Comparison of apolipoprotein D determination methods in breast cancer.
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.
Søiland
Håvard
H
Department of Surgery, Stavanger University Hospital, Stavanger, Norway.
Skaland
Ivar
I
Janssen
Emiel A M
EA
Gudlaugsson
Einar
E
Körner
Hartwig
H
Varhaug
Jan Erik
JE
Søreide
Jon Arne
JA
Baak
Jan P A
JP
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
C024328:APOD protein, human; D053399:Apolipoproteins D; D014408:Biomarkers, Tumor; D006023:Glycoproteins; D026901:Membrane Transport Proteins