title: Breast cancer relapse prediction based on multi-gene RT-PCR algorithm.
abstract: BACKGROUND
  Breast cancer is very heterogeneous disease at both the clinical and molecular levels. Most research is based on analysis of a single gene, but only complex investigation of genes involved in different cell processes such as apoptosis or signal transduction can help to better understand the biology of this type of tumour. Novel techniques such as microarrays and real-time RT-PCR allow performance of such complex research. Only this kind of approach can improve cancer treatment through individualisation of disease cases with different molecular backgrounds.
  
  
  METHODS
  We performed quantitative RT-PCR to analyze levels of expression of 10 genes in 119 patient samples: 4 with known good prognosis signature (WWOX, ESR1, CDH, BAX) and 6 previously reported as bad prognosis markers of breast cancer (KRT5, KRT14, KRT17, CCNE1, BCL2, BIRC5).
  
  
  RESULTS
  The algorithm composed of 10 genes distinguishes 2 statistically significant groups of patients with different rates of disease-free survival. However, when patients were divided into 2 groups according to estrogen receptor status, this algorithm could be applied only for a group with estrogen receptor negative breast cancer. High algorithm value is a good prognostic factor of disease-free survival for patients with estrogen negative breast cancers (HR=0.26; p=0.0039), but not for patients with ER positive tumors (p>0.05).
  
  
  CONCLUSIONS
  The presented multigene algorithm may be used for outcome evaluation for estrogen receptor-negative breast cancer patients.
authors.affiliation: Department of Molecular Cancerogenesis, Medical University of Lodz, Mazowiecka 6/8 Str., 92-215 Lodz, Poland. elzbieta.pluciennik@umed.lodz.pl
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Pluciennik
authors.forename: Maciej
authors.initials: M
authors.lastname: Krol
authors.forename: Magdalena
authors.initials: M
authors.lastname: Nowakowska
authors.forename: Renata
authors.initials: R
authors.lastname: Kusinska
authors.forename: Piotr
authors.initials: P
authors.lastname: Potemski
authors.forename: Radzislaw
authors.initials: R
authors.lastname: Kordek
authors.forename: Andrzej K
authors.initials: AK
authors.lastname: Bednarek
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics*; D018572:Disease-Free Survival; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D052138:Genes, Neoplasm / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012008:Recurrence; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*