title: CD24 expression is specific for tamoxifen-resistant ductal breast cancer cases.
abstract: BACKGROUND
  In breast cancer, the expression of CD24 represents a poorly recognised unfavourable prognostic factor. CD24 has been described to be potentially down-regulated by estrogen receptor alpha (ER). The present study was aimed at examining the predictive value of CD24 expression in tamoxifen-treated breast cancer cases.
  
  
  METHODS
  Sixty patients with primary invasive ductal breast cancers with post-operative tamoxifen treatment were enrolled in the study. Immmunohistochemical reactions were performed using monoclonal antibodies directed against CD24 and ER.
  
  
  RESULTS
  Cases demonstrating cytoplasmic-membranous expression of CD24 (CD24c-m) proved to be characterised by a significantly lower expression of ER as compared to CD24c-m-negative cases. A multivariate progression analysis based on the Cox proportional hazard model demonstrated that CD24c-m expression is an independent prognostic factor for poor overall survival.
  
  
  CONCLUSIONS
  The data from the present study suggested that CD24c-m expression is specific for tamoxifen-resistant breast cancer cases. CD24 should be subjected to comprehensive studies as a marker of resistance to tamoxifen treatment.
authors.affiliation: Institute of Pathology, Charité Campus Mitte, Berlin, Germany.
authors.forename: Pawel
authors.initials: P
authors.lastname: Surowiak
authors.forename: Verena
authors.initials: V
authors.lastname: Materna
authors.forename: Piotr
authors.initials: P
authors.lastname: Paluchowski
authors.forename: Rafal
authors.initials: R
authors.lastname: Matkowski
authors.forename: Andrzej
authors.initials: A
authors.lastname: Wojnar
authors.forename: Adam
authors.initials: A
authors.lastname: Maciejczyk
authors.forename: Marek
authors.initials: M
authors.lastname: Pudelko
authors.forename: Jan
authors.initials: J
authors.lastname: Kornafel
authors.forename: Manfred
authors.initials: M
authors.lastname: Dietel
authors.forename: Glen
authors.initials: G
authors.lastname: Kristiansen
authors.forename: Hermann
authors.initials: H
authors.lastname: Lage
authors.forename: Maciej
authors.initials: M
authors.lastname: Zabel
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D014408:Biomarkers, Tumor / Q000096:biosynthesis; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D051927:CD24 Antigen / Q000096:biosynthesis*; D018270:Carcinoma, Ductal, Breast / Q000188:drug therapy* / Q000378:metabolism* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D011237:Predictive Value of Tests; D011960:Receptors, Estrogen / Q000096:biosynthesis; D013629:Tamoxifen / Q000494:pharmacology*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D014408:Biomarkers, Tumor; D051927:CD24 Antigen; D011960:Receptors, Estrogen; D013629:Tamoxifen