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PURPOSE A previous study by the International Berlin-Frankfurt-Münster Study Group (I-BFM-SG) on childhood KMT2A-rearranged ( KMT2A-r) AML demonstrated the prognostic value of the fusion partner. This I-BFM-SG study investigated the value of flow cytometry-based measurable residual disease (flow-MRD) and evaluated the benefit of allogeneic stem-cell transplantation (allo-SCT) in first complete remission (CR1) in this disease. METHODS A total of 1,130 children with KMT2A-r AML, diagnosed between January 2005 and December 2016, were assigned to high-risk (n = 402; 35.6%) or non–high-risk (n = 728; 64.4%) fusion partner-based groups. Flow-MRD levels at both end of induction 1 (EOI1) and 2 (EOI2) were available for 456 patients and were considered negative (RESULTS The high-risk group had inferior EFS (30.3% high risk v 54.0% non-high risk; P < .0001), CIR (59.7% v 35.2%; P < .0001), and OS (49.2% v 70.5%; P < .0001). EOI2 MRD negativity was associated with superior EFS (n = 413; 47.6% MRD negativity v n = 43; 16.3% MRD positivity; P < .0001) and OS (n = 413; 66.0% v n = 43; 27.9%; P < .0001), and showed a trend toward lower CIR (n = 392; 46.1% v n = 26; 65.4%; P = .016). Similar results were obtained for patients with EOI2 MRD negativity within both risk groups, except that within the non–high-risk group, CIR was comparable with that of patients with EOI2 MRD positivity. Allo-SCT in CR1 only reduced CIR (hazard ratio, 0.5 [95% CI, 0.4 to 0.8]; P = .00096) within the high-risk group but did not improve OS. In multivariable analyses, EOI2 MRD positivity and high-risk group were independently associated with inferior EFS, CIR, and OS. CONCLUSION EOI2 flow-MRD is an independent prognostic factor and should be included as risk stratification factor in childhood KMT2A-r AML. Treatment approaches other than allo-SCT in CR1 are needed to improve prognosis.

PURPOSE We aimed to study prognostic factors and efficacy of allogeneic hematopoietic stem-cell transplantation (allo-HSCT) in first remission of patients with noninfant childhood acute lymphoblastic leukemia (ALL) with 11q23/ KMT2A rearrangements treated with chemotherapy regimens between 1995 and 2010. PATIENTS AND METHODS Data were retrospectively retrieved from 629 patients with 11q23/ KMT2A-rearranged ALL from 17 members of the Ponte-di-Legno Childhood ALL Working Group. Clinical and biologic characteristics, early response assessed by minimal residual disease at the end of induction (EOI) therapy, and allo-HSCT were analyzed for their impact on outcomes. RESULTS A specific 11q23/ KMT2A translocation partner gene was identified in 84.3% of patients, with the most frequent translocations being t(4;11)(q21;q23) (n = 273; 51.5%), t(11;19)(q23;p13.3) (n = 106; 20.0%), t(9;11)(p21_22;q23) (n = 76; 14.3%), t(6;11)(q27;q23) (n = 20; 3.8%), and t(10;11)(p12;q23) (n = 14; 2.6%); 41 patients (7.7%) had less frequently identified translocation partner genes. Patient characteristics and early response varied among subgroups, indicating large biologic heterogeneity and diversity in therapy sensitivity among 11q23/ KMT2A-rearranged ALL. The EOI remission rate was 93.2%, and the 5-year event-free survival (EFS) for the entire cohort was 69.1% ± 1.9%, with a range from 41.7% ± 17.3% for patients with t(9;11)-positive T-ALL (n = 9) and 64.8% ± 3.0% for patients with t(4;11)-positive B-ALL (n = 266) to 91.2% ± 4.9% for patients with t(11;19)-positive T-ALL (n = 34). Low EOI minimal residual disease was associated with favorable EFS, and induction failure was particularly predictive of nonresponse to further therapy and relapse and poor EFS. In addition, EFS was not improved by allo-HSCT compared with chemotherapy only in patients with both t(4;11)-positive B-ALL (n = 64 v 51; P = .10) and 11q23/ KMT2A-rearranged T-ALL (n = 16 v 10; P = .69). CONCLUSION Compared with historical data, prognosis of patients with noninfant 11q23/ KMT2A-rearranged ALL has improved, but allo-HSCT failed to affect outcome. Targeted therapies are needed to reduce relapse and treatment-related mortality rates.

Background COVID-19, the novel coronavirus, has caused a global pandemic affecting millions of people around the world. Risk factors for critical disease in adults are advanced age and underlying medical comorbidities, including cancer. Data are sparse on the effect of COVID-19 infection on pediatric patients with cancer during their active antineoplastic therapy. The optimal management of antineoplastic treatment during COVID-19 infection in this unique population is controversial. Aim To describe the severity and clinical course of COVID-19 infection in pediatric patients with cancer during active antineoplastic treatment and to study their course of treatment. Methods Clinical and laboratory data were collected from medical files of patients diagnosed with COVID-19, confirmed by polymerase chain reaction (PCR), who received active antineoplastic treatment between March 2020 and May 2021 in a large tertiary pediatric medical center. Results Eighteen patients with diverse pediatric cancers are described. They were infected with COVID-19 at different stages of their antineoplastic treatment regimen. Eight had an asymptomatic COVID-19 infection, nine had mild symptoms, and one had severe disease. All of them recovered from COVID-19 infection. Two patients experienced delays in their antineoplastic treatment; none of the other patients had delays or interruptions, including patients who were symptomatic for COVID-19. Conclusion In pediatric patients with cancer who test positive for COVID-19, yet are asymptomatic or have mild symptoms, the continuance of antineoplastic therapy may be considered.

