title: Breast cancer stromal elastosis is associated with mammography screening detection, low Ki67 expression and favourable prognosis in a population-based study.
abstract: BACKGROUND
  Mammography screen-detected breast cancers have a better prognosis than predicted from established prognostic markers. A search for additional features that are characteristic for these tumours and their prognosis is needed to reduce overtreatment, a recognized challenge in breast cancer patient management today. Here, we have investigated the occurrence and importance of tumour elastosis.
  
  
  METHODS
  We performed a population based retrospective study of breast cancers detected in the Norwegian Breast Cancer Screening Programme in Vestfold County during 2004-2009. In total, 197 invasive screen-detected cancers and 75 interval cancers in patients aged 50-69 years were compared with regard to standard clinico-pathological parameters and tumour shape, as well as ER, PR, HER2 and Ki67 expression. In particular, the presence of elastotic material in tumours was graded on a 4-tiered scale (score 0-3).
  
  
  RESULTS
  Screen-detected cancers had a significantly higher content of stromal elastosis than interval cancers (p < 0.001). High content of elastosis (score 3) correlated strongly with stellate tumour shape, low histological grade, and ER+/HER2- status. Further, high elastosis score was significantly associated with lower Ki67 expression. In survival analyses, cases with high elastosis demonstrated increased recurrence free (p = 0.03) and disease-specific survival (p = 0.11) compared to cases with low elastosis.
  
  
  CONCLUSIONS
  There is a strong correlation between the presence of tumour elastosis, stellate tumour shape and mammography detection of breast cancers. To our knowledge, this is the first time elastosis has been studied in relation to breast cancer detection method. Presence of elastosis is associated with low tumour cell proliferation (Ki67) and a good prognosis.
  The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_230.
authors.affiliation: Department of Pathology, Vestfold Hospital, Tønsberg, Norway. ying.chen@ahus.no.|Department of Pathology, Akershus University Hospital, Lørenskog, Norway. ying.chen@ahus.no.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
authors.affiliation: Department of Pathology, Vestfold Hospital, Tønsberg, Norway. tor.klingen@siv.no.
authors.forename: Tor A
authors.initials: TA
authors.lastname: Klingen
authors.affiliation: Centre for Cancer Biomarkers CCBIO, Department of Clinical Medicine, Section for Pathology, University of Bergen, Bergen, Norway. elisabeth.wik@k1.uib.no.|Department of Pathology, Haukeland University Hospital, Bergen, Norway. elisabeth.wik@k1.uib.no.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Wik
authors.affiliation: Department of Surgery, Vestfold Hospital, Tønsberg, Norway. hans.aas@siv.no.
authors.forename: Hans
authors.initials: H
authors.lastname: Aas
authors.affiliation: Department of Radiology, Vestfold Hospital, Tønsberg, Norway. einar.vigeland@siv.no.
authors.forename: Einar
authors.initials: E
authors.lastname: Vigeland
authors.affiliation: Institute of Informatics, University of Oslo, Oslo, Norway. knut@ifi.uio.no.
authors.forename: Knut
authors.initials: K
authors.lastname: Liestøl
authors.affiliation: Department of Pathology, Oslo University Hospital, 0424, Oslo, Norway. UXYSGA@ous-hf.no.
authors.forename: Øystein
authors.initials: Ø
authors.lastname: Garred
authors.affiliation: Department of Pathology, Oslo University Hospital, 0424, Oslo, Norway. jan.mahlen@medisin.uio.no.
authors.forename: Jan
authors.initials: J
authors.lastname: Mæhlen
authors.affiliation: Centre for Cancer Biomarkers CCBIO, Department of Clinical Medicine, Section for Pathology, University of Bergen, Bergen, Norway. lars.akslen@k1.uib.no.|Department of Pathology, Haukeland University Hospital, Bergen, Norway. lars.akslen@k1.uib.no.
authors.forename: Lars A
authors.initials: LA
authors.lastname: Akslen
authors.affiliation: Department of Pathology, Oslo University Hospital, 0424, Oslo, Norway. jon.lomo@ous-hf.no.
authors.forename: Jon
authors.initials: J
authors.lastname: Lømo
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000737:chemistry / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000401:mortality / Q000473:pathology / Q000628:therapy; D018572:Disease-Free Survival; D004547:Elastic Tissue / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology; D004549:Elastin / Q000032:analysis*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D019394:Ki-67 Antigen / Q000032:analysis*; D008327:Mammography; D008875:Middle Aged; D060787:Neoplasm Grading; D009364:Neoplasm Recurrence, Local; D009664:Norway; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D017154:Stromal Cells / Q000737:chemistry / Q000000981:diagnostic imaging / Q000473:pathology; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D019394:Ki-67 Antigen; D004549:Elastin