title: Prognostic value of estrogen receptor α and progesterone receptor conversion in distant breast cancer metastases.
abstract: BACKGROUND
  Changes in the receptor profile of primary breast cancers to their metastases (receptor conversion) have been described for the estrogen receptor α (ERα) and progesterone receptor (PR). The purpose of this study was to evaluate the impact of receptor conversion for ERα and PR on survival in a large group of distant non-bone breast cancer metastases.
  
  
  METHODS
  Receptor conversion was studied by immunohistochemistry in a group of 233 metastatic breast cancer patients. Kaplan-Meier overall survival curves were plotted, and differences between the curves were analyzed by log-rank analysis. The additional prognostic value of conversion to established prognosticators was studied by Cox regression.
  
  
  RESULTS
  Overall survival of patients showing conversion from positive to negative ERα or PR, or from negative to positive ERα or PR, or remaining receptor negative was comparable, and significantly worse than patients remaining receptor positive. ERα or PR receptor conversion from positive in the primary breast tumor to negative in distant metastases has independent negative prognostic value.
  
  
  CONCLUSIONS
  ERα or PR receptor conversion from positive in the primary breast cancer to negative in distant metastases has negative prognostic value.
authors.affiliation: Department of Pathology, University Medical Center Utrecht, Utrecht, the Netherlands.
authors.forename: Laurien D C
authors.initials: LD
authors.lastname: Hoefnagel
authors.forename: Cathy B
authors.initials: CB
authors.lastname: Moelans
authors.forename: S L
authors.initials: SL
authors.lastname: Meijer
authors.forename: Henk-Jan
authors.initials: HJ
authors.lastname: van Slooten
authors.forename: Pieter
authors.initials: P
authors.lastname: Wesseling
authors.forename: Jelle
authors.initials: J
authors.lastname: Wesseling
authors.forename: Pieter J
authors.initials: PJ
authors.lastname: Westenend
authors.forename: Joost
authors.initials: J
authors.lastname: Bart
authors.forename: Cornelis A
authors.initials: CA
authors.lastname: Seldenrijk
authors.forename: Iris D
authors.initials: ID
authors.lastname: Nagtegaal
authors.forename: Joost
authors.initials: J
authors.lastname: Oudejans
authors.forename: Paul
authors.initials: P
authors.lastname: van der Valk
authors.forename: Carla H
authors.initials: CH
authors.lastname: van Gils
authors.forename: Elsken
authors.initials: E
authors.lastname: van der Wall
authors.forename: Paul J
authors.initials: PJ
authors.lastname: van Diest
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality / Q000473:pathology*; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009362:Neoplasm Metastasis / Q000473:pathology*; D011379:Prognosis; D011980:Receptors, Progesterone / Q000378:metabolism*; D012189:Retrospective Studies
chemical_list: C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D011980:Receptors, Progesterone