Prevention and treatment of hyperuricemia with rasburicase in children with leukemia and non-Hodgkin's lymphoma.

To prevent acute renal failure in children at risk for developing tumor lysis syndrome due to acute lymphoblastic leukemia or non-Hodgkin's lymphoma treated according to international BFM protocols, we investigated recombinant urate oxidase (rasburicase) in the first Central European openlabeled, prospective, multicenter phase IV trial. Rasburicase was administered intravenously, at 0.2 mg/kg for 5 consecutive days to 36 patients. Blood levels of uric acid, creatinine, phosphorus, calcium, lactate dehydrogenase and complete blood count were measured daily during rasburicase treatment and on days 6, 7 and 12. Initial uric acid level decreased significantly by 4 hours (from 343 micromol/L to 58 micromol/L, p<0.001), except for one steroid-resistant patient who required hemodialysis on day 14 after having introduced combined cytostatic treatment. Comparing the data of a subgroup of 12 patients receiving rasburicase with that of a historic cohort of 14 patients treated with allopurinol indicated the superiority of rasburicase over allopurinol in prophylaxis and treatment of hyperuricemia in children with leukemia and lymphoma.

The role of ABC-transporter gene polymorphisms in chemotherapy induced immunosuppression, a retrospective study in childhood acute lymphoblastic leukaemia.

We examined the association of functional ABCB1 (MDR1) and ABCG2 (BCRP) polymorphisms with acute side effects of chemotherapy. Analyses were performed on clinical data from 138 patients treated with the ALL-BFM-95 protocol implying several substrates of these transporters. ABCB1 3435T>C, 2677G>T/A 1236C>T and ABCG2 421C>A genotypes were determined. A higher proportion of ABCB1 3435TT patients suffered excessive infectious complications than those harbouring at least one C allele (OR=2.5, p=0.03) during the whole half-year-long intensive phase of chemotherapy. Weaker associations were calculated when ABCB1 1236T-2677T-3435T haplotype homozygotes were tested against the remaining part of the population (OR=2.3, p=0.09). During the reinduction phase of therapy, the occurrence of severe leukocytopenia was similar among ABCB1 genotype groups. The frequency of any toxicities were not shown to differ according to the ABCG2 421C>A genotype. Our data suggest that the ABCB1 3435T>C genotype is associated with the infectious complications of the applied chemotherapy regimen.

[Treatment results with ALL-BFM-95 protocol in children with acute lymphoblastic leukemia in Hungary]. / Az ALL-bFM-95 protokollal szerzett hazai eredmények akut lymphoblastos leukaemiás gyermekek kezelésében.

BACKGROUND: In Hungary children (from 1 to 18 years of age) with de novo acute lymphoblastic leukemia were treated from January 1996 to October 2002, according to protocol ALL-BFM-95. AIM: The aim of this study was to evaluate the experience with this protocol, the treatment results according to the risk groups and to compare the Hungarian data with the international results. METHODS: Patients were stratified into 3 risk groups, based on initial white blood cell count, age, immunology, cytogenetics and response to treatment: standard, medium and high risk group. RESULTS: Three hundred sixty eight children entered the study (male-female ratio was 1.27:1, median age 6 years and 4 months). 110 (29.9%) children were in the standard, 210 (57.1%) in the medium and 48 (13%) in the high risk group. Duration of the chemotherapy was 2 years, except of the boys in the standard risk group, their maintenance therapy was 1 year longer. The overall complete remission rate was 93.2%. 20 (5.4%) children died in induction and 5 (1.4%) were non-responders. The 5-year overall survival for all patients was 78.5%, in the standard risk group 93.2%, in the medium risk group 78.4% and in the high risk group 44.5% with a minimum follow up of 1.19 years and median follow up of 4.85 years. From the 368 patients 272 (73.9%) are still in their first complete clinical remission and other 18 children are alive after relapse. In 14.7% of the patients relapse was diagnosed; the most common site was the bone marrow. In one patient second malignancy occurred. The 5-year event free survival for all patients was 72.6%, in the standard risk group 87.6%, in the medium risk group 72.1% and in the high risk group 39.9%. CONCLUSION: The treatment outcome of children with acute lymphoblastic leukemia improved remarkably over the last decades. 78% of children suffering from acute lymphoblastic leukemia could be cured with the ALL-BFM-95 protocol. The Hungarian results are comparable to those achieved by other leukaemia study groups in the world regarding the ALL-BFM-95 protocol.

[Experiences with Langerhans' cell histiocytosis in children in Hungary]. / Gyermekkori Langerhans-sejtes histiocytosissal szerzett magyarországi tapasztalataink.

BACKGROUND: Langerhans cell histiocytosis (LCH) in children is relatively rare, and the long-term analysis of therapy results has not been done yet in Hungary. PURPOSE: In this review we summarise the incidence, clinical features, prognostic risk factors and treatment results of children's LCH in Hungary, using data from the National Childhood Cancer Registry in Hungary in a 20-year period between 1981 and 2000. RESULTS: From January 1981 to December 2000, 111 children under 18 years of age were newly diagnosed with LCH in Hungary. The male-female ratio was 1.36:1, the mean age: 4 years 11 months. The minimal and median follow-up time was 3.48 years and 10.98 years respectively. 38 children had single-system disease, while in 73 cases we found systemic dissemination already at the time of diagnosis. Twenty-two patients were treated only by local surgery, 7 by surgery with local irradiation and 5 children received only local irradiation. In two cases remission was obtained with local steroid administration. 75 patient received chemotherapy. During the twenty years 14 children died, 9 due to the progression of the disease. Sixteen of the 111 patients had relapse with a mean of 2.16+/-1.29 years after the first diagnosis. Three patients with relapse got chemotherapy generally used in lymphoma and remission was achieved. The overall survival of all patients (n=111) was 88.3+/-3.1% at 5 years and 87.3+/-3.2% at 10 and 20 years. CONCLUSION: Childhood LCH is a well treatable disease and the survival rate is high. Even disseminated diseases have a quite good prognosis in childhood.

[Detection of n-myc gene amplification in neuroblastoma using polymerase chain reaction based methods]. / N-myc-amplifikáció vizsgálata neuroblastomában PCR-alapú módszerekkel.

We have used semiquantitative and real-time quantitative PCRs to detect n-myc gene-amplification in 21 frozen neuroblastoma biopsies and IMR 32 cell line in order to predict biological behaviour of the tumors. Two primer pairs were used in the semiquantitative method to co-amplify a 520-bp fragment of the beta -globin gene -used as a single copy reference standard -and a 258-bp fragment of the n-myc gene. After 30 cycles the PCR products were electrophoresed through an agarose gel and were compared to each other with use of a gel-densitometer. Real-time quantitative analysis was performed in a LightCycler instrument. A single primer pair was used to amplify a 120-bp fragment of the n-myc oncogene and a LC640-labelled fluorescent probe pair to detect the product. Calibration curve, which was set up from a serial dilution including samples with 1, 2, 10, 13, 25-fold n-myc oncogene amplification, was employed for quantitative analysis. Semiquantitative method did not show distinct difference between tumor groups with no amplification and less than 10-fold amplification, while quantitative LightCycler analysis was able to detect even 2-fold amplification. In situ PCRs were performed in two cases of differentiated tumor samples which contained n-myc amplification. We used biotinylated ATP labelling and the same primer pair as for the LightCycler analysis.In both cases differentiated cell forms did not show n-myc gene amplification, while considerable amplification was detected in the neuroblasts.