title: The survival gap between middle-aged and elderly colon cancer patients. Time trends in treatment and survival.
abstract: OBJECTIVE
  For several types of cancer, including colon cancer, the survival gap between middle-aged patients and elderly patients widened between 1988 and 1999 in Europe. The aim of our study was to describe treatments and compare survival rates over time (1991-2005) between middle-aged (<65 years), aged (65-74 years) and elderly (≥ 75 years) colon cancer patients in the mid-western part of the Netherlands to assess whether this survival gap further increased.
  
  
  METHODS
  All 8926 patients with invasive colon cancer diagnosed between 1991 and 2005 were selected from the Comprehensive Cancer Centre West. Relative survival was calculated. Relative Excess Risks of death (RER) were estimated using a multivariable generalized linear model with a Poisson distribution.
  
  
  RESULTS
  There were no significant changes in the treatment for stage I and II colon. Patients with stage III and IV more often received chemotherapy over time (from 9.6% to 54.3% and from 7.5% to 44.2% for all ages, respectively), while less stage IV patients were operated on (from 73.1% to 55.2%). Relative 5-year survival increased significantly for middle-aged patients (RER = 0.97, 95%CI = 0.95-0.98, p < 0.001), borderline significantly (RER = 0.98, 95%CI = 0.97-0.99, p = 0.05) for elderly patients and not significantly for aged patients (RER = 0.99, 95%CI = 0.97-1.00, p = 0.08) after adjustment for sex, age, grade, stage, and treatment.
  
  
  CONCLUSIONS
  The survival gap earlier found by the EUROCARE is confirmed for the mid-western part of the Netherlands, even after adjustment for age, sex, grade, stage and treatment. However, present study does not show an increase in the survival gap between middle-aged and elderly patients.
authors.affiliation: Department of Surgery, Leiden University Medical Centre, Albinusdreef 2, PO Box 9600 2300 RC, Leiden, The Netherlands.
authors.forename: C B M
authors.initials: CB
authors.lastname: van den Broek
authors.forename: J W T
authors.initials: JW
authors.lastname: Dekker
authors.forename: E
authors.initials: E
authors.lastname: Bastiaannet
authors.forename: P
authors.initials: P
authors.lastname: Krijnen
authors.forename: A J M
authors.initials: AJ
authors.lastname: de Craen
authors.forename: R A E M
authors.initials: RA
authors.lastname: Tollenaar
authors.forename: C J H
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: G J
authors.initials: GJ
authors.lastname: Liefers
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002423:Cause of Death; D017024:Chemotherapy, Adjuvant; D003082:Colectomy / Q000379:methods; D003110:Colonic Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D003131:Combined Modality Therapy; D016001:Confidence Intervals; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands; D016012:Poisson Distribution; D011379:Prognosis; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D016019:Survival Analysis; D013997:Time Factors