Cumulative incidence functions, Kaplan-Meier estimator, Cox regression, and logistic regression were used to investigate associations. RESULTS: In total, 867 patients were included. The median age was 10 years (range 2-17 years). At diagnosis, 32 (4%) were underweight, 632 (73%) were healthy weight, 127 (15%) were overweight, and 76 (9%) were obese. There was no difference in relapse risk, treatment-related mortality or overall mortality across BMI groups. The frequency of t(8;21) and inv(16) increased with increasing BMI. For obese patients, the sex, age, and country adjusted odds ratio of having t(8;21) or inv(16) were 1.9 (95% confidence interval (CI) 1.1-3.4) and 2.8 (95% CI 1.3-5.8), respectively, compared to healthy weight patients. CONCLUSIONS: This study did not confirm previous reports of associations between overweight and increased treatment-related or overall mortality in children. Obesity was associated with a higher frequency of t(8;21) and inv(16). AML cytogenetics appear to differ by BMI status.
    • Complex and monosomal karyotype are distinct cytogenetic entities with an adverse prognostic impact in paediatric acute myeloid leukaemia. A NOPHO-DBH-AML study.

      Bager, Ninna; Juul-Dam, Kristian L; Sandahl, Julie D; Abrahamsson, Jonas; Beverloo, Berna; de Bont, Eveline S J M; Ha, Shau-Yin; Jahnukainen, Kirsi; Jónsson, Ólafur G; Kaspers, Gertjan L; et al. (Wiley, 2018-11-01)
      Data on occurrence, genetic characteristics and prognostic impact of complex and monosomal karyotype (CK/MK) in children with acute myeloid leukaemia (AML) are scarce. We studied CK and MK in a large unselected cohort of childhood AML patients diagnosed and treated according to Nordic Society for Paediatric Haematology and Oncology (NOPHO)-AML protocols 1993-2015. In total, 800 patients with de novo AML were included. CK was found in 122 (15%) and MK in 41 (5%) patients. CK and MK patients were young (median age 2·1 and 3·3 years, respectively) and frequently had FAB M7 morphology (24% and 22%, respectively). Refractory disease was more common in MK patients (15% vs. 4%) and stem cell transplantation in first complete remission was more frequent (32% vs. 19%) compared with non-CK/non-MK patients. CK showed no association with refractory disease but was an independent predictor of an inferior event-free survival (EFS; hazard ratio [HR] 1·43, P = 0·03) and overall survival (OS; HR 1·48, P = 0·01). MK was associated with a poor EFS (HR 1·57, P = 0·03) but did not show an inferior OS compared to non-MK patients (HR 1·14, P = 0·62). In a large paediatric cohort, we characterized AML with non-recurrent abnormal karyotype and unravelled the adverse impact of CK and MK on prognosis.
    • Effect of age and body weight on toxicity and survival in pediatric acute myeloid leukemia: results from NOPHO-AML 2004.