Contains fulltext : 248362.pdf (Publisher’s version ) (Open Access) INTRODUCTION: One-quarter of the relapses in children with B-cell precursor acute lymphoblastic leukemia (BCP-ALL) occur very early (within 18 months, before completion of treatment), and prognosis in these patients is worse compared to cases that relapse after treatment has ended. METHODS: In this study, we performed a genomic analysis of diagnosis-relapse pairs of 12 children who relapsed very early, followed by a deep-sequencing validation of all identified mutations. In addition, we included one case with a good initial treatment response and on-treatment relapse at the end of upfront therapy. RESULTS: We observed a dynamic clonal evolution in all cases, with relapse almost exclusively originating from a subclone at diagnosis. We identified several driver mutations that may have influenced the outgrowth of a minor clone at diagnosis to become the major clone at relapse. For example, a minimal residual disease (MRD)-based standard-risk patient with ETV6-RUNX1-positive leukemia developed a relapse from a TP53-mutated subclone after loss of the wildtype allele. Furthermore, two patients with TCF3-PBX1-positive leukemia that developed a very early relapse carried E1099K WHSC1 mutations at diagnosis, a hotspot mutation that was recurrently encountered in other very early TCF3-PBX1-positive leukemia relapses as well. In addition to alterations in known relapse drivers, we found two cases with truncating mutations in the cohesin gene RAD21. CONCLUSION: Comprehensive genomic characterization of diagnosis-relapse pairs shows that very early relapses in BCP-ALL frequently arise from minor subclones at diagnosis. A detailed understanding of the therapeutic pressure driving these events may aid the development of improved therapies.

BACKGROUND: In addition to treatment response, cytogenetic and molecular aberrations are the most important prognostic factors in children with de novo acute myeloid leukemia (AML). However, little is known about cytogenetics at the time of relapse.METHODS: This international study analyzed the prognostic value of cytogenetic profiles and karyotypic changes in pediatric relapsed AML in relation to the probability of event-free (pEFS) and overall survival (pOS). For this purpose, cytogenetic reports from all patients registered on the Relapsed AML 2001/01 Study were reviewed and classified.RESULTS: Cytogenetic information at relapse was available for 403 (71%) of 569 registered patients. Frequently detected aberrations at relapse were t(8;21)(q22;q22) (n = 60) and inv(16)(p13.1q22)/t(16;16)(p13.1;q22) (n = 24), both associated with relatively good outcome (4-year pOS 59% and 71%, respectively). Monosomy 7/7q-, t(9;11)(p22;q23), t(10;11)(p12;q23), and complex karyotypes were associated with poor outcomes (4-year pOS 17%, 19%, 22%, and 22%, respectively). Of 261 (65%) patients for whom cytogenetic data were reliable at both diagnosis and relapse, pEFS was inferior for patients with karyotypic instability (n = 128, 49%), but pOS was similar. Unstable karyotypes with both gain and loss of aberrations were associated with inferior outcome. Early treatment response, time to relapse, and cytogenetic profile at time of relapse were the most important prognostic factors, both outweighing karytoypic instability per se.CONCLUSION: The cytogenetic subgroup at relapse is an independent risk factor for (event-free) survival. Cytogenetic assessment at the time of relapse is of high importance and may contribute to improved risk-adapted treatment for children with relapsed AML.

PURPOSE Off-label use of vemurafenib (VMF) to treat BRAFV600E mutation–positive, refractory, childhood Langerhans cell histiocytosis (LCH) was evaluated. PATIENTS AND METHODS Fifty-four patients from 12 countries took VMF 20 mg/kg/d. They were classified according to risk organ involvement: liver, spleen, and/or blood cytopenia. The main evaluation criteria were adverse events (Common Terminology Criteria for Adverse Events [version 4.3]) and therapeutic responses according to Disease Activity Score. RESULTS LCH extent was distributed as follows: 44 with positive and 10 with negative risk organ involvement. Median age at diagnosis was 0.9 years (range, 0.1 to 6.5 years). Median age at VMF initiation was 1.8 years (range, 0.18 to 14 years), with a median follow-up of 22 months (range, 4.3 to 57 months), whereas median treatment duration was 13.9 months (for 855 patient-months). At 8 weeks, 38 complete responses and 16 partial responses had been achieved, with the median Disease Activity Score decreasing from 7 at diagnosis to 0 ( P < .001). Skin rash, the most frequent adverse event, affected 74% of patients. No secondary skin cancer was observed. Therapeutic plasma VMF concentrations (range, 10 to 20 mg/L) seemed to be safe and effective. VMF discontinuation for 30 patients led to 24 LCH reactivations. The blood BRAFV600E allele load, assessed as circulating cell-free DNA, decreased after starting VMF but remained positive (median, 3.6% at diagnosis, and 1.6% during VMF treatment; P < .001) and was associated with a higher risk of reactivation at VMF discontinuation. None of the various empirical therapies (hematopoietic stem-cell transplantation, cladribine and cytarabine, anti-MEK agent, vinblastine, etc) used for maintenance could eradicate the BRAFV600E clone. CONCLUSION VMF seemed safe and effective in children with refractory BRAFV600E-positive LCH. Additional studies are needed to find effective maintenance therapy approaches.

Background Osteonecrosis is a major cause of acute and long-lasting complications of acute lymphoblastic leukemia (ALL) therapy in children. Our study aimed to evaluate the prevalence, characteristics, risk factors, and outcome of osteonecrosis in children with ALL. Procedure The cohort included 559 children aged 1-20 years diagnosed with ALL between 2003 and 2018 at two tertiary medical centers in Israel and enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. Symptomatic osteonecrosis was prospectively captured as an adverse event. Results Osteonecrosis occurred in 51 patients (9.1%). Ninety-four percent of the events were graded as moderate or severe (grades 3-4, Ponte di Legno Toxicity Working Group classification) and multiple bone involvement was common. Full resolution of osteonecrosis was documented in only 16% of the children (median follow-up 4.2 years). Stepwise logistic regression identified five risk factors for osteonecrosis, with a high predictive value (AUC = 0.88): older ageat ALL diagnosis, high-risk ALL group, T-cell immunophenotype, female gender, and a novel risk factor: bone pain at the time of leukemia diagnosis. In addition, osteonecrosis was less common among children of Arab ethnicity. Thrombophilia and an elevated age-adjusted body mass index were not confirmed as risk factors for osteonecrosis. Conclusion Due to the low rates of osteonecrosis resolution and its debilitating long-term impact, the identification of patients at high risk for osteonecrosis is important for their inclusion in further studies evaluating potential therapeutic adjustments.

