Pediatric Acute Myeloid Leukemia Post Cytotoxic Therapy—Retrospective Analysis of the Patients Treated in Poland from 2005 to 2022

SIMPLE SUMMARY: Acute myeloid leukemia post cytotoxic therapy (AML-pCT) is a rare complication of cancer treatment in childhood. We retrospectively analyzed the data of 40 children with AML-pCT, treated from 2005 to 2020. The most common primary malignancies were acute lymphoblastic leukemia and brain tumors. The probabilities of overall (OS), event-free (EFS), and relapse-free survival (RFS) in whole cohort were 0.49 ± 0.08, 0.43 ± 0.08, and 0.64 ± 0.10, respectively. Significant improvements in outcomes were observed in patients treated from 2015 to 2022 (two induction cycles followed by stem cell transplantation—SCT in 69% of patients) compared to the period 2005–2014 (four induction cycles followed by SCT in 49% of patients). The probabilities of EFS and RFS increased from 0.30 ± 0.10 and 0.46 ± 0.11 to 0.67 ± 0.12 and 1.0, respectively. The poorest outcome was found in AML post brain tumor, mainly due to toxic deaths. Treatment results in the group of patients with AML-pCT treated from 2015–2022 were comparable to outcomes in de novo AML. ABSTRACT: Acute P./myeloid leukemia post cytotoxic therapy (AML-pCT) is rare complication of cancer treatment in childhood. The objective of the study was to identify clinical characteristics and provide an analysis of the outcomes in pediatric AML-pCT. We retrospectively analyzed the data of 40 children with AML-pCT, treated from 2005 to 2020 within the Polish Pediatric Leukemia and Lymphoma Study Group. The most common primary malignancies were acute lymphoblastic leukemia (32.5%) and brain tumors (20%). The median latency period was 2.9 years (range: 0.7–12.9). Probabilities of overall (OS), event-free (EFS), and relapse-free survival (RFS) in the whole cohort were 0.49 ± 0.08, 0.43 ± 0.08, and 0.64 ± 0.10, respectively. Significant improvements in outcomes were observed in patients treated from 2015–2022 (two induction cycles followed by stem cell transplantation—SCT in 69% of patients) compared to 2005–2014 (four induction cycles followed by SCT in 49% of patients). The probability of EFS increased from 0.30 ± 0.10 to 0.67 ± 0.12 (p = 0.07) and RFS increased from 0.46 ± 0.11 to 1.0 (p = 0.01). The poorest outcome (OS and EFS 0.25 ± 0.20) was in AML post brain tumor, mainly due to deaths from toxicities. To conclude, treatment results achieved in patients with AML-pCT treated from 2015–2022, with two induction cycles followed by immediate SCT, were better than those reported by other authors, and comparable to the results in de novo AML.