Mixed phenotype acute leukemia: Biological profile, clinical characteristic and treatment outcomes: Report of the population-based study.

OBJECTIVES: The aim of this population-based, retrospective study was to analyze biological and clinical features and treatment results in children diagnosed with MPAL in all Polish pediatric oncology centers between 2007 and 2018. METHODS: Among 2893 children and adolescents diagnosed and treated for acute leukemia, 39 (1.35%) patients fulfilled the WHO criteria of MPAL. The T/myeloid phenotype was most prevalent. RESULTS: Cytogenetics findings were seen in 2 (5.1%), while chromosomal abnormalities were found in 14 (35.9%) patients. Thirty-two patients achieved CR-1, including 23 (92.0%) treated with ALL-directed chemotherapy and 9 (64.3%) treated with AML-type induction regimens. Within these patients, 4 (12.5%) died due to treatment-related complications and 11 (34.4%) relapsed. Nineteen (63.3%) patients underwent allo-HSCT in CR-1 and 14 (73.7%) of them have been in CR-1. In total, 17 (43.6%) patients remain in CR-1 for 1-12 years, including 14 (58.3%) with T/myeloid MPAL. The 5-year pOS and pEFS were 51.8% and 44.2%, respectively. The overall survival for ALL-directed therapy was significantly better than the one for AML-type chemotherapy (P = .001). It was also better for patients who underwent HSCT in CR-1 (P = .001). CONCLUSIONS: The prognosis of MPAL is unsatisfactory, but initial treatment with ALL-directed chemotherapy consolidated with allo-HSCT improves the outcomes in MPAL.

Fast consumption increases the risk of overweight and obesity

Background: Overweight and obesity are a problem negatively affecting human health. Besides the excess of energy from food, development of overweight can also result from food preferences, the frequency of meals and the speed of eating. Objective: The aim of this study was to analyse the effect of eating habits and physical activity on the occurrence of overweight and obesity. Material and method: The questionnaire survey concerning eating habits and physical activity was conducted among adults aged 20-59 (n=420) in Lublin province (Poland). The subjects were divided into two groups ­ normal (BMI 18.5-25 kg/m2, n=250) and overweight and obese (BMI≥25 kg/m2, n=170). One-way analysis of variance (ANOVA) and post-hoc Tukey's test as well as chi-square independence test were applied. In addition, the relative risk of overweight for groups divided according to their habits was determined. Results: The analysis of speed of eating was on the basis of subjective assessment of the subjects and as a relative speed of eating compared to family members and friends. In both methods of assessment, it has been shown that overweight and obesity facilitates fast food intake rate (p=0.0078 and p=0.0010, respectively) The relative risk of obesity and overweight increases almost twice (RR 1.79) when the number of meals consumed daily is between one and two compared to those having five meals a day. In addition, it has been shown that overweight facilitates low physical activity. Conclusions: Slowly consumed meals, high physical activity and having more than two meals a day promotes maintaining a normal body weight.

Clinical characteristics and analysis of treatment result in children with Ph-positive acute lymphoblastic leukaemia in Poland between 2005 and 2017.

OBJECTIVE: The aim of this study was to analyse the clinical characteristics and outcome of children diagnosed with Ph+ ALL. MATERIAL AND METHODS: A total of 2591 newly diagnosed ALL children were treated in Poland between the years 2005 and 2017. Of those, 44 were diagnosed with Ph(+) ALL. The patients were treated according to protocols: ALL IC-BFM 2002 and 2009 (26 patients), EsPhALL (12 patients), initially ALL IC-BFM and then EsPhALL (6 patients). RESULTS: The median of follow-up in the observed group was 3 years. Overall survival (OS) and event-free survival (EFS) of Ph+ ALL group were 0.73 and 0.64. OS and EFS of patients after HSCT were 0.78 and 0.66, while without HSCT were 0.6 and 0.6, P = 0.27 and 0.63. OS was 0.8 for patients treated with chemotherapy plus imatinib and 0.61 for chemotherapy alone, P = 0.22, while EFS was 0.66 (imatinib therapy) and 0. 61 (without imatinib), P = 0.41. CONCLUSION: Our study suggests that adding imatinib to intensive chemotherapy seems to improve outcome. However, this study was limited by a small number of patients and a variety of chemotherapy regimens with or without imatinib.

