Twenty years of Polish experience with three consecutive protocols for treatment of childhood acute myelogenous leukemia.

Until 1983, results of treatment of acute myelogenous leukemia (AML) in Poland with different regimens were very poor. In 1983, the Polish Pediatric Leukemia/Lymphoma Study Group introduced a unified treatment protocol--a modified version of BFM-83 protocol. This led to an increase in the curability of AML from 15% to approximately 32%. In 1994, a modification was made: the high-risk patients (>5% blasts in bone marrow on day 15 of therapy and all M5 cases) received two additional cycles with intermediate-dose cytarabine (ID-ARAC). This led to a nonsignificant improvement in the 5-year event-free survival (EFS) rate from 32 to 36%. A new treatment protocol employing idarubicin in place of daunorubicin was introduced in 1998 and produced better initial responses, increase in the number of patients attaining remission after induction therapy and proportional increase of standard-risk patients. The probability of 5-year EFS (pEFS) for the whole group of patients increased from 36 to 47%. In standard- and high-risk groups, the 5-year pEFS was 62 and 33%, respectively. The probability of 5-year disease-free survival was 58% in the whole group, and there were no differences between risk groups. Unsatisfactory treatment results in children classified into the high-risk group are principally due to the low remission rate.

Clinical efficacy, safety and pharmacokinetic properties of the factor VIII concentrate Haemoctin SDH in previously treated patients with severe haemophilia A.

Clinical efficacy, safety and pharmacokinetic properties of the high-purity double-virus inactivated plasma-derived factor VIII concentrate Haemoctin SDH (pdFVIII) were evaluated in three prospective open-label uncontrolled studies in previously treated patients (PTPs) with severe haemophilia A. The pharmacokinetic properties assessed at baseline and after 3 months of treatment are in accurate accordance with published data and remain unchanged over time (study A, n = 12). Mean terminal elimination half-life was 11.8 and 11.9 h, mean incremental recovery (IU dL(-1)/IU kg(-1)) was 2.3 and 2.0, respectively. Long-term efficacy and safety, in particular the potential immunogenicity, were investigated in a total of 53 PTPs (studies A and B) treated prophylactically and on-demand, as required. PdFVIII has shown to be effective in preventing and controlling bleeding episodes; 23.5% of patients were free of bleeding events. A total of 177 haemorrhages occurred with 74.0% resolving after a single infusion, 87.6% within two infusions. 98.3% of responses reported on haemorrhages were rated as 'excellent' or 'good'. Moreover, 'excellent' haemostatic efficacy has been demonstrated in 10 surgical procedures including general and severe orthopaedic interventions (study C). No complication occurred in any surgery. Few adverse events were reported, one patient developed a high-titre FVIII inhibitor without clinical relevance. In all three studies, over 6 million units were administered in nearly 4300 infusions, approximately 94% units or infusions were given for prophylaxis and only 6% for treatment on-demand. In conclusion, pdFVIII has shown to be effective, safe and well tolerated in long-term prophylaxis and treatment on-demand as well as after minor and major surgical procedures.

Acquired factor VIII inhibitor in a non-haemophilic boy.

We describe the case of a previously healthy 8-year-old non-haemophilic boy who developed a factor VIII inhibitor of unknown origin. The symptoms of this disease were haemorrhages in the muscles of the right thigh, numerous bruises and a large haematoma of the right crus with subsequent tissue necrosis. Activated and non-activated prothrombin complex concentrates were administered in the therapy of the haemorrhages. To eliminate factor VIII inhibitor, the patient was treated first with prednisone, then immunoglobulin G and finally with a combination of prednisone and cycylophosphamide, without any effect. A total spontaneous remission was observed after 15 months from the beginning of the disease.

In vitro comparative antileukemic activity of various glucocorticoids in childhood acute leukemia.

