title: Membranous CD24 expression as detected by the monoclonal antibody SWA11 is a prognostic marker in non-small cell lung cancer patients.
abstract: BACKGROUND
  Lung cancer is one of the most common malignant neoplasms worldwide and has a high mortality rate. To enable individualized therapy regimens, a better understanding of the molecular tumor biology has still to be elucidated. The expression of the cell surface protein CD24 has already been claimed to be associated with shorter patient survival in non-small cell lung cancer (NSCLC), however, the prognostic value and applicability of CD24 immunostaining in paraffin embedded tissue specimens has been questioned due to the recent acknowledgement of restricted epitope specificity of the commonly used antibody SN3b.
  
  
  METHODS
  A cohort of 137 primary NSCLC cases was immunostained with a novel CD24 antibody (clone SWA11), which specifically recognizes the CD24 protein core and the resulting expression data were compared with expression profiles based on the monoclonal antibody SN3b. Furthermore, expression data were correlated to clinico-pathological parameters. Univariate and multivariate survival analyses were conducted with Kaplan Meier estimates and Cox regression, respectively.
  
  
  RESULTS
  CD24 positivity was found in 34 % resp. 21 % (SN3b) of NSCLC with a membranous and/or cytoplasmic staining pattern. Kaplan-Meier analyses revealed that membranous, but not cytoplasmic CD24 expression (clone SWA11) was associated with lympho-nodular spread and shorter overall survival times (both p < 0.05). CD24 expression established by SN3b antibodies did not reveal significant clinicopathological correlations with overall survival, neither for cytoplasmic nor membranous CD24 staining.
  
  
  CONCLUSIONS
  Membranous CD24 immunoreactivity, as detected with antibody clone SWA11 may serve as a prognostic factor for lymphonodular spread and poorer overall survival. Furthermore, these results corroborate the importance of a careful distinction between membranous and cytoplasmic localisation, if CD24 is to be considered as a potential prognostic biomarker.
authors.affiliation: Institute of Pathology, University of Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Majores
authors.affiliation: Institute of Pathology, University of Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Schindler
authors.affiliation: Institute of Pathology, University of Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany.
authors.forename: Angela
authors.initials: A
authors.lastname: Fuchs
authors.affiliation: Institute of Pathology, University of Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Stein
authors.affiliation: New Pathology, Cologne, Germany.
authors.forename: Lukas
authors.initials: L
authors.lastname: Heukamp
authors.affiliation: Skin Cancer Unit, German Cancer Research Center (DKFZ), Heidelberg, Germany ; Department of Dermatology, Venereology and Allergology University Medical Center Mannheim, Ruprecht-Karl University of Heidelberg, Mannheim, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Altevogt
authors.affiliation: Institute of Pathology, University of Bonn, Sigmund-Freud-Str. 25, D-53127 Bonn, Germany.
authors.forename: Glen
authors.initials: G
authors.lastname: Kristiansen
keywords: CD24; Immunohistochemistry; NSCLC; Non-small cell lung cancer; Prognostic marker