Outcomes in patients with ETV6::RUNX1 or high-hyperdiploid B-ALL treated in the St. Jude Total Therapy XV/XVI studies.

Children with ETV6::RUNX1 or high-hyperdiploid B-acute lymphoblastic leukemia (B-ALL) have favorable outcomes. The St. Jude (SJ) classification considers these patients low-risk, regardless of their National Cancer Institute (NCI) risk, except when there is slow minimal residual disease (MRD) response or central nervous system/testicular involvement. We analyzed outcomes in children (aged 1-18.99 years) with these genotypes in the SJ Total XV and XVI studies (2000-2017). Patients with ETV6::RUNX1 (n = 222) or high-hyperdiploid (n = 296) B-ALL had 5-year event-free survival (EFS) of 97.7% ± 1.1% and 94.7% ± 1.4%, respectively. For ETV6::RUNX1, EFS was comparable for NCI standard-risk and high-risk patients (97.8% ± 1.2% and 97.5% ± 2.6%, respectively; P = 0.917) and for SJ low-risk and standard-risk patients (97.4% ± 1.2% and 100.0%; P = 0.360). Thirty-seven of 40 NCI high-risk patients who received SJ low-risk therapy had excellent EFS (97.3% ± 2.8%). For high-hyperdiploid B-ALL, EFS was worse for NCI high-risk patients than for standard-risk patients (87.6% ± 4.5% and 96.4% ± 1.3%; P = 0.016). EFS was similar for NCI standard-risk and high-risk patients classified as SJ low-risk (96.0% ± 1.5% and 96.9% ± 3.2%; P = 0.719); however, EFS was worse for NCI high-risk patients than for NCI standard-risk patients receiving SJ standard/high-risk therapy (77.4% ± 8.2% and 98.0% ± 2.2%; P = 0.004). NCI high-risk patients with ETV6::RUNX1 or high-hyperdiploid B-ALL who received SJ low-risk therapy had lower incidences of thrombosis (P = 0.013) and pancreatitis (P = 0.011) than those who received SJ standard/high-risk therapy. Contemporary MRD-directed therapy yielded excellent outcomes, except for NCI high-risk high-hyperdiploid B-ALL patients with slow MRD response, who require new treatment approaches. Among NCI high-risk patients, 93% with ETV6::RUNX1 and 54% with high-hyperdiploid B-ALL experienced excellent outcomes with a low-intensity regimen. These trials were registered at www.clinicaltrials.gov as #NCT00137111 and #NCT00549848.

Clinical networking results in continuous improvement of the outcome of patients with acute promyelocytic leukemia.

ABSTRACT: The introduction of all-trans retinoic acid combined with anthracyclines has significantly improved the outcomes for patients diagnosed with acute promyelocytic leukemia (APL), and this strategy remains the standard of care in countries in which arsenic trioxide is not affordable. However, data from national registries and real-world databases indicate that low- and middle-income countries (LMIC) still face disappointing results, mainly because of high induction mortality and suboptimal management of complications. The American Society of Hematology established the International Consortium on Acute Leukemias (ICAL) to address this challenge through international clinical networking. Here, we present the findings from the International Consortium on Acute Promyelocytic Leukemia study involving 806 patients with APL recruited from 2005 to 2020 in Brazil, Chile, Paraguay, Peru, and Uruguay. The induction mortality rate has notably decreased to 14.6% compared with the pre-ICAL rate of 32%. Multivariable logistic regression analysis revealed as factors associated with induction death: age of ≥40 years, Eastern Cooperative Oncology Group performance status score of 3, high-risk status based on the Programa Español de Tratamiento en Hematologia/Gruppo Italiano Malattie EMatologiche dell'Adulto classification, albumin level of ≤3.5 g/dL, bcr3 PML/RARA isoform, the interval between presenting symptoms to diagnosis exceeding 48 hours, and the occurrence of central nervous system and pulmonary bleeding. With a median follow-up of 53 months, the estimated 4-year overall survival rate is 81%, the 4-year disease-free survival rate is 80%, and the 4-year cumulative incidence of relapse rate is 15%. These results parallel those observed in studies conducted in high-income countries, highlighting the long-term effectiveness of developing clinical networks to improve clinical care and infrastructure in LMIC.

Clinical characteristics and outcomes of children with newly diagnosed acute myeloid leukemia and hyperleukocytosis managed with different cytoreductive methods.

