Single nucleotide polymorphism in IL1B is associated with infection risk in paediatric acute myeloid leukaemia.

We evaluated single nucleotide polymorphisms (SNPs) associated with infection risk in children with newly diagnosed acute myeloid leukaemia (AML). We conducted a multicentre, prospective cohort study that included children aged ≤18 years with de novo AML. DNA was isolated from blood lymphocytes or buccal swabs, and candidate gene SNP analysis was conducted. Primary outcome was the occurrence of microbiologically documented sterile site infection during chemotherapy. Secondary outcomes were Gram-positive and -negative infections, viridans group streptococcal infection and proven/probable invasive fungal infection. Interpretation was guided by consistency in risk alleles and microbiologic agent with previous literature. Over the study period 254 children and adolescents with AML were enrolled. Overall, 190 (74.8%) had at least one sterile site microbiologically documented infection. Among the 172 with inferred European ancestry and DNA available, nine significant associations were observed; two were consistent with previous literature. Allele A at IL1B (rs16944) was associated with decreased microbiologically documented infection, and allele G at IL10 (rs1800896) was associated with increased risk of Gram-positive infection. We identified SNPs associated with infection risk in paediatric AML. Genotype may provide insight into mechanisms of infection risk that could be used for supportive-care novel treatments.

The role of the MTHFR 677C>T polymorphism in methotrexate-induced liver toxicity: a meta-analysis in patients with cancer.

Methotrexate (MTX), one of the important pillars in the treatment of different forms of cancer, is associated with the development of hepatotoxicity. The 677C>T variant (rs1801133) in the methylenetetrahydrofolate reductase (MTHFR) gene might affect the development of hepatotoxicity. Results in literature are, however, contradictive. The aim of this study was to evaluate the role of the MTHFR 677C>T polymorphism in MTX-induced hepatotoxicity by analyzing a Dutch cohort of pediatric patients treated with high doses of MTX and subsequently performing a meta-analysis. Ninety-eight patients receiving 542 courses of high-dose MTX were genotyped for the MTHFR 677C>T variant. Hepatotoxicity was evaluated retrospectively according to common terminology criteria for adverse events-National Cancer Institute criteria. The influence of MTHFR 677C>T on hepatotoxicity was examined using a generalized estimating equation (GEE) analysis. A fixed-effect meta-analysis based on this and previous studies investigating the association between the MTHFR 677C>T polymorphism and uniformly coded hepatotoxicity was performed. The GEE analysis showed an increased risk of developing hepatotoxicity for T versus C allele (odds ratio (OR) 1.8; 95% confidence interval (CI) 1.0-3.2, P=0.04). This finding was not supported by the meta-analysis including seven studies and 1044 patients; the OR for the 677T versus C allele was 1.1 (95% CI 0.84-1.5, P=0.25). Heterogeneity between studies was observed, possibly related to differences in MTX dose and leucovorin rescue. In conclusion, in patients with cancer, the MTHFR 677T allele has only a minor role in the development of MTX-induced hepatotoxicity. Observed heterogeneity between studies warrants further study into (tailored) leucovorin rescue.

Merging of the National Cancer Institute-funded cooperative oncology group data with an administrative data source to develop a more effective platform for clinical trial analysis and comparative effectiveness research: a report from the Children's Oncology Group.

PURPOSE: The National Cancer Institute-funded cooperative oncology group trials have improved overall survival for children with cancer from 10% to 85% and have set standards of care for adults with malignancies. Despite these successes, cooperative oncology groups currently face substantial challenges. We are working to develop methods to improve the efficiency and effectiveness of these trials. Specifically, we merged data from the Children's Oncology Group (COG) and the Pediatric Health Information Systems (PHIS) to improve toxicity monitoring, to estimate treatment-associated resource utilization and costs, and to address important clinical epidemiology questions. METHODS: COG and PHIS data on patients enrolled on a phase III COG trial for de novo acute myeloid leukemia at 43 PHIS hospitals were merged using a probabilistic algorithm. Resource utilization summary statistics were then tabulated for the first chemotherapy course based on PHIS data. RESULTS: Of 416 patients enrolled on the phase III COG trial at PHIS centers, 392 (94%) were successfully matched. Of these, 378 (96%) had inpatient PHIS data available beginning at the date of study enrollment. For these, daily blood product usage and anti-infective exposures were tabulated and standardized costs were described. CONCLUSIONS: These data demonstrate that patients enrolled in a cooperative group oncology trial can be successfully identified in an administrative data set and that supportive care resource utilization can be described. Further work is required to optimize the merging algorithm, map resource utilization metrics to the National Cancer Institute Common Toxicity Criteria for monitoring toxicity, to perform comparative effectiveness studies, and to estimate the costs associated with protocol therapy.

Unrelated donor or partially matched related donor peripheral stem cell transplant with CD34+ selection and CD3+ addback for pediatric patients with leukemias.

