title: Age at death of patients with colorectal cancer and the effect of lead-time bias on survival in elective vs emergency surgery.
abstract: OBJECTIVE
  Colorectal cancer survival depends on stage at presentation, and current strategies aim for improvements through early detection. Previous studies have demonstrated improved survival from diagnosis but not increased life expectancy. While lead-time bias may account for variations in known prognostic indicators and also influence screening programmes, only age at death provides a true representation of the effectiveness of an intervention. We aimed to compare age at death for patients with colorectal cancer presenting on an emergency or elective basis.
  
  
  METHODS
  Patients presenting with colorectal cancer (2000-2006) were entered into a prospective database (analysis 1 December 2008). Fields included age at death, emergency/elective presentation, palliative/curative intent and disease stage.
  
  
  RESULTS
  One thousand six hundred and fifty patients (922 men) were identified. Elective patients presented younger than emergency patients (67.9 vs 70.6 years; P < 0.005). Dukes B patients presented older than Dukes D (P = 0.02). Mortality was 41% at time of analysis; no difference was seen in mean age at death between emergency and elective presentation (72.8 vs 72.0 years; P = 0.379) or palliative and curative intent (72.0 vs 72.5 years; P = 0.604).
  
  
  CONCLUSIONS
  Colorectal cancer is common in a population where actuarial life expectancy is limited. Current colorectal cancer early detection strategies may improve cancer-specific survival by increasing lead-time bias but do not influence overall life expectancy.
authors.affiliation: Lanarkshire Colorectal Study Group, Monklands Hospital, Airdrie, UK.
authors.forename: A J
authors.initials: AJ
authors.lastname: MacDonald
authors.forename: H
authors.initials: H
authors.lastname: McEwan
authors.forename: M
authors.initials: M
authors.lastname: McCabe
authors.forename: A
authors.initials: A
authors.lastname: Macdonald
mesh_terms: D000367:Age Factors; D015982:Bias; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000601:surgery; D017558:Elective Surgical Procedures; D004630:Emergencies; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008017:Life Expectancy; D008297:Male; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016019:Survival Analysis; D015996:Survival Rate