Resistance to glucocorticoids is nowadays one of the strongest adverse risk factors in the treatment of childhood acute lymphoblastic leukemia (ALL). Differential in vitro antileukemic activity of various glucocorticoids and their cross-resistance pattern in childhood acute lymphoblastic and myeloblastic leukemia was determined by means of the MTT assay in 49 successfully tested samples of childhood acute leukemia. The equivalent antileukemic concentrations of respective drugs against lymphoblasts in de novo ALL samples were: 35 microM of hydrocortisone; 8 microM of prednisolone; 1.6 microM of methylprednisolone; 0.47 microM of dexamethasone and 0.23 microM of betamethasone. In comparison to initial ALL samples, the group of relapsed ALL was more resistant to: prednisolone (38-fold, p=0.004), dexamethasone (>32-fold, p=0.004), methylprednisolone (37-fold, p=0.039), betamethasone (38-fold, p=0.018) and hydrocortisone (33-fold, p=0.030). The group of acute myeloid leukemia (AML) samples were resistant to: prednisolone (>83-fold, p<0.001), dexamethasone (>32-fold, p<0.004), methylprednisolone (>65-fold, p=0.003), betamethasone (>66-fold, p=0.004) and hydrocortisone (61-fold, p=0.007), when compared to ALL at presentation. A significant cross-resistance between all used glucocorticoids as well as between glucocorticoids and other tested anti-leukemic drugs was found. In some individual cases in vitro glucocorticoid cross-resistance was less pronounced and relatively good antileukemic activity of betamethasone was observed.

Correlation between clinical, radiological and ultrasonographical image of knee joints in children with haemophilia.

The aims of the study were to evaluate the clinical, radiological and ultrasonographical images of knee joints in children with severe haemophilia and von Willebrand's disease, to determine the correlation between these images and to assess the usefulness of ultrasonography (USG) in evaluating the intensity of haemophilic arthropathy. Thirty-nine boys were included in the study, all of them with a past history of knee bleeds. The average age of the children was 10.02 +/- 3.01 years. In patients with slight (1-3 points) and moderate (4-7 points) radiological changes in knee joint bones, an increase in synovial fluid, considerable hypertrophy and inflammation of the synovium were observed in USG. In haemophilic patients with severe (8-13 points) bone changes, the amount of fluid was usually normal and there was slight inflammation but considerable hypertrophy of the synovium. Radiological evaluation of haemophilic arthropathy was made according to the Pettersson classification. A good correlation between the degree of cartilage damage in USG and the progression of bone changes in radiographs was found. Cartilage and bone damage progressed with the increase in the number of intra-articular haemorrhages into the knee joint. In our opinion USG is useful in evaluating the fluid, synovium and cartilage of joints in haemophiliacs.

Evidence for linkage of familial Diamond-Blackfan anemia to chromosome 8p23.3-p22 and for non-19q non-8p disease.

Diamond-Blackfan anemia (DBA) is a rare congenital hypoplastic anemia that usually presents early in infancy and is inherited in 10% to 20% of cases. Linkage analysis has shown that DBA in many of both dominant and recessive DBA families mapped to chromosome 19q13.2 leading to the cloning of a gene on chromosome 19q13.2 that encodes a ribosomal protein, RPS19. However, subsequently, mutations of the RPS19 gene have only been identified in 25% of all patients with DBA. This study analyzed 14 multiplex DBA families, 9 of which had 19q13.2 haplotypes inconsistent with 19q linkage. A genome-wide search for linked loci suggested the presence of a second DBA locus in a 26.4-centimorgan (cM) interval on human chromosome 8p. Subsequently, 24 additional DBA families were ascertained and all 38 families were analyzed with additional polymorphic markers on chromosome 8p. In total, 18 of 38 families were consistent with linkage to chromosome 8p with a maximal LOD score with heterogeneity of 3.55 at D8S277 assuming 90% penetrance. The results indicate the existence of a second DBA gene in the 26.4-cM telomeric region of human chromosome 8p23.3-p22, most likely within an 8.1-cM interval flanked by D8S518 and D8S1825. Seven families were inconsistent with linkage to 8p or 19q and did not reveal mutations in the RPS19 gene, suggesting further genetic heterogeneity. (Blood. 2001;97:2145-2150)

Release of cytokines and soluble cytokine receptors after intravenous anti-D treatment in children with chronic thrombocytopenic purpura.

