title: Validation of a tissue microarray to study differential protein expression in inflammatory and non-inflammatory breast cancer.
abstract: OBJECTIVE
  Inflammatory breast cancer (IBC) is an aggressive subtype of breast cancer with poor prognosis. The mechanisms responsible for the aggressive clinical evolution are incompletely understood. We constructed a tissue microarray (TMA) and validated its use in translational IBC research. Differential expression of proteins that might play a role in causing the IBC phenotype was studied.
  
  
  RESULTS
  A TMA containing 34 IBC and 41 non-stage matched non-IBC tumours was constructed. Five core biopsies were taken for each IBC and three cores for each non-IBC tumour. The TMA was validated using three approaches: (1) the excellent concordance between immunohistochemical results of the initial pathological examination and the results obtained with the TMA for ER, PR and HER2/neu (kappa > 0.74); (2) the known differential expression between IBC and non-IBC for four bio-markers in IBC (ER, PR, p53 and HER2/neu) was confirmed ( p < 0.01); (3) the HER2/neu status using three different antibodies (CB11, TAB250 and HercepTest) was highly concordant (kappa > 0.75). Furthermore, the overexpression of E-Cadherin and RhoC GTPase in IBC ( p < 0.05) was confirmed. We did not find a differential expression pattern for carbonic anhydrase IX (CA IX) and EGFR.
  
  
  CONCLUSIONS
  Using different approaches, we have validated the use of our TMA for studying differential protein expression in IBC and non-IBC. We confirm the overexpression of E-Cadherin and RhoC GTPase in IBC. The lack of differential expression for CA IX and EGFR might suggest the pathways are equally utilised in both types of breast cancer.
authors.affiliation: Translational Cancer Research Group, Laboratory of Pathology, University Hospital Antwerp, University of Antwerp, Edegem, Belgium. gert.van.den.eynden@gvagroup.be
authors.forename: G G
authors.initials: GG
authors.lastname: Van den Eynden
authors.forename: I
authors.initials: I
authors.lastname: Van der Auwera
authors.forename: S
authors.initials: S
authors.lastname: Van Laere
authors.forename: C G
authors.initials: CG
authors.lastname: Colpaert
authors.forename: P
authors.initials: P
authors.lastname: van Dam
authors.forename: S
authors.initials: S
authors.lastname: Merajver
authors.forename: C G
authors.initials: CG
authors.lastname: Kleer
authors.forename: A L
authors.initials: AL
authors.lastname: Harris
authors.forename: E A
authors.initials: EA
authors.lastname: Van Marck
authors.forename: L Y
authors.initials: LY
authors.lastname: Dirix
authors.forename: P B
authors.initials: PB
authors.lastname: Vermeulen
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry* / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry* / Q000378:metabolism; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008875:Middle Aged; D040081:Protein Array Analysis / Q000379:methods*; D014176:Protein Biosynthesis; D011506:Proteins / Q000032:analysis
chemical_list: D011506:Proteins