Paediatric chronic myeloid leukaemia: Is it really a different disease?

Challenges in Management of Pediatric Chronic Myeloid Leukemia (pCML) in the Low-Middle Income Countries (LMICs): Insights from an International CML Foundation (iCMLf) Multi-National Survey

Despite being a rare disease, high-income countries (HICs) have formulated guidelines for management of pediatric CML (pCML). We conducted a survey amongst 24 physicians from 22 Low-Middle Income Countries (LMICs) to gather information regarding their practice and experience in treating children with pCML. Rarity of pCML, lack of adequate expertise, and setting-adapted guidelines along with limitations in diagnostic infrastructure as well as challenges in accessing tyrosine kinase inhibitors (TKIs) were identified as major barriers in optimum management of patients. For the first time in literature, our findings provide valuable insights into the multifaceted challenges faced in managing pCML in LMICs.

Philadelphia Chromosome Positive and Philadelphia-Like Acute Lymphoblastic Leukemia in Children and Adolescents: Current Management, Controversies and Emerging Concepts

Philadelphia chromosome positive (Ph+) acute lymphoblastic lymphoma (ALL) is an uncommon subtype of ALL in children, seen in 2-5% cases. Diagnostic evaluation includes conventional karyotyping and detection of BCR-ABL1 translocation by fluorescence in-situ hybridization (FISH) or reverse transcriptase polymerase chain reaction (RT-PCR). For children, the frontline management includes combination of intensive chemotherapy along with imatinib (300-340 mg/m2/d) or dasatinib (60-80 mg/m2/d). Imatinib/dasatinib should be introduced in induction as soon as results for BCR-ABL are available. Minimal residual disease (MRD) monitoring is essential; multi-parametric flowcytometry and immunoglobulin/T-cell receptor rearrangement PCR are the preferred methods. Intrathecal therapy with at least 12 doses of methotrexate is adequate for central nervous system (CNS) prophylaxis, but cranial radiation is necessary for CNS3 involvement. Allogeneic hematopoietic stem cell transplantation (HSCT) in first remission may be considered in high-risk cases (persistent MRD positivity/induction failure). Maintenance therapy with tyrosine kinase inhibitors (TKI) in children is debatable, with potential concerns for long term adverse effects. At relapse, the choice of TKI is guided by the presence of BCR-ABL tyrosine kinase domain resistance mutations, although the frequency of resistance mutations in children are lower. Allogeneic HSCT is essential for consolidation in second remission, if not done. Ph-like ALL is a newly recognized molecular entity, with gene expression profile similar to Ph+ALL and poor survival outcomes. In resource-constrained settings, a stepwise cost-effective diagnostic evaluation should be considered among high-risk patients without recurrent genetic abnormalities. Current treatment strategies remain similar to Ph-negative ALL. Enrolment in clinical trials is encouraged for such children to evaluate potential targeted agents in this subtype.

Impact of Tyrosine Kinase Inhibitors (TKIs) on Growth in Children and Adolescents with Chronic Myeloid Leukemia: A Systematic Review

BACKGROUND

Chronic Myeloid Leukemia (CML) is a rare myeloproliferative disease in childhood. Treatment in CML includes Tyrosine Kinase Inhibitors (TKIs), which inhibit the cytoplasmic kinase BCR/ABL. Tyrosine kinases play a key role in the secretion of growth hormone and insulin-like growth factor 1 (IGF-1).

OBJECTIVE

The aim of this systematic review was to study the effect of TKIs on the growth of children and adolescents with CML.

METHODS

English-language publications were searched in the PubMed/Cochrane library/Google Scholar databases (2002-2023), and retrieved studies were assessed according to PRISMA-Statement and Newcastle- Ottawa-scale.

RESULTS

The search strategy yielded 1066 articles. After applying the inclusion/exclusion criteria, 941 were excluded based on title screening and 111 on abstract review. The systematic review included 14 articles (11 retrospective observational studies/3 clinical trials). Twelve studies reported data on the prevalence of growth disorders after the administration of 1st generation TKIs (imatinib). Two studies reported a negative effect of 2nd generation TKIs (dasatinib/nilotinib) on physical growth. Four studies recorded a decrease in height z-score after treatment compared to baseline. Two 1st-generation TKIs studies reported data on children's final height; one reported restoration of final height to normal after the onset of puberty, despite initial slowing, and the final height was lower than mid-parental target height. Serum IGF-1 levels were reported in 2 studies to be within normal range, while in 3 studies, a significant decrease was documented. Considerable study heterogeneity was observed related to dosage/duration of treatment/disease phase/stage of puberty/ethnicity.

CONCLUSION

A negative effect of TKIs on the growth and final height of children was noted.