INTRODUCTION: Immunoglobulin anti-D administration is one of several methods used in treating children with chronic immune thrombocytopenic purpura. Fc receptor blockade of the reticuloendothelial cell system and of mononuclear phagocytes is an important mechanism of the action of anti-D in ITP. Recently other possible mechanisms by which anti-D works in ITP have been considered. METHODS: The aim of this study was to obtain a better understanding of the effect of anti-D administration on cytokine, soluble cytokine receptors and platelet count in children with chronic ITP and to determine the pre-treatment plasma cytokine profile in this group of patients. Eighteen children with chronic ITP were examined. In our study the impact of anti-D on the cytokine network was evaluated by analysing serum levels of IL-6, IL-8, tumor necrosis alpha and soluble TNF receptors I and II by the EASIA method before and 1, 3, 20 and 40 h then seven days and one month after anti-D infusion. RESULTS: Anti-D caused a significant increase in platelet count 20 h postinfusion in 10 out of 18 children, 96 h postinfusion in three children and 168 h postinfusion in one child. The mean duration of the response was four weeks. A significant and rapid increase in plasma levels of IL-6, IL-8 and TNF-alpha was seen within 1 to 20 h after anti-D infusion. This increase was accompanied by a prolonged elevation of soluble TNF receptors. There was a significant correlation between TNF-alpha and IL-8, IL-8 and IL-6, TNF-alpha and sTNFRI, and sTNF receptors I and II. CONCLUSION: These data demonstrate that anti-D infusion caused changes in the cytokine network and raises the question of whether the therapeutic effectiveness of anti-D is related to its immunomodulating properties.

[Treatment regimen for children and adolescents with Hodgkin's disease designed to decrease late complications of radiotherapy]. / Program leczenia choroby hodgkina u dzieci i mlodziezy zmierzajacy do ograniczenia powiklan po radioterapii.

Between 1997 to 1999 in 9 centres of the Polish Paediatlic Leukemia/Lymphoma Study Group, 167 children and adolescents (aged 2-19 years) with stage 1 to IV Hodgkin's disease (HD) were treated according to a regimen with a limited use of radiotherapy (RT). All patients received B-DOPA and MVPP chemotherapy. The number of cycles of chemotherapy was adjusted in respective risk groups. In 13 children with stage IA and IIA disease with favourable prognostic factors chemotherapy alone was used. In other patients the dose of RT applied to lymphatic regions was 15-46,4 Gy. In case of a small tumour at presentation and good response to initial chemotherapy the RT dose was 15-16 Gy. In other cases doses of 25-30 Gy were planned. The use of higher doses, particularly exceeding 35 Gy, in eleven patients, was not justified. Among all the 167 patients, three oftliem (1.2%) with advanced disease (Stage III-1V) did not achieve first remission. The 4-year overall survival (OS), relapse free survival (RFS) and event free survival (EPS) were 99%. 93% and 90%, respectively. Relapses occurred in 8 children (first remission lasted for 4-29 (median = 9 months). All 13 children in whom chemotherapy alone was used remain in first remission. In the group of children who received RT in the dose of 15-16 Gy relapse occurred in one child. Our preliminary analysis indicates that limited use of RT in selected cases of HD in children and adolescents did not show worse results of treatment. However, the assessment of possible influence of this regimen on the decreased rate of late complications requires longer follow-up.

Echocardiographic assessment of right atrial thrombus related to the implanted port device in patient receiving chemotherapy for non-Hodgkin's lymphoma.

The case of a potentially life-threatening complication related to the use of implanted port device in a 8 year old Non-Hodgkin's Lymphoma patient receiving chemotherapy is described. The device was inserted in early 1997 and used repeatedly for chemotherapy without any complications. In late 1997 during routine screening for cardiac left ventricular function before re-introduction of chemotherapy, an abnormal 1.43 x 1.53 cm mass, consistent with a non-mobile thrombus was found in the right atrium. The initial thrombolytic therapy with recombinant tissue plasmin activator (rt-PA) infused by a central venous catheter was combined with daily echocardiographic examination in order to assess both the timing and mode of thrombus resolution. After 8 days systemic fibrinolytic therapy was discontinued as major hemorrhage from venipuncture sites occurred and the clot dissolution was not obtained. Patient underwent right atriotomy utilizing cardiopulmonary bypass and subsequent surgical thrombus removal was successful. The study evaluated the contribution of two-dimensional echocardiography (2D) in the follow-up of vascuport and other central venous catheter (CVC) location and early diagnosis of related complications such as thrombi. The authors consider that pulmonary flow analyzed with Doppler echocardiography as a reliable, suitable and non-invasive method to evaluate increased pulmonary artery pressure in children with right atrial thrombi and probability of pulmonary microembolism or embolism. As the incidence of right atrial thrombi is highly associated with the catheter tip position in the right atrium, in contrast to their positioning in the superior vena cava or in its junction with the right atrium, the authors recommend that special attention and effort should be given to placing of the catheter tip in the superior vena cava or in its junction with the right atrium avoiding the right atrium during the implantation procedure. The surgical right atrium thrombus removal in patients with no clot dissolution despite systemic thrombolytic treatment underscores the importance of surgical therapy in treating this life-threatening complication of indwelling catheters.

