title: Oestrogen receptor status, treatment and breast cancer prognosis in Icelandic BRCA2 mutation carriers.
abstract: The impact of an inherited BRCA2 mutation on the prognosis of women with breast cancer has not been well documented. We studied the effects of oestrogen receptor (ER) status, other prognostic factors and treatments on survival in a large cohort of BRCA2 mutation carriers.
  
  
  
  We identified 285 breast cancer patients with a 999del5 BRCA2 mutation and matched them with 570 non-carrier patients. Clinical information was abstracted from patient charts and pathology records and supplemented by evaluation of tumour grade and ER status using archived tissue specimens. Univariate and multivariate hazard ratios (HR) were estimated for breast cancer-specific survival using Cox regression. The effects of various therapies were studied in patients treated from 1980 to 2012.
  
  
  
  Among mutation carriers, positive ER status was associated with higher risk of death than negative ER status (HR=1.94; 95% CI=1.22-3.07, P=0.005). The reverse association was seen for non-carriers (HR=0.71; 95% CI: 0.51-0.97; P=0.03).
  
  
  
  Among BRCA2 carriers, ER-positive status is an adverse prognostic factor. BRCA2 carrier status should be known at the time when treatment decisions are made.
authors.affiliation: Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland.|Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.|Department of Pathology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Jon G
authors.initials: JG
authors.lastname: Jonasson
authors.affiliation: Cancer Research Laboratory, Biomedical Centre, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
authors.forename: Olafur A
authors.initials: OA
authors.lastname: Stefansson
authors.affiliation: Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.|Department of Oncology, Landspitali University Hospital, Reykjavik, Iceland.|Department of Genetics and Molecular Medicine, University Hospital, Reykjavik, Iceland.
authors.forename: Oskar T
authors.initials: OT
authors.lastname: Johannsson
authors.affiliation: Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.|Department of Oncology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Helgi
authors.initials: H
authors.lastname: Sigurdsson
authors.affiliation: Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.|Department of Pathology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Bjarni A
authors.initials: BA
authors.lastname: Agnarsson
authors.affiliation: Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland.
authors.forename: Gudridur H
authors.initials: GH
authors.lastname: Olafsdottir
authors.affiliation: Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland.|Department of Oncology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Kristin K
authors.initials: KK
authors.lastname: Alexiusdottir
authors.affiliation: Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland.
authors.forename: Hrefna
authors.initials: H
authors.lastname: Stefansdottir
authors.affiliation: Department of Pathology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Munoz Mitev
authors.affiliation: Department of Pathology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Katrin
authors.initials: K
authors.lastname: Olafsdottir
authors.affiliation: Department of Pathology, Landspitali University Hospital, Reykjavik, Iceland.
authors.forename: Kristrun
authors.initials: K
authors.lastname: Olafsdottir
authors.affiliation: Laboratory of Cell Biology, Department of Pathology, University Hospital, Reykjavik, Iceland.
authors.forename: Adalgeir
authors.initials: A
authors.lastname: Arason
authors.affiliation: Department of Genetics and Molecular Medicine, University Hospital, Reykjavik, Iceland.
authors.forename: Vigdis
authors.initials: V
authors.lastname: Stefansdottir
authors.affiliation: Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland.
authors.forename: Elinborg J
authors.initials: EJ
authors.lastname: Olafsdottir
authors.affiliation: Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.|Laboratory of Cell Biology, Department of Pathology, University Hospital, Reykjavik, Iceland.|Biomedical Centre, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
authors.forename: Rosa B
authors.initials: RB
authors.lastname: Barkardottir
authors.affiliation: Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.|Cancer Research Laboratory, Biomedical Centre, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
authors.forename: Jorunn E
authors.initials: JE
authors.lastname: Eyfjord
authors.affiliation: Womens' College Research Institute, University of Toronto, Toronto, ON, Canada.
authors.forename: Steven A
authors.initials: SA
authors.lastname: Narod
authors.affiliation: Icelandic Cancer Registry, Icelandic Cancer Society, Reykjavik, Iceland.|Faculty of Medicine, Laeknagardur, University of Iceland, Reykjavik, Iceland.
authors.forename: Laufey
authors.initials: L
authors.lastname: Tryggvadóttir
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000737:chemistry / Q000235:genetics* / Q000401:mortality / Q000628:therapy; D004967:Estrogens; D005260:Female; D024522:Genes, BRCA2; D006801:Humans; D007055:Iceland / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009154:Mutation; D009376:Neoplasms, Hormone-Dependent / Q000737:chemistry / Q000235:genetics* / Q000401:mortality / Q000628:therapy; D016609:Neoplasms, Second Primary / Q000453:epidemiology / Q000235:genetics; D009386:Neoplastic Syndromes, Hereditary / Q000235:genetics* / Q000401:mortality / Q000628:therapy; D011379:Prognosis; D016016:Proportional Hazards Models; D011960:Receptors, Estrogen / Q000032:analysis*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D004967:Estrogens; D011960:Receptors, Estrogen