title: Estrogen Receptor and HER2 Status on Disseminated Tumor Cells and Primary Tumor in Patients with Early Breast Cancer.
abstract: BACKGROUND
  We evaluated both estrogen receptor (ER) and human epidermal growth factor receptor 2 (HER2) status on disseminated tumor cells (DTCs) in the bone marrow of 54 patients with early breast cancer and compared these with the corresponding primary tumor (PT).
  
  
  METHODS
  Bone marrow aspirates were obtained at the time of first surgery, and ER and HER2 status on DTCs was assessed simultaneously by immunocytochemistry using a triple fluorescence staining method.
  
  
  RESULTS
  The median number of DTCs was 13 (range 1-95). The concordance rate between ER status on DTC and PT was 74%. Patients with an ER-positive PT were significantly more likely to have at least one ER-positive DTC (34 out of 42) than patients with an ER-negative PT (6 out of 12; P = .031). Thirty-nine (93%) of the 42 patients with ER-positive PT had at least one ER-negative DTC. The concordance rate between HER2 status on DTC and PT was 52%. The probability of having at least one HER2-positive DTC was not related to the HER2 status of the PT (P = 0.56). Twenty-two (46%) of the 48 patients with a HER2-negative PT had at least one HER2-positive DTC. All the six patients with a HER2-positive PT had at least one HER2-negative DTC.
  
  
  CONCLUSIONS
  Taken together, our study confirms that ER and/or HER2 status may differ between DTC and PT. This discordance could be important for patients lacking ER or HER2 expression on the PT but showing ER-positive or HER2-positive DTC because they might benefit from an endocrine and/or HER2-targeted therapy.
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital Ulm, Prittwitzstr. 43, 89075, Ulm, Germany.
authors.forename: Bernadette A S
authors.initials: BA
authors.lastname: Jäger
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Charlotte
authors.initials: C
authors.lastname: Finkenzeller
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Carolin
authors.initials: C
authors.lastname: Bock
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Leonie
authors.initials: L
authors.lastname: Majunke
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Julia K
authors.initials: JK
authors.lastname: Jueckstock
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Andergassen
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Julia K
authors.initials: JK
authors.lastname: Neugebauer
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Aurelia
authors.initials: A
authors.lastname: Pestka
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital Ulm, Prittwitzstr. 43, 89075, Ulm, Germany. Electronic address: thomas.friedl@uniklinik-ulm.de.
authors.forename: Thomas W P
authors.initials: TW
authors.lastname: Friedl
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Udo
authors.initials: U
authors.lastname: Jeschke
authors.affiliation: Department of Gynecology and Obstetrics, University Hospital Ulm, Prittwitzstr. 43, 89075, Ulm, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Janni
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany; Université Paul Sabatier Toulouse III, 118 Route de Narbonne, 31400, Toulouse, France.
authors.forename: Sophie F
authors.initials: SF
authors.lastname: Doisneau-Sixou
authors.affiliation: Department of Gynecology and Obstetrics, Ludwig-Maximilians-University Munich, Maistraße 11, 80337, München, Germany.
authors.forename: Brigitte K
authors.initials: BK
authors.lastname: Rack