title: Cascade pattern recognition structure for improving quantitative assessment of estrogen receptor status in breast tissue carcinomas.
abstract: OBJECTIVE
  To develop and validate a computer-based approach for the quantitative assessment of estrogen receptor (ER) status in breast tissue specimens for breast cancer management.
  
  
  METHODS
  Microscopy images of 32 immunohistochemically (IHC) stained specimens of breast cancer biopsies were digitized and were primarily assessed for ER status (percentage of positively stained nuclei) by a histopathologist. A pattern recognition system was designed for automatically assessing the ER status of the IHC-stained specimens. Nuclei were automatically segmented from background by a pixel-based unsupervised clustering algorithm and were characterized as positively stained or unstained by a supervised classification algorithm. This cascade structure boosted the system's classification accuracy.
  
  
  RESULTS
  System performance in correctly characterizing the nuclei was 95.48%. When specifying each case's ER status, system performance was statistically not significantly different to the physician's assessment (p = 0.13); when ranking each case to a particular 5-scale ER-scoring system (giving the chance of response to endocrine treatment), the system's score and the physician's score were in agreement in 29 of 32 cases.
  
  
  CONCLUSIONS
  The need for reliable and operator independent ER-status estimation procedures may be served by the design of efficient pattern recognition systems to be employed as support opinion tools in clinical practice.
authors.affiliation: Medical Image Processing and Analysis Group, Laboratory of Medical Physics, School of Medicine, University of Patras, Greece. skostopoulos@upatras.gr
authors.forename: Spiros
authors.initials: S
authors.lastname: Kostopoulos
authors.forename: Dionisis
authors.initials: D
authors.lastname: Cavouras
authors.forename: Antonis
authors.initials: A
authors.lastname: Daskalakis
authors.forename: George C
authors.initials: GC
authors.lastname: Kagadis
authors.forename: Ioannis
authors.initials: I
authors.lastname: Kalatzis
authors.forename: Pantelis
authors.initials: P
authors.lastname: Georgiadis
authors.forename: Panagiota
authors.initials: P
authors.lastname: Ravazoula
authors.forename: George
authors.initials: G
authors.lastname: Nikiforidis
mesh_terms: D001706:Biopsy; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000601:surgery; D003937:Diagnosis, Differential; D009367:Neoplasm Staging; D011960:Receptors, Estrogen / Q000378:metabolism*; D013673:Technology Assessment, Biomedical
chemical_list: D011960:Receptors, Estrogen