      Løhmann, Ditte J A; Abrahamsson, Jonas; Ha, Shau-Yin; Jónsson, Ólafur G; Koskenvuo, Minna; Lausen, Birgitte; Palle, Josefine; Zeller, Bernward; Hasle, Henrik; 1Aarhus University Hospital; dadolfsen@gmail.com. 2Queen Silvia Childrens Hospital, Gothenburg, Sweden; 3Queen Mary Hospital and Hong Kong Pediatric Hematology & Oncology Study Group (HKPHOSG), Hong Kong,; 4Landspitalinn, Reykjavik, Iceland; 5Childrens Hospital and Helsinki University Central Hospital, Helsinki, Finland; 6Rigshospitalet, University of Copenhagen, Denmark; 7Uppsala University, Uppsala, Sweden; 8Oslo University Hospital, Oslo, Norway; 9Aarhus University Hospital Skejby, Denmark. (Pavia, 2016-07-28)
      Treatment for pediatric acute myeloid leukemia is very toxic and the association between outcome and age and body mass index is unclear. We investigated effect of age and body mass index on toxicity and survival in pediatric acute myeloid leukemia. We studied all patients who completed first induction course of NOPHO-AML 2004 (n=318). Toxicity following induction and consolidation courses (n=6) was analyzed. The probabilities of toxicity and death were determined using time-to-event analyses with Cox multivariate proportional hazard regression for comparative analyses. Age 10-17 years was associated with sepsis with hypotension (hazard ratio 2.3 (95% confidence interval 1.1-4.6)). Overweight (>1 standard deviation) was associated with requiring supplemental oxygen (1.9 (1.0-3.5)). The 5-year event-free and overall survival were 47 % and 71%. Children aged 10-17 years showed a trend for inferior 5-year overall survival compared to children aged 2-9 (64% versus 76%, p=0.07). Infants showed a trend for superior 5-year event-free survival (66% versus 43%, p=0.06). Overweight children aged 10-17 showed a trend for superior survival (5-year event-free survival 59% versus 40%, p=0.09 and 5-year overall survival 78% versus 56%, p=0.06) compared to healthy weight children aged 10-17. In conclusion children aged 10-17 and overweight children had a higher risk of grade 3-4 toxicity. Children aged 10-17 showed inferior survival, but, unexpectedly, in this age group overweight children tended to have increased survival. This suggests different pharmacokinetics of chemotherapeutic drugs in adolescents and warrants further studies.
    • Extramedullary leukemia in children with acute myeloid leukemia: A population-based cohort study from the Nordic Society of Pediatric Hematology and Oncology (NOPHO).

      Støve, Heidi Kristine; Sandahl, Julie Damgaard; Abrahamsson, Jonas; Asdahl, Peter H; Forestier, Erik; Ha, Shau-Yin; Jahnukainen, Kirsi; Jónsson, Ólafur G; Lausen, Birgitte; Palle, Josefine; et al. (Wiley, 2017-12)
      The prognostic significance of extramedullary leukemia (EML) in childhood acute myeloid leukemia is not clarified.
    • Gemtuzumab ozogamicin as postconsolidation therapy does not prevent relapse in children with AML: results from NOPHO-AML 2004.

      Hasle, Henrik; Abrahamsson, Jonas; Forestier, Erik; Ha, Shau-Yin; Heldrup, Jesper; Jahnukainen, Kirsi; Jónsson, Ólafur Gísli; Lausen, Birgitte; Palle, Josefine; Zeller, Bernward; et al. (2012-08-02)
      There are no data on the role of postconsolidation therapy with gemtuzumab ozogamicin (GO; Mylotarg) in children with acute myeloid leukemia (AML). The NOPHO-AML 2004 protocol studied postconsolidation randomization to GO or no further therapy. GO was administered at 5 mg/m(2) and repeated after 3 weeks. We randomized 120 patients; 59 to receive GO. Survival was analyzed on an intention-to-treat basis. The median follow-up for patients who were alive was 4.2 years. Children who received GO showed modest elevation of transaminase and bilirubin without signs of veno-occlusive disease. Severe neutropenia followed 95% and febrile neutropenia 40% of the GO courses. Only a moderate decline in platelet count and a minor decrease in hemoglobin occurred. Relapse occurred in 24 and 25 of those randomized to GO or no further therapy. The median time to relapse was 16 months versus 10 months (nonsignificant). The 5-year event-free survival and overall survival was 55% versus 51% and 74% versus 80% in those randomized to receive GO or no further therapy, respectively. Results were similar in all subgroups. In conclusion, GO therapy postconsolidation as given in this trial was well tolerated, showed a nonsignificant delay in time to relapse, but did not change the rate of relapse or survival (clinicaltrials.gov identifier NCT00476541).
    • Hyperleucocytosis in paediatric acute myeloid leukaemia - the challenge of white blood cell counts above 200 × 10(9) /l. The NOPHO experience 1984-2014.