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy, yet data regarding long-term ovarian reserve of female survivors are limited. The aim of this study was to investigate whether there is a differential pattern of anti-Mullerian hormone (AMH) levels in female childhood ALL survivors compared with the normal age-matched population. In a cohort of 56 female childhood ALL survivors (median age 29 years; median follow-up 20.6 years), a negative correlation was found between age at leukemia diagnosis and age-adjusted anti-Mullerian hormone (AMH) levels (

Background: COVID-19, the novel coronavirus has caused a global pandemic affecting millions of people around the world. Although children, including children with cancer, have been found to be affected less commonly and less severely than adults, indirect effects of the pandemic on the diagnosis and treatment of children with cancer have been less described. Methods: A survey was performed in the four largest tertiary pediatric hematology-oncology medical centers in Israel. Clinical and laboratory data were collected from the medical files of patients diagnosed or treated with cancer during April-October 2020. Results: Seventeen patients are described, who had significant delay in diagnosis or treatment of cancer. These represent approximately 10% of all the pediatric cancer diagnosed during the study period in these centers. A main cause of delay was fear of exposure to COVID-19 (fears felt by the patient, parent, physician, or decision-makers at the institution; or the implementation of national guidelines). Delays also resulted from co-infection with COVID-19 and the attribution of the oncologic symptoms to the infection. In addition, treatment was delayed of patients already diagnosed with cancer, due to COVID-19 infection detected in the patient, a family member, or a bone marrow donor. Conclusion: Fear from the COVID-19 pandemic may result in delayed diagnosis and treatment of children with cancer, which may carry a risk to dismal prognosis. It is crucial that pediatricians and patients alike remember that other diseases still prevail and must be thought of and treated in a timely fashion.

Venous thromboembolism (VTE) is a serious complication of acute lymphoblastic leukemia (ALL) therapy. The aim of this population-based study was to evaluate the rate, risk factors, and long-term sequelae of VTE in children treated for ALL. The cohort included 1191 children aged 1&ndash, 19 years diagnosed with ALL between 2003&ndash, 2018, prospectively enrolled in two consecutive protocols: ALL-IC BFM 2002 and AIEOP-BFM ALL 2009. VTEs occurred in 89 patients (7.5%). Long-term sequelae were uncommon. By univariate analysis, we identified four significant risk factors for VTEs: Severe hypertriglyceridemia (p = 0.005), inherited thrombophilia (p &lt, 0.001), age &gt, 10 years (p = 0.015), and high-risk ALL group (p = 0.039). In addition, the incidence of VTE was significantly higher in patients enrolled in AIEOP-BFM ALL 2009 than in those enrolled in ALL-IC BFM 2002 (p = 0.001). Severe VTE occurred in 24 children (2%), all of whom had at least one risk factor. Elevated triglyceride levels at diagnosis did not predict hypertriglyceridemia during therapy. In a multivariate analysis of 388 children, severe hypertriglyceridemia and inherited thrombophilia were independent risk factors for VTE. Routine evaluation for these risk factors in children treated for ALL may help identify candidates for intervention.

INTRODUCTION: Since the beginning of COVID-19 pandemic, it is known that the severe course of the disease occurs mostly among the elderly, whereas it is rare among children and young adults. Comorbidities, in particular, diabetes and hypertension, clearly associated with age, besides obesity and smoke, are strongly associated with the need for intensive treatment and a dismal outcome. A weaker immunity of the elderly has been proposed as a possible explanation of this uneven age distribution. Thus, there is concern that children treated for cancer may allso be at risk for an unfavourable course of infection. Along the same line, anecdotal information from Wuhan, China, mentioned a severe course of COVID-19 in a child treated for leukaemia. AIM AND METHODS: We made a flash survey on COVID-19 incidence and severity among children on anticancer treatment. Respondents were asked by email to fill in a short Web-based survey. RESULTS: We received reports from 25 countries, where approximately 10,000 patients at risk are followed up. At the time of the survey, more than 200 of these children were tested, nine of whom were positive for COVID-19. Eight of the nine cases had asymptomatic to mild disease, and one was just diagnosed with COVID-19. We also discuss preventive measures that are in place or should be taken and treatment options in immunocompromised children with COVID-19. CONCLUSION: Thus, even children receiving anticancer chemotherapy may have a mild or asymptomatic course of COVID-19. While we should not underestimate the risk of developing a more severe course of COVID-19 than that observed here, the intensity of preventive measures should not cause delays or obstructions in oncological treatment.

COVID-19, the novel coronavirus, has caused a global pandemic affecting millions of people around the world. Risk factors for critical disease in adults are advanced age and underlying medical comorbidities, including cancer. Data are sparse on the effect of COVID-19 infection on pediatric patients with cancer during their active antineoplastic therapy. The optimal management of antineoplastic treatment during COVID-19 infection in this unique population is controversial.To describe the severity and clinical course of COVID-19 infection in pediatric patients with cancer during active antineoplastic treatment and to study their course of treatment.Clinical and laboratory data were collected from medical files of patients diagnosed with COVID-19, confirmed by polymerase chain reaction (PCR), who received active antineoplastic treatment between March 2020 and May 2021 in a large tertiary pediatric medical center.Eighteen patients with diverse pediatric cancers are described. They were infected with COVID-19 at different stages of their antineoplastic treatment regimen. Eight had an asymptomatic COVID-19 infection, nine had mild symptoms, and one had severe disease. All of them recovered from COVID-19 infection. Two patients experienced delays in their antineoplastic treatment; none of the other patients had delays or interruptions, including patients who were symptomatic for COVID-19.In pediatric patients with cancer who test positive for COVID-19, yet are asymptomatic or have mild symptoms, the continuance of antineoplastic therapy may be considered.

