RESUMO
The clinical value of serial minimal residual disease (MRD) monitoring in core binding factor (CBF) acute myeloid leukemia (AML) by quantitative RT-PCR was prospectively assessed in 278 patients [163 with t(8;21) and 115 with inv(16)] entered in the United Kingdom MRC AML 15 trial. CBF transcripts were normalized to 10(5) ABL copies. At remission, after course 1 induction chemotherapy, a > 3 log reduction in RUNX1-RUNX1T1 transcripts in BM in t(8;21) patients and a > 10 CBFB-MYH11 copy number in peripheral blood (PB) in inv(16) patients were the most useful prognostic variables for relapse risk on multivariate analysis. MRD levels after consolidation (course 3) were also informative. During follow-up, cut-off MRD thresholds in BM and PB associated with a 100% relapse rate were identified: for t(8;21) patients BM > 500 copies, PB > 100 copies; for inv(16) patients, BM > 50 copies and PB > 10 copies. Rising MRD levels on serial monitoring accurately predicted hematologic relapse. During follow-up, PB sampling was equally informative as BM for MRD detection. We conclude that MRD monitoring by quantitative RT-PCR at specific time points in CBF AML allows identification of patients at high risk of relapse and could now be incorporated in clinical trials to evaluate the role of risk directed/preemptive therapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Biomarcadores Tumorais/genética , Leucemia Mieloide Aguda/tratamento farmacológico , Recidiva Local de Neoplasia/diagnóstico , Neoplasia Residual/diagnóstico , Proteínas de Fusão Oncogênica/genética , Reação em Cadeia da Polimerase em Tempo Real , Adolescente , Adulto , Idoso , Cromossomos Humanos Par 21/genética , Cromossomos Humanos Par 8/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Feminino , Humanos , Leucemia Mieloide Aguda/mortalidade , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/mortalidade , Estadiamento de Neoplasias , Neoplasia Residual/genética , Neoplasia Residual/mortalidade , Prognóstico , Estudos Prospectivos , RNA Mensageiro/genética , Proteína 1 Parceira de Translocação de RUNX1 , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Medição de Risco , Taxa de Sobrevida , Translocação Genética/genética , Adulto JovemAssuntos
Medula Óssea/metabolismo , Linfoma de Burkitt/genética , Linfoma de Burkitt/patologia , Adulto , Idoso , Antineoplásicos/uso terapêutico , Linfoma de Burkitt/diagnóstico , Linfoma de Burkitt/tratamento farmacológico , Citogenética , Feminino , Humanos , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Gene expression mapping using microarray analysis has identified useful gene signatures for predicting outcome. However, little of this has been translated into clinically effective diagnostic tools as microarrays require high quality fresh-frozen tissue samples. We describe a methodology of multiplexed in situ hybridization (ISH) using a novel combination of quantum dot (QD)-labeled oligonucleotide probes and spectral imaging analysis in routinely processed, formalin-fixed paraffin embedded human biopsies. The conditions for QD-ISH were optimized using a poly d(T) oligonucleotide in decalcified bone marrow samples. Single and multiplex QD-ISH was performed in samples with acute leukemia and follicular lymphoma using oligonucleotide probes for myeloperoxidase, bcl-2, survivin, and XIAP. Spectral imaging was used for post hybridization tissue analysis, enabling separation of spatially colocalized signals. The method allows quantitative characterization of multiple gene expression using non-bleaching fluorochromes. This is expected to facilitate multiplex in situ transcript detection in routinely processed human clinical tissue.
Assuntos
Perfilação da Expressão Gênica/métodos , Hibridização In Situ/métodos , Pontos Quânticos , RNA Mensageiro/análise , Biópsia , Fixadores , Formaldeído/química , Humanos , Sondas de Oligonucleotídeos/químicaRESUMO
The core-binding factor (CBF) leukemias comprise acute myeloid leukemia (AML) with t(8;21) and inv(16)/t(16;16), characterized by the presence of the AML1-ETO and CBFbeta-MYH11 fusion genes, respectively. These leukemia-associated genes can now be sensitively and reliably quantified by real-time reverse transcription polymerase chain reaction (RT-PCR) techniques and thus can serve as molecular targets for monitoring residual leukemia. Studies to date suggest that quantitative monitoring of minimal residual disease (MRD) in CBF-positive AML is useful in distinguishing patients at high risk of relapse from those in durable remission. Preliminary results of MRD monitoring by real-time RT-PCR in this subset of AML patients are promising and provide the basis for further evaluation by quantitative analysis in large prospective clinical trials.
