Gene expression signatures predictive of early response and outcome in high-risk childhood acute lymphoblastic leukemia: A Children's Oncology Group Study [corrected].

Purpose: To identify children with acute lymphoblastic leukemia (ALL) at initial diagnosis who are at risk for inferior response to therapy by using molecular signatures.

Patients And Methods: Gene expression profiles were generated from bone marrow blasts at initial diagnosis from a cohort of 99 children with National Cancer Institute-defined high-risk ALL who were treated uniformly on the Children's Oncology Group (COG) 1961 study. For prediction of early response, genes that correlated to marrow status on day 7 were identified on a training set and were validated on a test set.

Biologic pathways associated with relapse in childhood acute lymphoblastic leukemia: a Children's Oncology Group study.

Outcome for children with childhood acute lymphoblastic leukemia (ALL) who relapse is poor. To gain insight into the mechanisms of relapse, we analyzed gene-expression profiles in 35 matched diagnosis/relapse pairs as well as 60 uniformly treated children at relapse using the Affymetrix platform. Matched-pair analyses revealed significant differences in the expression of genes involved in cell-cycle regulation, DNA repair, and apoptosis between diagnostic and early-relapse samples.