Early treatment Response and events definition
To identify the early prognostic factors, we evaluated leukemic blasts
counts in bone marrow by morphology on days 46 and minimal residual
disease(MRD) on days 19 and 46 during first induction.Diagnosis of
complete remission(CR) was based
solely on bone marrow morphology with a cutoff value of 5% of leukemic
blasts on treatment day 46.Bone marrow MRD no lower than
10-5 is defined as positive.It is considered as good
(Prednisone good responders, PGR) if the peripheral blast count on
treatment day 5 is lower than 1×109/L, whereas it is
poor(PPR) if patients show no lower than
1×109/L.Patients were defined as having a
poor early response(PER) if
MRD≥1% on day treatment 19.
FISH andcytogenetic risk group
Pretreatment bone marrow (BM) aspirates were taken at diagnosis and at
least 1-2 milliliters of bone marrow aspirates were analyzed by
fluorescence in situ hybridization(FISH) for CDKN2A deletion,BCR-ABL1
fusion gene,TEL-AML1 fusion gene,E2A-PBX1 fusion gene,MLL
rearrangement,MYC translocation,SIL-TAL1 fusion gene,P53-CEP17,CRLF2
rearrangement.We analyzed interphase cells according to the instructions
of the probe manufacturer(America Abbott).
Patients were divided into two exclusionary cytogenetic risk groups
based on the following cytogenetic abnormalities:high risk (BCR-ABL1,MLL
rearrangements, chromosome <44 or t[17;19]/E2A-HIF) or
intermediate risk (all extra cases with abnormal or normal
cytogenetics).