Outcome of acute lymphoblastic leukemia in children with down syndrome-Polish pediatric leukemia and lymphoma study group report.

Children with Down syndrome (DS) have a 20-fold increased risk of developing leukemia compared with the general population. The aim of the study was to analyze the outcome of patients diagnosed with Down syndrome and acute lymphoblastic leukemia (ALL) in Poland between the years 2003 and 2010. A total of 1848 children were diagnosed with ALL (810 females and 1038 males). Of those, 41 (2.2%) had DS. The children were classified into three risk groups: a standard-risk group-14 patients, an intermediate-risk group-24, a high-risk group-3. All patients were treated according to ALLIC 2002 protocol. The median observation time of all patients was 6.1 years, and in patients with DS 5.3 years. Five-year overall survival (OS) was the same in all patients (86% vs 86%, long-rank test, p = .9). The relapse-free survival (RFS) was calculated as 73% in patients with DS and 81% in patients without DS during a median observation time (long-rank test, p = .3). No statistically significant differences were found in the incidence of nonrelapse mortality between those two groups of patients (p = .72). The study was based on children with ALL and Down syndrome who were treated with an identical therapy schedule as ALL patients without DS, according to risk group. This fact can increase the value of the presented results.

Changes in cell death of peripheral blood lymphocytes isolated from children with acute lymphoblastic leukemia upon stimulation with 7 Hz, 30 mT pulsed electromagnetic field.

Pulsed electromagnetic field (PEMF) influenced the viability of proliferating in vitro peripheral blood mononuclear cells (PBMCs) isolated from Crohn's disease patients as well as acute myeloblastic leukemia (AML) patients by induction of cell death, but did not cause any vital changes in cells from healthy donors. Experiments with lymphoid U937 and monocytic MonoMac6 cell lines have shown a protective effect of PEMF on the death process in cells treated with death inducers. The aim of the current study was to investigate the influence of PEMF on native proliferating leukocytes originating from newly diagnosed acute lymphoblastic leukemia (ALL) patients. The effects of exposure to PEMF were studied in PBMCs from 20 children with ALL. PBMCs were stimulated with three doses of PEMF (7 Hz, 30 mT) for 4 h each with 24 h intervals. After the last stimulation, the cells were double stained with annexin V and propidium iodide dye to estimate viability by flow cytometric analysis. The results indicated an increase of annexin V positive as well as double stained annexin V and propidium iodide positive cells after exposure to threefold PEMF stimulation. A low-frequency pulsed electromagnetic field induces cell death in native proliferating cells isolated from ALL patients. The increased vulnerability of proliferating PBMCs to PEMF-induced interactions may be potentially applied in the therapy of ALL. The analysis of expression of apoptosis-related genes revealed changes in mRNA of some genes engaged in the intrinsic apoptotic pathway belonging to the Bcl-2 family and the pathway with apoptosis-inducing factor (AIF) abundance upon PEMF stimulation of PBMCs.

Embryonal tumor with abundant neuropil and true rosettes: an autopsy case-based update and review of the literature.

INTRODUCTION: Embryonal tumor with abundant neuropil and true rosettes (ETANTR) is a rare subtype of primitive neuroectodermal tumors first reported in 2000. It is rare among the group of embryonal central nervous system tumors with approximately 50 reported cases. ETANTR has been suggested to be a separate entity among this group of tumors. CASE REPORT: Herein, we present only the second autopsy case of ETANTR, which occurred in a 17-month-old boy, and was located in the brainstem. The tumor was inoperable, and despite chemotherapy, the child died 3 months after initial hospitalization. A brain only autopsy was performed. DISCUSSION: Neuropathological and neuroimaging examinations suggest ETANTR grew by expansion rather than invasion distorting anatomical structures of the posterior fossa. We suggest that the characteristic histopathological picture of the tumor is the result of multifocal and dispersed germinative activity surrounded by mature neuropil-like areas. CONCLUSION: ETANTR is a pediatric tumor occurring in children under 4 with a significantly poor prognosis with more cases and research required to characterize this rare embryonal tumor.