Unmodified peripheral stem cell transplants are associated with an increased risk of extensive chronic GVHD. T depletion may reduce this risk, but the risk of graft failure or relapse may increase. To decrease the risks of both extensive chronic GVHD and graft failure, we added back a defined dose of CD3+ cells to CD34+ selected PSCs. Twenty-four patients were evaluable for outcome analysis. Donors were unrelated (23) or related (1). Conditioning was thiotepa, cyclophosphamide, and total body irradiation. Cyclosporine was used post transplant. Following CD34+ selection, a total of 5 x 10(5)/kg CD3+ cells were infused. Donors were matched for 12 patients. The median CD34+ dose infused was 7.1 x 10(6)/kg. Engraftment occurred in all patients at a median of 14 days (10-19). Twelve patients are alive in remission 15-34 months (median, 25) post PSCT. GVHD occurred in 17 patients, but was >grade II in only 2. Chronic GVHD occurred in 61.5% of evaluable patients, but was limited to skin and perioral cavity. Two patients relapsed, and 10 patients died of non-relapse causes. This study demonstrates that PSCT with CD34+ selection and a defined dose of CD3+ results in prompt engraftment and may limit development of extensive chronic GVHD.

Unrelated donor bone marrow transplantation for children with severe aplastic anemia: minimal GVHD and durable engraftment with partial T cell depletion.

Both increased graft rejection and increased graft vs host disease (GVHD) remain obstacles to success for unrelated donor (URD) BMT for patients with SAA. Partial T cell depletion (PTCD) may decrease the risk of severe GVHD, while still maintaining sufficient donor T lymphocytes to ensure engraftment. We report on 12 patients with SAA who underwent PTCD URD BMT. All patients had failed medical therapy or relapsed following initial responses, and were transfusion dependent. The median age was 6 years, and there were five males. Donors were matched for four patients, and mismatched for eight. All patients received total body irradiation with either Ara-C or thiotepa and cyclophosphamide. PTCD was accomplished using monoclonal antibody T10B9 or OKT3 and complement. All patients engrafted, with a median time of 18 days to ANC >500. Only one patient had greater than grade II acute GVHD; two patients had limited and one patient extensive chronic GVHD. Nine patients are alive and transfusion independent at a median months post BMT. Three patients died from infection or renal failure. This series suggests that an aggressive immunosuppressive conditioning regimen with PTCD results in successful engraftment and minimal GVHD in pediatric patients with SAA, even with HLA mismatched donors.

Outcomes of transplantation with partial T-cell depletion of matched or mismatched unrelated or partially matched related donor bone marrow in children and adolescents with leukemias.

Graft-versus-host disease (GVHD) remains a major barrier to successful hematopoietic stem cell transplant for patients who lack a matched related donor. Partial T-cell depletion (TCD) of the graft may decrease the risk of severe GVHD with unrelated donors (URD) and partially matched related donors (PMRD) while retaining an antileukemic effect. We analyzed our experience using URD and PMRD for pediatric patients with leukemias from 1990 to 2001. A subgroup of 'matched' URD donor pairs was retrospectively analyzed for high-resolution class I. Partial TCD was accomplished with monoclonal antibody T10B9 or OKT3 and complement. There were 76 URD (45% matched) and 28 PMRD recipients. Event-free survival (EFS) was 38.3%, and overall survival (OS) 45.1% at 3 years. On multivariate analysis, there was no difference in survival based upon marrow source, but nonrelapse mortality was higher with the use of PMRD. Relapse occurred in 6% of ALL patients, and 22.8% of AML/MDS patients. Grades III-IV GVHD was observed in only 6.7% of patients. Partial TCD allows use of matched or mismatched URD, or PMRD with little mortality from GVHD, durable engraftment, and no increase in relapse risk.

An unexpectedly high incidence of Epstein-Barr virus lymphoproliferative disease after CD34+ selected autologous peripheral blood stem cell transplant in neuroblastoma.

The risk of Epstein-Barr virus lymphoproliferative disease (EBV-LPD) increases with the use of highly immunosuppressive therapies. Allogeneic BMT, especially supported by T-cell-depleted stem cell products, is a risk factor for EBV-LPD. Although the risk of EBV-LPD after autologous transplantation is low, case reports of this complication in the autologous setting exist. We report a higher incidence than previously described of EBV-LPD in children undergoing sequential high-dose chemotherapy supported with CD34 selected peripheral blood stem cells (CD34+ PBSC). The median time to LPD after tandem transplant was 3 months (range 1-5 months). Five patients out of 156 (3.5%) developed EBV-LPD while enrolled on two trials of tandem autologous SCT in high-risk pediatric malignancies. Both studies employed five cycles of induction therapy, followed by tandem autologous PBSC transplants. In all, 108 out of 156 patients received CD34+ PBSC; 48 received unselected PBSC. All patients contracting LPD were from the CD34 selected group. Treatment of EBV-LPD included rituximab in four out of five patients, i.v.Ig in two out of five patients, and gancyclovir in two out of five patients. EBV-LPD resolved in four out of five patients. We conclude that the combination of tandem SCT and CD34 selection may have increased immunosuppression in these patients to a point where there is an elevated risk of EBV-LPD.

Randomized trial of busulfan vs total body irradiation containing conditioning regimens for children with acute lymphoblastic leukemia: a Pediatric Blood and Marrow Transplant Consortium study.

