Association of diabetes mellitus with prostate cancer: nested case-control study (Prostate testing for cancer and treatment study)

Int J Cancer. 2011 Jan 15;128(2):440-6. doi: 10.1002/ijc.25360. Epub 2010 Apr 5.


Observational studies suggest that diabetes is associated with a decreased risk of prostate cancer, but few are population based or have investigated associations with cancer stage or duration of diabetes. We report a case-control study nested within the population-based Prostate testing for cancer and Treatment (ProtecT) study ISRCTN20141297. Men aged 50-69 years based around 9 UK cities were invited for a prostate-specific antigen (PSA) test between June 2002 and November 2006. Amongst 55,215 PSA-tested men, 1,966 had histologically confirmed prostate cancer; of these, 1,422 (72.3%) completed the questionnaire and 1,291 (65.7%) had complete data for analysis. We randomly selected 6,479 age- (within 5 years) and general practice-matched controls. The prevalence of diabetes was 89/1,291 (6.9%) in cases and 555/6,479 (8.6%) in controls. Diabetes was associated with a reduced risk of prostate cancer (odds ratio = 0.78; 95% confidence interval: 0.61-0.99). There was weak evidence that the inverse association was greater for well- versus poorly differentiated cancers (p = 0.07). The magnitude of the inverse association did not change with increasing duration of diabetes (p for trend = 0.95). Diabetes is associated with a decreased risk of PSA-detected prostate cancer. These data add to the evidence of the association of diabetes with prostate cancer in the PSA era.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Body Mass Index
  • Case-Control Studies
  • Diabetes Mellitus / epidemiology*
  • Humans
  • Male
  • Middle Aged
  • Prostate-Specific Antigen / blood
  • Prostatic Neoplasms / prevention & control*
  • Time Factors


  • Prostate-Specific Antigen

Associated data

  • ISRCTN/ISRCTN20141297