title: Encapsulated papillary carcinoma of the breast: a study of invasion associated markers.
abstract: Encapsulated papillary carcinoma (EPC) of the breast is a distinct histological subtype characterised by malignant epithelial proliferation supported by fibrovascular stalks. Although EPC typically lacks myoepithelial cells, it shows indolent clinical course. The classification of EPC as an in situ, or invasive disease, remains a matter of debate.
  
  
  METHODS
  In this study, the authors investigated a panel of invasion-associated markers in a series of EPC and compared their expression with control groups of non-papillary ductal carcinoma in situ (DCIS) and conventional invasive carcinomas. The expression pattern of four matrix metalloproteinases (MMP-1, MMP-2, MMP-7 and MMP-9), transforming growth factor receptor beta, vascular endothelial growth factor (VEGF) and E-cadherin were assessed in the tumour cell and/or stromal tissue, and the results were analysed.
  
  
  RESULTS
  EPC showed higher expression levels of both MMP-1 and MMP-9 compared with DCIS, and no significant differences were observed between EPC and invasive carcinoma. Expression of MMP-2 and MMP-7 levels were similar in EPC and DCIS, but both showed lower levels compared with invasive tumours. EPC showed higher expression of E-cadherin and transforming growth factor receptor ß1 compared with both DCIS and invasive cancer. No difference in the stromal expression of MMPs or tumour expression of VEGF was detected.
  
  
  CONCLUSIONS
  EPC exhibits an expression pattern of invasion-associated markers, which is intermediate in nature between DCIS and invasive cancer, providing further support of the unique biological features of EPC, and which may explain its clinically indolent behaviour.
authors.affiliation: Department of Histopathology, University of Nottingham, Nottingham University Hospitals NHS Trust, Nottingham, UK. emadrakha@yahoo.com
authors.forename: Emad A
authors.initials: EA
authors.lastname: Rakha
authors.forename: May
authors.initials: M
authors.lastname: Tun
authors.forename: Enaam
authors.initials: E
authors.lastname: Junainah
authors.forename: Ian O
authors.initials: IO
authors.lastname: Ellis
authors.forename: Andrew
authors.initials: A
authors.lastname: Green
mesh_terms: D015703:Antigens, CD; D014408:Biomarkers, Tumor / Q000032:analysis*; D001943:Breast Neoplasms / Q000737:chemistry* / Q000473:pathology*; D015820:Cadherins / Q000032:analysis; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000737:chemistry* / Q000473:pathology*; D002291:Carcinoma, Papillary / Q000737:chemistry* / Q000473:pathology*; D016009:Chi-Square Distribution; D004739:England; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D020781:Matrix Metalloproteinase 1 / Q000032:analysis; D020778:Matrix Metalloproteinase 2 / Q000032:analysis; D020783:Matrix Metalloproteinase 7 / Q000032:analysis; D020780:Matrix Metalloproteinase 9 / Q000032:analysis; D009361:Neoplasm Invasiveness; D011379:Prognosis; D017346:Protein Serine-Threonine Kinases / Q000032:analysis; D000077293:Receptor, Transforming Growth Factor-beta Type I; D018125:Receptors, Transforming Growth Factor beta / Q000032:analysis; D012189:Retrospective Studies; D017154:Stromal Cells / Q000737:chemistry / Q000473:pathology; D046888:Tissue Array Analysis; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; C513384:CDH1 protein, human; D015820:Cadherins; D018125:Receptors, Transforming Growth Factor beta; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D017346:Protein Serine-Threonine Kinases; D000077293:Receptor, Transforming Growth Factor-beta Type I; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7; C522361:MMP2 protein, human; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9; C522360:MMP1 protein, human; D020781:Matrix Metalloproteinase 1