title: Early T-cell precursor acute lymphoblastic leukaemia.
abstract: OBJECTIVE
  Early T-cell precursor (ETP) leukaemias have been recently recognized as a form of T-cell acute lymphoblastic leukaemia (T-ALL) with a poor prognosis. The purpose of this review is to outline the most recent advances in the biology, genetics and prognostic significance of this aggressive disease.
  
  
  RESULTS
  Detailed immunophenotypic analyses have defined ETP T-ALLs as a distinct group of T-ALL with a poor prognosis. Transcriptionally, ETP T-ALLs and early immature T-ALLs, a broader group of tumours characterized by very early arrest in T-cell differentiation, are most related to haematopoietic stem cells and myeloid progenitors. Consistently, these leukaemias show lower frequencies of prototypical T-ALL lesions such as CDKN2A/B deletions and activating mutations in NOTCH1 and show a higher prevalence of mutations typically associated with the pathogenesis of acute myeloid leukaemias (AMLs).
  
  
  CONCLUSIONS
  ETP and early immature T-ALLs are characterized by a very early differentiation arrest and show unique genetic and transcriptional features that overlap both with T-ALL and with AML. Given the unique biology and poor prognosis associated with the ETP T-ALL group, there is an urgent need of new tailored therapeutic strategies for the treatment of this disease.
authors.affiliation: Institute for Cancer Genetics and Department of Pediatrics, Columbia University Medical Center, New York, New York 10032, USA.
authors.forename: J Erika
authors.initials: JE
authors.lastname: Haydu
authors.forename: Adolfo A
authors.initials: AA
authors.lastname: Ferrando
mesh_terms: D014408:Biomarkers, Tumor / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D016130:Immunophenotyping; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D011379:Prognosis; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D014408:Biomarkers, Tumor