title: Cyclin A is a proliferative marker with good prognostic value in node-negative breast cancer.
abstract: BACKGROUND
  Proliferative markers are not recommended as prognostic factors for clinical use in breast cancer due to lack of standardization in methodology. However, proliferation is driving several gene expression signatures emphasizing the need for a reliable proliferative marker for clinical use. Studies suggest that cyclin A is a prognostic marker with satisfying reproducibility. We investigated cyclin A as a prognostic marker in node-negative breast cancer using previously defined cutoff values.
  
  
  METHODS
  In a case-control study, we defined 190 women who died from breast cancer as cases and 190 women alive at the time for the corresponding case's death as controls. Inclusion criteria were tumor size <or=50 mm, no lymph node metastases and no adjuvant chemotherapy. Tumor tissues were immunostained for cyclin A using commercially available antibodies.
  
  
  RESULTS
  We found a statistically significant association between expression of cyclin A and breast cancer death in a univariate model: odds ratio for cyclin A(ave) 2.7 [95% confidence interval (CI), 1.7-4.3] and cyclin A(max) 3.4 (CI, 2.1-5.5). Corresponding odds ratio for Ki67 were Ki67(ave) 1.9 (CI, 1.2-3.1) and Ki67(max) 1.7 (CI, 1.1-2.7) and for grade 3.1 (CI, 1.8-5.1). Cyclin A was strongly correlated to Ki67 and grade why a model including all was not appropriate.
  
  
  CONCLUSIONS
  Cyclin A is a prognostic factor for breast cancer death in node-negative patients using standardized methodology regarding scoring and cutoff values. Adding cyclin A as a proliferative marker to established clinicopathologic factors will improve the separation of low and high risk breast cancer.
authors.affiliation: Department of Oncology, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ahlin
authors.forename: Wenjing
authors.initials: W
authors.lastname: Zhou
authors.forename: Marit
authors.initials: M
authors.lastname: Holmqvist
authors.forename: Lars
authors.initials: L
authors.lastname: Holmberg
authors.forename: Cecilia
authors.initials: C
authors.lastname: Nilsson
authors.forename: Karin
authors.initials: K
authors.lastname: Jirström
authors.forename: Carl
authors.initials: C
authors.lastname: Blomqvist
authors.forename: Rose-Marie
authors.initials: RM
authors.lastname: Amini
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Fjällskog
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000473:pathology*; D016022:Case-Control Studies; D019925:Cyclin A / Q000096:biosynthesis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008207:Lymphatic Metastasis; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism
chemical_list: D014408:Biomarkers, Tumor; D019925:Cyclin A; D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human