A comprehensive analysis of cytogenetics, molecular profile, and survival among pediatric acute myeloid leukemia: a prospective study from a tertiary referral center.

Am J Blood Res 2022;12(6):177-189 www.AJBlood.us /ISSN:2160-1992/AJBR0145367 Original Article A comprehensive analysis of cytogenetics, molecular profile, and survival among pediatric acute myeloid leukemia: a prospective study from a tertiary referral center Jagdish Prasad Meena1, Harshita Makkar1, Aditya Kumar Gupta1, Sameer Bakhshi2, Ritu Gupta3, Deepshi Thakral3, Anita Chopra3, Pranay Tanwar3, Ashish Datt Upadhyay4, Nivedita Pathak1, Rachna Seth1 Division of Pediatric Oncology, Department of Pediatrics, 2Department of Medical Oncology, Dr. B.R.A. IRCH, Laboratory Oncology Unit, Dr. B.R.A. IRCH, 4Department of Biostatistics, All India Institute of Medical Sciences, New Delhi 110029, India 1 3 Received July 15, 2022; Accepted November 15, 2022; Epub December 15, 2022; Published December 30, 2022 Abstract: Background and aims: The objectives of this study were to investigate the cyto-molecular profile and survival of pediatric acute myeloid leukemia (AML). Methods: This prospective study was carried out in a tertiary care hospital from October 2018 to December 2020. Karyotype and cytogenetics analyses were done to identify chromosomal aberrations in pediatric AML. The targeted molecular panel utilized the polymerase chain reaction (PCR), reverse transcription-polymerase chain reaction (RT-PCR), and fragment analysis. Results: A total of 70 patients of AML with aged ≤18 years were enrolled in this study. The cytogenetic analyses revealed abnormal/recurrent cytogenetic abnormalities (CA) in 64.3% of patients and normal cytogenetics (CN) in 35.7% of patients. FAB M2 subtype showed frequent aberrant expression of the CD19 marker. CD7, CD11b, and CD36a were significantly present in the absence of molecular markers. Common chromosomal abnormalities were t(translocation) (8;21) (55%), monosomy/deletion 7 (13%), monosomal karyotype (5%) and complex karyotype (3%). The fusion transcripts RUNX1-RUNX1T1 [t(8;21)] (41%) and CBFB-MYH11 [t(16;16)] (3%) were detected by RT-PCR and FLT3-TKD D835 mutation (1.5%) by allele-specific oligo PCR. Fragment analysis revealed NPM1 (8%) mutation and FLT-ITD (9.5%) mutations. Complete remission was achieved in all evaluable patients. The median follow-up period of our patients was 225 days (IQR 28; 426 days). The median event-free survival (EFS) in all patients was 11.9 months (95% CI, 5-12.6 months). The forty months overall survival probability (pOS) was 58% in all patients. Conclusion: The majority of patients had abnormal/recurrent cytogenetics abnormalities. FAB M2 subtype showed frequent aberrant expression of the CD19. The absence of molecular markers may suggest the presence of CD7, CD11b, and CD36a expression. The overall survival has increased considerably in LMIC. Keywords: Acute myeloid leukemia, karyotype, cytogenetics, molecular, children, survival Introduction AML is a heterogeneous hematologic malignancy characterized by clonal expansion of myeloid blasts in the bone marrow, peripheral blood, and other tissues. It has varied presentations and is 2nd most common childhood leukemia after acute lymphoblastic leukemia (ALL). Pediatric AML comprises 15-20% of leukemia, with an incidence of seven cases per million in <15 years of age [1]. AML blasts are malignant myeloid progenitor cells that fail to differentiate, proliferating in the bone marrow and invad- ing peripheral blood and other organs, such as the central nervous system. Pediatric AML has better survival than adults because of the more frequent presence of good prognostic genetic features and higher tolerance to intensive treatment in children [2]. The treatment outcome of AML depends on the initial response to therapy and molecular and cytogenetic aberrations. Chromosomal abnormalities are recognized as important diagnostic and prognostic indicators [3]. The most frequent cytogenetic abnormalities are balanced Cytomolecular analysis of pediatric acute myeloid leukemia chromosomal rearrangements in pediatric AML. Unbalanced chromosomal abnormalities, such as monosomy 5 and 7, are less frequent in children and are associated with poor outcomes [3]. The cytogenetic and molecular abnormalities are involved in the pathogenesis of AML, and clonal chromosomal abnormalities are found in 70-85% of pediatric AML [4]. Several cyto-molecular events define the distinct subtypes of AML in childhood. These changes can be used as markers and help better define therapy targets, thereby reducing the toxicity of current treatment strategies [5]. The immunophenotypic features, molecular abnormalities, and recurrent mutations observed in AML provide potent markers for detecting measurable or minimal residual disease (MRD), which is an important prognostic marker in the treatment of AML [6]. The prognosis for children with AML has significantly improved over the last three decades due to the advancements in diagnostic technology, hematopoietic stem cell transplant (HSCT), and the introduction of newer chemotherapeutic agents. However, the overall survival of AML remains <70% [5]. The scenario of AML treatment is different in low-middleincome countries (LMIC), like India, where resources are limited and adequate supportive care facilities are not universally available in all centers [7]. A few families of children with AML do not opt for treatment, and many patients die of treatment-related toxicity. There are limited data available in the literature on AML from LMIC regarding the cyto-molecular profile and treatment outcome. Hence, this study aimed to evaluate the cyto-molecular analyses and outcomes of pediatric AML in India. Materials and methods Study design and patients This prospective study was conducted from October 2018 to December 2020 at the Department of Pediatrics, Department of Medical Oncology, and Laboratory Oncology Unit in All India Institute of Medical Sciences (AIIMS), New Delhi, India. We obtained approval from the Institute Ethics Committee at AIIMS (IEC383/06.07.2018, RP-7/2018) for this study. Newly diagnosed patients with AML were eligible for enrolment if they were ≤18 years of age 178 and parents or legally authorized representatives (LAR) signed the informed consent. The exclusion criteria included mixed phenotyping acute leukemia (MPAL), secondary leukemia, AML with Down syndrome, and acute promyelocytic leukemia (APML). In all patients, karyotype/cytogenetics analyses were done to identify chromosomal aberrations, and polymerase chain reaction (PCR), reverse transcriptionpolymerase chain reaction (RT-PCR), and fragment analysis were utilized for the targeted molecular panel. The demographics, clinical characteristics, laboratory parameters, and survival were compared between the two groups [abnormal cytogenetics/recurrent cytogenetic abnormalities AML patients (CA-AML) vs normal cytogenetics AML patients (CN-AML)]. The demographic profile and clinical and laboratory parameter assessments included the following: Baseline demographics: We recorded the age, ge (...truncated)