[Clinical tolerance of high-dose methotrexate used in consolidation therapy in children with acute lymphoblastic leukemia]. / Tolerancja kliniczna metotreksatu, stosowanego w wysokich dawkach w leczeniu konsolidacyjnym ostrej bialaczki limfoblastycznej u dzieci.

The objective of the thesis was the evaluation of the clinical tolerance of methotrexate (Mtx), administered in two high doses (2 g/m2 and 3 g/m2) in 218 children with acute lymphoblastic leukemia in 829 chemotherapy cycles. The assessment of the frequency and intensity of the most common adverse early effects of the therapy was keeping with the extended toxicity scale according to the National Cancer Institute Common Toxicity Criteria (NCI-CTC). Tolerance of HD-Mtx was good, observed toxicities were not severe (most commonly of grade 1 and 2) nor prolonged. The most common early complications of the HD-Mtx therapy were: hepatic dysfunction, nausea and vomiting and infections, affecting 60%, 45-50% and 40-55% of patients, respectively. Based on the present investigations, the high risk group for severe early complications and toxicities of Mtx therapy included: patients with delayed Mtx elimination, children above 10 years of life and patients during the first HD-Mtx cycle.

[Hemophagocytic lymphohistiocytosis: diagnostic problems in pediatrics]. / Limfohistiocytoza hemofagocytarna: problemy diagnostyczne w pediatrii.

Hemophagocytic lymphohistiocytosis (HLH), also known as hemophagocytic syndrome (HS), is a life-threatening hyperinflammatory condition caused by uncontrolled proliferation of activated lymphocytes and histiocytes producing excessively proinflammatory cytokines. HLH can occur in all age groups. The most common syndromes are: prolonged fever, hepatosplenomegaly, unspecific neurological symptoms, pancytopenia, hemophagocytosis. Characteristic biochemical markers include high triglycerides, ferritin and decreased fibrinogen. There are two forms of HLH, primary (genetic) and acquired (secondary to infections, malignant and autoimmune diseases). Occurrence of both forms of HLH, acquired and genetic, is induced by infections, usually viral or by other triggering agents. Despite established diagnostic criteria many cases probably remain unrecognized. The main diagnostic difficulty is low specificity of symptoms, and in secondary form contemporary occurrence of symptoms of underlying disease. The aim of HLH treatment is to suppress hyperinflammation, what can be achieved by use of immunosuppressive/immunomodulating agents or cytostatics. Patients with genetic form of HLH require hematopoietic stem cell transplantation. Awareness of the symptoms and diagnostic criteria of HLH is important for early diagnosis and immediate application of life-saving therapy.

[Hemophagocytic syndrome in children with different underlying conditions]. / Zespól hemofagocytarny u dzieci w róznych jednostkach chorobowych.

