Characteristics, Treatment Complexity, and Outcome of Mixed-Phenotype Acute Leukemia in Children in a Low-Middle-Income Country.

Background: Mixed-phenotype acute leukemia (MPAL) in children is an uncommon subtype of acute leukemia that cannot be definitively assigned to a specific lineage. There is no consensus on the best approach to therapy. Management is more complex in low-middle-income countries (LMICs). Aim: To evaluate the clinicopathological characteristics and outcomes of patients with MPAL in a developing country. Patients and Methods: A retrospective descriptive study of 42 pediatric patients newly diagnosed with MPAL from July 2007 until December 2017. Results: The immunophenotyping was T/Myeloid in 24 patients (57.1%) and B/Myeloid in 16 (38.1%). Three subjects had MLL gene rearrangement, two had Philadelphia-positive chromosomes, and eight had FMS-like tyrosine kinase 3 (FLT3-ITD) internal tandem duplication (FLT3-ITD) with a ratio >0.4. Two subjects died before starting chemotherapy. Ten patients (25%) received acute lymphoblastic leukemia (ALL) induction, and all achieved complete remission (CR) with no induction deaths and no shift of therapy. Thirty patients (75%) started therapy with acute myeloid leukemia (AML) induction: five (16.6%) died during induction, 17 (56.7%) achieved CR, and 10 patients received maintenance ALL therapy after ending AML treatment. Four of the eight patients with induction failure were switched to ALL therapy. The 5-year event-free survival (EFS) and overall survival (OS) rates were 56.7% [standard error (SE): 8.1%] and 61% (SE: 8%), while the cumulative incidence of relapse was 21.7% (SE: 6.7%), with a median follow-up duration of 5.8 years. Patients treated with ALL-directed therapy had a 5-year EFS rate of 111 70% (SE: 14%) and OS rate of 78.8% (SE: 13%). Patients treated with ALL-directed therapy had a 5-year EFS rate of 70% (SE: 14.5%) and OS rate of 78.8% (SE: 13%). FLT3-ITD mutation showed a significantly lower 5-year EFS rate of 28.6% (SE: 17%) vs. 75% (SE: 9%) for the wild type, p = 0.032. Undernourished patients with a body mass index (BMI) z-score ≤-2 at presentation had a significantly lower 5-year EFS rate of 20% (SE: 17%) compared to 61.8% (SE: 8%) for patients with BMI z-score >-2, p = 0.015. Conclusion: This study supports ALL-directed therapy for pediatric MPAL in a setting of LMIC. Given the poor outcome of FLT3-ITD, the role of FLT3 inhibitor needs to be explored in this subset of cases.

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.

Outcome of Childhood Acute Myeloid Leukemia With FLT3-ITD Mutation: The Experience of Children's Cancer Hospital Egypt, 2007-17.

INTRODUCTION: The presence of FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutation in pediatric acute myeloid leukemia (AML) is associated with high rates of induction failure and worse survival. Its presence places the patient into a high-risk group. We aimed to describe the outcome of pediatric AML with FLT3-ITD mutation. PATIENTS AND METHODS: We performed a retrospective analysis of cases of AML from July 2007 till July 2017 at Children's Cancer Hospital Egypt. RESULTS: Seventy-one patients had FLT3 gene mutation out of 687 patients with AML. Sixty-five patients had FLT3 gene mutation with allelic ratio > 0.4; 43 (66.1%) of 65 patients experienced complete remission (CR). Of the 43 patients, 16 patients maintained CR, 18 patients relapsed after first CR, 8 patients died, and 1 patient was lost to follow-up. Patients with relapsing disease died after salvage chemotherapy, except for one patient, who was alive after second CR. Allogeneic bone marrow transplantation (allo-BMT) was performed for 9 (13.8%) of 65 patients in first CR, of whom 8 were alive and in CR, and 1 patient experienced disease relapse and died. Seven patients (10.7%) were alive without allo-BMT. Three years' overall and event-free survival for patients with FLT3-ITD mutation with high allelic ratio was 26.9% and 22.8%, respectively. Three years' overall and event-free survival for patients treated with allo-BMT was 77.8% and 78.8%, respectively, versus patients treated without allo-BMT, 16.3% and 12.8%, respectively. CONCLUSION: FLT3-ITD mutation in pediatric AML was associated with poor treatment outcomes, and the survival of relapsing patients was extremely poor. Allo-BMT in first remission was the best treatment option. Alternative donor transplants and FLT3 inhibitors are needed to improve outcome in developing countries.

