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.