MLL-SEPTIN6 fusion recurs in novel translocation of chromosomes 3, X, and 11 in infant acute myelomonocytic leukaemia and in t(X;11) in infant acute myeloid leukaemia, and MLL genomic breakpoint in complex MLL-SEPTIN6 rearrangement is a DNA topoisomerase II cleavage site.

We examined the MLL translocation in two cases of infant AML with X chromosome disruption. The G-banded karyotype in the first case suggested t(X;3)(q22;p21)ins(X;11)(q22;q13q25). Southern blot analysis showed one MLL rearrangement. Panhandle PCR approaches were used to identify the MLL fusion transcript and MLL genomic breakpoint junction. SEPTIN6 from chromosome band Xq24 was the partner gene of MLL. MLL exon 7 was joined in-frame to SEPTIN6 exon 2 in the fusion transcript. The MLL genomic breakpoint was in intron 7; the SEPTIN6 genomic breakpoint was in intron 1. Spectral karyotyping revealed a complex rearrangement disrupting band 11q23. FISH with a probe for MLL confirmed MLL involvement and showed that the MLL-SEPTIN6 junction was on the der(X). The MLL genomic breakpoint was a functional DNA topoisomerase II cleavage site in an in vitro assay. In the second case, the karyotype revealed t(X;11)(q22;q23). Southern blot analysis showed two MLL rearrangements. cDNA panhandle PCR detected a transcript fusing MLL exon 8 in-frame to SEPTIN6 exon 2. MLL and SEPTIN6 are vulnerable to damage to form recurrent translocations in infant AML. Identification of SEPTIN6 and the SEPTIN family members hCDCrel and MSF as partner genes of MLL suggests a common pathway to leukaemogenesis.

Human granulocyte colony-stimulating factor in children with high-risk acute lymphoblastic leukemia: a Children's Cancer Group Study.

PURPOSE: To investigate the effect of granulocyte colony-stimulating factor (G-CSF) on hematopoietic toxicities, supportive care requirements, time to complete intensive therapy, and event-free survival (EFS) and overall survival (OS) in children with high-risk acute lymphoblastic leukemia (HR-ALL). PATIENTS AND METHODS: A total of 287 children with HR-ALL were randomly assigned to intensive chemotherapy regimens (New York I [NY I] or NY II) as part of the Children's Cancer Group (CCG)-1901 protocol. The induction phases consisted of five drugs (vincristine, prednisone, l-asparaginase, daunorubicin, and cyclophosphamide). Initial consolidation comprised six-agent chemotherapy combined with 18 Gy of total-brain irradiation. Patients were randomly assigned to receive G-CSF (5 microg/kg/day) during either induction or initial consolidation. A crossover study analysis was done on the 259 patients who completed both phases of therapy. RESULTS: The mean time to neutrophil recovery (>/= 0.5 x 109/L) was reduced with G-CSF (16.7 v 19.1 days, P =.0003); however, patients who received G-CSF did not have significantly reduced episodes of febrile neutropenia (149 v 164, P =.41), positive blood cultures (57 v 61, P =.66), or serious infections (75 v 79, P =.62). Hospitalization (14.0 v 13.9 days, P =.87) and induction therapy completion times (NY I, 30.3 v 31.3 days, P =.11; NY II, 33.4 v 32.3 days, P =.40) were not significantly altered. There were no differences in 6-year EFS (P =.24) or OS (P =.54) between patients receiving or not receiving G-CSF on CCG-1901, NY I and NY II. CONCLUSION: Children with high-risk ALL do not appear to benefit from prophylactic G-CSF.

Phase II study of high-dose chemotherapy before radiation in children with newly diagnosed high-grade astrocytoma: final analysis of Children's Cancer Group Study 9933.

BACKGROUND: High-grade astrocytomas (HGA) carry a dismal prognosis and compose nearly 20% of all childhood brain tumors. The role of high-dose chemotherapy (HDCT) in the treatment of HGA remains unclear. METHODS: In a nationwide study, The Children's Cancer Group (CCG) prospectively evaluated 102 children with HGA and postoperative residual disease for efficacy and toxicity of four courses of HDCT before radiotherapy (RT). Patients were randomly assigned to one of three couplets of drugs: carboplatin/etoposide (Regimen A), ifosfamide/etoposide (Regimen B), or cyclophosphamide/etoposide (Regimen C). After HDCT, all patients were to receive local RT followed by lomustine and vincristine. Twenty-six patients were excluded after central neuroradiographic review (n = 8) or pathology review (n = 18). RESULTS: Of 76 evaluable patients (median age, 11.95 yrs; range, 3-20 yrs), 30 patients relapsed during HDCT, and 11 others did not complete HDCT because of toxicity. Nonhematologic serious toxicities were common (29%), and 21% of patients did not receive RT. Objective response rates were not associated with amount of residual disease and did not statistically differ between regimens: 27% (Regimen A), 8% (Regimen B), and 29% (Regimen C). Overall survival (OS) was 24% +/- 5% at 5 years and did not differ between groups. Median time to an event was longest for Regimen A (283 days compared with 83 and 91 days for Regimens B and C, respectively). The five-year, event-free survival (EFS) rate for all patients was 8% +/- 3% and 14% +/- 7% for Regimen A (P = 0.07). CONCLUSIONS: OS and EFS were not affected by histologic grade. Patients who responded to HDCT had a nominally higher survival rate (P = 0.03 for trend). The authors conclude that these commonly used HDCT regimens provide no additional clinical benefit to conventional treatment in HGA, regardless of the amount of measurable residual tumor.

Breast-feeding and neuroblastoma, USA and Canada.

OBJECTIVE: Researchers have suggested an inverse association between breast-feeding and risk of childhood cancer. We investigated the association between breast-feeding and neuroblastoma in a large case-control study in the United States and Canada. METHODS: Maternal reports of breast-feeding were compared among 393 children six months or older who had neuroblastoma and were identified through the Children's Cancer Group and the Pediatric Oncology Group and 376 age-matched controls identified by random-digit telephone dialing in a telephone interview case-control study. RESULTS: Children with neuroblastoma were less likely to have breast-fed than control children (odds ratio (OR) = 0.6; 95% confidence interval (CI) = 0.5-0.9). The association between breast-feeding and neuroblastoma increased with breast-feeding duration (0-3 months OR = 0.7, CI = 0.4-1.0; 13+ months OR = 0.5, CI = 0.3-0.9). CONCLUSION: Breast-feeding was inversely associated with neuroblastoma and should be encouraged among healthy mothers. Additional research on possible mechanisms of this association may be warranted.