Clinical significance of early T-cell precursor acute lymphoblastic leukaemia: results of the Tokyo Children's Cancer Study Group Study L99-15

Br J Haematol. 2012 Feb;156(3):358-65. doi: 10.1111/j.1365-2141.2011.08955.x. Epub 2011 Nov 30.


Early T-cell precursor acute lymphoblastic leukaemia (ETP-ALL) is a recently identified subtype of T-ALL with distinctive gene expression and cell marker profiles, poor response to chemotherapy and a very high risk of relapse. We determined the reliability of restricted panel of cell markers to identify EPT-ALL using a previously classified cohort. Then, we applied the cell marker profile that best discriminated ETP-ALL to a cohort of 91 patients with T-ALL enrolled in the Tokyo Children's Cancer Study Group L99-15 study, which included allogeneic stem cell transplantation (allo-SCT) for patients with poor prednisone response. Five of the 91 patients (5·5%) met the ETP-ALL criteria. There were no significant differences in presenting clinical features between these and the remaining 86 patients. Response to early remission induction therapy was inferior in ETP-ALL as compared with T-ALL. The ETP-ALL subgroup showed a significantly poorer event-free survival (4-year rate; 40%) than the T-ALL subgroup (70%, P=0·014). Of note, three of four relapsed ETP-ALL patients survived after allo-SCT, indicating that allo-SCT can be effective for this drug-resistant subtype of T-ALL.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Antigens, CD / analysis
  • Antigens, Neoplasm / analysis
  • Antineoplastic Combined Chemotherapy Protocols / therapeutic use
  • Child
  • Child, Preschool
  • Combined Modality Therapy
  • Disease-Free Survival
  • Drug Resistance, Neoplasm
  • Female
  • Humans
  • Immunophenotyping
  • Infant
  • Japan / epidemiology
  • Kaplan-Meier Estimate
  • Male
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / classification
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / drug therapy
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / epidemiology*
  • Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / surgery
  • Prednisone / administration & dosage
  • Remission Induction
  • Stem Cell Transplantation
  • Transplantation, Homologous
  • Treatment Outcome


  • Antigens, CD
  • Antigens, Neoplasm
  • Prednisone