title: Pulmonary involvement in pediatric-onset multisystem Langerhans cell histiocytosis: effect on course and outcome.
abstract: OBJECTIVE
  To assess the effect of pulmonary involvement on the course and outcome of multisystem Langerhans cell histiocytosis (MS-LCH) in children.
  
  
  METHODS
  We conducted a retrospective analysis of 420 consecutive patients with MS-LCH. In this analysis, the term "risk organs" is defined as involvement of the liver, spleen, and/or hematopoietic system. The effect of pulmonary involvement on survival was assessed with multivariate Cox regression with adjustment for risk organs involvement and age.
  
  
  RESULTS
  Pulmonary involvement in MS-LCH was present at diagnosis in 102 patients (24%). Of the 318 patients without pulmonary involvement at diagnosis, it developed in 28 within a median of 10 months (range, 1 month-5.5 years). The 5-year overall survival rate in patients without risk organ involvement at diagnosis was 96% in patients without pulmonary involvement and 94% in those with pulmonary involvement. In patients with risk organ involvement at diagnosis, the 5-year overall survival rate was 73% in patients without pulmonary involvement and 65% in patients with pulmonary involvement. In multivariate analysis, pulmonary involvement at diagnosis had no significant impact on survival rats (P = .109, hazard ratio = 1.5).
  
  
  CONCLUSIONS
  In multivariate analysis, pulmonary involvement was not an independent prognostic variable and should therefore be excluded from the definition of risk organ involvement in MS-LCH.
authors.affiliation: Children's Cancer Research Institute, Vienna, Austria.
authors.forename: Leila
authors.initials: L
authors.lastname: Ronceray
authors.forename: Ulrike
authors.initials: U
authors.lastname: Pötschger
authors.forename: Gritta
authors.initials: G
authors.lastname: Janka
authors.forename: Helmut
authors.initials: H
authors.lastname: Gadner
authors.forename: Milen
authors.initials: M
authors.lastname: Minkov
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005260:Female; D006646:Histiocytosis, Langerhans-Cell / Q000150:complications*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008171:Lung Diseases / Q000209:etiology*; D008297:Male; D011379:Prognosis; D012189:Retrospective Studies