In:
Journal of Clinical Oncology, American Society of Clinical Oncology (ASCO), Vol. 24, No. 10 ( 2006-04-01), p. 1507-1515
Abstract:
To determine whether minimal residual disease (MRD) measured by Wilms' tumor gene 1 (WT1) expression is a prognostic marker in pediatric acute myeloid leukemia (AML), we quantified WT1 transcript by real-time quantitative-polymerase chain reaction in 92 AML at diagnosis and during follow-up. Patients and Methods Patients (median age, 6 years; cytogenetics, favorable 27%, intermediate 59%, poor 13%) were treated between 1995 and 2002 and enrolled in Leucémie aiguë Myéloblastique Enfant (LAME) 89/91, LAME 99 pilot study and Acute Promyelocytic Leukemia French collaborative protocols. With a median follow-up of 26 months, event-free survival was 56% with a standard deviation (SD) of 5% and overall survival of 62.5% with an SD of 6%. WT1 copy number was normalized by TATA box binding protein gene transcripts and expressed as WT1/TBP × 1,000 ratio. Median WT1 ratio in normal patient controls was 12 (range, 0 to 57). A level over two SD than normal bone marrow controls (ie, WT1 ratio 〉 50), was considered as significant overexpression. Results At diagnosis, WT1 overexpression was detected in 78% of patients (72 of 92 patients; median copy ratio, 2231). The WT1 values were significantly higher (P = .01) in favorable cytogenetics and lower (P 〈 .0001) in M5-FAB subtype, 11q23 rearrangements (P 〈 .001), and infants (P = .003) and demonstrate a strong correlation with fusion transcript AML1-ETO, PML-RARα expression. After induction treatment, WT1 ratio was analyzed in 46 of 72 patients and found above 50 in nine of 36 patients and five of 25 patients at D35-50 and 3 to 5 months, respectively. WT1 ratio 〉 50 after induction is an independent prognostic risk factor of relapse (P = .002) and death (P = .02). Conclusion WT1 quantification is an informative molecular marker for MRD in pediatric AML and is now performed as prospective analysis in ELAM02 protocol.
Type of Medium:
Online Resource
ISSN:
0732-183X
,
1527-7755
DOI:
10.1200/JCO.2005.03.5303
Language:
English
Publisher:
American Society of Clinical Oncology (ASCO)
Publication Date:
2006
detail.hit.zdb_id:
2005181-5
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