Statins Moderate Effect of Metformin on Prostate Cancer
(HealthDay News) – For men with type 2 diabetes treated with metformin, prostate cancer (PCa) incidence varies depending on statin use, with a significantly reduced risk for patients taking a combination of metformin and statins.
Donna M. Lehman, PhD, from the University of Texas Health Science Center in San Antonio, and colleagues analyzed data from 5,042 men with type 2 diabetes treated in the Veteran Administration Health Care System. Participants had no history of prior cancer and were treated exclusively with metformin or sulfonylurea as a hypoglycemic medication between 1999–2005.
During a mean follow-up of five years, the researchers found that 7.5% of men had a PCa diagnosis. Metformin correlated with a significantly lower PCa incidence among patients on statins (hazard ratio [HR], 0.69; 17 cases in 533 metformin users vs. 135 cases in 2,404 sulfonylureas users) and an elevated PCa incidence among patients not on statins (HR, 2.15; 22 cases in 175 metformin users vs. 186 cases in 1,930 sulfonylureas users). When compared with those patients taking neither medication, patients treated with metformin and statins had a PCa incidence HR of 0.32.
"Among men with type 2 diabetes, PCa incidence among metformin users varied by their statin use," the authors write. "The potential beneficial influence on PCa by combination use of metformin and statin may be due to synergistic effects."