title: Down's syndrome and acute lymphoblastic leukaemia: clinical features and response to treatment.
abstract: OBJECTIVE
  To examine the clinical and biological features of acute lymphoblastic leukaemia in children with Down's syndrome (DS), to compare their survival with other children, and to determine if entry to trials and survival has improved.
  
  
  METHODS
  Examination of presenting features and response to treatment in patients treated in two consecutive national trials, MRC UKALL X and XI.
  
  
  RESULTS
  The proportion of children with DS was significantly higher in UKALL XI (1.9%) than UKALL X (0.9%). Children with DS tended to be under 10 years and to have the common ALL subtype. Cytogenetic analysis showed that favourable features, such as high hyperdiploidy and t(12;21) were less frequent but also that there was a lack of translocations associated with a poor prognosis. Children with DS showed no increase in risk of relapse at any site but their survival and event free survival were inferior to other children. These results were caused by an increased number of infective deaths during remission (11% compared to 2%). At five years overall survival was 73% in DS children compared with 82% in other children; event free survival was 53% compared to 63% in non-DS children.
  
  
  CONCLUSIONS
  Entry of children with DS to national trials has increased and survival has improved. However they remain at risk of relapse and also of treatment related mortality. These findings emphasise the need for both intensive chemotherapy and optimal supportive care.
authors.affiliation: Molecular Haematology Unit, Camelia Botnar Laboratories, Institute of Child Health, 30 Guilford Street, London WCIN 1EH, UK. j.chessells@ich.ucl.ac.uk
authors.forename: J M
authors.initials: JM
authors.lastname: Chessells
authors.forename: G
authors.initials: G
authors.lastname: Harrison
authors.forename: S M
authors.initials: SM
authors.lastname: Richards
authors.forename: C C
authors.initials: CC
authors.lastname: Bailey
authors.forename: F G
authors.initials: FG
authors.lastname: Hill
authors.forename: B E
authors.initials: BE
authors.lastname: Gibson
authors.forename: I M
authors.initials: IM
authors.lastname: Hann
mesh_terms: D002648:Child; D002675:Child, Preschool; D002869:Chromosome Aberrations; D025063:Chromosome Disorders; D002986:Clinical Trials as Topic; D020732:Cytogenetic Analysis; D018572:Disease-Free Survival; D004314:Down Syndrome / Q000150:complications* / Q000235:genetics / Q000401:mortality; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D007223:Infant; D008297:Male; D008727:Methotrexate / Q000627:therapeutic use; D018579:Patient Selection; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000150:complications* / Q000188:drug therapy / Q000401:mortality; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate
chemical_list: D007166:Immunosuppressive Agents; D008727:Methotrexate