Chronic Myeloid Leukemia: A retrospective study of clinical and pathological features

Chronic myeloid leukemia (CML), is one of the myeloproliferative disorders with a characteristic cytogenetic abnormality resulting in the BCR-ABL fusion gene. Imatinib Mesylate is an effective agent for treating patients in all stages of CML. According to the annual Iraqi cancer registry 2019, the total number of chronic myeloproliferative disorders was 338. The percentage and incidence rates were 0.94% and 0.86%, respectively, with a higher incidence rate in males than females (1.12 in males and 0.60 in females). In this registry, no details about CML, so this study aimed to estimate the number of CML patients who attended the national center of hematology from 2005 until 2020 and investigate their epidemiological and clinic-pathological data. All data were obtained from the National Center of Hematology /Baghdad. Data regarding annual admission, number of deaths, and information about age, regions, and sex, were collected from patient cards. Interview and history taking from the patient and reviewing their clinical features at diagnosis were performed, and then statistical analysis was achieved. Two hundred sixteen patients were registered as CML; among them, 163 are still alive, while 53 died. The mean age at diagnosis was 40.39 ±14.30, with a male-to-female ratio of 1:1.16. The pediatrics age group comprises 3.7% of total cases and 1.8 % and 9.4% in the alive and dead groups, respectively. The percentages of death were higher in the pediatric age group, 62,5%( 5 /8), followed by the patient group who were ≥60 years, 42.1%(8/19), while it was the least in adults < 60 years, 21.1% (40/189). In conclusion, the studied patients with CML were younger than the globally reported ages at diagnosis, with predominant female patients. Females had better survival, while children and the elderly were the worse. Most patients were symptomatic at diagnosis; however, a good outcome is achieved when treated with IM. Keywords: CML, Imatinib, leukemia,

Real-World Experience of Treating Pediatric Chronic Myeloid Leukemia: Retrospective Study from a Cancer Center in Southern India

Introduction Chronic myeloid leukemia (CML) is rare in children and constitutes 2% of all leukemia. We present our institute experience in treating pediatric CML for 20 years.

Objectives There is a paucity of data on pediatric CML from India, hence we would like to present treatment responses and survival rates in our pediatric population treated with tyrosine kinase inhibitors at our center.

Materials and Methods Patients aged less than 18 years, diagnosed with CML from 2000 to 2019, and treated with imatinib were analyzed retrospectively considering demographic features, treatment characteristics, and survival outcomes. Descriptive analysis was done for the baseline characteristics. Event-free survival (EFS) and overall survival (OS) were calculated using the Kaplan-Meier method and the factors were compared using the log-rank test.

Results During the study period, 95 patients were diagnosed with CML of which 54 (56.8%) were males. The most common stage at presentation was the chronic phase (CP) with 84 (88.4%) patients followed by accelerated phase (AP) and blast crisis (BC) with 6 (6.3%) and 5 (5.3%) patients respectively. The median duration of follow-up for all patients was 98 months. EFS and OS at 8 years for patients with CML-CP were 43.1% and 80.4% respectively. Complete hematological response, complete cytogenetic response, and major molecular response was documented in 91 (95.7%), 73 (76.8%), and 63 (66.3%) patients respectively.

Conclusion Outcomes in pediatric CML are comparable to that of adults. Imatinib is well tolerated in children.

Real-world Experience of Imatinib in Pediatric Chronic Phase Chronic Myeloid Leukemia: A Single-center Experience From India

INTRODUCTION

Chronic myeloid leukemia (CML) is an uncommon malignancy in children in which tyrosine kinase inhibitors (TKIs) have significantly improved outcome in recent years.

PATIENTS AND METHODS

We performed a retrospective analysis of CML patients (≤ 18 years old) presenting to our center between January 2005 and December 2018 with respect to baseline demographics, response to imatinib, and real-world management of those with a suboptimal response.

RESULTS

A total of 124 patients were diagnosed with CML with 99 (80%) in the chronic phase. There was a male preponderance (males:females = 3.1:1) with a median age of 13 years. The common presenting clinical features were splenomegaly (90.9%) and fever (51.5%) with a median leukocyte count of 165 × 103/μL. The proportion of patients attaining a complete hematologic response (CHR) at 3 months, a complete cytogenetic response (CCyR) at 12 months, and a major molecular response at 12 months were 79.7%, 54.1%, and 50.9%, respectively. At a median follow-up of 67.4 months, the 5-year overall survival rate and the event-free survival (EFS) rate were 92% ± 3% and 64% ± 6%, respectively. Failure to achieve CCyR at 12 months was associated with poor EFS beyond 1 year (hazard ratio = 2.865, P = .044). Among 15 patients not achieving CHR at 3 months, dose escalation of imatinib resulted in the attainment of CHR in 13 (87%) patients. Seven patients in the cohort had a loss of the established response to imatinib because of documented poor compliance.

CONCLUSION

Imatinib remains the frontline treatment of choice in CML with a reasonable outcome in children, especially when financial affordability, availability of second-generation TKIs, and poor compliance still remain major challenges in management. Dose escalation of imatinib remains an option in patients with a suboptimal response.