title: Diabetes mellitus and risk of endometrial cancer: a meta-analysis.
abstract: OBJECTIVE
  Diabetes has been associated with a statistically significantly increased risk of endometrial cancer in most, but not all studies. To provide a quantitative assessment of the association between diabetes and risk of endometrial cancer, we conducted a meta-analysis of case-control studies and cohort studies.
  
  
  METHODS
  We identified studies by a literature search of PubMed and Embase through to January 2007 and by searching the reference lists of relevant articles. Summary relative risks (RRs) with 95% CIs were calculated using random-effects model.
  
  
  RESULTS
  The analysis of diabetes (largely type 2) and endometrial cancer is based on 16 studies (three cohort and 13 case-control studies), including 96,003 participants and 7,596 cases of endometrial cancer. Twelve of the studies showed a statistically significantly increased risk and four a non-significant increased risk of endometrial cancer. In our meta-analysis we found that diabetes was statistically significantly associated with an increased risk of endometrial cancer (summary RR 2.10, 95% CI 1.75-2.53). The risk estimates were somewhat stronger among case-control (RR 2.22, 95% CI 1.80-2.74) than among cohort studies (RR 1.62, 95% CI 1.21-2.16), stronger among studies adjusting only for age (RR 2.74, 95% CI 1.87-4.00) compared with multivariate adjustment (RR 1.92, 95% CI 1.58-2.33) and slightly lower in studies performed in the USA than in those performed Europe. The analysis of type 1 diabetes and endometrial cancer was based on three studies and found a statistically significant positive association (summary RR 3.15, 95%CI 1.07-9.29).
  
  
  CONCLUSIONS
  Results from the meta-analysis support a relationship between diabetes and increased risk of endometrial cancer.
authors.affiliation: Division of Nutritional Epidemiology, The National Institute of Environmental Medicine, Karolinska Institutet, PO Box 210, 171 77, Stockholm, Sweden. emilie.friberg@ki.se
authors.forename: E
authors.initials: E
authors.lastname: Friberg
authors.forename: N
authors.initials: N
authors.lastname: Orsini
authors.forename: C S
authors.initials: CS
authors.lastname: Mantzoros
authors.forename: A
authors.initials: A
authors.lastname: Wolk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D015331:Cohort Studies; D048909:Diabetes Complications / Q000209:etiology*; D003920:Diabetes Mellitus / Q000175:diagnosis*; D016889:Endometrial Neoplasms / Q000150:complications* / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008875:Middle Aged; D015999:Multivariate Analysis; D012306:Risk