Clinical featurea | BCP ALL (%) | T-ALL (%) |
|---|
Number of patients | 663 | 101 |
Male:female ratio | 1.2 | 2.9 |
Median age (years) | 4.8 | 9.4 |
High hyperdiploid (HeH)b | 187 (30%) | 3 (3%) |
t(12;21)ETV6/RUNX1c | 163 (26%) | 0 (0%) |
Undefinedd | 105 (17%) | 54 (54%) |
Non-recurrente | 100 (16%) | 37 (37%) |
11q23/MLLc | 28 (4.5%) | 4 (4%) |
t(1;19)TCF3/PBX1c | 23 (3.5%) | 0 (0%) |
dic(9;20)c | 20 (3%) | 0 (0%) |
t(9;22)BCR/ABL1 | 19 (3%) | 1 (<1%) |
iAMP21c | 10 (1.5%) | 0 (0%) |
<45 chromosomes | 5 (<1%) | 0 (0%) |
>67 chromosomes | 3 (<1%) | 2 (2%) |
First relapsef | 24 | 3 |
Second relapsef | 5 | 0 |
- aThe diagnosis was established at a pediatric oncology center by analysis of bone marrow aspirates with respect to morphology, immunophenotype, and cytogenetics of the leukemic cells. Immunophenotypes (BCP ALL or T-ALL) were defined according to the European Group for the Immunological Characterization of Leukemias. Chromosome banding of bone marrow and/or peripheral blood samples was performed using standard methods. The definition and description of clonal abnormalities followed the recommendations of International System for Human Cytogenetic Nomenclature. Karyotypes were centrally reviewed.
- bHigh hyperdiploidy (HeH) was defined as a modal number more than 50 chromosomes.
- cFluorescence in situ hybridization and/or reverse-transcriptase polymerase chain reaction were applied to identify t(12;21), t(1;19), 11q23, dic(9;20)(p11-13;q11), and iAMP(21q22).
- dUndefined includes patients with no karyotype information available.
- eNon-recurrent includes patients with chromosomal abnormalities other than those defined in the recurrent groups.
- fDetailed information on relapse samples is available in Additional file 2: Table S15.
