title: Overall survival is improved in mucinous adenocarcinoma of the colon.
abstract: BACKGROUND
  Debate persists regarding the relationship between mucin expression and outcome in colon cancer. This arises due to discrepancy in the definition of mucinous adenocarcinoma and the combination of both colon and rectal cancers in analyses. This study examines the relationship between increased mucin production and outcomes in colon cancer.
  
  
  METHODS
  Cases were classified according to the World Health Organization classification of mucinous adenocarcinoma of the colon. Accordingly, tumors were categorized as either (a) mucinous adenocarcinoma of the colon (greater than 50% of the extracellular matrix occupied by mucin) or (b) non-mucinous adenocarcinoma of the colon. Overall survival and disease-free survival were calculated. A stepwise Cox proportional hazards regression model was employed to determine the risk of death/disease recurrence. Kaplan-Meier estimates of overall survival and disease-free survival were plotted for each group and compared using a log-rank test.
  
  
  RESULTS
  On univariate analysis, mucinous adenocarcinoma was associated with reduced risk of death (P = 0.01). On multivariate analysis, mucinous adenocarcinoma was also associated with reduced risk of death (hazard ratio (HR) 0.33, 95% confidence interval (CI) 0.14-0.79, P = 0.01). Kaplan-Meier estimates confirmed improved rate of survival in the mucinous vs. non-mucinous group (P = 0.01). Mucinous adenocarcinoma did not affect disease-free survival (HR 0.75, 95% CI 0.46-1.21, P = 0.22). A comparison of Kaplan-Meier estimates for systemic recurrence demonstrated significant increases in systemic recurrence in the group with no mucin production (P = 0.04) but not for locoregional recurrence (P = 0.24).
  
  
  CONCLUSIONS
  Histopathological evidence of mucinous adenocarcinoma in colon cancer is associated with improved outcomes.
authors.affiliation: Department of Colorectal Surgery, University Hospital Limerick, Limerick, Ireland.
authors.forename: J
authors.initials: J
authors.lastname: Hogan
authors.forename: J P
authors.initials: JP
authors.lastname: Burke
authors.forename: G
authors.initials: G
authors.lastname: Samaha
authors.forename: E
authors.initials: E
authors.lastname: Condon
authors.forename: D
authors.initials: D
authors.lastname: Waldron
authors.forename: P
authors.initials: P
authors.lastname: Faul
authors.forename: J Calvin
authors.initials: JC
authors.lastname: Coffey
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000628:therapy; D002288:Adenocarcinoma, Mucinous / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D003110:Colonic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000628:therapy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local; D009367:Neoplasm Staging; D016016:Proportional Hazards Models