title: Colorectal specialization and survival in colorectal cancer.
abstract: OBJECTIVE
  It is recognized that higher surgeon volume is associated with improved survival in colorectal cancer. However, there is a paucity of national studies that have evaluated the relationship between surgical specialization and survival.
  
  
  METHODS
  We used the Surveillance, Epidemiology, and End Results Medicare cancer registry to examine the association between colorectal specialization (CRS) and disease-specific survival (DSS) between 2001 and 2009. A total of 21,432 colon cancer and 5893 rectal cancer patients who underwent elective surgical resection between 2001 and 2009 were evaluated. Univariate and multivariate Cox survival analysis was used to identify the association between surgical specialization and cancer-specific survival.
  
  
  RESULTS
  Colorectal specialists performed 16.3% of the colon and 27% of the rectal resections. On univariate analysis, specialization was associated with improved survival in Stage II and Stage III colon cancer and Stage II rectal cancer. In multivariate analysis, however, CRS was associated with significantly improved DSS only in Stage II rectal cancer [hazard ratio (HR) 0.70, P = 0.03]. CRS was not significantly associated with DSS in either Stage I (colon HR 1.14, P = 0.39; rectal HR 0.1.26, P = 0.23) or Stage III (colon HR 1.06, P = 0.52; rectal HR 1.08, P = 0.55) disease. When analysis was limited to high volume surgeons only, the relationship between CRS and DSS was unchanged.
  
  
  CONCLUSIONS
  CRS is associated with improved DSS following resection of Stage II rectal cancer. A combination of factors may contribute to long-term survival in these patients, including appropriate surgical technique, multidisciplinary treatment decisions and guideline-adherent surveillance. CRS probably contributes positively to these factors resulting in improved survival.
authors.affiliation: Division of Colon and Rectal Surgery, Department of General Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: G M
authors.initials: GM
authors.lastname: Hall
authors.affiliation: Division of Colon and Rectal Surgery, Department of General Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: S
authors.initials: S
authors.lastname: Shanmugan
authors.affiliation: Division of Colon and Rectal Surgery, Department of General Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: J I S
authors.initials: JI
authors.lastname: Bleier
authors.affiliation: Department of General Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: A N
authors.initials: AN
authors.lastname: Jeganathan
authors.affiliation: Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.|Division of General Internal Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Epstein
authors.affiliation: Division of Colon and Rectal Surgery, Department of General Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.|Department of General Surgery, Philadelphia VA Medical Center, Philadelphia, Pennsylvania, USA.
authors.forename: E C
authors.initials: EC
authors.lastname: Paulson
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002983:Clinical Competence / Q000706:statistics & numerical data; D003082:Colectomy / Q000379:methods / Q000401:mortality*; D003110:Colonic Neoplasms / Q000401:mortality / Q000601:surgery*; D003107:Colorectal Surgery / Q000379:methods / Q000706:statistics & numerical data*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality / Q000601:surgery*; D012189:Retrospective Studies; D013038:Specialization
keywords: Colon cancer; rectal cancer; specialization; survival