title: Characteristics affecting survival after locally advanced colorectal cancer in Quebec.
abstract: BACKGROUND
  We estimated the relations of sociodemographic, organizational, disease, and treatment variables with the risk of death from colorectal cancer (crc) in a Quebec population-based sample of patients with locally advanced crc (lacrc) who underwent tumour resection with curative intent.
  
  
  METHODS
  Information from medical records and administrative databases was obtained for a random sample of 633 patients surgically treated for stages ii-iii rectal and stage iii colon cancer and declared to the Quebec cancer registry in 1998 and 2003. We measured personal, disease, and clinical management characteristics, relative survival, and through multivariate modelling, relative excess rate (rer) of death.
  
  
  RESULTS
  The relative 5- and 10-year survivals in this cohort were 67.7% [95% confidence interval (ci): 65.8% to 69.6%] and 61.2% (95% ci: 58.3% to 64.0%) respectively. Stage T4, stage N2, and emergency rather than elective surgery affected 18%, 24% and 10% of patients respectively. Those disease progression characteristics each independently increased the rer of death by factors of 2 to almost 5. Grade, vascular invasion, and tumour location were also significantly associated with the rer for death. Receiving guideline-adherent treatment was associated with a 60% reduction in the rer for death (0.41; 95% ci: 0.28 to 0.61), an effect that was consistent across age groups. Clear margins (proximal-distal, radial) and clinical trial enrolment were each associated with a nonsignificant 50% reduction in the rer. Of patients less than 70 years of age and 70 years of age and older, 81.3% and 42.0% respectively received guideline-adherent treatment.
  
  
  CONCLUSIONS
  This study is the first Quebec population-based examination of patients with lacrc and their management, outcomes, and outcome determinants. The results can help in planning crc control strategies at a population level.
authors.affiliation: Institut national de santé publique du Québec, Quebec City, QC; ; Département de santé publique et médecine préventive, chu de Québec-Université Laval, Quebec City, QC; ; Département de médecine sociale et préventive, Faculté de médecine, Université Laval, Quebec City, QC;
authors.forename: L
authors.initials: L
authors.lastname: Perron
authors.affiliation: Institut national de santé publique du Québec, Quebec City, QC;
authors.forename: J M
authors.initials: JM
authors.lastname: Daigle
authors.affiliation: Institut national de santé publique du Québec, Quebec City, QC;
authors.forename: N
authors.initials: N
authors.lastname: Vandal
authors.affiliation: Institut national de santé publique du Québec, Quebec City, QC;
authors.forename: M H
authors.initials: MH
authors.lastname: Guertin
authors.affiliation: Institut national de santé publique du Québec, Quebec City, QC; ; Département de médecine sociale et préventive, Faculté de médecine, Université Laval, Quebec City, QC; ; Centre de recherche du chu de Québec-Université Laval, Centre hospitalier universitaire de Québec, Quebec City, QC.
authors.forename: J
authors.initials: J
authors.lastname: Brisson
keywords: Colorectal neoplasms; medical records; multivariate analyses; population-based studies; registries; relative excess hazard rate for death; relative survival; treatment outcomes