title: Bone marrow recurrence after initial intensive treatment for childhood acute lymphoblastic leukemia.
abstract: BACKGROUND
  The authors studied the clinical outcome of 106 children with acute lymphoblastic leukemia (ALL) who developed a bone marrow recurrence as the first adverse event after contemporary intensified therapy.
  
  
  METHODS
  Endpoints were the rates and lengths of second remission, the cumulative incidence of second hematologic recurrence, second event-free survival (EFS), and survival.
  
  
  RESULTS
  Bone marrow recurrences were isolated in 79 patients, and combined with an extramedullary site in 27 patients. The median time to recurrence was 2.6 years (range, 0.3-11.6 years). Seventy-six patients (71.7%) attained a second remission (median length, 0.7 year; range, 0.03-13.3 years). The 5-year survival probability among all patients was 24.2% +/- 4.2% (standard error). On multivariate analysis, time to first disease recurrence and blast cell lineage were found to be independent predictors of a second EFS (P = 0.008 and P = 0.028, respectively). The 5-year EFS estimate in patients with an initial disease remission of >/= 36 months was 42.6% +/- 7.8% but was only 12.5% +/- 3.9% among children with a short duration of disease remission (< 36 months). These estimates were 28.7% +/- 4.9% and 5.0% +/- 3.4%, respectively, for B blast and T blast cell lineages.
  
  
  CONCLUSIONS
  Despite acceptable long-term second EFS rates for certain subgroups, overall bone marrow recurrence after intensified first-line therapy for childhood ALL signals a poor outcome.
authors.affiliation: Department of Hematology/Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee, USA. gaston.rivera@stjude.org
authors.forename: Gaston K
authors.initials: GK
authors.lastname: Rivera
authors.forename: Yinmei
authors.initials: Y
authors.lastname: Zhou
authors.forename: Michael L
authors.initials: ML
authors.lastname: Hancock
authors.forename: Amar
authors.initials: A
authors.lastname: Gajjar
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rubnitz
authors.forename: Raul C
authors.initials: RC
authors.lastname: Ribeiro
authors.forename: John T
authors.initials: JT
authors.lastname: Sandlund
authors.forename: Melissa
authors.initials: M
authors.lastname: Hudson
authors.forename: Mary
authors.initials: M
authors.lastname: Relling
authors.forename: William E
authors.initials: WE
authors.lastname: Evans
authors.forename: Ching-Hon
authors.initials: CH
authors.lastname: Pui
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001752:Blast Crisis / Q000453:epidemiology* / Q000473:pathology; D001853:Bone Marrow / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018572:Disease-Free Survival; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology / Q000473:pathology; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology*; D011336:Probability; D011379:Prognosis; D016016:Proportional Hazards Models; D012074:Remission Induction; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D017678:Sex Distribution; D015996:Survival Rate