# The outcome in pediatric acute myeloblastic leukemia; results of the first-line treatment and contribution of hematopoietic stem cell transplantation to survival of relapsed patients

## TL;DR

This study examines the long-term outcomes of children with acute myeloblastic leukemia and evaluates the role of stem cell transplantation in improving survival.

## Contribution

The study provides a detailed analysis of treatment outcomes and the impact of hematopoietic stem cell transplantation in relapsed pediatric AML patients.

## Key findings

- The complete remission rate was 87.8% with a 5.8% mortality during induction.
- Hematopoietic stem cell transplantation in second remission improved survival for relapsed patients.
- Fifteen-year overall survival was 69.6%, comparable to international standards.

## Abstract

To analyze the long-term outcome of pediatric patients with acute myeloblastic leukemia.

Data from 69 patients 0–18 years of age diagnosed between December 2001 and October 2019 were analyzed in April 2023. Patients received MRC-AML10 chemotherapy (2ADE+MACE+MidAC). No maintenance chemotherapy or preventive cranial radiotherapy was administered. Twelve patients with Down syndrome and 15 patients with promyelocytic leukemia were in the cohort. Patients with Down syndrome received reduced chemotherapy (cumulative anthracycline 420 mg/m2, cytarabine 3.4 g/m2, etoposide 1400 mg/m2). ATRA was added to chemotherapy in promyelocytic leukemia.

Four patients (5.8%) died in the induction (two typhlitis, one intracranial hemorrhage, and one resistant disease). The complete remission rate of 66 patients was 87.8%. There was one death due to cardiotoxicity. Total infection-related deaths were 7.2%. Seven patients with high-risk criteria and one with resistant disease underwent hematopoietic stem cell transplantation (HSCT) following the first-line treatment. All seven patients in remission were alive and disease-free. The relapse rate was 34.4% (n = 21). Four patients developing marrow relapse were disease-free in the second remission after salvage and maintenance chemotherapy. Thirteen patients (18.84%) underwent HSCT in the second remission and 8 are alive and disease-free. The mean follow-up period of patients from diagnosis was 185 ± 13 months. Thirty-four patients (49.2%) were alive and disease-free in the first remission whereas another two patients in the first remission developed secondary malignancy. In good, standard, and poor risk groups, event-free survival (EFS) rates were 68.2%, 52.9%, and 10%, and overall survival (OS) rates were 86.4%, 79.4%, and 20%, respectively. Fifteen years of EFS and OS of the whole cohort were 49.3% and 69.6%, respectively.

When compared with national data and multicenter studies of developed countries, survival rates were acceptable.