Amount of stroma is associated with mammographic density and stromal expression of oestrogen receptor in normal breast tissues

Research output: Contribution to journalArticle

Abstract

Following female sex and age, mammographic density is considered one of the strongest risk factors for breast cancer. Despite the association between mammographic density and breast cancer risk, little is known about the underlying histology and biological basis of breast density. To better understand the mechanisms behind mammographic density we assessed morphology, proliferation and hormone receptor status in relation to mammographic density in breast tissues from healthy women. Tissues were obtained from 2012–2013 by ultrasound-guided core needle biopsy from 160 women as part of the Karma (Karolinska mammography project for risk prediction for breast cancer) project. Mammograms were collected through routine mammography screening and mammographic density was calculated using STRATUS. The histological composition, epithelial and stromal proliferation status and hormone receptor status were assessed through immunohistochemical staining. Higher mammographic density was significantly associated with a greater proportion of stromal and epithelial tissue and a lower proportion of adipose tissue. Epithelial expression levels of Ki-67, oestrogen receptor (ER) and progesterone receptor (PR) were not associated with mammographic density. Epithelial Ki-67 was associated with a greater proportion of epithelial tissue, and epithelial PR was associated with a greater proportion of stromal and a lower proportion of adipose tissue. Epithelial ER was not associated with any tissues. In contrast, expression of ER in the stroma was significantly associated with a greater proportion of stroma, and negatively associated with the amount of adipose tissue. High mammographic density is associated with higher amount of stroma and epithelium and less amount of fat, but is not associated with a change in epithelial proliferation or receptor status. Increased expressions of both epithelial PR and stromal ER are associated with a greater proportion of stroma, suggesting hormonal involvement in regulating breast tissue composition.

Details

Authors
  • Marike Gabrielson
  • Flaminia Chiesa
  • Janna Paulsson
  • Carina Strell
  • Catharina Behmer
  • Katarina Rönnow
  • Kamila Czene
  • Arne Östman
  • Per Hall
External organisations
  • Karolinska Institutet
  • Unilabs AB
  • Helsingborg Hospital
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Cancer and Oncology

Keywords

  • Breast cancer, Breast tissue, Histology, Hormone receptor status, Mammographic density, Stromal breast tissue
Original languageEnglish
Pages (from-to)253-261
Number of pages9
JournalBreast Cancer Research and Treatment
Volume158
Issue number2
StatePublished - 2016 Jul 1
Publication categoryResearch
Peer-reviewedYes
Externally publishedYes