Association of diabetes mellitus with prostate cancer: Nested case–control study (Prostate testing for cancer and Treatment study)

✍ Scribed by Emma L. Turner; Janet Athene Lane; Jenny L. Donovan; Michael J. Davis; Chris Metcalfe; David E. Neal; Freddie C. Hamdy; Richard M. Martin

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: French
• Weight: 143 KB
• Volume: 128
• Category: Article
• ISSN: 0020-7136
• DOI: 10.1002/ijc.25360

✦ Synopsis

Abstract

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.