Introduction KMT2A-rearranged (KMT2A-r) acute myeloid leukemia (AML) is a heterogeneous genetic subgroup with a frequency of about 25% in children with AML. At the 62 nd ASH annual meeting last year, we reported on the differences in outcome of various KMT2A subgroups based on translocation partner and the significance of minimal residual disease (MRD) status during and after induction as a follow-up study of Balgobind et al., Blood 2009. The impact of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in first complete remission (CR1) and the presence of additional cytogenetic aberrations (ACAs) on prognosis have not yet been described for our cohort. Methods Data on allo-HSCT in CR1 and the presence of ACAs of 1256 KMT2A-r de novo pediatric AML patients from 15 AML study groups affiliated with the I-BFM Study Group, diagnosed between 2005 and 2016, were retrospectively collected and studied. Karyotypes were reviewed and classified by two of the authors (RW&CH). Based on translocation partners, patients were classified to the KMT2A high-risk subgroup (6q27, 10p11.2, 10p12, 4q21, and 19p13.3) or non-high-risk subgroup (9p22, 19p13, 19p13.1, 1q21, Xq24, 17q21, 1p32, and 17q12). These two categories have been used to estimate a Cox model. Patients with unknown translocation partners were excluded from these analyses (n=126). Flow cytometry MRD levels at the end of induction course 1 (EOI1) and 2 (EOI2) Results Of 1256 pediatric patients with KMT2A-r AML, data on HSCT in CR1 and ACAs were available for 1186 (94.4%) and 1204 patients (95.9%), respectively; 211 (17.8%) patients received HSCT in CR1 and ACAs were present in 601 (49.9%) patients. Compared with the KMT2A non-high-risk subgroup, patients in the KMT2A high-risk subgroup underwent HSCT in CR1 more often (23.8% vs 15.0%; P < .001). ACAs were borderline significantly more common in the KMT2A high-risk subgroup (54.1% vs 46.4%; P = .015). Univariate analysis of the probability of DFS (Table 1) showed that the KMT2A high-risk subgroup (HR 2.1; 95% CI, 1.7-2.5), age ≥10 years (HR 1.4; 95% CI, 1.2-1.7), and MRD ≥0.1 at EOI1 (HR 1.5; 95% CI, 1.1-1.9) were associated with DFS. HSCT in CR1 was a borderline significant prognostic factor (HR 0.7; 95% CI, 0.6-0.9). In a multivariate analysis for DFS (n=515) (Table 1), the KMT2A high-risk subgroup (HR 2.0; 95% CI, 1.6-2.6), MRD ≥0.1 at EOI1 (HR 1.7; 95% CI, 1.2-2.3), and HSCT in CR1 (HR 0.6; 95% CI, 0.4-0.9) were associated with DFS. Univariate analysis of the probability of OS (Table 1) showed that the KMT2A high-risk subgroup (HR 1.8; 95% CI, 1.5-2.2), age ≥10 years (HR 1.6; 95% CI 1.3-2.0), WBC ≥100 x10 9/L (HR 1.4; 95% CI, 1.1-1.7), the presence of ACAs (HR 1.4; 95% CI, 1.2-1.7), and MRD ≥0.1 at EOI1 (HR 2.1; 95% CI, 1.6-2.7) were associated with OS. HSCT in CR1 was not associated with OS. The effect of HSCT in CR1 was not significantly different between the KMT2A high-risk and non-high-risk subgroups. In a multivariate analysis for OS (n=557) (Table 1), the KMT2A high-risk subgroup (HR 1.9; 95% CI, 1.4-2.5), age ≥10 years (HR 1.5; 95% CI, 1.1-1.9), the presence of ACAs (HR 1.6; 95% CI, 1.2-2.1), and MRD positivity at EOI1 (HR 1.9; 95% CI, 1.4-2.5) were associated with OS. Conclusions In this cohort of KMT2A-r pediatric AML patients, the presence of ACAs at diagnosis was independently associated with inferior OS, but not with DFS. This may be due to the exclusion of refractory patients in DFS analysis, who were significantly more common in the group of patients with ACAs. Analysis has yet to be performed to distinguish karyotype complexity. In addition, allo-HSCT in CR1 was an independent predictor of improved DFS, but was not a prognostic factor for OS. Figure 1 Figure 1. Disclosures Abrahamsson: wedish Children´s Cancer Foundation. Research grants and 50% senior research position for clinical research on pediatric leukemia: Research Funding. Locatelli: Amgen: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Novartis: Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Miltenyi: Speakers Bureau; Medac: Speakers Bureau; Jazz Pharamceutical: Speakers Bureau; Takeda: Speakers Bureau.

ABL-class fusions other than BCR-ABL1 characterize around 2-3% of precursor B-cell acute lymphoblastic leukemia. Case series indicated that patients suffering from these subtypes have a dismal outcome and may benefit from the introduction of tyrosine kinase inhibitors. We analyzed clinical characteristics and outcome of 46 ABL-class fusion positive cases other than BCR-ABL1 treated according to AIEOP-BFM (Associazione Italiana di Ematologia-Oncologia Pediatrica-Berlin-Frankfurt-Munster) ALL 2000 and 2009 protocols; 13 of them received a tyrosine kinase inhibitor (TKI) during different phases of treatment. ABL-class fusion positive cases had a poor early treatment response: minimal residual disease levels of ≥5×10-4 were observed in 71.4% of patients after induction treatment and in 51.2% after consolidation phase. For the entire cohort of 46 cases, the 5-year probability of event-free survival was 49.1+8.9% and that of overall survival 69.6+7.8%; the cumulative incidence of relapse was 25.6+8.2% and treatment-related mortality (TRM) 20.8+6.8%. One out of 13 cases with TKI added to chemotherapy relapsed while eight of 33 cases without TKI treatment suffered from relapse, including six in 17 patients who had not received hematopoietic stem cell transplantation. Stem cell transplantation seems to be effective in preventing relapses (only three relapses in 25 patients), but was associated with a very high TRM (6 patients). These data indicate a major need for an early identification of ABL-class fusion positive acute lymphoblastic leukemia cases and to establish a properly designed, controlled study aimed at investigating the use of TKI, the appropriate chemotherapy backbone and the role of hematopoietic stem cell transplantation. (Registered at: clinicaltrials.gov identifier: NTC00430118, NCT00613457, NCT01117441).

