Relapsed childhood acute myeloid leukemia: prognostic factors and outcomes: experience from a single oncology center

Introduction: Over recent decades, significant progress in the treatment of childhood acute myeloid leukemia (AML) has been made. However, the relapsed disease remains a challenge. The aim of this study was to analyze therapy results in pediatric patients treated for relapsed AML in a single oncology center, with a particular focus on prognostic factors. Materials and methods: Data from patients younger than 19 years with AML diagnosed between January 1994 and December 2020 treated in the Department of Pediatric Hematology and Oncology in Bydgoszcz, Poland was analyzed, with detailed analysis of patients with relapsed disease. Results: A total of 77 children were diagnosed with AML in the analyzed period and 21 had a relapsed disease (27.3%). Bone marrow relapse was the most common. The risk factors of relapse included white blood cells >100 G/L at initial diagnosis and classification to the high risk group. Late relapse was related to poorer outcomes. The 5-year probability of overall survival for the entire group was 28.6%, and this was significantly higher in patients who achieved second remission compared to those who did not (44.9% vs. 0.0%, p <0.001). The main reason for death was progression of disease, which occurred in 10 patients. Conclusions: Outcomes in relapsed AML in children are still dismal. Lack of second remission suggests the need for experimental therapy.