Acute promyelocytic leukemia (APL) is a rare subtype of acute myeloid leukemia (AML) characterized by chromosomal translocation forming the fusion protein that blocks the differentiation of myeloid progenitors and increases the self-renewal of leukemia cells. The introduction of all-trans retinoic acid (ATRA) and arsenic trioxide (ATO) has dramatically improved outcomes in APL, making it a leading example of successful treatment through differentiation of cancer cells. However, life-threatening side effects and treatment resistance may develop; therefore, modulation of the safety and efficacy of these drugs may contribute to further improving treatment results. Recently, zinc, involved in the structure and function of transcription factors, has received special attention for its potential role in the development and treatment response of cancer. Zinc homeostasis is disrupted in APL, with intracellular accumulation stabilizing oncogenic proteins. Zinc depletion promotes degradation of PML–RARA and induces apoptosis, while supplementation enhances genotoxic stress in leukemic cells but protects normal hematopoiesis. Zinc also regulates key transcription factors involved in differentiation and proliferation, including RUNX2, KLF4, GFI1, and CREB. In this review, we examine how zinc may impact zinc-finger (ZnF) and non-ZnF transcription factors and differentiation therapy in APL, thereby identifying potential strategies to enhance treatment efficacy and minimize side effects.

Outcome measures of pediatric acute myeloid leukemia (AML) improved considerably between 1990 and 2011 in Hungary. Since 2012, efforts of the Hungarian Pediatric Oncology-Hematology Group (HPOG) included the reduction in the number of treatment centers, contemporary diagnostic procedures, vigorous supportation, enhanced access to hematopoietic stem cell transplantation (HSCT), and to targeted therapies. The major aim of our study was to evaluate AML treatment results of HPOG between 2012 and 2019 with 92 new patients registered (52 males, 40 females, mean age 7.28 years). Two periods were distinguished: 2012–2015 and 2016–2019 (55 and 37 patients, respectively). During these periods, 2 y OS increased from 63.6% to 71.4% (p = 0.057), and the 2 y EFS increased significantly from 56.4% to 68.9% (p = 0.02). HSCT was performed in 37 patients (5 patients received a second HSCT). We demonstrate advances in the diagnosis and treatment of acute promyelocytic leukemia (APL) in two cases. Early diagnosis and follow-up were achieved by multidimensional flow cytometry and advanced molecular methods. Both patients were successfully treated with all-trans retinoic acid and arsenic-trioxide, in addition to chemotherapy. In order to meet international standards of pediatric AML management, HPOG will further centralize treatment centers and diagnostic facilities and join efforts with international study groups.

Background: Neuroblastoma (NB) is one of the most common solid tumors in children, still showing a high mortality rate despite recent advances in therapy. A recent breakthrough was the introduction of Dinutuximab beta, yielding further improvements in survival. Dinutuximab beta is an anti-GD2 monoclonal antibody that targets GD2 expressed on the cell surface of neuroblastoma cells. Evidence suggests that Dinutuximab beta combined with Nivolumab may offer an effective synergistic treatment approach. Methods: In our center, immunotherapy was introduced in 2021 as part of maintenance treatment. The aim of this retrospective study was to analyze our data with a focus on the response, side effect profile and tolerability of Dinutuximab beta in HR and relapsed or refractory (r/r) NB. Results: Between 2021 and 2024, we treated 15 patients with neuroblastoma. Twelve patients had high-risk disease, of whom five received Dinutuximab beta as part of maintenance treatment according to protocol HR-NBL 1.8/SIOPEN. Two patients achieved complete remission after immunotherapy. One achieved long-lasting remission, while another relapsed. Three patients with inoperable tumors developed a partial response, but they relapsed and were diagnosed with metastases later. These patients subsequently initiated treatment with Temozolomide + Irinotecan in combination with Dinutuximab beta and also with Nivolumab as a relapse protocol. Therapeutic responses were assessed by the imaging, pathology and flow cytometry analysis of bone marrow. Apart from one complication (hypotension as part of capillary leak syndrome) subsiding spontaneously, no other severe adverse events were observed. Conclusions: Our experiences confirm that immunotherapy, including Dinutuximab beta and Nivolumab, is safe and well tolerated. The standardization of the application of Dinutuximab beta and in combination with novel therapeutic agents in maintenance and refractory/relapsed cases may contribute to improved treatment outcome results.