Status of minimal residual disease after induction predicts outcome in both standard and high‐risk Ph‐negative adult acute lymphoblastic leukaemia. The Polish Adult Leukemia Group ALL 4‐2002 MRD Study

Summary The treatment of adults with Philadelphia‐negative acute lymphoblastic leukaemia (ALL) depends on the presence of risk factors including age, white blood cell count, immunophenotype and time to complete remission. In recent years, status of minimal residual disease (MRD) has been postulated as an additional risk criterion. This study prospectively evaluated the significance of MRD. Patients were treated with a uniform Polish Adult Leukemia Group (PALG) 4‐2002 protocol. MRD status was assessed after induction and consolidation by multiparametric flow cytometry. Out of 132 patients included (age, 17–60 years), 116 patients were suitable for analysis. MRD level ≥0·1% of bone marrow cells after induction was found to be a strong and independent predictor for relapse in the whole study population (P