Manufacturing of a prothrombin complex concentrate aiming at low thrombogenicity.

The paper describes the production of a prothrombin complex concentrate (PCC) with high virus safety and a well-balanced content of vitamin K-dependent clotting factors and inhibitors. Solid-phase extraction is followed in a second step by optimized anion exchange chromatography using a radial column. A step for virus removal by nanofiltration is introduced in addition to the solvent/detergent step. By speeding up the chromatographic step, the period of time required for production is reduced considerably. The activities of the four vitamin K-dependent clotting factors II, VII, IX and X are in ratios of about 1:1:1:1. Protein C, Protein S, and Protein Z are also present in therapeutically effective concentrations. The product shows no thrombogenicity, in either in vivo nor in vitro models. Clinical investigations show that the PCC is a safe and efficient preparation for the substitutive treatment of FIX or FVII in patients suffering from the respective deficiencies. All bleeding episodes have been efficiently controlled with relatively low doses of the concentrate. The surgical procedures have been conducted without any problems in severely FIX and FVIII deficient patients.

[High risk acute lymphoblastic leukaemia in children. Preliminary report after introducing a new version of New York (1997) protocol adjusted to the age of the patients. Report of the Polish Paediatric Leukaemia/Lymphoma Study Group]. / Ostra bialaczka limfoblastyczna u dzieci w grupie duzego ryzyka. Wstepne obserwacje po wprowadzeniu kolejnej modyfikacji (1997) protokolu Nowy York dostosowanej do wieku. Raport Polskiej Pediatrycznej Grupy ds. Leczenia Bialaczki i Chloniaków.

The paper presents the experience of the Polish Paediatric Leukaemia/Lymphoma Study Group in the treatment of high-risk acute lymphoblastic leukaemia in children using a new version of the New York (1997-1999). Protocol with treatment intensity adjusted according to the age of the patients. From April 1997 to December 1999 a group of 49 children with leukocytosis ranging from 50 900/mm3 to 580 000/mm3 (median 122 000/mm3) and 6 children with leukocytosis below 50 000/mm3 and poor response to steroids were treated with this protocol. Children below 10 years (43 patients) were treated according to the previous protocol, children above 10 years (12 patients) were treated with intensified protocol (high doses of ARA-C in consolidation and intermediate doses of Mtx in maintenance). Induction was identical for all patients. Complete remission was achieved in 92.6% patients. There were 2 relapses. Six children died - 3 without remission, 2 due to a relapse, 1 due to treatment complications. The current opinions concerning classification of HRG-ALL and treatment possibilities in this group of children are discussed.

[Intermediate doses of cytosine arabinoside in the treatment of acute non-lymphoblastic leukaemia in children]. / Sredniowysokie dawki arabinozydu cytozyny w leczeniu dzieci z ostra bialaczka nielimfoblastyczna.

Between 1995-1997, at 7 centres of the Polish Paediatric Leukaemia/Lymphoma Study Group (PPLLSG) treatment was started in 102 children with acute non-lymphoblastic leukaemia. Sixty-two children treated according to the new protocol adjusted for risk factors were evaluated. Thirty-one patients belonged to standard risk and 23 to high risk group. Eight children were not evaluated due to early death. Out of 62 children, 44 (70,9%) achieved remission; in standard and high risk groups the rates of remission were 87,5% and 73%, respectively. Four-year event-free survival (EFS), relapse-free survival (RFS) and overall survival (OS) probability in all patients were: 40,2%, 42% and 59% respectively, in standard risk group: 49,5%, 52,5%, 59,1%; in high risk group: 42%, 43,4% and 57,8%. In comparison with the previous period (1983-1994) EFS increased from 30% to 42%, which was statistically insignificant.

[Results of treatment of children with chronic myelogenous leukaemia (CML) obtained by the Polish Paediatric Leukaemia/Lymphoma Study Group]. / Wyniki leczenia dzieci chorych na przewlekla bialaczke, szpikowa (CML) w materiale Polskiej Pediatrycznej Grupy ds Leczenia Bialaczek i Chloniaków u Dzieci.

