title: Prognostic implications of BAX protein expression and microsatellite instability in all non-metastatic stages of primary colon cancer treated by surgery alone.
abstract: OBJECTIVE
  This study examined whether the apoptosis-related protein, BAX, or the microsatellite-instability phenotype provide prognostic information in patients with resected colon cancer.
  
  
  METHODS
  A total of 371 stage I-III patients that previously underwent radical surgery were included (mean follow-up 51.8 months). BAX expression was examined by immunohistochemical staining; high-frequency microsatellite instability (MSI+) was determined by assessing the specific marker, BAT26, using single-strand conformation polymorphism (SSCP)-based analysis.
  
  
  RESULTS
  High BAX expression was found in 66.4% of patients. MSI+ tumors were observed in 14.8% of 344 patients. Univariate analysis showed that unlike MSI, low BAX expression was significantly correlated with poor disease-specific overall survival (OS) in stages I-III (p = 0.04). Multivariate subgroup analyses revealed that unlike MSI, low BAX was an independent predictor for OS in stage II (p = 0.009); however, in stages I or III, BAX or MSI were not independent predictors of OS.
  
  
  CONCLUSIONS
  In stage II colon cancer treated with surgery alone, BAX protein expression may be a predictor for prognosis.
authors.affiliation: Department of Internal Medicine I, University Hospital, 72076, Tübingen, Germany. oliver.nehls@med.uni-tuebingen.de
authors.forename: Oliver
authors.initials: O
authors.lastname: Nehls
authors.forename: Holger G
authors.initials: HG
authors.lastname: Hass
authors.forename: Thomas
authors.initials: T
authors.lastname: Okech
authors.forename: Silke
authors.initials: S
authors.lastname: Zenner
authors.forename: Chih-Jen
authors.initials: CJ
authors.lastname: Hsieh
authors.forename: Mario
authors.initials: M
authors.lastname: Sarbia
authors.forename: Franz
authors.initials: F
authors.lastname: Borchard
authors.forename: Hans-Helmut
authors.initials: HH
authors.lastname: Gruenagel
authors.forename: Vera
authors.initials: V
authors.lastname: Gaco
authors.forename: Rainer
authors.initials: R
authors.lastname: Porschen
authors.forename: Michael
authors.initials: M
authors.lastname: Gregor
authors.forename: Bodo
authors.initials: B
authors.lastname: Klump
mesh_terms: D000368:Aged; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D053842:Microsatellite Instability; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009367:Neoplasm Staging; D010641:Phenotype; D011379:Prognosis; D051028:bcl-2-Associated X Protein / Q000378:metabolism*
chemical_list: D051028:bcl-2-Associated X Protein