title: Expression of estrogen receptor, progesterone receptor, and Ki67 in normal breast tissue in relation to subsequent risk of breast cancer.
abstract: Although expression of estrogen receptor (ER), progesterone receptor (PR), and cell proliferation marker Ki67 serve as predictive and prognostic factors in breast cancers, little is known about their roles in normal breast tissue. Here in a nested case-control study within the Nurses' Health Studies (90 cases, 297 controls), we evaluated their expression levels in normal breast epithelium in relation to subsequent breast cancer risk among women with benign breast disease. Tissue microarrays were constructed using cores obtained from benign biopsies containing normal terminal duct lobular units and immunohistochemical stained for these markers. We found PR and Ki67 expression was non-significantly but positively associated with subsequent breast cancer risk, whereas ER expression was non-significantly inversely associated. After stratifying by lesion subtype, Ki67 was significantly associated with higher risk among women with proliferative lesions with atypical hyperplasia. However, given the small sample size, further studies are required to confirm these results.
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Hannah
authors.initials: H
authors.lastname: Oh
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: A Heather
authors.initials: AH
authors.lastname: Eliassen
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Molin
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
authors.forename: Stephanie A
authors.initials: SA
authors.lastname: Smith-Warner
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Beck
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Stuart J
authors.initials: SJ
authors.lastname: Schnitt
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Collins
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: James L
authors.initials: JL
authors.lastname: Connolly
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA.
authors.forename: Laleh
authors.initials: L
authors.lastname: Montaser-Kouhsari
authors.affiliation: Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA, USA; Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Kornelia
authors.initials: K
authors.lastname: Polyak
authors.affiliation: Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA; Channing Division of Network Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Rulla M
authors.initials: RM
authors.lastname: Tamimi