Background/Aim: Pediatric acute myeloid leukemia (AML) is a heterogenous disease; however, development of diagnostic methods has led to a better understanding of its nature and improvement in therapy outcomes. In this study, we evaluated treatment results in children with AML treated in a single oncology center in comparison with international results. Patients and Methods: Data from 77 children with AML treated in a single oncology center between 1994 and 2020 were analyzed. Patients had been treated according to five consecutive therapy protocols: AML NOPHO 88; ANLL 98; BFM AML 2004; BFM AML 2012, and BFM AML 2019. Five-year overall survival (OS), 5-year event-free survival (EFS) and 5-year relapse-free survival (RFS) were evaluated for each therapy protocol to determine prognostic factors and clarify differences between international and individual center results. Results: During the observational period, 5-year OS increased from 55.6% to 85.7%, 5-year EFS from 45.7% to 87.5% and 5-year RFS from 51.4% to 85.7%. Hematopoietic cells transplantation (HCT) introduction in early 2000’ improved treatment outcomes in the high-risk group, what has been mostly seen in the results of 5-year EFS. Treatment-related mortality was the most frequent cause of death in the analyzed group. Conclusion: Despite the significant improvement in therapy of pediatric AML, treatment outcomes remain unsatisfying. Introduction of HCT relevantly improved therapy results, especially in the high-risk group. International cooperation is crucial because of the small patient numbers in individual oncology centers.

Background/Aim: Pediatric patients with primary refractory or relapsed B-cell non-Hodgkin lymphoma (B-NHL) have highly unfavorable prognosis. In this study, we retrospectively analyzed outcomes in pediatric B-NHL patients treated in a single center in Poland from 1995 to 2022, with emphasis on therapy results in patients with progression or relapse. Patients and Methods: The primary objectives were a 5-year probability of overall survival (pOS) and a 5-year probability of event-free survival (pEFS). The secondary objectives involved the assessment of prognostic factors. Results: A total of 76 children were eligible for the analysis. The 5-year pOS was 76.7%, and the 5-year pEFS was 72.9%. At diagnosis, elevated lactate dehydrogenase activity, the presence of B symptoms, bone marrow, skeletal or mediastinal involvement, and stage IV disease were associated with inferior outcomes. Nine children experienced progression and four relapse. The 5-year pOS for patients with progression was 38.1%. Two patients treated with hematopoietic stem cell transplantation (HSCT) as part of salvage therapy survived. However, only one out of seven patients who were treated without HSCT survived. The 5-year pOS was 0.0% in patients with relapsed disease. Conclusion: The most significant factor related to outcomes in pediatric B-NHL is therapy response, with a high mortality rate in children with refractory disease and relapse. There is no consensus on the salvage therapy approach; however, HSCT appears to be the optimal choice.

Therapy results in pediatric Hodgkin lymphoma reflect remarkable progress in pediatric oncology. In the last decade, relevant development of new therapeutic options for children with refractory or relapsed disease has been made. In this study, we retrospectively analyzed therapy results and risk factors in children treated in a single oncology center according to five therapeutic protocols. Data from 114 children treated by a single institution between 1997 and 2022 were analyzed. Classic Hodgkin lymphoma therapy results were divided into four therapeutic periods: 1997–2009, 2009–2014, 2014–2019, and 2019–2022. For nodular lymphocyte-predominant Hodgkin lymphoma, data from one therapeutic protocol was analyzed. For the entire group, the 5-year probability of overall survival was 93.5%. There were no statistically significant differences between therapeutic periods. The occurrence of B symptoms at diagnosis and incidence of relapse were risk factors for death (p = 0.018 and p < 0.001). Relapse occurred in 5 cases. The 5-year probability of relapse-free survival for the entire group was 95.2%, without significant differences between groups. Patients treated between 1997 and 2009 had over a sixfold higher risk for events, defined as primary progression, relapse, death, or incidence of secondary malignancies (OR = 6.25, p = 0.086). The 5-year probability of event-free survival for all patients was 91.3%. Five patients died, and the most common cause of death was relapse. Modern therapeutic protocols in pediatric Hodgkin lymphoma are marked by excellent outcomes. Patients with disease relapses have a notably high risk of death, and the development of new therapeutic options for this group remains one of the main goals of current trials.

