Residual disease detected by multidimensional flow cytometry signifies high relapse risk in patients with de novo acute myeloid leukemia: a report from Children's Oncology Group.

Publication Type:

Journal Article

Source:

Blood (2012)

Keywords:

2012, Clinical Research Division, June 2012

Abstract:

Early response to induction chemotherapy is a predictor of outcome in AML. We determined the prevalence and significance of post-induction residual disease (RD) by multidimensional flow cytometry (MDF) in children treated on COG AML protocol AAML03P1. Post-induction marrow specimens at the end of induction (EOI) 1 or 2 or at the end of therapy (EOT) from 249 patients were prospectively evaluated by MDF for RD and presence of RD was correlated with disease characteristics and clinical outcome. Of the 188 patients in morphologic complete remission (CR) at EOI1, 46 (24%) had MDF-detectable disease. Those with and without RD at the EOI1 had a 3 year relapse risk of 60% and 29%, respectively (P < 0.001); the corresponding relapse-free survival (RFS) was 30% and 65% (P < 0.001). Presence of RD at the EOI2 and EOT was similarly predictive of poor outcome. RD was detected in 28% of standard-risk patients in CR and was highly associated with poor RFS (P = 0.008). In a multivariate analysis including cytogenetic and molecular risk factors, RD was an independent predictor of relapse (P<0.001). MDF identifies patients at risk of relapse and poor outcome and can be incorporated into clinical trials for risk-based therapy allocation. This study is registered at www.clinicaltrials.gov under NCT00070174.