title: Patients with CD133-negative colorectal liver metastasis have a poor prognosis after hepatectomy.
abstract: BACKGROUND
  The prognostic factors for patients with colorectal cancer liver metastasis (L-Mets) have not been fully described.
  
  
  METHODS
  Resected specimens were obtained surgically from 1998 to 2008 at our university hospital. We investigated whether the status of two primary lesion cancer stem biomarkers, CD44 and CD133, were maintained in L-Mets and whether these markers were L-Mets prognostic factors. To investigate the CD133 and CD44 status, proliferation, invasiveness, and chemoresistance were examined immunohistochemically by using MIB-1, E-cadherin, and ABC-G2.
  
  
  RESULTS
  The CD44-positive rate in primary lesions and L-Mets was 41.4 and 58.7 %, respectively. There was no correlation of CD44 expression between primary lesions and L-Mets (r = 0.250, p = 0.071). The CD133-positive rate in primary lesions and L-Mets was 53.6 and 44.6 %, respectively. There was no correlation of CD133 expression between primary lesions and L-Mets (r = 0.219, p = 0.135). In the CD133-negative group, the MIB-1 index was significantly higher than in the CD133-positive group (61.6 vs. 46.3 %, p = 0.003), and E-cadherin expression was significantly lower in the CD133-negative group compared with the CD133-positive group (29.3 vs. 46.8 %, p = 0.001). Absence of CD133 expression in L-Mets correlated with poor overall survival (p = 0.006), and multivariate regression analysis showed that it was an independent marker for poor survival (hazard ratio 0.320, p = 0.0016).
  
  
  CONCLUSIONS
  The absence of CD133 expression in L-Mets was an independent marker and a poor prognostic factor, possibly because of increased proliferation and invasiveness.
authors.affiliation: Department of Gastroenterological Surgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Kuniya
authors.initials: K
authors.lastname: Tanaka
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Takeda
authors.forename: Hirotoshi
authors.initials: H
authors.lastname: Akiyama
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Ichikawa
authors.forename: Yoji
authors.initials: Y
authors.lastname: Nagashima
authors.forename: Itaru
authors.initials: I
authors.lastname: Endo
mesh_terms: D000071916:AC133 Antigen; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters / Q000032:analysis; D000368:Aged; D015703:Antigens, CD / Q000032:analysis*; D014408:Biomarkers, Tumor / Q000032:analysis*; D015820:Cadherins / Q000032:analysis; D049109:Cell Proliferation; D015179:Colorectal Neoplasms / Q000737:chemistry* / Q000473:pathology; D019008:Drug Resistance, Neoplasm; D005260:Female; D006023:Glycoproteins / Q000032:analysis*; D006498:Hepatectomy; D006801:Humans; D018960:Hyaluronan Receptors / Q000032:analysis*; D019394:Ki-67 Antigen / Q000032:analysis; D008113:Liver Neoplasms / Q000737:chemistry* / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000032:analysis; D010455:Peptides / Q000032:analysis*; D011379:Prognosis; D015996:Survival Rate
chemical_list: C116614:ABCG2 protein, human; D000071916:AC133 Antigen; D000070997:ATP Binding Cassette Transporter, Subfamily G, Member 2; D018528:ATP-Binding Cassette Transporters; D015703:Antigens, CD; D014408:Biomarkers, Tumor; D015820:Cadherins; D006023:Glycoproteins; D018960:Hyaluronan Receptors; D019394:Ki-67 Antigen; D009363:Neoplasm Proteins; C000606023:PROM1 protein, human; D010455:Peptides