BACKGROUND Therapy outcomes for childhood acute lymphoblastic leukemia (ALL) had substantially improved in the last decades, but variability across racial and ethnic groups was identified in some clinical studies. In this study, we aimed to investigate whether such a difference in outcome is found in the diverse ethnicities in Israel as well. METHODS A retrospective study was conducted among 1154 patients (855 Jews, 195 Muslims, 52 Bedouins, 26 Druze, and 26 others) aged 1 to 21 years, who were diagnosed with ALL between 1989 and 2011 and were treated according to the same Berlin-Frankfurt-Muenster-based Israel National Study protocols. RESULTS Bedouins had a higher incidence of t(1;19) (16% vs 3% for non-Bedouins) and a lower incidence of high-hyperdiploidy (10% vs 25% for non-Bedouins) (P = 0.01). Five-year event-free survival (EFS) and overall survival (OS) were poorer for the Bedouins (60.3% ± 7.2% and 63.1% ± 7.2%, respectively) compared with the Jews, Muslims, and Druze (80.4% ± 1.4%, 77.3% ± 3.2%, and 84% ± 7.3%, respectively, for EFS [P = 0.02], and 86.3% ± 1.2%, 82.3% ± 2.9%, and 88.3% ± 6.4%, respectively, for OS [P = 0.002]). Adherence to intensive chemotherapy was similar between the Muslims and the Bedouins. CONCLUSIONS Our findings suggest that the Bedouins, a highly inbred ethnic Arab people, may be considered a higher risk group that may need more intensive chemotherapy and/or supportive care in order to improve their outcome.

PURPOSE We determined the prognostic factors and utility of allogeneic hematopoietic cell transplantation among children with newly diagnosed hypodiploid acute lymphoblastic leukemia (ALL) treated in contemporary clinical trials. PATIENTS AND METHODS This retrospective study collected data on 306 patients with hypodiploid ALL who were enrolled in the protocols of 16 cooperative study groups or institutions between 1997 and 2013. The clinical and biologic characteristics, early therapeutic responses as determined by minimal residual disease (MRD) assessment, treatment with or without MRD-stratified protocols, and allogeneic transplantation were analyzed for their impact on outcome. RESULTS With a median follow-up of 6.6 years, the 5-year event-free survival rate was 55.1% (95% CI, 49.3% to 61.5%), and the 5-year overall survival rate was 61.2% (95% CI, 55.5% to 67.4%) for the 272 evaluable patients. Negative MRD at the end of remission induction, high hypodiploidy with 44 chromosomes, and treatment in MRD-stratified protocols were associated with a favorable prognosis, with a 5-year event-free survival rate of 75% (95% CI, 66.0% to 85.0%), 74% (95% CI, 61.0% to 89.0%), and 62% (95% CI, 55.0% to 69.0%), respectively. After exclusion of patients with high hypodiploidy with 44 chromosomes and adjustment for waiting time to transplantation and for covariables in a Poisson model, disease-free survival did not differ significantly ( P = .16) between the 42 patients who underwent transplantation and the 186 patients who received chemotherapy only, with an estimated 5-year survival rate of 59% (95% CI, 46.5% to 75.0%) versus 51.5% (95% CI, 44.7% to 59.4%), respectively. Transplantation produced no significant impact on outcome compared with chemotherapy alone, especially among the subgroup of patients who achieved a negative MRD status upon completion of remission induction. CONCLUSION MRD-stratified treatments improved the outcome for children with hypodiploid ALL. Allogeneic transplantation did not significantly improve outcome overall and, in particular, for patients who achieved MRD-negative status after induction.

Contains fulltext : 204641.pdf (Publisher’s version ) (Open Access) Genetic abnormalities provide vital diagnostic and prognostic information in pediatric acute lymphoblastic leukemia (ALL) and are increasingly used to assign patients to risk groups. We recently proposed a novel classifier based on the copy-number alteration (CNA) profile of the 8 most commonly deleted genes in B-cell precursor ALL. This classifier defined 3 CNA subgroups in consecutive UK trials and was able to discriminate patients with intermediate-risk cytogenetics. In this study, we sought to validate the United Kingdom ALL (UKALL)-CNA classifier and reevaluate the interaction with cytogenetic risk groups using individual patient data from 3239 cases collected from 12 groups within the International BFM Study Group. The classifier was validated and defined 3 risk groups with distinct event-free survival (EFS) rates: good (88%), intermediate (76%), and poor (68%) (P < .001). There was no evidence of heterogeneity, even within trials that used minimal residual disease to guide therapy. By integrating CNA and cytogenetic data, we replicated our original key observation that patients with intermediate-risk cytogenetics can be stratified into 2 prognostic subgroups. Group A had an EFS rate of 86% (similar to patients with good-risk cytogenetics), while group B patients had a significantly inferior rate (73%, P < .001). Finally, we revised the overall genetic classification by defining 4 risk groups with distinct EFS rates: very good (91%), good (81%), intermediate (73%), and poor (54%), P < .001. In conclusion, the UKALL-CNA classifier is a robust prognostic tool that can be deployed in different trial settings and used to refine established cytogenetic risk groups.

