In patients with prostate cancer (PCa) undergoing radical prostatectomy (RP), those with type 2 diabetes mellitus may have a higher risk of harboring high-grade tumors on final pathological examination, according to a new Italian study.
Firas Abdollah, MD, of San Raffaele Hospital in Milan, Italy and colleagues examined 2,060 consecutive men who underwent RP between 2001 and 2009. Among these patients, 7.1% had type 2 diabetes. The researchers defined a high-grade tumor as having a Gleason score higher than than 8. The patients had a mean age of 64 years (range 45-85) and a mean level of total PSA of 9 ng mL.
A significantly higher percentage of diabetic patients had high-grade tumor on biopsy compared with nondiabetics (16.3% vs. 7.6%), according to a report in Prostate Cancer and Prostatic Diseases (2011;14:74-78). Diabetics also had a larger proportion of high-grade tumors discovered in RP specimens (21.1% vs. 11.7%).
Diabetic and nondiabetic subjects were similar with respect to PSA levels, clinical stage, and pathological stage. After adjusting for confounders, diabetic patients had a 2.7-fold and 2.4 fold increased risk of harboring high-grade tumors on biopsy and on pathological examination of RP specimens, respectively.
The correlation between diabetes mellitus and PCa has been addressed in several studies, but the new study is the first European study to investigate the relationship between the two diseases in patients undergoing RP. The findings suggest that diabetic patients may be predisposed to develop a high-grade tumor, so regular PSA screening may be advisable to detect PCa at early stages.