title: Stage-specific frequency and prognostic significance of aneuploidy in patients with sporadic colorectal cancer--a meta-analysis and current overview.
abstract: OBJECTIVE
  Aneuploidy has long been suggested as an independent prognostic marker for colorectal cancer (CRC) patients and could thus aid for individualized medicine. However, due to a large spectrum of deviating studies, expert panels do not recommend ploidy assessment. In order to clarify a potential bias of stage-specific frequency of aneuploidy, we now conducted a meta-analysis combined with a systematic review regarding aneuploidy and prognosis.
  
  
  METHODS
  A systematic, web-based search process retrieved 1935 studies published in English between 1990 and 2011. The defined endpoint for the meta-analysis was an increase in aneuploidy frequency between early- (Dukes A, B and UICC I, II; n = 3632 samples) and late-stage (Dukes C, D and UICC III, IV; n = 3440 samples) colorectal carcinomas.
  
  
  RESULTS
  Of 1935 studies initially identified, 17 image (2130 patients) and 20 (7023 patients) flow cytometric studies were analyzed in detail. The meta-analysis (7072 patients) revealed late-stage CRC to be more frequently aneuploid than early-stage CRC (odds ratio 1.51, 95 % CI 1.37-1.67; p = 0.0007). Independent of tumor stage, the overall range of aneuploidy was 39 to 81 % (median 58 %), and altogether, 21 (54.1 %) studies described a significant prognostic impact of aneuploidy for overall, disease-specific, and recurrence-free survival, respectively.
  
  
  CONCLUSIONS
  A substantial number of studies showed a prognostic importance of aneuploidy in CRC. Furthermore, the higher frequency of aneuploidy in late-stage CRC implies an increase in genomic instability with CRC progression, indicating aneuploidy to be also a stage-specific prognostic marker.
authors.affiliation: Section of Translational Surgical Oncology and Biobanking, Department of Surgery, University of Lübeck and University Medical Center Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 16, 23538, Lübeck, Germany.
authors.forename: Tilman
authors.initials: T
authors.lastname: Laubert
authors.forename: Sandra
authors.initials: S
authors.lastname: Freitag-Wolf
authors.forename: Michael
authors.initials: M
authors.lastname: Linnebacher
authors.forename: Alexandra
authors.initials: A
authors.lastname: König
authors.forename: Brigitte
authors.initials: B
authors.lastname: Vollmar
authors.forename: Jens K
authors.initials: JK
authors.lastname: Habermann
mesh_terms: D000782:Aneuploidy; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000473:pathology*; D005434:Flow Cytometry; D006801:Humans; D009367:Neoplasm Staging; D016017:Odds Ratio; D011379:Prognosis; D016019:Survival Analysis