Our aim was to identify miRNAs that can predict risk of relapse in pediatric patients with acute lymphoblastic leukemia (ALL). Following high-throughput miRNA expression analysis (48 samples), five miRs were selected for further confirmation performed by real time quantitative PCR on a cohort of precursor B-cell ALL patients (n = 138). The results were correlated with clinical parameters and outcome. Low expression of miR-151-5p, and miR-451, and high expression of miR-1290 or a combination of all three predicted inferior relapse free survival (P = 0.007, 0.042, 0.025, and

ABL-class fusions other than BCR-ABL1 (or Ph+) are found in 2-3% of precursor B-cell acute lymphoblastic leukemia (pB-ALL) in children and adolescents. Occasional reports suggest that this rare ALL subtype has a poor prognosis and patients can benefit from treatment with tyrosine kinase inhibitors (TKIs). Aim of this retrospective study is to investigate the presenting features, treatment response and outcome in ABL-class fusion positive cases identified within large cohorts of patients treated in AIEOP-BFM ALL trials. This retrospective survey of ABL-class fusion positive pB-ALL other than Ph+ ALL was performed in patients aged 1-17 years at the diagnosis, treated from October 2000 to August 2018 according to the AIEOP-BFM (Associazione-Italiana- di- Ematologia-Oncologia Pediatrica-Berlin-Frankfurt-Münster) ALL 2000 and 2009 protocols in Austria, Australia, Czech Republic, Germany, Israel, Italy and Switzerland. While ABL-class fusions screening was not required by protocols, it was performed in some patients, according to centers' policies, usually after poor early treatment response. Overall, 46 ABL-class fusion positive cases with ABL1 fusions (N=15), ABL2 fusions (N=5), CSF1R fusions (N=3) and PDGFRB rearrangements (N=23) were identified. Compared with other pB-ALL children and adolescents, the ABL-class fusion positive cases presented with higher proportions of patients aged 10 years or older (52.2 vs. 22.2, P< .0001), hyperleukocytosis (WBC ≥100x109/l, 41.3 vs. 6.3, P< .0001), or poor minimal residual disease (MRD) response (>5x10-4 levels were observed in 65.2% vs. 18%, P< .0001 of patients after induction treatment phase IA and in 45.7% vs. 4.8%, P< .0001 after consolidation phase IB). For the entire cohort of 46 cases, the 5-year probability of event-free survival (EFS) was 49.1+8.9% and that of overall survival (OS) 69.6+7.8%; the cumulative incidence of relapse (CI) was 25.6+8.2% and treatment-related mortality 20.8+6.8%. Although not prescribed by the protocols, 13 patients received a TKI during different phases of treatment (TKI group), by choice of treating physicians, generally due to poor early treatment response. Eight TKI patients with high MRD levels at the end of induction phase IA received the TKI during consolidation phase IB, and six of them achieved either a low positive or negative MRD level at the end of consolidation phase IB. Nine of the 13 patients treated with TKIs underwent hematopoietic stem cell transplantation (HSCT) and only 1/9 (TKI+HSCT) relapsed. Thirty-three cases did not receive any TKI (no-TKI group) and eight of them relapsed; 6/17 patients treated with chemotherapy only, versus only 2/16 who underwent HSCT. Overall, 25 patients underwent HSCT, and of them 3 relapsed and 6 died of treatment-related complications. In patients with a WBC higher or lower than 100x109/L, the 5-year EFS was 36.8+12.7% vs. 59.9+11.6%, respectively (P= .21), and the 5-year OS was significantly lower in patients with a high WBC (48.8+12.9% vs. 87.4+6.8%, P= .036). This difference was more pronounced in the no-TKI group with a 5-year EFS 27.8+13.6% vs 61.8+12.7%, (P= .07), and an OS of 36.7+14.6% vs 94.4+5.4%, respectively (P= .0015). Presenting features, treatment response and outcome in this cohort of ABL-class fusion positive patients are markedly similar to those of patients with Ph+ ALL included in the EsPhALL studies. Our results suggest that TKIs and HSCT may be beneficial in reducing the risk of relapse. Thus there is an urgent need for large international cooperative controlled studies to investigate the impact of TKI, in combination with an appropriate chemotherapy backbone and the role of HSCT. To this purpose, an early identification of patients with ABL-class fusion positive acute lymphoblastic leukemia will be necessary. Disclosures Izraeli: sightdx: Consultancy; novartis: Honoraria; prime oncology: Speakers Bureau. Locatelli:Miltenyi: Honoraria; bluebird bio: Consultancy; Novartis: Consultancy, Membership on an entity's Board of Directors or advisory committees; Amgen: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bellicum: Consultancy, Membership on an entity's Board of Directors or advisory committees. White:BMS: Honoraria, Research Funding; AMGEN: Honoraria, Speakers Bureau. Schrappe:Together with study group from SHIRE, JazzPharma, Servier, SigmaTau, Amgen, and Novartis.: Research Funding; SHIRE, Servier, and JazzPharma: Honoraria.

Neutral lipid storage disease (Chanarin-Dorfman syndrome) is a rare autosomal recessive disorder of lipid metabolism, characterized by systemic accumulation of neutral lipids in multiple tissues. We report a case of a 14-year-old girl with generalized ichthyosis, liver cirrhosis, and a hearing impairment. A peripheral blood smear demonstrated marked cytoplasmatic vacuoles in most polymorphonuclear cells (Jordan's anomaly). Bone marrow examination revealed vacuoles in myeloid precursors. Genetic analysis showed that the patient was homozygous for the p.Arg312Ter mutation in the CGI-58 gene, a key enzyme in lipid metabolism. The peripheral blood smear is diagnostic, and should be performed in any patient with ichthyosis.