Hemophagocytic syndrome (HS) is a life-threatening condition of hyperinflammation. Main symptoms are: prolonged fever, cytopenia, hepatosplenomegaly, hemophagocytosis, hyperferritinemia, hypertriglyceridemia and hypofibrinogenemia. Primary genetic form and secondary HS associated with infections, malignancies or autoimmune disorders can be distinguished. Untreated HS in most cases leads to death. We analyzed retrospectively 7 cases of HS in children (3 girls, 4 boys; aged 10 days -14 years) treated in 3 different pediatric centers from 2004 to 2009. In 3 cases HS was associated with infections (EBV, CMV, Bacillus Calmette Guerin - BCG), in 1 child with non-Hodgkin anaplastic large cell lymphoma (ALCL), in 1 patients probably with side effect of antiepileptic drug. In 2 cases cause of HS remained unknown. Fever, hepatomegaly, pan- or bicytopenia and hyperferritinemia were present in all children. In addition, splenomegaly was noted in 6 cases, hemophagocytosis in 6 children, impaired function or decreased number of NK cells in 4 cases, hypofibrino-genemia in 5 and hypotriglyceridemia in 4 patients. Among other symptoms and signs we observed: lymphadenopathy, hepatic failure, oedema, rash, neurological symptoms, increased level of LDH and inflammatory markers. In one child acute pancreatitis occurred. Among others, antibiotics, antiviral and immunosuppressive drugs were used in therapy. HLH-2004 protocol was applied in 4 cases. Patient with ALCL was treated with chemotherapy and allogeneic stem cell transplantation. Four patients are alive, 2 died because of HS, child with ALCL died because of generalized infection in peritrans-plantation period. In case of prolonged fever, splenomegaly and cytopenia diagnosis of HS should be considered. Following tests are recommended: complete blood count, ferritin, triglycerides, fibrinogen, bone marrow aspiration and NK cell assessment. Patients should be also screened for infections and malignancies. Early diagnosis of HS and underlying condition is crucial to start lifesaving therapy.

Chemical stability of fructans in apple beverages and their influence on chronic constipation.

The aim of this study was to analyse the concentration of reducing sugars in beverages based on apple juice with the addition of 2 and 4% of native and high polymerized inulin as well as oligofructose. Moreover, the effect of the consumption of this potentially prebiotic beverage containing highly polymerized inulin (12 g per 300 mL) on constipation was analysed. Pasteurization of the studied beverages followed by 120-day storage at ambient temperature, carried out in three independent trials, did not cause the hydrolysis of fructans into reducing sugars. Sensory analysis showed that the presence of fructans in beverages based on apple juice did not change the colour, clarity, odour, flavour, sweetness and acidity in comparison to apple juice. A placebo-controlled, randomized study involving 20 volunteers of age 20-29 with symptoms related to chronic constipation showed that the consumption of juice enriched with highly polymerized inulin significantly (p≤ 0.05) increased the frequency of bowel movements and facilitated defecation. The final conclusion is that fructans in beverages based on apple juice are chemically stable, do not affect sensory sensation and can help those with chronic constipation.

Disseminated Juvenile Xanthogranuloma and Hemophagocytic Lymphohistiocytosis Developed During Treatment of Acute Lymphoblastic Leukemia: Case Report.

The association between acute lymphoblastic leukemia (ALL), non-Langerhans cell histiocytosis (non-LCH), and hemophagocytic lymphohistiocytosis (HLH), to the best of our knowledge, has not been published to date. Juvenile xanthogranuloma (JXG), as a type of non-LCH, is usually a benign disease limited to the skin. Systemic involvement is rarely reported. The present case report describes a 15-year-old boy diagnosed with disseminated JXG involving skin and bone marrow concurrent with severe symptoms of HLH during ALL therapy. Examination of immunoglobulin heavy chain genes in B-cell precursor leukemic blasts and histiocytes in the skin and bone marrow revealed identical rearrangements, confirming clonal relationship between both diseases. Implementation of corticosteroids, vinblastine, etoposide, cyclosporine, and tocilizumab resulted in partial skin lesion resolution with no improvement of bone marrow function; therefore, hematopoietic stem cell transplantation (HSCT) was eventually performed. The patient's hematological and general status has improved gradually; however, remarkable recovery of skin lesions was observed after empirical antitubercular therapy. Mycobacterium spp. infection should be considered as a possible secondary HLH trigger. Triple association of ALL, non-LCH, and HLH highlights heterogeneity of histiocytic disorders and possible common origin of dendritic and lymphoid cells.

Polymorphisms of SLC19A1 80 G>A, MTHFR 677 C>T, and Tandem TS Repeats Influence Pharmacokinetics, Acute Liver Toxicity, and Vomiting in Children With Acute Lymphoblastic Leukemia Treated With High Doses of Methotrexate.

