title: Prognostic impact of absolute lymphocyte counts at the end of remission induction in childhood acute lymphoblastic leukemia.
abstract: BACKGROUND
  Absolute lymphocyte counts (ALC) during treatment have been associated with outcome in children and adults with hematologic malignancies. However, the impact of ALC relative to that of other prognostic factors on the outcome of children with acute lymphoblastic leukemia (ALL) treated in recent trials is unknown.
  
  
  METHODS
  Outcomes of 399 patients aged ≤18 years with newly diagnosed ALL who were enrolled in the Total Therapy XV study at St. Jude Children's Research Hospital were analyzed according to ALC at the end of remission induction therapy.
  
  
  RESULTS
  An ALC ≥500 cells/μL was significantly more prevalent among patients with B-lineage ALL, in those with favorable presenting features, and in those who achieved negative minimal residual disease (MRD) status on day 43 of treatment. Both overall survival (OS) and event-free survival (EFS) were superior among patients with higher ALC, but only the association with OS was statistically significant in a univariate analysis. In multivariable analyses, ALC was not a significant predictor of outcome after controlling for age, leukocyte count, lineage, risk group, and MRD status at the end of induction (P > .1 for all comparisons). However, among MRD-negative patients, those with low ALC had a 5-year OS rate of 84.2% ± 8.9% versus 97.3% ± 1.0% for patients with higher ALC (P = .036).
  
  
  CONCLUSIONS
  ALC at the end of induction is related to favorable presenting features and good initial treatment response but does not independently predict outcome in the context of contemporary, MRD-guided therapy.
authors: Department of Oncology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA. jeffrey.rubnitz@stjude.org
authors: Jeffrey E
authors: JE
authors: Rubnitz
authors: Patrick
authors: P
authors: Campbell
authors: Yinmei
authors: Y
authors: Zhou
authors: John T
authors: JT
authors: Sandlund
authors: Sima
authors: S
authors: Jeha
authors: Raul C
authors: RC
authors: Ribeiro
authors: Hiroto
authors: H
authors: Inaba
authors: Deepa
authors: D
authors: Bhojwani
authors: Mary V
authors: MV
authors: Relling
authors: Scott C
authors: SC
authors: Howard
authors: Dario
authors: D
authors: Campana
authors: Ching-Hon
authors: CH
authors: Pui
mesh_terms: D002648:Child; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000473:pathology*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000097:blood* / Q000473:pathology / Q000628:therapy*; D011379:Prognosis; D016016:Proportional Hazards Models; D012074:Remission Induction; D016896:Treatment Outcome