title: Comparison of apolipoprotein D determination methods in breast cancer.
abstract: BACKGROUND
  Apolipoprotein D (ApoD) is a promising prognostic and predictive factor in breast cancer, but the analysis methods and results vary.
  
  
  METHODS
  Determination of ApoD content by immunoelectrophoresis in tumour cytosol (EPC), immunohistochemistry (IHC) in whole sections (WS) and tissue micro arrays (TMA) were compared in 283 breast carcinomas.
  
  
  RESULTS
  With EPC, 45% and with IHC, 71% of the tumours were ApoD-positive. Correlation between the degrees of ApoD positivity by ECP and IHC was poor (R2=0.04), caused by higher sensitivity of the IHC (resulting in many ECP negative carcinomas being IHC positive) and ApoD positivity of normal tissues and cysts (resulting in ApoD positivity by ECP in up to 33% of the IHC negative cases). Discrepancies between WS and TMA were considerable due to tumour heterogeneity.
  
  
  CONCLUSIONS
  In breast cancer, IHC ApoD determination is superior to EPC analysis, but intratumor heterogeneity must be carefully considered when using TMA technology.
authors.affiliation: Department of Surgery, Stavanger University Hospital, Stavanger, Norway.
authors.forename: Håvard
authors.initials: H
authors.lastname: Søiland
authors.forename: Ivar
authors.initials: I
authors.lastname: Skaland
authors.forename: Emiel A M
authors.initials: EA
authors.lastname: Janssen
authors.forename: Einar
authors.initials: E
authors.lastname: Gudlaugsson
authors.forename: Hartwig
authors.initials: H
authors.lastname: Körner
authors.forename: Jan Erik
authors.initials: JE
authors.lastname: Varhaug
authors.forename: Jon Arne
authors.initials: JA
authors.lastname: Søreide
authors.forename: Jan P A
authors.initials: JP
authors.lastname: Baak
mesh_terms: D000368:Aged; D053399:Apolipoproteins D / Q000032:analysis* / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000032:analysis* / Q000378:metabolism; D001943:Breast Neoplasms / Q000737:chemistry* / Q000378:metabolism / Q000473:pathology; D003600:Cytosol / Q000737:chemistry / Q000378:metabolism; D005260:Female; D006023:Glycoproteins / Q000032:analysis* / Q000378:metabolism; D006801:Humans; D007122:Immunoelectrophoresis / Q000379:methods; D007150:Immunohistochemistry / Q000379:methods; D026901:Membrane Transport Proteins / Q000032:analysis* / Q000378:metabolism; D046228:Microarray Analysis / Q000379:methods; D008875:Middle Aged; D013194:Staining and Labeling / Q000379:methods
chemical_list: C024328:APOD protein, human; D053399:Apolipoproteins D; D014408:Biomarkers, Tumor; D006023:Glycoproteins; D026901:Membrane Transport Proteins