Introduction: High dose methotrexate (HD-Mtx) is highly effective and significantly improves overall acute lymphoblastic leukemia (ALL) patients survival. The pharmacodynamics of Mtx depends on the polymorphism of genes encoding proteins engaged in the folate metabolism pathway. The aim of the current study is to determine the relationship between variants of folate metabolism-related genes and the frequency of acute toxicities of HD-Mtx. Material and Methods: A group of 133 patients aged 1.5-18.1 years (median: 6.3) was treated in accordance with the ALL-IC-2002 and ALL-IC-2009 protocols. The following polymorphisms were determined: 80 G>A SLC19A1 (solute carrier family 19 member 1; rs1051266) with direct DNA sequencing, as well as 677 C>T MTHFR (methylenetetrahydrofolate reductase; rs1801133) and the tandem repeats of the TS (thymidylate synthase) with PCR technique. HD-Mtx organ toxicities were evaluated based on the laboratory tests results and the National Cancer Institute criteria. Results: In patients with genotypes AA for SLC19A1 and CC or CT for MTHFR Mtx steady state concentrations (Css) and AUCinf were distinctly higher. In patients with genotype 3R/3R for TS initial elimination rate constant was significantly higher (P = 0.003). Patients receiving Mtx at the dose of 5 g/m2 had lower clearance (4.35 vs. 8.92 L/h/m2) as compared to the ones receiving 2 g/m2 that indicates non-linear Mtx elimination at the higher dose. Liver impairment was the most frequently observed toxicity. The homozygous genotype was associated with a significantly higher incidence of hepatic toxicity for both the SLC19A1 (P = 0.037) and TS (P = 0.002). Logistic regression analysis indicated an increased risk of vomiting for the 2R/3R genotype of the TS gene (OR 3.20, 95% CI 1.33-7.68, P = 0.009) and for vomiting and hepatic toxicity for the 3R/3R genotype (vomiting: OR 3.39, 95% CI 1.12-10.23, P = 0.031; liver toxicity: OR 2.28, 95% CI 1.05-4.95, P = 0.038). None of the acute toxicities differed between the analyzed dosing groups. Conclusions: Determination of polymorphisms of SLC19A1, MTHFR, and TS genes might allow for a better prior selection of patients with higher risk of elevated Mtx levels. Our study is the first one to report the increased risk of hepatotoxicity and vomiting in patients with TS polymorphisms.

First-line treatment failure in childhood acute lymphoblastic leukemia: The polish pediatric leukemia and lymphoma study group experience.

The aim of this study was to evaluate the risk factors of relapse and treatment-related deaths in acute lymphoblastic leukemia (ALL) in children residing in Poland.A total of 1872 patients with newly diagnosed ALL, treated according to the ALL IC-BFM 2002 protocol in 14 Polish pediatric hematology centers from 2002 to 2012 were included in the study. Three-hundred eighty-four patients experienced treatment failure. The last follow-up was 31 December, 2016.Univariate analysis identified factors in each risk group that were significantly different between children whose treatment failed and those who remained in the first remission. Multivariate analysis demonstrated that only the age of 10 years or over at primary diagnosis in the high-risk group was an adverse prognostic factor. To facilitate the analysis, patients were divided into three groups: relapsed children who survived; relapsed children who died; children without relapse who died due to toxicity.Our analysis showed that age older than 10 years is a particular risk factor for the failure of first-line of treatment, both in terms of relapse and treatment-related mortality.

Clinical Outcome in Pediatric Patients with Philadelphia Chromosome Positive ALL Treated with Tyrosine Kinase Inhibitors Plus Chemotherapy-The Experience of a Polish Pediatric Leukemia and Lymphoma Study Group.

