Table 1. Patient characteristics (N = 100 patients).
| Characteristics | |
| Age (yr), median (range) | 5.2 (1.4–16) |
| 1 y to less than 10 y | 80 |
| at least 10 y | 20 |
| Gender, No. | |
| Male | 57 |
| Female | 43 |
| WBC count at diagnosis, No. | |
| <10,000/µL | 61 |
| 10,000/µL–100,000/µL | 35 |
| >100,000/µL | 3 |
| >200,000/µL | 1 |
| Risk group, No. | |
| Standard-risk patients | 69 |
| modified CCG-1881 | 2 |
| modified CCG-1891 | 12 |
| modified CCG-1952 | 55 |
| High-risk patients | |
| modified CCG-1882 | 31 |
| FAB classification, No. | |
| L1 | 75 |
| L2 | 19 |
| Not identified | 6 |
| Immunophenotype, No. | |
| Precursor B | 92 |
| Precursor T | 6 |
| Not available | 2 |
| Cytogenetics, No. | |
| t(12;21);TEL-AML1 | 17 |
| t(9;22);BCR-ABL1 | 2 |
| t(1;19);E2A-PBX1 | 1 |
| p16 deletion | 2 |
| hyperploidy | 12 |
| hypoploidy | 4 |
| Complex karyotype | 4 |
| Normal karyotype | 44 |
| Down syndrome (21 trisomy) | 2 |
| Others | 7 |
| Not available | 5 |
| CNS involvement, No. | |
| Absent | 89 |
| Present | 5 |
| Not available | 6 |
| Day 7 BM response to treatment, No. | |
| Leukemic blasts less than 25% | 73 |
| Leukemic blasts at least 25% | 27 |
| Event | |
| Relapse | 12 |
| BM | 4 |
| CNS | 3 |
| Testis | 2 |
| BM+CMS | 2 |
| BM+testis | 1 |
| Death | 4 |
| Secondary malignancy | 0 |
| Grade 3,4 toxicity during treatment | |
| Hyperbilirubinemia | 1 |
| Liver enzyme dysfunction | 23 |
| Febrile neutropenia without sepsis | 13 |
| Sepsis | 15 |
Abbreviation: CCG, Children's Cancer Group.; BM, bone marrow; CNS, central nervous system.