      Zeller, Bernward; Glosli, Heidi; Forestier, Erik; Ha, Shau-Yin; Jahnukainen, Kirsi; Jónsson, Ólafur G; Lausen, Birgitte; Palle, Josefine; Hasle, Henrik; Abrahamsson, Jonas; et al. (Wiley, 2017-08)
      Hyperleucocytosis in paediatric acute myeloid leukaemia (AML) is associated with increased morbidity and mortality. We studied hyperleucocytosis in 890 patients with AML aged 0-18 years registered in the Nordic Society of Paediatric Haematology and Oncology (NOPHO) registry, with special focus on very high white blood cell counts (WBC >200 × 10/l). Eighty-six patients (10%) had WBC 100-199 × 10(9) /l and 57 (6%) had WBC ≥200 × 10(9) /l. Patients with WBC ≥200 × 10(9) /l had a high frequency of t(9;11) and a paucity of trisomy 8. Due to the high frequency of deaths within the first 2 weeks (30% vs. 1% for all others), overall survival in this group was inferior to patients with WBC <200 × 10(9) /l (39% vs. 61%). Main cause of early death was intracranial haemorrhage and leucostasis. Twenty-six per cent of these patients never started antileukaemic protocol therapy. Leukapheresis or exchange transfusion was used in 24% of patients with hyperleucocytosis without impact on survival. Patients with hyperleucocytosis surviving the first week had identical survival as patients with lower WBC. We conclude that death within the first days after diagnosis is the major challenge in patients with high WBC and advocate rapid initiation of intensive chemotherapy.
    • Ploidy and clinical characteristics of childhood acute myeloid leukemia: A NOPHO-AML study.

      Sandahl, Julie Damgaard; Kjeldsen, Eigil; Abrahamsson, Jonas; Ha, Shau-Yin; Heldrup, Jesper; Jahnukainen, Kirsi; Jónsson, Olafur G; Lausen, Birgitte; Palle, Josefine; Zeller, Bernward; et al. (Wiley-Blackwell, 2014-08)
      We report the first large series (n = 596) of pediatric acute myeloid leukemia (AML) focusing on modal numbers (MN) from the population-based NOPHO-AML trials. Abnormal karyotypes were present in 452 cases (76%) and numerical aberrations were present in 40% (n = 237) of all pediatric AML. Among patients with an abnormal karyotype, the MN 46 was most common (n = 251; 56%) of which 36 (8%) were pseudodiploid with numerical aberrations, followed by MN 47 (n = 80; 18%) and MN 43-45 (n = 48; 8%). No cases had MN less than 43. Hyperdiploid AML with MN 48-65 comprised 11% of all cases and was associated with early onset (median age 2 years), female sex (57%), and a dominance of acute megakaryoblastic leukemia (AMKL) (29%). Hypodiploidy constituted 8% of all AML and was associated with older age (median age 9 years), male predominance (60%), FAB M2 (56%), and t(8;21)(q22;q22) (56%) with loss of sex chromosomes. Inferior outcome was observed for hypodiploid cases (5-year event-free survival 40% and 5-year overall survival 40%) but did not reach statistical significance. Chromosomes were gained in a nonrandom pattern, where chromosomes 8, 21, 19, and 6 were the most commonly gained. In conclusion, based on MNs, two cytogenetic subgroups with characteristic clinical features are described; hypodiploidy found in 8% and associated with high median age, male sex, t(8;21)(q22;q22), and FAB M2 and possibly associated with inferior outcome (P = 0.13), and hyperdiploidy with MN 48-65 in 11% associated with early onset, female sex, and AMKL.
    • Trisomy 8 in pediatric acute myeloid leukemia: A NOPHO-AML study.

