Search

Background: Treatment response has become one of the most important prognostic factors in childhood acute lymphoblastic leukemia. We evaluated the significance of the complete clearance of peripheral leukemic blasts on survival in children with acute lymphoblastic leukemia., Design and Methods: Seven hundred and fifty-four children diagnosed with acute lymphoblastic leukemia, consecutively enrolled from 1999 to 2003 in the TCCSG L99-15 study, were eligible for analysis. Patients were stratified into three risk groups based on presenting features, such as age and the leukocyte count before starting the treatment, followed by reclassification into three categories 7 days after prednisolone monotherapy based on the peripheral blast count; 0/microL (Day8NoBlasts), 1-999/microL and >or= 1,000/microL., Results: After 7 days of prednisolone monotherapy, 249 patients (33%) were classified as Day8NoBlasts, 392 patients (52%) had blast counts of 1-999/microL, and 113 patients (15%) had blast counts >or= 1,000/microL. The event-free survival for all patients was 79.6+/-1.6 (SE)% at 4 years, whereas that for patients with Day8NoBlasts was 90.4+/-2.0% (n=249) and the event-free survival for the other patients was 74.2+/-2.2% (n=504) (log rank p<0.001). The event-free survival for Day8NoBlasts patients with B-lineage acute lymphoblastic leukemia and T-cell acute lymphoblastic leukemia was 89.8+/-2.1% (n=226) and 95.7+/-4.3% (n=23), respectively. In a multivariate analysis, age at diagnosis, the initial white blood cell count, immunophenotype, and gender did not remain as independent risk factors for treatment failure, whereas Day8NoBlasts and marked hyperdiploidy (more than 50 chromosomes) became statistically significant., Conclusions: Children with Day8NoBlasts constituted one third of all the cases with childhood acute lymphoblastic leukemia with an excellent outcome, and should be candidates for curative management with less intensive treatment.

Background: As a first step to formulate a new treatment strategy for refractory acute lymphoblastic leukemia (ALL) in infants, clinical results and immunophenotypic and cytogenetic data were analyzed and compared with those from overseas., Methods: There were 62 infants with ALL who were treated between 1977 and 1995 at 30 institutions affiliated with the Tokyo Children's Cancer Study Group. Clinical and laboratory data obtained from these infants (all under 1 year of age) were retrospectively studied., Results: The morphological diagnoses were FAB-L1 for 51 patients (82.2%) and FAB-L2 for 11 patients (17.8%). Hepatomegaly and splenomegaly were found in 40 (70.0%) and 40 patients (68.3%), respectively. The mean (+/- SEM) leukocyte count at diagnosis was 205,900 +/- 35,700/microL. The involvement of the central nervous system was evident in nine of 36 patients who were subjected to lumbar puncture, while three of these nine patients were free of neurological symptoms at diagnosis. Thirty-one patients (55.4%) were CD10 negative and 14 (25.0%) were CD10 positive. Thirty-one of 47 patients (65.9%) exhibited chromosomal abnormalities, including 28 patients (59.6%) with 11q23 abnormalities. Rearrangements in the MLL gene were found in nine of 13 infants (69.2%) examined. Translocation of 11q23 and/or MLL gene rearrangement (11q23/MLL) was significantly associated with the absence of the CD10 antigen. Hyperleukocytosis of more than 50,000/microL and 11q23/MLL gene rearrangements were related to a poor prognosis. The probability of an event-free survival in 62 infants was 13.1 +/- 4.8% at 48 months., Conclusions: New therapeutic strategies and large-scale cooperative prospective trials are needed to improve the prognosis of ALL in infants.