title: Disease-specific mortality among stage I-III colorectal cancer patients with diabetes: a large population-based analysis.
abstract: OBJECTIVE
  The aim of our study was to investigate overall and disease-specific mortality of colorectal cancer patients with diabetes.
  
  
  METHODS
  In this population-based study, we included all colorectal cancer patients, newly diagnosed with stage I-III cancer, between 1997 and 2007 in the registration area of the Eindhoven Cancer Registry. Stage of cancer, cancer treatment and comorbidities were actively collected by reviewing hospital medical records. Data on patients with and without diabetes were linked to Statistics Netherlands to assess vitality, date of death and underlying cause of death. Follow-up of all patients was completed until 1 January 2009.
  
  
  RESULTS
  We included 6,974 patients with colon cancer and 3,888 patients with rectal cancer, of whom 820 (12%) and 404 (10%), respectively, had diabetes at the time of cancer diagnosis. During follow-up, death occurred in 611 (50%) of 1,224 cancer patients with diabetes and 3,817 (40%) of 9,638 cancer patients without diabetes. Multivariate Cox regression analyses, adjusted for age, sex, socioeconomic status, stage, lymph nodes examined, adjuvant therapy and year of diagnosis, showed that overall mortality was significantly higher for colon (HR 1.12, 95% CI 1.01, 1.25) and rectal (HR 1.21, 95% CI 1.03, 1.41) cancer patients with diabetes than for those without. Disease-specific mortality was only significantly increased for rectal cancer patients (HR 1.30, 95% CI 1.06, 1.60).
  
  
  CONCLUSIONS
  Diabetes at the time of rectal cancer diagnosis was independently associated with an increased risk of colorectal cancer mortality compared with no diabetes, suggesting a specific interaction between diabetes and rectal cancer. Future in-depth studies including detailed diabetes- and cancer-related variables should elucidate pathways.
authors.affiliation: Comprehensive Cancer Centre South (CCCS)/Eindhoven Cancer Registry, PO Box 231, 5600 AE, Eindhoven, the Netherlands. L.vd.poll@ikz.nl
authors.forename: L V
authors.initials: LV
authors.lastname: van de Poll-Franse
authors.forename: H R
authors.initials: HR
authors.lastname: Haak
authors.forename: J W W
authors.initials: JW
authors.lastname: Coebergh
authors.forename: M L G
authors.initials: ML
authors.lastname: Janssen-Heijnen
authors.forename: V E P P
authors.initials: VE
authors.lastname: Lemmens
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology*; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000401:mortality*; D018450:Disease Progression; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies; D055815:Young Adult