title: Laser scanning cytometry quantification of estrogen receptors in breast cancer.
abstract: OBJECTIVE
  To describe the laser scanning cytometry (LSC) processing and analysis developed for the quantitative analysis of estrogen receptor (ER) content in routine paraffin sections of breast carcinomas.
  
  
  METHODS
  Histologic sections of archival, paraffin-embedded tissues from 30 breast carcinomas were labeled for ER with fluoresceinated monoclonal antibody. ER expression was quantified by LSC and expressed as percent positive tumor cells and as histogram distributions of receptor expression per cell. Duplicate sections of the same tumors were stained for ER by a conventional immunoperoxidase reaction and percent positive tumor cells counted visually.
  
  
  RESULTS
  Percent ER-positive tumor cells by LSC of immunofluorescence-stained sections correlated well with conventional (visual) counts of immunoperoxidase-stained duplicate sections when the latter were categorized as low, intermediate or high percent of positive cells. In addition, the marked variation in relative number of ER binding sites per cell could be quantified by LSC and displayed in histogram distribution.
  
  
  CONCLUSIONS
  LSC measurements are fast and objective and can be carried out on sections of paraffin-embedded tissue after routine processing in the pathology laboratory. In addition, LSC data provide the relative number of ER binding sites per unit of DNA; that may reveal clinically significant skewed distributions or subpopulations of tumor cells.
authors.affiliation: Department of Pathology, New York Medical College, Valhalla, New York, USA.
authors.forename: W
authors.initials: W
authors.lastname: Gorczyca
authors.forename: M
authors.initials: M
authors.lastname: Davidian
authors.forename: J
authors.initials: J
authors.lastname: Gherson
authors.forename: R
authors.initials: R
authors.lastname: Ashikari
authors.forename: Z
authors.initials: Z
authors.lastname: Darzynkiewicz
authors.forename: M R
authors.initials: MR
authors.lastname: Melamed
mesh_terms: D001943:Breast Neoplasms / Q000737:chemistry* / Q000648:ultrastructure; D005260:Female; D005453:Fluorescence; D006801:Humans; D019044:Image Cytometry / Q000379:methods*; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D007834:Lasers; D011960:Receptors, Estrogen / Q000032:analysis* / Q000276:immunology
chemical_list: D011960:Receptors, Estrogen