title: The CIN4 chromosomal instability qPCR classifier defines tumor aneuploidy and stratifies outcome in grade 2 breast cancer.
abstract: OBJECTIVE
  Quantifying chromosomal instability (CIN) has both prognostic and predictive clinical utility in breast cancer. In order to establish a robust and clinically applicable gene expression-based measure of CIN, we assessed the ability of four qPCR quantified genes selected from the 70-gene Chromosomal Instability (CIN70) expression signature to stratify outcome in patients with grade 2 breast cancer.
  
  
  METHODS
  AURKA, FOXM1, TOP2A and TPX2 (CIN4), were selected from the CIN70 signature due to their high level of correlation with histological grade and mean CIN70 signature expression in silico. We assessed the ability of CIN4 to stratify outcome in an independent cohort of patients diagnosed between 1999 and 2002. 185 formalin-fixed, paraffin-embedded (FFPE) samples were included in the qPCR measurement of CIN4 expression. In parallel, ploidy status of tumors was assessed by flow cytometry. We investigated whether the categorical CIN4 score derived from the CIN4 signature was correlated with recurrence-free survival (RFS) and ploidy status in this cohort.
  
  
  RESULTS
  We observed a significant association of tumor proliferation, defined by Ki67 and mitotic index (MI), with both CIN4 expression and aneuploidy. The CIN4 score stratified grade 2 carcinomas into good and poor prognostic cohorts (mean RFS: 83.8±4.9 and 69.4±8.2 months, respectively, p = 0.016) and its predictive power was confirmed by multivariate analysis outperforming MI and Ki67 expression.
  
  
  CONCLUSIONS
  The first clinically applicable qPCR derived measure of tumor aneuploidy from FFPE tissue, stratifies grade 2 tumors into good and poor prognosis groups.
authors.affiliation: 2nd Department of Pathology, Semmelweis University, Budapest, Hungary.
authors.forename: Attila Marcell
authors.initials: AM
authors.lastname: Szász
authors.forename: Qiyuan
authors.initials: Q
authors.lastname: Li
authors.forename: Aron C
authors.initials: AC
authors.lastname: Eklund
authors.forename: Zsófia
authors.initials: Z
authors.lastname: Sztupinszki
authors.forename: Andrew
authors.initials: A
authors.lastname: Rowan
authors.forename: Anna-Mária
authors.initials: AM
authors.lastname: Tőkés
authors.forename: Borbála
authors.initials: B
authors.lastname: Székely
authors.forename: András
authors.initials: A
authors.lastname: Kiss
authors.forename: Miklós
authors.initials: M
authors.lastname: Szendrői
authors.forename: Balázs
authors.initials: B
authors.lastname: Győrffy
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Szállási
authors.forename: Charles
authors.initials: C
authors.lastname: Swanton
authors.forename: Janina
authors.initials: J
authors.lastname: Kulka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000782:Aneuploidy; D001943:Breast Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology*; D043171:Chromosomal Instability; D005260:Female; D020869:Gene Expression Profiling; D006801:Humans; D016130:Immunophenotyping; D008875:Middle Aged; D060787:Neoplasm Grading; D010641:Phenotype; D011379:Prognosis; D011960:Receptors, Estrogen / Q000378:metabolism; D015203:Reproducibility of Results; D012189:Retrospective Studies
chemical_list: D011960:Receptors, Estrogen