title: Distinctive disease subgroups according to differentiation stages in adult patients with T-cell acute lymphoblastic leukemia.
abstract: OBJECTIVE
  The categorization of T-cell acute lymphoblastic leukemia (T-ALL) into four subgroups according to the degree of thymic differentiation was proposed in 1995, and this categorization scheme has been described in the World Health Organization classification 4th edition with minor changes. The aim of this study is to explore the clinical significance of leukemia cell differentiation stages in patients with T-ALL.
  
  
  METHODS
  We analyzed 36 adult T-ALL patients, including six patients (17%) in pro-T stage, 16 (44%) in pre-T stage, three (8%) in cortical-T stage, and 11 (31%) in medullary-T stage. Pro-T and pre-T stages were arbitrarily clustered as the immature group, and cortical-T and medullary-T stages as the mature group.
  
  
  RESULTS
  Patients in the immature group had unique presentations, including lower lactate dehydrogenase levels, lower frequency of mediastinal tumor, and higher expression of myeloid antigens than the mature group. There was no difference in the treatment strategies between both groups. Although patients in the immature group had a lower complete remission (CR) rate when compared with the mature group (45% vs. 79%, respectively; P = 0.04), the 3-yr overall survival (OS) for both groups was comparable (27% vs. 38%, respectively; P = 0.66). Such discrepancy between the CR rates and the OS could be partially explained by survival benefit of allogeneic transplantation observed in the immature group but not in the mature group.
  
  
  CONCLUSIONS
  These findings indicate that T-ALL patients can be categorized into two biologically distinctive subgroups according to the differentiation stages, and this stratification might enable prospective identification of patients with poor chemotherapy response.
authors: Department of Medicine and Clinical Science, Gunma University Graduate School of Medicine, Gunma, Japan. hiroakis@ked.biglobe.ne.jp
authors: Hiroaki
authors: H
authors: Shimizu
authors: Hiroshi
authors: H
authors: Handa
authors: Nahoko
authors: N
authors: Hatsumi
authors: Satoru
authors: S
authors: Takada
authors: Takayuki
authors: T
authors: Saitoh
authors: Toru
authors: T
authors: Sakura
authors: Shuichi
authors: S
authors: Miyawaki
authors: Yoshihisa
authors: Y
authors: Nojima
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D000971:Antineoplastic Combined Chemotherapy Protocols; D002454:Cell Differentiation / Q000276:immunology; D018572:Disease-Free Survival; D005260:Female; D018380:Hematopoietic Stem Cell Transplantation; D006801:Humans; D016130:Immunophenotyping; D053208:Kaplan-Meier Estimate; D007621:Karyotyping; D008297:Male; D008875:Middle Aged; D054218:Precursor T-Cell Lymphoblastic Leukemia-Lymphoma / Q000145:classification* / Q000276:immunology / Q000473:pathology* / Q000628:therapy; D012189:Retrospective Studies; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015703:Antigens, CD