RESUMO
PURPOSE: The International Berlin-Frankfurt-Münster (BFM) study group conducted a study on pediatric acute lymphoblastic leukemia (ALL). Minimal residual disease (MRD) was assessed using flow cytometry (FCM), and the impact of early intensification and methotrexate (MTX) dose on survival was evaluated. PATIENTS AND METHODS: We included 6,187 patients younger than 19 years. MRD by FCM refined the risk group definition previously used in the ALL intercontinental-BFM 2002 study on the basis of age, WBC count, unfavorable genetic aberrations, and treatment response measured morphologically. Patients at intermediate risk (IR) and high risk (HR) were randomly assigned to protocol augmented protocol I phase B (IB) versus IB regimen. MTX doses of 2 versus 5 g/m2 every 2 weeks, four times, were evaluated in precursor B-cell-ALL (pcB-ALL) IR. RESULTS: The 5-year event-free survival (EFS ± SE) and overall survival (OS ± SE) rates were 75.2% ± 0.6% and 82.6% ± 0.5%, respectively. Their values in risk groups were standard risk (n = 624), 90.7% ± 1.4% and 94.7% ± 1.1%; IR (n = 4,111), 77.9% ± 0.7% and 85.7% ± 0.6%; and HR (n = 1,452), 60.8% ± 1.5% and 68.4% ± 1.4%, respectively. MRD by FCM was available in 82.6% of cases. The 5-year EFS rates in patients randomly assigned to protocol IB (n = 1,669) and augmented IB (n = 1,620) were 73.6% ± 1.2% and 72.8% ± 1.2%, respectively (P = .55), while those in patients receiving MTX doses of 2 g/m2 (n = 1,056) and MTX 5 g/m2 (n = 1,027) were 78.8% ± 1.4% and 78.9% ± 1.4%, respectively (P = .84). CONCLUSION: The MRDs were successfully assessed using FCM. An MTX dose of 2 g/m2 was effective in preventing relapse in non-HR pcB-ALL. Augmented IB showed no advantages over the standard IB.[Media: see text].
Assuntos
Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Criança , Humanos , Lactente , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Metotrexato/uso terapêutico , Fatores de Risco , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Intervalo Livre de Doença , Resultado do TratamentoRESUMO
The clinical characteristics of chronic myeloid leukemia (CML) in lymphoid blast crisis (BC) can resemble those of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph ALL). Because of this, there can be concern as to whether a patient with newly diagnosed Ph leukemia has Ph ALL or CML in lymphoid BC. This distinction has significant potential therapeutic implications because most children with Ph ALL are now treated with chemotherapy plus a tyrosine kinase inhibitor, whereas allogeneic stem cell transplant is usually recommended for any patient with CML that presents in or later develops BC.