Diabetes and prostate cancer screening in black and white men

Purpose: Prior studies conducted primarily among white men find a reduced risk of prostate cancer associated with time since developing diabetes. While biologic explanations are plausible, the association may in part arise from more frequent prostate cancer screening among those with a diabetes diagnosis. The purpose of the present study was to investigate the association between diabetes and prostate cancer screening. Methods: We examined differences in prostate cancer screening (prostate-specific antigen and/or digital rectal examination) testing practices after a diabetes diagnosis among lower-income persons living in the southeastern United States and enrolled in the Southern Community Cohort Study between 2002 and 2009. Baseline in-person interviews collected information on history of diabetes and prostate cancer screening from 18,809 black and 6,404 white men aged 40-79 years. Results: After adjustment for confounding, diabetic black [odds ratio (OR) 1.12, 95 % confidence interval (CI) 1.01-1.25] and white (OR 1.25, 95 % CI 1.03-1.51) men were more likely to undergo recent prostate cancer screening compared to non-diabetic men of the same race. The increased risk for prostate cancer screening, however, occurred primarily within the first 12 months after diabetes diagnosis. Conclusions: Our results suggest that a diabetes diagnosis modestly increases the likelihood of having a prostate cancer screening test for both black and white men. The prevalence of screening was higher nearer to the time of diabetes diagnosis, which may contribute to an early increase in prostate cancer detection followed by lower prostate cancer detection after an extended time.