Clinical significance of minimal residual disease in peripheral blood on day 8 induction in childhood B-precursor acute lymphoblastic leukemia: Report from Children's Cancer Hospital in Egypt.

e21008 Background: Minimal residual disease (MRD) in childhood acute lymphoblastic leukemia (ALL) during the early stages of therapy is statistically significant indicator of outcome. Aim: To study the prognostic significance of MRD by flow-cytometry in peripheral blood (PB) on day-8 induction in pediatric B-precursor ALL. Patients and Methods: This study included 140 newly diagnosed pediatric B-precursor ALL patients treated at the Children’s Cancer Hospital-Egypt during the period between mid of March 2010 and end of September 2011. ALL patients received adopted protocol of St. Jude Children’s Research Hospital total study XV for low or standard/high risk ALL. Results: The 3-year relapse-free survival (RFS) and event-free survival (EFS) were 87±3.5% and 82±3.7% respectively. Median follow up was 34.9 months (range 24–42). MRD PB day-8 < 1% was encountered in 78% of patients. Patients with day-8 MRD < 1% had 3-year RFS of 90.6±3.4% compared to 73±10.7% for day-8 MRD ≥ 1% (P =0.042). The prognostic factor...