title: Assessment of Minimal Residual Disease in Standard-Risk AML.
abstract: BACKGROUND
  Despite the molecular heterogeneity of standard-risk acute myeloid leukemia (AML), treatment decisions are based on a limited number of molecular genetic markers and morphology-based assessment of remission. Sensitive detection of a leukemia-specific marker (e.g., a mutation in the gene encoding nucleophosmin [NPM1]) could improve prognostication by identifying submicroscopic disease during remission.
  
  
  METHODS
  We used a reverse-transcriptase quantitative polymerase-chain-reaction assay to detect minimal residual disease in 2569 samples obtained from 346 patients with NPM1-mutated AML who had undergone intensive treatment in the National Cancer Research Institute AML17 trial. We used a custom 51-gene panel to perform targeted sequencing of 223 samples obtained at the time of diagnosis and 49 samples obtained at the time of relapse. Mutations associated with preleukemic clones were tracked by means of digital polymerase chain reaction.
  
  
  RESULTS
  Molecular profiling highlighted the complexity of NPM1-mutated AML, with segregation of patients into more than 150 subgroups, thus precluding reliable outcome prediction. The determination of minimal-residual-disease status was more informative. Persistence of NPM1-mutated transcripts in blood was present in 15% of the patients after the second chemotherapy cycle and was associated with a greater risk of relapse after 3 years of follow-up than was an absence of such transcripts (82% vs. 30%; hazard ratio, 4.80; 95% confidence interval [CI], 2.95 to 7.80; P<0.001) and a lower rate of survival (24% vs. 75%; hazard ratio for death, 4.38; 95% CI, 2.57 to 7.47; P<0.001). The presence of minimal residual disease was the only independent prognostic factor for death in multivariate analysis (hazard ratio, 4.84; 95% CI, 2.57 to 9.15; P<0.001). These results were validated in an independent cohort. On sequential monitoring of minimal residual disease, relapse was reliably predicted by a rising level of NPM1-mutated transcripts. Although mutations associated with preleukemic clones remained detectable during ongoing remission after chemotherapy, NPM1 mutations were detected in 69 of 70 patients at the time of relapse and provided a better marker of disease status.
  
  
  CONCLUSIONS
  The presence of minimal residual disease, as determined by quantitation of NPM1-mutated transcripts, provided powerful prognostic information independent of other risk factors. (Funded by Bloodwise and the National Institute for Health Research; Current Controlled Trials number, ISRCTN55675535.).
authors.affiliation: From the Molecular Oncology Unit and Cancer Genetics Laboratory, Department of Medical and Molecular Genetics, Guy's Hospital (A.I.), the Department of Medical and Molecular Genetics (M.A.S., J.V.J., E.S., D.G.) and Department of Asthma, Allergy and Respiratory Science (H.F., F.M.), Faculty of Life Sciences and Medicine, King's College London, the Department of Haematology, University College London (Y.P., D.C.L., R.E.G.), and the Innovation Department, Cancer Research UK (N.B.), London, the Experimental Cancer Medicine Centre (A. Gilkes) and Department of Haematology (R.K.H., A.K.B.), Cardiff University School of Medicine, and the Haematology Clinical Trials Unit, Cardiff University (A. Grech), Cardiff, West Midlands Regional Genetics Laboratory, Birmingham (J.M., K.W., S.A., M.G.), MRC Molecular Haematology Unit, Weatherall Institute of Molecular Medicine and Department of Haematology, University of Oxford and Oxford University Hospitals NHS Trust, and the National Institute for Health Research Oxford Biomedical Research Centre (P.V.), Oxford, the Department of Clinical Immunology, University of Birmingham, Birmingham (S.D.F.), and the Centre for Clinical Haematology, Nottingham University Hospital, Nottingham (N.R.) - all in the United Kingdom.
authors.forename: Adam
authors.initials: A
authors.lastname: Ivey
authors.forename: Robert K
authors.initials: RK
authors.lastname: Hills
authors.forename: Michael A
authors.initials: MA
authors.lastname: Simpson
authors.forename: Jelena V
authors.initials: JV
authors.lastname: Jovanovic
authors.forename: Amanda
authors.initials: A
authors.lastname: Gilkes
authors.forename: Angela
authors.initials: A
authors.lastname: Grech
authors.forename: Yashma
authors.initials: Y
authors.lastname: Patel
authors.forename: Neesa
authors.initials: N
authors.lastname: Bhudia
authors.forename: Hassan
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authors.lastname: Farah
authors.forename: Joanne
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authors.lastname: Mason
authors.forename: Kerry
authors.initials: K
authors.lastname: Wall
authors.forename: Susanna
authors.initials: S
authors.lastname: Akiki
authors.forename: Michael
authors.initials: M
authors.lastname: Griffiths
authors.forename: Ellen
authors.initials: E
authors.lastname: Solomon
authors.forename: Frank
authors.initials: F
authors.lastname: McCaughan
authors.forename: David C
authors.initials: DC
authors.lastname: Linch
authors.forename: Rosemary E
authors.initials: RE
authors.lastname: Gale
authors.forename: Paresh
authors.initials: P
authors.lastname: Vyas
authors.forename: Sylvie D
authors.initials: SD
authors.lastname: Freeman
authors.forename: Nigel
authors.initials: N
authors.lastname: Russell
authors.forename: Alan K
authors.initials: AK
authors.lastname: Burnett
authors.forename: David
authors.initials: D
authors.lastname: Grimwade
mesh_terms: D001483:Base Sequence; D004273:DNA, Neoplasm / Q000032:analysis; D059472:Exome; D020869:Gene Expression Profiling; D006801:Humans; D015470:Leukemia, Myeloid, Acute / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D018365:Neoplasm, Residual / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D000090243:Nucleophosmin; D011379:Prognosis; D012008:Recurrence; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D059467:Transcriptome
chemical_list: D004273:DNA, Neoplasm; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D000090243:Nucleophosmin