A Comparison between Three Different Automated Total 25-hydroxyvitamin D Immunoassay Methods and Ultra Performance Liquid Chromatography.

OBJECTIVE: Vitamin D is a fat soluble vitamin responsible for calcium metabolism and more recently discovered effects. This led to an increase in requests for vitamin D test by clinicians. New automated assays have been introduced for 25-hydroxyvitamin D measurement. METHODS: Results from these new method have to be related to a Standard method to obtain best results for practical usage. In our study, one hundred venous blood samples were analyzed for 25-OH vitamin D on three immunological methods in our lab and correlated with ultra-performance liquid chromatography (UPLC) method as a reference method. RESULTS: Statistically analysis of results obtained for correlations between the 3 methods against the reference UPLC was done by Spearman's Correlation. It showed positive correlation in all methods with significant p value < 0.001. Differences and biases between methods were evaluated using a Bland-Altman plot and Cohen's Kappa agreement. Best agreement was found in Cobas 6000 followed by the Access2 then comes Architect.  Conclusions: All immunoassays can be used in routine 25(OH) D measurements, still some methods are better than others. A clinical laboratory must at least be aware of its method to avoid misinterpretation of results.

RAS Pathway Mutation Patterns in Patients With Juvenile Myelomonocytic Leukemia: A Developing Country Single-center Experience.

INTRODUCTION: Juvenile myelomonocytic leukemia (JMML) is a rare clonal myelodysplastic/myeloproliferative neoplasm of early childhood. Historically, it was difficult to diagnose clinically, as patients present with manifestations shared with other hematologic malignancies or viral infections. It is now clear that JMML is a disease of hyperactive RAS signaling. PATIENTS AND METHODS: We examined the bone marrow of 41 Egyptian children with JMML by direct sequencing for mutations in the RAS pathway genes. RESULTS: Mutations were detected in 33 (80%) of 41 patients. We identified 12 (29%) of 41 patients with PTPN11 mutation; 18 (44%) of 41 with RAS mutation; 9 (22%) of 41 with NRAS mutation; 9 (22%) of 41 with KRAS mutation; and 3 (7%) of 41 with CBL mutation. Eleven (92%) of the PTPN11 mutations were detected in exon 3 and 1 (8%) in exon 13. Seven of the NRAS mutations were in exon 2, and 2 were in exon 3. All KRAS mutations were in exon 2. The 3 cases with CBL mutation were homozygous mutations in exon 8. All the mutations detected in PTPN11, NRAS/KRAS, and the CBL genes were previously reported missense mutations in JMML. CONCLUSION: Our results demonstrate that Egyptian children diagnosed with JMML have high frequency of NRAS/KRAS mutations and lower frequency of PTPN11 mutations as compared with previous studies. The concept of mutually exclusive RAS pathway mutations was clearly observed in our patients. All cancer centers in our region should start implementing molecular diagnostic methods before confirming the diagnosis of JMML and before offering hematopoietic stem cell transplantation.

Does Salvage Chemotherapy Regimen Intensity Embark on Clearance of Bone Marrow Neuroblastoma?

Introduction: Neuroblastoma (NBL) is the most common extracranial solid tumor in children. It accounts for 15% of the deaths from cancer in the pediatric age group. Approximately half of the newly diagnosed children are at "high risk" (HR) of treatment failure. This study aim was to evaluate the impact of salvage chemotherapy ICE (ifosfamide, carboplatin, and etoposide) versus TC (topotecan/cyclophosphamide) when administered to NBL HR patients having residual bone marrow disease after primary tumor control on the first line treatment regimen. Materials and Methods: The present retrospective study included two groups of eligible stage 4 NBL patients with persistent bone marrow disease. Group (1), 29 patients, received ICE whereas less intensive TC was administered to Group (2), 32 patients. Data analysis included epidemiological variables, pathology subtype, MYCN gene status, primary tumor response and their correlation with bone marrow disease clearance on each regimen. Results: A higher tendency of complete bone marrow clearance was reported in patients who received ICE compared to TC; 41.4% versus 25.0%, respectively. However, the difference was not statistically significant (p= 0.174). Conclusion: TC regimen appears to be a good alternative to ICE as salvage treatment in an attempt to clear NBL bone marrow residual, with the privilege of being less toxic and can be given on outpatient basis. Further randomized trials of larger study sample size with survival impact analysis are warranted.