Retrospective analysis of 102 children with CML from 9 paediatric centres in Poland has been performed. A total number of 102 children: 58 boys and 44 girls aged 1-17 years (median 9.4 years old) with CML, treated in the period 1975-1999 were included in the study. Forty eight of 102 (47.1 %) children were treated with cytostatic drugs without IFN alpha: busulfan, hydroxyurea, 6-mercaptopurine or etoposide (VP-16). Fifty four of 102 (52.9%) patients were treated with interferon alpha (IFN alpha) after cytoreductive pretreatment. Thirty out of 102 (29.4%) patients underwent stem cell transplantation (SCT): 24 - matched related donor allo-BMT, 2 - matched unrelated donor allo-BMT, 1 - partially matched related donor T-cell depleted allo-PBPCT, 1 - syngeneic allo-BMT and 2 - autologous PBPCT. Overall survival analysis revealed that 46 of the 102 (45.1%) children remained alive: 5/35 (14.3%) children treated with cytostatics alone, 22/37 (59.5%) children treated with IFN alpha and 19/30 (63.3%) children treated with SCT. Among SCT survivors there are 10/17 (58.8%) children treated with IFN alpha prior to SCT and 9/13 (69.2%) children treated with cytostatics alone prior to SCT. The probability of 5-year survival is 0.51 in the group treated with SCT (median follow-up 58 months); 0.43 in the group treated with IFN alpha (median follow-up 53 months) and 0.23 in the group treated with cytostatics (median follow-up 31 months). Our data show, that BMT is the treatment of choice in CML in children. IFN alpha could be successfully applied as an alternative treatment for those, who do not have a suitable donor for allogeneic SCT. Better outcome in post BMT children, who were not treated with IFN alpha prior to SCT requires confirmation by studies on larger groups of patients. However, it seems to be justified to stop IFN alpha therapy at least 3 months before SCT. The main reason for unsuccessful treatment outcome in patients with CML in Poland remains the still insufficient access to MUD-BMT.

[Preliminary results of BFM 96 protocol in treatment of childhood ALL relapse in the experience of the Polish Paediatric Leukaemia /Lymphoma Study Group]. / Wstepne wyniki leczenia i nawrotu ostrej bialaczki limfoblastycznej cobl wg programu BFM 96 u Dzieci w Materiale Polskiej Grupy ds. Leczenia Bialaczek i Chloniaków.

Between 1998 and 1999, 36 children aged from 3 months to 18 years (10 girls and 26 boys) with first relapse of acute lymphoblastic leukaemia were included in the study. The children were treated according to the BFM 96 relapse protocol. There were 24 cases with early (including 9 children with very early) and 12 cases with late relapse ( BM-20, local extra BM-6, combined 10). The overall second complete remission (CR) rate was 83,33%. The probability of overall EFS after 2 years was 73,3%. The results obtained with BFM 96 chemotherapy in children with first late relapse are acceptable. For children with early relapses, megachemotherapy with BMT in second remission should be used.

[Adverse reactions associated with the use of L-asparaginase during therapy of patients with nB non-Hodgkin's lymphoma. Report of the Polish Paediatric LeuKaemia/Lymphoma Study Group]. / Objawy niepozadane leczenia preparatami L-asparaginazy u chorych z nieziarniczym chloniakiem zlosliwym typu NB w oparciu o material Polskiej Pediatrycznej Grupy ds. Leczenia Bialaczek i Chloniaków Zlosliwych u dzieci.

The aim of the study was to determine the side effects of asparaginase administration during treatment protocol for childhood non-Hodgkin's lymphoma (NHL). Drug adverse reactions occurred in 20/66 of patients (30,3%) treated in 9 centres in Poland between 1993 and 1998. The most common side effects were coagulation disturbances in 12/66 of the children (18,2%), which occurred due to reduced production of important coagulation factors. Six patients (9,1%) developed impairment of liver function (9,1%). Drug toxicity caused the modifications of treatment protocol in 12/66 (18,2%) of patients, mainly in the induction phase; 3 children died due to relapse of disease.

[Results of the treatment of myelodysplastic syndrome (MDS)obtained by the Polish Paediatric Leukaemia /Lymphoma Study Group]. / Wyniki leczenia zespolów mielodysplastycznych (MDS) uzyskane przez Polska Pediatryczna Grupe ds Leczenia Bialaczek i Chloniaków u dzieci.

Sixty children with MDS treated in six centres of the Polish Paediatric Leukaemia/Lymphoma Study Group in the period 1975-1999 were included in the study. In 20 children RAEB-T, in 13 RA, in 21 RAEB and in 6 CMML were diagnosed. Our own and literature data showed that BMT is the best therapy for children with MDS. We need a new comprehensive protocol for the diagnosis and treatment of children with MDS in Poland.

