title: Prognostic significance of early lymphocyte recovery in pediatric osteosarcoma.
abstract: BACKGROUND
  Evidence suggests early lymphocyte recovery after chemotherapy predicts superior outcome for patients with cancer, a phenomenon not previously investigated in osteosarcoma. This study determined the prognostic significance of early lymphocyte recovery for pediatric patients with osteosarcoma.
  
  
  METHODS
  We reviewed data of 19 consecutive patients treated for osteosarcoma at our institution from 1997 to 2007. After initial chemotherapy, patients were separated into two groups: early versus late lymphocyte recovery, using a threshold absolute lymphocyte count of ≥ 800 cells/µl on day 14 (ALC-14).
  
  
  RESULTS
  The 5-year overall survival (OS) for our cohort was 73.7% [± 10.1 standard error (SE)]. Thirteen patients (68%) had an ALC-14 ≥ 800 cells/µl, with 12/13 alive and 5-year OS of 92.3% (± 7.4 SE). In contrast, six patients (32%) had an ALC-14 < 800 cells/µL, with 1/6 alive and 5-year OS of 33.3% (± 19.2 SE). The difference is statistically significant (P = 0.0013, log-rank test). Two patients presented with multifocal disease at diagnosis, had late lymphocyte recovery and died. One patient presented with metastatic disease, had early lymphocyte recovery and is alive. Six patients developed relapsed disease with a 5-year OS of 33.3% (± 19.2 SE). The majority (5/6) of patients with relapsed disease died while on active therapy. The only survivor in this group had an ALC-14 > 800 cells/µl and recently completed relapse therapy.
  
  
  CONCLUSIONS
  These data demonstrate that early lymphocyte recovery represents a significant prognostic indicator for osteosarcoma. Early identification and risk stratification therapy based on the ALC-14 threshold may improve outcomes and our knowledge of this disease.
authors: Department of Pediatric Medical Education, Arnold Palmer Medical Center, Orlando Health, Orlando, Florida, USA.
authors: Colin
authors: C
authors: Moore
authors: Don
authors: D
authors: Eslin
authors: Alejandro
authors: A
authors: Levy
authors: Jessica
authors: J
authors: Roberson
authors: Vincent
authors: V
authors: Giusti
authors: Robert
authors: R
authors: Sutphin
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001859:Bone Neoplasms / Q000188:drug therapy* / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D018655:Lymphocyte Count; D008214:Lymphocytes / Q000502:physiology*; D008297:Male; D012516:Osteosarcoma / Q000188:drug therapy* / Q000276:immunology; D011379:Prognosis; D020127:Recovery of Function; D012307:Risk Factors; D015996:Survival Rate; D055815:Young Adult