BACKGROUND: Hyperleukocytosis in patients with acute myeloid leukemia (AML) has been associated with worse outcomes. For cytoreduction, leukapheresis has been used but its clinical utility is unknown, and low-dose cytarabine (LD-cytarabine) is used as an alternative method. METHODS: Children with newly diagnosed AML treated between 1997 and 2017 in institutional protocols were studied. Hyperleukocytosis was defined as a leukocyte count of ≥100 × 109 /L at diagnosis. Clinical characteristics, early complications, survival data, and effects of cytoreductive methods were reviewed. Among 324 children with newly diagnosed AML, 49 (15.1%) presented with hyperleukocytosis. Initial management of hyperleukocytosis included leukapheresis or exchange transfusion (n = 16, considered as one group), LD-cytarabine (n = 18), hydroxyurea (n = 1), and no leukoreduction (n = 14). RESULTS: Compared with patients who received leukapheresis, the percentage decrease in leukocyte counts following intervention was greater among those who received LD-cytarabine (48% vs. 75%; p = .02), with longer median time from diagnosis to initiation of protocol therapy (28.1 vs. 95.2 hours; p < .001). The incidence of infection was higher in patients (38%) who had leukapheresis than those who receive LD-cytarabine (0%) or leukoreduction with protocol therapy (14%) (p = .008). No differences were noted in the outcomes among the intervention groups. Although patients with hyperleukocytosis had higher incidences of pulmonary and metabolic complications than did those without, no early deaths occurred, and the complete remission, event-free survival, overall survival rates, and outcomes of both groups were similar. CONCLUSION: LD-cytarabine treatment appears to be a safe and effective means of cytoreduction for children with AML and hyperleukocytosis.

Characterisation of children and adolescents with acute lymphoblastic leukaemia who presented without peripheral blood blasts at diagnosis.

Of 1003 children with acute lymphoblastic leukaemia (ALL), 147 (14.7%) presented without peripheral blood blasts (PBB). While absence of PBB was not independently associated with survival outcomes when compared to those with PBB, patients without PBB had distinct genetic and clinical characteristics. Notably, we identified a novel genotype-phenotype relationship, in that the patients without PBB had a significantly higher incidence of hyperdiploid B-ALL, accounting for almost half of all patients without PBB (46.9% vs. 22.7%, p < 0.001). Further, absence of PBB was associated with decreased rates of leukaemia involvement of the central nervous system (p < 0.001).

Clinical significance of mitochondrial DNA content in acute promyelocytic leukaemia.

Although a growing body of evidence demonstrates that altered mtDNA content (mtDNAc) has clinical implications in several types of solid tumours, its prognostic relevance in acute promyelocytic leukaemia (APL) patients remains largely unknown. Here, we show that patients with higher-than-normal mtDNAc had better outcomes regardless of tumour burden. These results were more evident in patients with low-risk of relapse. The multivariate Cox proportional hazard model demonstrated that high mtDNAc was independently associated with a decreased cumulative incidence of relapse. Altogether, our data highlights the possible role of mitochondrial metabolism in APL patients treated with ATRA.

Reduced-intensity therapy for pediatric lymphoblastic leukemia: impact of residual disease early in remission induction.

Legacy data show that ∼40% of children with acute lymphoblastic leukemia (ALL) were cured with limited antimetabolite-based chemotherapy regimens. However, identifying patients with very-low-risk (VLR) ALL remains imprecise. Patients selected based on a combination of presenting features and a minimal residual disease (MRD) level <0.01% on day 19 of induction therapy had excellent outcomes with low-intensity treatment. We investigated the impact of MRD levels between 0.001% and <0.01% early in remission induction on the outcome of VLR ALL treated with a low-intensity regimen. Between October of 2011 and September of 2015, 200 consecutive patients with B-precursor ALL with favorable clinicopathologic features and MRD levels <0.01%, as assessed by flow cytometry in the bone marrow on day 19 and at the end of induction therapy, received reduced-intensity therapy. The 5-year event-free survival was 89.5% (± 2.2% standard error [SE]), and the overall survival was 95.5% (± 1.5% SE). The 5-year cumulative incidence of relapse (CIR) was 7% (95% confidence interval, 4-11%). MRD levels were between 0.001% and <0.01% on day 19 in 29 patients. These patients had a 5-year CIR that was significantly higher than that of patients with undetectable residual leukemia (17.2% ± 7.2% vs 5.3% ± 1.7%, respectively; P = .02). Our study shows that children with VLR ALL can be treated successfully with decreased-intensity therapy, and it suggests that the classification criteria for VLR can be further refined by using a more sensitive MRD assay.

SIOP PODC adapted risk stratification and treatment guidelines: Recommendations for acute myeloid leukemia in resource-limited settings.