      Laursen, Anne Cathrine Lund; Sandahl, Julie Damgaard; Kjeldsen, Eigil; Abrahamsson, Jonas; Asdahl, Peter; Ha, Shau-Yin; Heldrup, Jesper; Jahnukainen, Kirsi; Jónsson, Ólafur G; Lausen, Birgitte; et al. (Wiley-Blackwell, 2016-09)
      Trisomy 8 (+8) is a common cytogenetic aberration in acute myeloid leukemia (AML); however, the impact of +8 in pediatric AML is largely unknown. We retrospectively investigated 609 patients from the NOPHO-AML database to determine the clinical and cytogenetic characteristics of +8 in pediatric AML and to investigate its prognostic impact. Complete cytogenetic data were available in 596 patients (98%) aged 0-18 years, diagnosed from 1993 to 2012, and treated according to the NOPHO-AML 1993 and 2004 protocols in the Nordic countries and Hong Kong. We identified 86 patients (14%) with +8. Trisomy 8 was combined with other cytogenetic aberrations in 68 patients (11%) (+8 other) and in 18 patients (3%), it was the sole abnormality (+8 alone). Trisomy 8 was associated with FAB M5 (36%) but otherwise clinically comparable with non-trisomy 8 patients. Trisomy 8 was favorable in patients of young age and with t(9;11). Trisomy 8 alone was associated with older age (median age 10.1 years), FAB M2 (33%), and FLT3-ITD mutations (58%). The 5-year event-free survival for patients with +8 alone was 50% and 5-year overall survival was 75%. In conclusion, +8 is one of the most common cytogenetic aberrations in pediatric AML. Trisomy 8 positive AML is a heterogeneous group and the majority of cases have additional cytogenetic aberrations. Patients with +8 alone differed from patients with +8 other and were associated with older age, FAB M2, and FLT3-ITD aberrations. There were no differences in survival despite the more frequent occurrence of FLT3-ITD in +8 alone. © 2016 Wiley Periodicals, Inc.
    • Use of granulocyte colony-stimulating factor and risk of relapse in pediatric patients treated for acute myeloid leukemia according to NOPHO-AML 2004 and DB AML-01.

      Løhmann, Ditte J A; Asdahl, Peter H; Abrahamsson, Jonas; Ha, Shau-Yin; Jónsson, Ólafur G; Kaspers, Gertjan J L; Koskenvuo, Minna; Lausen, Birgitte; De Moerloose, Barbara; Palle, Josefine; et al. (Wiley, 2019-06-01)
      Supportive-care use of granulocyte colony-stimulating factor (G-CSF) in pediatric acute myeloid leukemia (AML) remains controversial due to a theoretical increased risk of relapse and limited impact on neutropenic complications. We describe the use of G-CSF in patients treated according to NOPHO-AML 2004 and DB AML-01 and investigated associations with relapse. Patients diagnosed with de novo AML completing the first week of therapy and not treated with hematopoietic stem cell transplantation in the first complete remission were included (n = 367). Information on G-CSF treatment after each course (yes/no) was registered prospectively in the study database and detailed information was gathered retrospectively from each center. Descriptive statistics were used to describe G-CSF use and Cox regression to assess the association between G-CSF and risk of relapse. G-CSF as supportive care was given to 128 (35%) patients after 268 (39%) courses, with a large variation between centers (0-93%). The use decreased with time-the country-adjusted odds ratio was 0.8/diagnostic year (95% confidence interval [CI] 0.7-0.9). The median daily dose was 5 μg/kg (range 3-12 μg/kg) and the median cumulative dose was 75 μg/kg (range 7-1460 μg/kg). Filgrastim was used in 82% of G-CSF administrations and infection was the indication in 44% of G-CSF administrations. G-CSF was associated with increased risk of relapse-the adjusted hazard ratio was 1.5 (95% CI 1.1-2.2). G-CSF as supportive care was used in a third of patients, and use decreased with time. Our results indicate that the use of G-CSF may be associated with an increased risk of relapse.