title: Prognostic relevance of cyclin E expression in operable breast cancer.
abstract: BACKGROUND
  Cyclin E is an important regulator of cell-cycle progression. High levels of cyclin E protein in breast cancer have been reported in association with higher disease stage, poor histological differentiation of tumor, and lack of steroid receptors. Data concerning the prognostic relevance of cyclin E expression in breast cancer are conflicting. The aim of this retrospective study was to evaluate the prognostic relevance of cyclin E expression assessed by immunohistochemistry in patients with operable invasive ductal breast cancer.
  
  
  METHODS
  The expression of cyclin E was analyzed by immunostaining in 174 women with breast cancer after radical mastectomy with a median follow-up period of 58 months. Tumor samples were judged to be negative (<2%) or positive (> or =2%) according to the percentage of cells showing the nuclear staining pattern. Ninety-nine (56.9%) tumor samples were regarded as cyclin E-positive.
  
  
  RESULTS
  Positive staining for cyclin E determined poor prognosis compared with cyclin E-negative patients in all cases (five-year cancer-specific survival rate of 64.5 vs. 84.5%, p=0.005), in the node-positive group (50.9 vs. 82.1%, p=0.008), and in patients treated with adjuvant chemotherapy (71.0 vs. 96.6%, p=0.008). In a multivariate analysis, high expression of cyclin E was associated with a higher risk of death in the node-positive group (hazard ratio: 3.2, 95%CI: 1.3-8.2, p=0.015).
  
  
  CONCLUSIONS
  It was demonstrated that a high expression of cyclin E measured by immunohistochemistry was a significant factor of poor prognosis, especially in the node-positive group.
authors.affiliation: Department of Chemotherapy, Medical University of Łodź, Copernicus Memorial Hospital, Łodź, Poland. piotrpo@mp.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Potemski
authors.forename: Renata
authors.initials: R
authors.lastname: Kusińska
authors.forename: Grazyna
authors.initials: G
authors.lastname: Pasz-Walczak
authors.forename: Janusz H
authors.initials: JH
authors.lastname: Piekarski
authors.forename: Cezary
authors.initials: C
authors.lastname: Watała
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Płuciennik
authors.forename: Andrzej K
authors.initials: AK
authors.lastname: Bednarek
authors.forename: Radzislaw
authors.initials: R
authors.lastname: Kordek
mesh_terms: D000368:Aged; D001943:Breast Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology / Q000601:surgery*; D017024:Chemotherapy, Adjuvant; D019927:Cyclin E / Q000378:metabolism*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008875:Middle Aged; D015999:Multivariate Analysis; D015513:Oncogene Proteins / Q000378:metabolism*; D011379:Prognosis; D016016:Proportional Hazards Models
chemical_list: C475820:CCNE1 protein, human; D019927:Cyclin E; D015513:Oncogene Proteins