Survival outcome of intermediate risk neuroblastoma at Children Cancer Hospital Egypt.

AIM: The study aims to evaluate survival outcome in newly diagnosed pediatric intermediate risk neuroblastoma patients treated at the Children Cancer Hospital - Egypt and their relation to various clinical and pathological factors. METHODS: The study included stage 3 patients <1.5 years, children 1.5 years or older with stage 3 disease and favorable histopathological features, infants (<1 year) with International Neuroblastoma Staging System (INSS) stage 4 disease, stage 4 children 1-1.5 years with favorable biology, and infants stage 4 s (with unfavorable biologic features). Patients received systemic chemotherapy, in the form of etoposide and carboplatin alternating with cyclophosphamide, doxorubicin and vincristine, administered at 3-week intervals, with a total of 6 or 8 cycles guided by reaching objective overall response (complete/very good partial/partial response). RESULTS: The study included 136 patients, 67 males and 69 females. 101 patients had abdominal primary tumors, 28 had mediastinal masss and 7 with masses in the neck; 68% were stage 3 and the remaining (n = 44) had metastatic disease. The three-year overall survival (OS) and event-free survival (EFS) estimates were 94% ±â€¯2% and 90.9% ±â€¯2.5%, respectively. OS and EFS by gender, age, pathology and INPC were all statistically not significantly different. Moreover, OS for patients having surgery versus no surgery (inoperable residual only) was statistically significant (98.4% ±â€¯1.6% & 88.7% ±â€¯5.3%, respectively, p = .034). CONCLUSION: A very high rate of survival is currently achievable in patients with intermediate risk neuroblastoma by chemotherapy or chemotherapy and surgery. In addition to response, our plan is to adopt biologically-based treatment to reduce treatment-induced complications among survivors.

Clinical significance of immunophenotypic markers in pediatric T-cell acute lymphoblastic leukemia.

BACKGROUND: Cell-marker profiling has led to conflicting conclusions about its prognostic significance in T-ALL. AIM: To investigate the prevalence of the expression of CD34, CD10 and myeloid associated antigens (CD13/ CD33) in childhood T-ALL and to relate their presence to initial clinical and biologic features and early response to therapy. PATIENTS AND METHODS: This study included 67 consecutive patients with newly diagnosed T-ALL recruited from the Children's Cancer Hospital in Egypt during the time period from July 2007 to June 2008. Immunophenotypic markers and minimal residual disease (MRD) were studied by five-color flow cytometry. RESULTS: The frequency of CD34 was 34.9% , CD10 33.3% , while CD13/CD33 was 18.8%. No significant association was encountered between CD34, CD10 or myeloid antigen positivity and the presenting clinical features as age, sex, TLC and CNS leukemia. Only CD10(+) expression had significant association with initial CNS involvement (p=0.039). CD34 and CD13/CD33 expression was significantly associated with T-cell maturation stages (p<0.05). No relationship was observed for age, TLC, gender, NCI risk or CNS involvement with early response to therapy illustrated by BM as well as MRD day 15 and day 42. CD34(+), CD13/CD33(+) and early T-cell stage had high MRD levels on day 15 that was statistically highly significant (p<0.01), but CD10(+) had statistically significant lower MRD level on day 15 (p=0.049). However, only CD34 retained its significance at an MRD cut-off level of 0.01%. CONCLUSIONS: CD34, CD10, CD13/CD33 expression, as well as T-cell maturation stages, may have prognostic significance in pediatric T-ALL as they have a significant impact on early clearance of leukemic cells detected by MRD day 15.