Conditioning regimens for children with ALL have generally included total body irradiation (TBI), which may result in significant sequelae. The primary aim of this study was to evaluate the outcome for children with ALL undergoing allogeneic stem cell transplant (SCT) with either busulfan (Bu) or TBI regimens. Patients <21 years with ALL undergoing allogeneic SCT were eligible. Conditioning included either Bu or TBI, with etoposide 40 mg/kg and cyclophosphamide 120 mg/kg. Randomization was stratified based upon duration of remission, remission status, and prior cranial irradiation. A total of 43 patients were enrolled; 21 received Bu and 22 TBI. Median patient age was 8 years (0.5-20 years). Remission status included 12 patients in CR1, 25 in CR2, and six in CR3. At a median follow-up of 43 months, event-free survival (EFS) is 45% at 3 years, with 29% EFS in the Bu arm and 58% in the TBI arm (P=0.03). There was no significant difference between Bu and TBI for patients who received stem cells from related donors (36 vs 58%, P=0.3). However, for URD, EFS was 20% for Bu and 57% for TBI (P=0.04). Relapses were similar in both arms. This randomized prospective study suggests that Bu is inferior to TBI for pediatric patients with ALL undergoing allogeneic SCT.

Group sequential methods and sample size savings in biomarker-disease association studies.

Molecular epidemiological association studies use valuable biosamples and incur costs. Statistical methods for early genotyping termination may conserve biosamples and costs. Group sequential methods (GSM) allow early termination of studies on the basis of interim comparisons. Simulation studies evaluated the application of GSM using data from a case-control study of GST genotypes and prostate cancer. Group sequential boundaries (GSB) were defined in the EAST-2000 software and were evaluated for study termination when early evidence suggested that the null hypothesis of no association between genotype and disease was unlikely to be rejected. Early termination of GSTM1 genotyping, which demonstrated no association with prostate cancer, occurred in >90% of the simulated studies. On average, 36.4% of biosamples were saved from unnecessary genotyping. In contrast, for GSTT1, which demonstrated a positive association, inappropriate termination occurred in only 6.6%. GSM may provide significant cost and sample savings in molecular epidemiology studies.

Nucleotide substitution in the ectodomain of trail receptor DR4 is associated with lung cancer and head and neck cancer.

Allelic loss of chromosome 8p21-22 occurs frequently in cancer, including lung and head and neck squamous cell cancer. The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptors, including proapoptotic DR4 and KILLER/DR5, are located on 8p21-22. TRAIL receptors are candidate tumor suppressor genes, because their inactivation would be expected to result in deficient apoptotic signaling. To investigate the involvement of DR4 in human cancer, we have determined the genomic structure of DR4 and screened 31 lung cancer cell lines [14 small cell lung cancer and 17 non-small cell lung cancer (NSCLC)], many with deletions at 8p21-22, and 21 primary NSCLC samples for mutations in DR4. We found two missense alterations in the ectodomain of DR4. One, at nucleotide 626, changes a cytosine to a guanine (C626G) and results in a substitution of an arginine for threonine. The other, at nucleotide 422, changes a guanine to adenine (G422A) and results in a substitution of a histidine for arginine. Using genomic DNA sequencing and RFLP analysis, we show that these two alterations cosegregated in 96% of all of the samples (n = 243) evaluated (tumor and normal). The frequency of being homozygous for both altered alleles was 35% in the lung cancer cell lines but only 13% in age- and race-matched controls, which was a significant increase (chi(2) = 5.2, P = 0.023). The frequency of homozygosity for both alleles was also significantly increased in the primary NSCLC samples (chi(2) = 9.2, P = 0.002) as compared with the age- and race-matched controls. To determine whether the altered alleles are specific for lung cancer, we evaluated 19 head and neck squamous cell cancer and 25 gastric adenocarcinoma samples. Forty-seven % of the former and 44% of the latter were homozygous for both the C626G and G422A alterations, and this was significantly elevated relative to age- and race-matched controls (chi(2) = 8.6, P = 0.003 and chi(2) = 8.2, P = 0.004). These alterations result in amino acid changes in or near the ligand-binding domain of DR4 and, based on the crystal structure of DR5 and its homology with DR4, have the potential to affect TRAIL binding to DR4. Our results suggest that the altered DR4 alleles may be associated with, and should be investigated additionally as potential markers for, predisposition to common malignancies.

Acute myeloid leukaemia in children.

Acute myeloid leukaemia (AML) is characterized by a block in differentiation and an unregulated proliferation of myeloid progenitor cells. While the cause of AML in children is unknown, risk factors that have been identified include exposure to toxins such as ethanol, pesticides and dietary topoisomerase II inhibitors, prior chemotherapy with alkylating agents or topoisomerase II inhibitors, constitutional disorders such as Down's syndrome and type I neurofibromatosis, and haematopoietic failure syndromes such as Fanconi anaemia and severe congenital neutropenia. With intensified chemotherapy including high-dose Ara-C, followed in many cases by bone marrow transplantation, and with improvements in supportive care, current survival rates approach 50%. Future advances in paediatric AML will include better risk stratification to determine optimal treatment and targeted cytotoxic therapy.