title: Microvascular proliferation in luminal A and basal-like breast cancer subtypes.
abstract: OBJECTIVE
  The aims of this study were to examine microvessel density (MVD), proliferating MVD (pMVD) and Vascular Proliferation Index (VPI) in basal-like phenotype (BP) and luminal A subtypes of breast cancer and to study their prognostic value.
  
  
  METHODS
  Dual-colour immunohistochemistry for von Willebrand factor and Ki67 was done on sections from 62 luminal A and 62 BP tumours matched for grade and selected from 909 breast cancers previously reclassified into molecular subtypes. Associations between MVD, pMVD and VPI, molecular subtypes and breast cancer prognosis were estimated using linear regression and survival analyses.
  
  
  RESULTS
  Both pMVD (difference 1.9 microvessels/mm(2) (p=0.002)) and VPI (difference 1.7 percentage points (p=0.014)) were higher in BP tumours compared with luminal A. No clear difference between subtypes was found for MVD. However, only MVD was associated with prognosis. HR for breast cancer death for all cases was 1.10 (95% CI 1.02 to 1.18) per 10 vessels increase. Among luminal A tumours, HR was 1.22 per 10 vessels increase (p<0.001) and in BP it was 1.04 (p=0.37).
  
  
  CONCLUSIONS
  High MVD was associated with poor prognosis in luminal A, but not in BP cancers. Vascular proliferation was higher in BP, indicating a more active angiogenesis than in luminal A tumours. The luminal A subgroup comprised mostly histopathological grade 3 cancers in this selected series, and further studies are needed to clarify whether MVD provides additional prognostic information for luminal A tumours irrespective of grade. This may contribute to stratification of this large group of patients and may aid in identifying tumours with a particularly good prognosis.
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Maria Ryssdal
authors.initials: MR
authors.lastname: Kraby
authors.affiliation: Department of Clinical Medicine, Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway.
authors.forename: Kristi
authors.initials: K
authors.lastname: Krüger
authors.affiliation: Central Norway Regional Health Authority, Trondheim, Norway Department of Public Health and General Practice, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Signe
authors.initials: S
authors.lastname: Opdahl
authors.affiliation: Department of Public Health and General Practice, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Lars J
authors.initials: LJ
authors.lastname: Vatten
authors.affiliation: Department of Clinical Medicine, Centre for Cancer Biomarkers, University of Bergen, Bergen, Norway Department of Pathology, Haukeland University Hospital, Bergen, Norway.
authors.forename: Lars A
authors.initials: LA
authors.lastname: Akslen
authors.affiliation: Department of Laboratory Medicine, Children's and Women's Health, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Anna M
authors.initials: AM
authors.lastname: Bofin
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000098:blood supply* / Q000401:mortality / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D053208:Kaplan-Meier Estimate; D055806:Microvessels / Q000473:pathology; D008875:Middle Aged; D009389:Neovascularization, Pathologic / Q000473:pathology*
keywords: ANGIOGENESIS; BREAST CANCER; BREAST PATHOLOGY; CANCER RESEARCH; IMMUNOHISTOCHEMISTRY