title: Cyclin E1 is a strong prognostic marker for death from lymph node negative breast cancer. A population-based case-control study.
abstract: BACKGROUND
  A large proportion of women with lymph node negative breast cancer treated with systemic adjuvant treatment do not benefit from such therapy since the patient is already cured by local treatment. Several studies have suggested that proliferation markers are strong prognostic factors in early breast cancer. Cyclins are probably the most specific markers of cell proliferation. Previously high expression of cyclin E has been associated with breast cancer recurrence.
  
  
  METHODS
  In this study we investigate the prognostic value of cyclin E1 in node negative breast cancer patients. In a population-based cohort 186 women who died from breast cancer were defined as cases and 186 women alive at the corresponding time as controls. Inclusion criteria were tumour size ≤ 50 mm, no lymph node metastases and no adjuvant chemotherapy. The study was designed to detect an odds ratio of 2.5 with a power of 90% and significance level of 0.05. Cyclin E1 was determined with immunohistochemistry (IHC) on tissue microarray (TMA).
  
  
  RESULTS
  High expression of cyclin E1 was significantly associated with breast cancer death, in both uni- and multivariate analyses with odds ratios (OR) 2.3 [univariate, 95% confidence interval (CI) 1.5-3.6] and 2.1 (multivariate, 95% CI 1.2-3.5).
  
  
  CONCLUSIONS
  Cyclin E1 is a strong prognostic factor for breast cancer death in a population-based and node negative patient cohort and can identify high-risk patients in this group.
authors.affiliation: Department of Oncology, Uppsala University Hospital , Uppsala , Sweden.
authors.forename: Claudia
authors.initials: C
authors.lastname: Lundgren
authors.forename: Cecilia
authors.initials: C
authors.lastname: Ahlin
authors.forename: Lars
authors.initials: L
authors.lastname: Holmberg
authors.forename: Rose-Marie
authors.initials: RM
authors.lastname: Amini
authors.forename: Marie-Louise
authors.initials: ML
authors.lastname: Fjällskog
authors.forename: Carl
authors.initials: C
authors.lastname: Blomqvist
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D014408:Biomarkers, Tumor / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism* / Q000401:mortality* / Q000473:pathology; D016022:Case-Control Studies; D049109:Cell Proliferation; D019925:Cyclin A / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism; D019927:Cyclin E / Q000378:metabolism*; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008198:Lymph Nodes / Q000473:pathology; D016017:Odds Ratio; D015513:Oncogene Proteins / Q000378:metabolism*; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D047368:Tumor Burden
chemical_list: D014408:Biomarkers, Tumor; D019925:Cyclin A; D019926:Cyclin B; D019927:Cyclin E; D019394:Ki-67 Antigen; D015513:Oncogene Proteins; D018719:Erb-b2 Receptor Tyrosine Kinases; C475820:CCNE1 protein, human; C508053:ERBB2 protein, human