Background/Aim: Non-B non-Hodgkin lymphomas (NHL) represent over 30 T/NK lymphoma types. The majority of them are T-cell lymphoblastic lymphomas (TLL) and anaplastic large cell lymphomas (ALCL). Other rare non-B NHLs represent a diverse group of neoplasms, usually excluded from clinical trials. This study analyzed outcomes in pediatric patients with non-B NHL in a single oncology center with particular emphasis on patients with rare NHLs. Patients and Methods: We retrospectively analyzed data from patients <18 years with newly diagnosed non-B NHL treated at the Department of Pediatric Hematology and Oncology in Bydgoszcz between 2002 and 2022. The probability of 5-year overall survival (pOS) and event-free survival (pEFS) were calculated for the entire cohort and patients with TLL and ALCL. The clinical course for patients with rare non-B NHL was described in detail. Results: Twenty-six children were eligible for analysis. Fourteen patients were diagnosed with ALCL, nine with TLL, and three with rare NHL types (subcutaneous panniculitis-like T-cell lymphoma, extranodal NK/T-cell lymphoma and hydroa vacciniforme-like lymphoproliferative disease associated lymphoma). For the entire group, the 5-year pOS was 83.7% and the 5-year pEFS was 72.4%. For TLL and ALCL, the outcomes were comparable with those achieved in clinical trials. Patients with rare NHL were treated according to individualized therapy recommendations based on physicians’ expertise and available case report descriptions. Conclusion: There is a lack of knowledge on optimal therapeutic strategies for rare NHLs. It is crucial to create trials dedicated to uncommon NHLs and establish therapy guidelines for these patients.

Background/Objectives: Over the past three decades, significant progress has been made in understanding the biology of neuroblastoma. The integration of prognostic factors has facilitated risk stratification and the development of targeted treatment approaches. This study aims to analyze the outcomes of pediatric patients with neuroblastoma treated at a single oncology center over a 30-year period. Methods: This retrospective study analyzed data from patients aged 0–18 years with neuroblastoma, treated at the Department of Pediatric Hematology and Oncology in Bydgoszcz, Poland, between 1993 and 2023. The study endpoints included the 5-year probability of overall survival (pOS), event-free survival (pEFS), and relapse-free survival (pRFS), analyzed separately for low/intermediate- and high-risk groups. Results: Seventy-five patients met the inclusion criteria. Thirty-two children were categorized as high-risk patients and forty-three as low/intermediate risk. During the study period, outcomes in the low/intermediate-risk group improved significantly (the 5-year pOS 85.7% vs. 100.0%, p = 0.019; the 5-year pRFS 85.7% vs. 100.0%, p = 0.662; the 5-year pEFS 83.3% vs. 100.0%, p = 0.038). In the high-risk group, outcomes improved but did not reach statistical significance (the 5-year pOS 0.0% vs. 41.1%, p = 0.342; the 5-year pRFS 0.0% vs. 32.5%, p = 0.180; and the 5-year pEFS 0.0% vs. 21.5%, p = 0.537). Sixteen patients experienced relapse, of whom only three survived; stem cell transplantation at relapse significantly improved survival (OS 0.0% vs. 50.0%, p = 0.001). In the multivariable analysis, stage at diagnosis was a prognostic factor for pOS (HR 6.0; 95%CI 0.7–49.6, p = 0.096), while pelvic localization was a risk factor for pRFS (HR 3.0; 95%CI 0.8–10.5; p = 0.084). Conclusions: This analysis highlights significant advancements in the diagnosis and treatment of neuroblastoma. Nevertheless, outcomes for high-risk patients and those who experience relapse remain poor, underscoring the need for further therapeutic improvements.