The treatment of children with Philadelphia chromosome positive acute lymphoblastic leukemia (ALL Ph+) is currently unsuccessful. The use of tyrosine kinase inhibitors (TKIs) combined with chemotherapy has modernized ALL Ph+ therapy and appears to improve clinical outcome. We report herein the toxicity events and results of children with ALL Ph+ treated according to the EsPhALL2010 protocol (the European intergroup study of post-induction treatment of Philadelphia chromosome positive ALL) in 15 hemato-oncological centers in Poland between the years 2012 and 2019. The study group included 31 patients, aged 1-18 years, with newly diagnosed ALL Ph+. All patients received TKIs. Imatinib was used in 30 patients, and ponatinib was applied in one child due to T315I and M244V mutation. During therapy, imatinib was replaced with dasatinib in three children. The overall survival of children with ALL Ph+ treated according to the EsPhALL2010 protocol was 74.1% and event-free survival was 54.2% after five years. The cumulative death risk of the study group at five years was estimated at 25.9%, and its cumulative relapse risk was 30%. Our treatment outcomes are still disappointing compared to other reports. Improvements in supportive care and emphasis placed on the determination of minimal residual disease at successive time points, which will impact decisions on therapy, may be required.

Results of two consecutive treatment protocols in Polish children with acute lymphoblastic leukemia.

The aim of the study was to retrospectively compare the effectiveness of the ALL IC-BFM 2002 and ALL IC-BFM 2009 protocols and the distribution of risk groups by the two protocols after minimal residual disease (MRD) measurement as well as its impact on survival. We reviewed the medical records of 3248 patients aged 1-18 years with newly diagnosed ALL who were treated in 14 hemato-oncological centers between 2002 and 2018 in Poland. The overall survival (OS) of 1872 children with ALL treated with the ALL IC 2002 protocol was 84% after 3 years, whereas the OS of 1376 children with ALL treated with the ALL IC 2009 protocol was 87% (P < 0.001). The corresponding event-free survival rates were 82% and 84% (P = 0.006). Our study shows that the ALL IC-BFM 2009 protocol improved the results of children with ALL compared to the ALL IC-BFM 2002 protocol in Poland. This analysis confirms that MRD marrow assessment on day 15 of treatment by FCM-MRD is an important predictive factor.

[Osteoarticular pains as early manifestation of malignancies in children]. / Bóle kostno-stawowe jako wczesna manifestacja chorób nowotworowych u dzieci.

Based on the rewiew of the literature and own clinical observations, we presented examples of the most common pediatric onco-hematologic malignancies, that are manifested early by osteoarticular complaints. When these complaints predominate in the clinical presentation, they lead the diagnosis towards nonmalignant conditions, that are most common cause of such symptoms in children, like injuries, nonspecific reactive arthritis or inflammatory connective tissue diseases. However, in acute lymphoblastic leukaemia, the most prevalent childhood malignancy, bone and joint pains are present early in 40-60% of cases and they frequently anticipate any abnormalities in complete blood counts. Findings reported in the literature and own observations indicate that these complaints correlate with: lower white cell counts, lower percentage of blast cells in the peripheral blood and lower incidence of organomegaly - that may delay the decision of bone marrow aspiration. In our study we have also presented 4 cases of other malignancies in children, who were complaining of the osteoarticular pains, that limited they activity, long time before the beginning of treatment in Department of Oncology and Pediatric Hematology of University's Pediatric Hospital in Cracow. Long-lasting and intensive osteoarticular complains, that restraint normal activity and do not resolve during rest, spinal compression symptoms, coexisting adenopathy, hepatosplenomegaly, weight loss, change of behaviour, unexplicained fever must be recognized as specific "red flags". Oncologic vigilance must be inspired by discreet hematological abnormalites (like increased anemia, lower white cell counts with lymphocytosis, mild thrombocytopenia) -that indicate bone marrow infiltration, as well as high erythrocyte sedimentation rate, accompanied by moderately elevated C-reactive protein - characteristic for malignancy. Basic and commonly accessible radiological imaging may provide valuable information, because it can reveal tumors, osteolytic lesions or destruction of bone architecture. Laboratory tests of lactate dehydrogenase (LDH) and uric acid level, often raised in malignancies are also helpful. The aim of this study was to focus the attention of pediatricians to the necessity of including malignancy in the differential diagnosis of intensive or unexplained osteoarticular complaints.