In low- and middle-income countries (LMICs), limited resources, suboptimal risk stratification, and disproportionate patient-to-infrastructure ratio result in low survival of patients with acute myeloid leukemia (AML). A high incidence of relapse, inherent to the biology, renders management arduous. The challenge of treating AML in LMICs is of balancing the intensity of myelosuppressive chemotherapy, which appears necessary for cure, with available supportive care, which influences treatment-related mortality. The recommendations outlined in this paper are based on published evidence and expert opinion. The principle of this adapted protocol is to tailor treatment to available resources, reduce preventable toxic death, and direct limited resources toward those children who are most likely to be cured.

Reduced-dose intensity therapy for pediatric lymphoblastic leukemia: long-term results of the Recife RELLA05 pilot study.

Treatment-related mortality is common among children with acute lymphoblastic leukemia (ALL) treated in poor-resource settings. We applied a simplified flow cytometric assay to identify patients with precursor B-cell ALL (B-ALL) at very low risk (VLR) of relapse and treated them with a reduced-intensity treatment plan (RELLA05). VLR criteria include favorable presenting features (age ≥ 1 and < 10 years), white blood cell count of <50 ×109/L, lack of extramedullary leukemia, and minimal residual disease level of <0.01% on remission induction day 19. Except for 2 doses of daunorubicin, treatment of patients with VLR B-ALL consisted of a combination of agents with relatively low myelotoxicity profiles, including corticosteroids, vincristine, L-asparaginase, methotrexate, and 6-mercaptopurine. Cyclophosphamide, systemic cytarabine, and central nervous system radiotherapy were not used. Of 454 patients with ALL treated at the Instituto de Medicina Integral Professor Fernando Figueira in Recife, Brazil, between December 2005 and June 2015, 101 were classified as having VLR B-ALL. There were no cases of death resulting from toxicity or treatment abandonment during remission induction. At a median follow-up of 6.6 years, there were 8 major adverse events: 6 relapses, 1 treatment-related death (from septicemia) during remission, and 1 secondary myeloid leukemia. The estimated 5-year event-free and overall survival rates were 92.0% ± 3.9% and 96.0% ± 2.8%, respectively. The 5-year cumulative risk of relapse was 4.24% ± 2.0%. The treatment was well tolerated. Episodes of neutropenia were of short duration. Patients with B-ALL selected by a combination of presenting features and degree of early response can be successfully treated with a mildly myelosuppressive chemotherapy regimen.

Comprehensive analysis of dose intensity of acute lymphoblastic leukemia chemotherapy.

Chemotherapy dosages are often compromised, but most reports lack data on dosages that are actually delivered. In two consecutive acute lymphoblastic leukemia trials that differed in their asparaginase formulation, native E. coli L-asparaginase in St. Jude Total 15 (T15, n=365) and pegaspargase in Total 16 (T16, n=524), we tallied the dose intensities for all drugs on the low-risk or standard-risk arms, analyzing 504,039 dosing records. The median dose intensity for each drug ranged from 61-100%. Dose intensities for several drugs were more than 10% higher on T15 than on T16: cyclophosphamide (P<0.0001 for the standard- risk arm), cytarabine (P<0.0001 for the standard-risk arm), and mercaptopurine (P<0.0001 for the low-risk arm and P<0.0001 for the standardrisk arm). We attributed the lower dosages on T16 to the higher asparaginase dosages on T16 than on T15 (P<0.0001 for both the low-risk and standard-risk arms), with higher dose-intensity for mercaptopurine in those with anti-asparaginase antibodies than in those without (P=5.62x10-3 for T15 standard risk and P=1.43x10-4 for T16 standard risk). Neutrophil count did not differ between protocols for low-risk patients (P=0.18) and was actually lower for standard-risk patients on T16 than on T15 (P<0.0001) despite lower dosages of most drugs on T16. Patients with low asparaginase dose intensity had higher methotrexate dose intensity with no impact on prognosis. The only dose intensity measure predicting a higher risk of relapse on both studies was higher mercaptopurine dose intensity, but this did not reach statistical significance (P=0.03 T15; P=0.07 T16). In these intensive multiagent trials, higher dosages of asparaginase compromised the dosing of other drugs for acute lymphoblastic leukemia, particularly mercaptopurine, but lower chemotherapy dose intensity was not associated with relapse.

Cure4Kids: Two decades of knowledge transfer.

Cure4Kids is a free web-based knowledge platform for professionals providing care for children with cancer and hematologic diseases, offering its users a comprehensive suite of learning opportunities. It has been a resource for the pediatric oncology community across the world for the past two decades, with 60,107 users having logged in 1,412,514 times with 22,045,553 content hits. A transformation of Cure4Kids is being planned and will include an improved user interface, increased interactivity, and more content.