title: Risk factors for excess mortality in the first year after curative surgery for colorectal cancer.
abstract: BACKGROUND
  Thirty-day mortality after surgery for colorectal cancer may vastly underestimate 1-year mortality. This study aimed to quantify the excess mortality in the first postoperative year of stage I-III colorectal cancer patients and to identify risk factors for excess mortality.
  
  
  METHODS
  All 2,131 patients who were operated with curative intent for stage I-III colorectal cancer in the western region of the Netherlands between January 1, 2006, and December 31, 2008, were analyzed. Thirty-day mortality and relative survival were calculated. In addition, relative excess risk (RER) of death was estimated by a multivariable model.
  
  
  RESULTS
  Thirty-day mortality was 4.9%. One-year mortality was 12.4%. Risk factors for excess mortality in the first postoperative year for colon cancer patients were emergency surgery (excess mortality 29.7%, RER 2.5, 95% confidence interval 2.5-5.0), a Charlson score of >1 (excess mortality 12.6%, RER 2.3, 95% confidence interval 1.5-3.7), stage II or III disease (excess mortality 14.9%, RER 3.9, 95% confidence interval 1.9-8.1), and postoperative adverse events (excess mortality 22.6%, RER 2.1, 95% confidence interval 1.4-3.2).
  
  
  CONCLUSIONS
  The 30-day mortality rate highly underestimates the risk of dying in the first year after surgery, with excess 1-year mortality rates varying from 15 to 30%. This excess mortality was especially prominent in patients with comorbidities, higher stages of disease, emergency surgery, and postoperative surgical complications.
authors.affiliation: Department of Surgery, Leiden University Medical Centre, Leiden, The Netherlands.
authors.forename: Gea A
authors.initials: GA
authors.lastname: Gooiker
authors.forename: Jan Willem T
authors.initials: JW
authors.lastname: Dekker
authors.forename: Esther
authors.initials: E
authors.lastname: Bastiaannet
authors.forename: Lydia G M
authors.initials: LG
authors.lastname: van der Geest
authors.forename: Jos W S
authors.initials: JW
authors.lastname: Merkus
authors.forename: Cornelis J H
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: Rob A E M
authors.initials: RA
authors.lastname: Tollenaar
authors.forename: Gerrit-Jan
authors.initials: GJ
authors.lastname: Liefers
mesh_terms: D000367:Age Factors; D000368:Aged; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000601:surgery*; D015897:Comorbidity; D004638:Emergency Treatment / Q000401:mortality*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007902:Length of Stay; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D011183:Postoperative Complications / Q000401:mortality*; D011379:Prognosis; D012307:Risk Factors; D012737:Sex Factors; D012959:Socioeconomic Factors; D015996:Survival Rate; D013997:Time Factors