Grade 3 and 4 Toxicity Profiles During Therapy of Childhood Acute Lymphoblastic Leukemia.

BACKGROUND/AIM: The risk factors, clinical features and non-hematological toxicity profiles during chemotherapy in acute lymphoblastic leukemia (ALL) patients treated in pediatric hematology centres were analysed. MATERIALS AND METHODS: A total of 902/1872 children were reported as having grade 3 or 4 toxicity. RESULTS: Among the analysed toxicities, infection and gastrointestinal and liver toxicities were the most common. The median follow-up was 6.8 years. Overall survival and event-free survival rates for the analysed group were lower than those reported for the group without grade ≥3 toxicity. In univariate analysis, we identified the number of toxic episodes, the risk group and remission status that had a significant impact on the outcome. Multivariate analysis demonstrated the risk group and the number of toxic episodes ≥3 to be statistically significant for the results. CONCLUSION: The toxic profiles investigated in our report should be used in future efforts to decrease the burden of side effects during chemotherapy.

Imatinib in the treatment of chronic myeloid leukemia in children and adolescents is effective and well tolerated: Report of the Polish Pediatric Study Group for the Treatment of Leukemias and Lymphomas.

BACKGROUND: Chronic myeloid leukemia (CML) constitutes only 2-3% of all leukemias in pediatric patients. Philapelphia chromosome and BCR-ABL fusion are genetic hallmarks of CML, and their presence is crucial for targeted molecular therapy with tyrosine kinase inhibitors (TKIs), which replaced hematopoietic stem cell transplantation (HSCT) as a standard first-line therapy. The disease in pediatric population is rare, and despite molecular and clinical similarities to CML in adults, different approach is needed, due to the long lifetime expectancy and distinct developmental characteristics of affected children. OBJECTIVES: The objective of this study is to evaluate treatment with imatinib in Polish pediatric patients with CML. MATERIAL AND METHODS: We analyzed the results of treatment with imatinib in 57 pediatric patients (June 2006 - January 2016) from 14 Polish pediatric hematology and oncology centers. RESULTS: In the study group, 40 patients continued imatinib (median follow-up: 23.4 months), while in 17 the treatment was terminated (median follow-up: 15.1 months) due to therapy failure. In the latter group, 13 patients underwent HSCT, while 4 switched to second-generation TKIs. The 5-year overall survival rate (OS) in the study group was 96%, and the 5-year event-free survival (EFS) was 81%. CONCLUSIONS: Our results confirm that the introduction of TKI therapy has revolutionized the treatment of CML in the pediatric population by replacing the previous method of treatment with HSCT and allowing a high percentage of OS and EFS.

[Treatment results in children with the standard risk acute lymphoblastic leukemia treated with high dose of methotrexate (5.0 g/m2). 11 years of the Polish Pediatric Leukemia/Lymphoma Study Group experience]. / Wyniki leczenia ostrej bialaczki limfoblastycznej grupy standardowego ryzyka (ALL-SR) u dzieci z zastosowaniem wysokich dawek metotreksatu (HD-MTX 5,0 g/m2)--11 lat doswiadczen Polskiej Pediatrycznej Grupy ds. Leczenia Bialaczek i Chloniaków.

Since 01.07.1993 to 30.09.2004, 675 children with ALL-SR were diagnosed and treated according to the modified ALL-BFM 90 protocol. Subject to statistical analysis (Kaplan-Meier method) were thus 197 children with ALL-SR treated with HD-MTX in a dose 5.0g/ m2. Among them, 21 patients failed to respond to therapy: 2 (1.0%) early deaths, 2 (1.0%) deaths during I complete remission, 16 (8.2%) relapses, 1 (0.5%) second neoplasm. Relapses occured: 12 (6.2%) in bone marrow, 2 (1.0%) in central nervous system, 1 (0.5%) in testicle and in 1 (0.5%) child combined relapse was observed. Probability rates for 11-year event free survival (EFS) was 0.80 (0.03). Application of high dose of methotrexate is safety and effective in prevention of relapses, especially meningeal and testicular involvement.