Outcome for relapsed paediatric acute myeloid leukaemia (AML) remains poor. Strong prognostic factors at first relapse are lacking, which hampers optimization of therapy. We assessed the frequency of molecular aberrations (FLT3, NRAS, KRAS, KIT, WT1 and NPM1 genes) at first relapse in a large set (n = 198) of relapsed non-French-American-British M3, non-Down syndrome AML patients that received similar relapse treatment. We correlated molecular aberrations with clinical and biological factors and studied their prognostic relevance. Hotspot mutations in the analysed genes were detected in 92 out of 198 patients (46.5%). In 72 of these 92 patients (78%), molecular aberrations were mutually exclusive for the currently analysed genes. FLT3-internal tandem repeat (ITD) (18% of total group) mutations were most frequent, followed by NRAS (10.2%), KRAS (8%), WT1 (8%), KIT (8%), NPM1 (5%) and FLT3-tyrosine kinase domain (3%) mutations. Presence of a WT1 aberration was an independent risk factor for second relapse (Hazard Ratio [HR] = 2.74, P = 0.013). In patients who achieved second complete remission (70.2%), WT1 and FLT3-ITD aberrations were independent risk factors for poor overall survival (HR = 2.32, P = 0.038 and HR = 1.89, P = 0.045 respectively). These data show that molecular aberrations at first relapse are of prognostic relevance and potentially useful for risk group stratification of paediatric relapsed AML and for identification of patients eligible for personalized treatment.

Introduction After treatment response, cytogenetics and molecular aberrations are the most important prognostic factors in children with de novo acute myeloid leukemia (AML). However, little is known about the impact of cytogenetics at relapse. This international retrospective study aimed to provide insight into the prognostic impact of cytogenetic profiles and the role of karyotype changes from diagnosis to relapse in pediatric patients with relapsed AML. Methods Cytogenetic reports from patients registered to the Relapsed AML 2001/01 Study and diagnosed between 2001 and 2010 were centrally reviewed and classified by two independent researchers plus a cytogenetic expert. Patients with refractory or relapsed AML and available cytogenetics at relapse were included in order to assess the prognostic impact of different cytogenetic subgroups at relapse. Patients with karyotypes available at both diagnosis and relapse were included in order to study the impact of karyotype changes. Recurrent cytogenetic aberrations present in ≥5 patients defined the subgroups. Changes at relapse were categorized as: no change, gain, loss, both gain and loss, or structural other aberration(s). Primary endpoints were the probabilities of event-free survival (pEFS) and overall survival (pOS). Univariate analyses were conducted using chi-square tests, binary univariate logistic regression or Kaplan Meier estimates with a log-rank test. Multivariable Cox regression analyses were conducted to evaluate the independent impact of cytogenetic profiles and karyotype changes at relapse. For these analyses, cytogenetic subgroups were regrouped into good risk (GR) cytogenetics [t(8;21)(q22;q22) or inv(16)/t(16;16)(p13.1;q22)] or "other". Results Of the 569 registered patients, 402 patients (71%) had available cytogenetic information at relapse. Frequently detected aberrations at relapse were t(8;21) (n=60, 15%) and inv(16)/t(16;16) (n=24, 6%), both indicating a relatively good prognosis. Although patient numbers were small (n=5), t(6;9)(p23;q34) also had a relatively good outcome. Monosomy 7/7q-, t(9;11)(p22;q23), t(10;11)(p12;q23) and complex karyotypes had a relatively poor outcome. Figure 1 shows the Kaplan Meier curves of the investigated cytogenetic subgroups with corresponding patient numbers. In total, 306 patients (54%) with available karyotypes at both diagnosis and relapse were included to study cytogenetic changes. Patients with any change (n=148, 48%) had inferior outcome compared to patients without changes (3-year pEFS 21% [SE, 3.4%] versus 39% [SE, 3.9%]; overall P After multivariable adjustment (final models including cytogenetics at relapse, time to relapse GR cytogenetics at relapse were significantly associated with better early treatment response. Subsequently, response to treatment at day 28 (Creutzig et al. Haematologica 2014) was an important mediator. If this prognostic parameter was included in the models, the effect of changes diminished, but GR cytogenetics at relapse remained an important prognostic factor associated with superior outcome (pEFS: HR 0.53 [95% CI 0.35-0.81], pOS: HR 0.51 [95% CI 0.32-0.80]). Conclusion Together with early treatment response, the cytogenetic profile at relapse is an important prognostic factor. In particular t(8;21) and inv(16)/t(16;16) at relapse were associated with a favorable outcome. Furthermore, cytogenetic changes between diagnosis and relapse were associated with inferior outcome. Future studies should explore the mechanism(s) of these changes, being either clonal evolution or clonal selection. Interpretation of our results is hampered by the retrospective design of the study, small subgroup numbers and missing cytogenetic and molecular data. Nonetheless, these findings suggest that assessing cytogenetics at time of relapse is of high importance, and can be used for risk group adapted treatment. Disclosures Reinhardt: Boehringer Ingelheim: Membership on an entity's Board of Directors or advisory committees; Pfizer: Membership on an entity's Board of Directors or advisory committees; Jazz Pharma: Other: Travel Accomodation; Celgene: Membership on an entity's Board of Directors or advisory committees; Celgene: Research Funding.

Aim: microRNAs (miRs) have been implicated in many malignancies. Our aim was to identify specific miRNAs that can predict risk of relapse in pediatric acute lymphoblastic leukemia (ALL) patients treated on BFM protocols, better than the current risk group stratification. Currently, the main method for risk group stratification is based on the amount of minimal residual disease (MRD) assessed at specific time points by real time quantitative PCR (RQ-PCR). Material and methods: Following microRNA expression analysis performed on 48 bone marrow samples at diagnosis, we focused on several miRs that correlated with at least 3 of the established prognostic markers in ALL to be validated in a cohort of 138 B-lineage ALL samples. Of the miRs studied, down regulated miR-151-5p and miR-451 and upregulated miR-1290 significantly correlated with outcome. Results: Low expression of miR-151-5p, miR-451 or of both together resulted in significantly worse relapse free survival (RFS) (56%, 63% and 47%, respectively) compared to RFS rates when either or both miRs were highly expressed (80%, 78% and 78%, respectively) (p=0.007, 0.042 and 0.002, respectively). High expression of miR-1290 resulted in worse RFS compared to those that expressed low levels (54% versus 81%; p=0.014). When combining the 3 miRs, a patient expressing low levels of both miRs and/or high levels of miR-1290 had a RFS of 54% (p=0.004). Furthermore, the expression of the 3 miRs could distinguish within the TEL-AML1 negative cohort two groups; one with 80% and the other with 44% RFS (p=0.004). Multivariate Cox regression analysis identified low expression of both miRs and/or high expression of miR-1290 as an independent prognostic marker in the PCR-MRD non-high risk cohort. Patients expressing abnormal levels of the 3 miRs had a 4.47-fold increased risk for relapse (p=0.037). Deletion of IKZF1 gene is a known adverse prognostic marker in B-lineage ALL. In 85 patients, IKZF1 status was analyzed and 9 patients were found to harbor the deletion. The expression of the 3 miRs could still identify an adverse group of patients with 69% RFS within the group with no deletion (p=0.004). When adding IKZF1 and TEL-AML1 status to the Multivariate analysis in addition to PCR-MRD, the expression of the 3 miRs remained a significant independent marker with a 24 fold increased risk for relapse (p=0.011). Figure 1 Figure 1. Conclusion: Our results identify the combination of miR-151-5p, miR-451 and miR-1290 as a novel biomarker for outcome in pediatric B-lineage ALL patients, already at time of diagnosis. This may lead to improved risk group stratification and enable early therapeutic intervention that may result in better RFS. Disclosures No relevant conflicts of interest to declare.