[Abdominal presentation of B-cell non-Hodgkin's lymphoma (B-NHL) - surgical treatment and its results. Report of the Polish Paediatric Leukaemia/Lymphoma Study Group]. / Manifestacja brzuszna chloniaka B-komórkowego u dzieci - interwencja chirurgiczna i wyniki leczenia. Raport PPGLBC.

The aim of this study was to analyse the effect of LMB-89 protocol and surgical procedure at initial laparotomy on the outcome in children with abdominal B-cell NHL. The initial surgery intervention was: complete resection (20% pts), subtotal resection (20%), partial resection (4%), biopsy (36%). Postoperative complications occurred in 5 children. Complete recovery (CR) was achieved in 92% pts. There were 4% non responder patients. Two patients died before CR evaluation (tumour lysis syndrome; bleeding and multi organ failure after initial surgery). One patient died in CCR from sepsis probably influenced by the previous local operation. 10.8% patients relapsed. The estimate EFS for all patients with AB-NHL is 81%, 85% for stage III and 73% for stage IV. Major surgery in advanced stages is not recommended since it delays chemotherapy and fails to improve overall survival.

[The incidence and treatment of the first relapse in children with Hodgkin's disease]. / Wystepowanie i leczenie pierwszej wznowy choroby Hodgkina u dzieci.

From January 1988, to December 1997, among 447 children with Hodgkin's disease (HD) who underwent initial treatment in seven centres of the Polish Paediatric Leukaemia/Lymphoma Study Group, 442 patients obtained a complete remission (CR). The initial treatment consisted of multidrug chemotherapy (B-DOPA and MVPP) combined with local radiotherapy. Relapses occurred in 35 cases (7,9%). Two patients from other centres were also included in this analysis. Four patients were lost to follow-up; 33 patients with relapses were analysed. Early relapses (first complete remission (CR) shorter than 12 months) occurred in 17 cases. Treatment of the first relapse consisted of different types of multidrug chemotherapy. Six patients underwent high-dose chemotherapy and peripheral blood stem cells transplantation. Radiotherapy was used in 19 children. Second CR was achieved in 28 patients (85%). In 10 children (36%) second relapse occurred after 4 to 21 months (median = 10). In 17 cases the second CR lasted 12-14 (median=54) months. The probability of the 7-year freedom from second relapse was 64%. Eleven patients died; one of them in second CR due to toxic liver damage. Results of treatment in children with early relapses were significantly worse. In 17 patients with early relapse, and 16 children with late relapse, the second CR was achieved in 70% and 100% of cases, respectively. The probability of the 7-year overall survival, freedom from second relapse and event-free survival in children with early and late relapse was: 42, 58, 40%, and 94, 69, and 66%, respectively. The therapeutic results in the subgroups of children with relapses treated with different methods were not comparable because of the small number of children in each group. The use of multidrug chemotherapy with or without radiotherapy allows to achieve a long lasting second CR in more than 50% of children with HD who relapsed after initial combined modality treatment. The optimal treatment of relapsed HD in patients initially treated with multidrug chemotherapy with or without of radiotherapy, is currently unknown.

[G-CSF and GM-CSF in treatment of neutropaenia after chemotherapy in children with neoplasms]. / G-CSF i GM-CSF w leczeniu neutropenii po chemioterapii nowotworów u dzieci.

A total number of 608 cycles of G-CSF and/or GM-CSF was applied in 280 patients aged from 6 months to 20 years during neutropaenia associated with chemotherapy of children's neoplasms (NHL-124, NBL-42, RMS-36, Nephroblastoma-18, Osteosarcoma-17, Ewing's Sarcoma-14, Hepatoblastoma-6, Neurofibrosarcoma-6, PNET-5, Medulloblastoma-3, Fibrohistiocytoma-3, Angiosarcoma-2, other - 4). G-CSF - Neupogen (Filgastrim, Hoffman La Roche - 492 cycles) and GM-CSF - Leucomax (Molgramostim, Shering Plough - 116 cycles) were administered 5 mg/kg/day s.c. Forty one children with malignancies (NHL -21 cases, solid tumours -17) treated before cytokines were in use served as a control group. Our study demonstrated that G-CSF and GM-CSF therapy, gives a shorter period of neutropaenia, reduction of the number of febrile days, decreased frequency of infection and shortened its duration.