title: Quantitative expression of estrogen receptor on relapse biopsy for ER-positive breast cancer: prognostic impact.
abstract: BACKGROUND
  The aim of this study was to evaluate the prognostic impact of quantitative estrogen receptor (ER) expression at relapse for ER-positive breast cancer with ER-positive recurrence.
  
  
  METHODS
  A total of 81 patients with ER-positive primary breast cancer and ER-positive paired recurrence were included. ER expression was evaluated as the percentage of tumor cells staining for ER under immunohistochemistry. Samples were defined as ER-high (ER>50%) or ER-low (ER≥10% and ≤50%).
  
  
  RESULTS
  Quantitative ER expression on relapse biopsy was an independent prognostic factor for overall survival in multivariate analysis, both as a continuous (hazard ratio=0.8; 95% confidence interval=0.7-0.92, p=0.001) and as a categorical (ER-high vs. ER-low; hazard ratio=0.26; 95% confidence interval=0.11-0.59, p=0.001) variable. Patients whose status changed from ER-high (primary BC) to ER-low (relapse) had the poorest outcome, with a 10-year overall survival rate of 14%.
  
  
  CONCLUSIONS
  Even in the case of maintenance of ER-positivity on primary and relapse of breast cancer, recurrence biopsy provides prognostic information.
authors: Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy Division of Medical Oncology 2, Venetian Oncology Institution IRCCS, Padova, Italy mariavittoria.dieci@unipd.it.
authors: Maria Vittoria
authors: MV
authors: Dieci
authors: Department of Medical and Surgical Sciences of Mother, Child and Adult, Modena, Italy.
authors: Federico
authors: F
authors: Piacentini
authors: Department of Medical and Surgical Sciences of Mother, Child and Adult, Modena, Italy.
authors: Massimo
authors: M
authors: Dominici
authors: Department of Medical and Surgical Sciences of Mother, Child and Adult, Modena, Italy.
authors: Claudia
authors: C
authors: Omarini
authors: INSERM U981, Gustave Roussy Institute, Villejuif, France.
authors: Aicha
authors: A
authors: Goubar
authors: Department of Pathology, University Hospital, Modena, Italy.
authors: Guido
authors: G
authors: Ficarra
authors: Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy Division of Medical Oncology 2, Venetian Oncology Institution IRCCS, Padova, Italy.
authors: Pierfranco
authors: P
authors: Conte
authors: Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy Division of Medical Oncology 2, Venetian Oncology Institution IRCCS, Padova, Italy.
authors: Valentina
authors: V
authors: Guarneri
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011379:Prognosis; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D012008:Recurrence
chemical_list: D011960:Receptors, Estrogen
keywords: Metastatic breast cancer; estrogen receptor; receptor discordance