title: L1 is associated with favorable outcome in neuroblastomas in contrast to adult tumors.
abstract: BACKGROUND
  Neuroblastoma is the most common solid tumor in childhood with unconventional clinical behavior. L1, a neuronal cell adhesion molecule, is associated with poor survival in malignant adult tumors. The aim of the current study was to determine expression of L1 in pediatric neuroblastoma.
  
  
  METHODS
  L1 expression was assessed on a tissue microarray with 66 surgically resected neuroblastoma samples by immunohistochemistry with a monoclonal antibody and peroxidase method. Additionally, mRNA expression was analyzed by reverse transcriptase-polymerase chain reaction with L1-specific primers. Data were correlated survival data by log rank test and Cox regression multivariate analysis.
  
  
  RESULTS
  L1 was detected in 57 (86%) of 66 neuroblastomas, whereas 9 (14%) were L1 negative. Median survival of all children was 72 months. Analysis with Kaplan-Meier method revealed a surprising and contrary finding to adult tumor entities: an association of L1 positivity with better event-free and overall survival (P < .001 and P < .01 by log rank test). Multivariate Cox regression analysis showed an independent prognostic impact of L1 negativity for event-free and overall survival of the children (P < .05).
  
  
  CONCLUSIONS
  In contrast to adult tumor entities, where L1 is associated with aggressive clinical behavior, our data show that L1 predicts good outcome in children with neuroblastoma. This novel finding suggests an inverse role of L1 in neuroblastoma. Future studies might focus on the molecular basis of the varying effect of L1 in different tumors.
authors.affiliation: Department of Pediatric Surgery, University Medical Center, 04103, Leipzig, Germany. rwachowiak@gmx.de
authors.forename: Robin
authors.initials: R
authors.lastname: Wachowiak
authors.forename: Henning C
authors.initials: HC
authors.lastname: Fiegel
authors.forename: Jussuf T
authors.initials: JT
authors.lastname: Kaifi
authors.forename: Alexander
authors.initials: A
authors.lastname: Quaas
authors.forename: Annika
authors.initials: A
authors.lastname: Krickhahn
authors.forename: Paulus G
authors.initials: PG
authors.lastname: Schurr
authors.forename: Rudolf
authors.initials: R
authors.lastname: Erttmann
authors.forename: Melitta
authors.initials: M
authors.lastname: Schachner
authors.forename: Dietrich
authors.initials: D
authors.lastname: Kluth
authors.forename: Guido
authors.initials: G
authors.lastname: Sauter
authors.forename: Jakob R
authors.initials: JR
authors.lastname: Izbicki
mesh_terms: D000328:Adult; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002675:Child, Preschool; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007124:Immunoenzyme Techniques; D007223:Infant; D009367:Neoplasm Staging; D039842:Neural Cell Adhesion Molecule L1 / Q000235:genetics / Q000378:metabolism*; D009447:Neuroblastoma / Q000235:genetics / Q000378:metabolism* / Q000601:surgery; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015996:Survival Rate; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D039842:Neural Cell Adhesion Molecule L1; D012333:RNA, Messenger