Aim: microRNAs (miRNAs) have been implicated in many malignancies. Our aim was to identify specific miRNAs that can predict risk of relapse in pediatric acute lymphoblastic leukemia (ALL) patients treated on BFM protocols, better than the current risk group stratification. Currently, the main method for risk group stratification is based on the amount of minimal residual disease (MRD) assessed at specific time points by real time quantitative PCR (RQ-PCR). Material and methods: Following microRNA expression analysis, we decided to focus on miR-151-5p and miR-451 that significantly correlated with known prognostic factors in ALL. Validation was performed by measuring the expression levels of miR-151-5p and miR-451 by RQ- PCR on a cohort of B-lineage ALL patients treated by a Berlin-Frankfurt-Munster (BFM) protocol following exclusion of Philadelphia positive patients (n=123). Results: Low expression of miR-151-5p, miR-451 or of both together resulted in significantly worse relapse free survival (RFS) (61%, 64% and 43%, respectively) compared to RFS rates when either or both miRNAs were highly expressed (83%, 82% and 82%, respectively) (p=0.023, 0.03 and 0.0001, respectively). Multivariate Cox regression analysis identified low expression of both miRNAs as an independent prognostic marker. Patients expressing low expression levels of both miRs had a 8.8-fold increased risk for relapse (p=0.003). Deletion of IKZF1 gene is a known adverse prognostic marker in B-lineage ALL. In 88 patients, IKZF1 status was analyzed and 9 patients were found to harbor the deletion. The expression of both miRs could still identify an adverse group of patients with only 50% RFS within the group with no deletion (p Even in a non-BFM treated B-lineage ALL cohort from The Netherlands, the expression levels of both miRs significantly correlated with outcome (p=0.003). Conclusion: Our results identify miR-151-5p and miR-451 as novel biomarkers for outcome in pediatric B-lineage ALL patients, regardless of treatment protocol. This may lead to improved risk group stratification and better RFS. Citation Format: Smadar Avigad, Iedan RN Verly, Gertjan JL Kaspers, Jacqueline Cloos, Anat Ohali, Michal Hameiri-Grossman, Keren Shichrur, Eva Fronkova, Jan Trka, Drorit Luria, Yona Kodman, Hadar Mirsky, Dafna Gaash, Marta Jeison, Galia Avrahami, Sarah Elitzur, Gil Gilad, Batia Stark, Isaac Yaniv. Increased risk of relapse in non-high-risk children with pediatric B-lineage acute lymphoblastic leukemia can be predicted at diagnosis by microRNA expression. [abstract]. In: Proceedings of the AACR Special Conference on Pediatric Cancer at the Crossroads: Translating Discovery into Improved Outcomes; Nov 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2013;74(20 Suppl):Abstract nr B34.

Abstract 2507 Aim: microRNAs (miRNAs) have been implicated in many malignancies. Our aim was to identify specific miRNAs that can predict risk of relapse in pediatric acute lymphoblastic leukemia (ALL) patients treated according to BFM protocols already at diagnosis. The current risk group stratification is based on the amount of minimal residual disease (MRD) assessed at specific time points by real time quantitative PCR (RQ-PCR). Material and methods: Following miRNA expression analysis, we decided to focus on miR-151-5p and miR-451 that significantly correlated with known prognostic factors in ALL. Validation was performed by measuring the expression levels of miR-151-5p and miR-451 by RQ-PCR on bone marrow samples at diagnosis of 101 B-lineage ALL patients excluding Philadelphia positive patients. Results: Low expression of miR-151-5p, miR-451 or of both together resulted in significantly worse relapse free survival (RFS) (43%, 58% and 38%, respectively) compared to RFS rates when either or both miRNAs were highly expressed (81%, 75% and 75%, respectively) (p=0.001, 0.044 and 0.001, respectively). Moreover, following PCR-MRD stratification, low expression of miR-451 or both miRNAs remained significant within the PCR-MRD medium risk group (p=0.00001) and within the standard group for both miRNAs (p=0.024). Multivariate Cox regression analysis identified low expression of both miRNAs as an independent prognostic marker with 11.7 fold increased risk for relapse (p=0.002). After excluding patients harboring the adverse genetic markers Ikaros deletion and P2RY8-CRLF2 rearrangement, a patient expressing low levels of both miRs had a 35 fold risk to relapse (p=0.005). Analyzing a non-BFM treated B-lineage ALL cohort from The Netherlands, both miRNAs significantly correlated with outcome (p=0.003). Conclusion: Our results identify miR-151-5p and miR-451 as novel biomarkers for outcome in pediatric B-lineage ALL patients, regardless of treatment protocol. This may allow earlier and improved risk group stratification already at diagnosis, enabling exploration of early therapeutic interventions. Disclosures: No relevant conflicts of interest to declare.