Background: Several studies have shown a protective effect of diabetes mellitus (DM) on incidence of prostate cancer; however, the data are not consistent. Moreover, whether or not DM is associated with a positive result among patients referred for prostate biopsy due to abnormal PSA and/or abnormal digital rectal examination is not clear.
Methods: A retrospective review of 3162 consecutive men who underwent prostate biopsy between January 2000 and July 2009 at the Atlanta Veterans Affairs Medical Center was performed. Men with positive and negative biopsies were compared for various demographic and clinical factors. The data were analyzed using logistic regression models with results expressed as adjusted odds ratios (ORs) with corresponding 95% confidence intervals (CI).
Results: DM was associated with increased odds of positive biopsy in the overall cohort (OR 1.26, 95% CI: 1.01-1.55; P = 0.04). Subjects with DM had higher odds of more aggressive disease (Gleason ≥ 7) than those without the condition (OR 1.31, 95% CI: 0.98-1.74; P = 0.07). Race had no significant impact on these results.
Conclusions: In this large series of prostate biopsies, diabetes is associated with higher odds of positive biopsy and higher Gleason grade. More studies investigating the role of DM and its associated comorbidities in prostate carcinogenesis are needed.