AUA 2013: Diabetes may raise risk of aggressive prostate cancer

Prostate cancer patients who also have long-term diabetes mellitus and/or diabetes with organ failure may have a higher likelihood of developing more aggressive, poorly differentiated disease, new study data suggest.

“Our database analysis revealed that prostate cancer patients with long-term DM and/or DM with organ failure are all at a higher risk of harboring a poorly differentiated tumor,” said first author Alessandro Nini, MD, of the Urological Research Institute, University Vita-Salute San Raffaele, Milan, Italy.

“This should be considered when advising diabetic patients about prostate cancer screening and management.”

Dr. Nini obtained data from 104,822 prostate cancer patients in the Surveillance, Epidemiology, and End Results Medicare database. The patients had received different treatment modalities and were diagnosed between 1992 and 2005. Dr. Nini employed logistic regression analyses to test the relationship between the patients’ diabetes status and two endpoints: poorly differentiated tumors (Gleason score 8-10) and locally advanced prostate cancer (T3-T4 disease).

After adjusting for all other covariates, diabetic patients were 5% more likely to harbor poorly differentiated prostate cancer. Diabetes was seen to increase the risk of high-grade tumor in univariable and multivariable analyses for the prediction of high-grade tumor, and emerged as a predictive factor for locally advanced tumor in univariable analysis. At sub-analysis, patients with long-term diabetes in excess of 35 months and diabetes with organ failure were 15% and 21% respectively more likely to harbor poorly differentiated prostate cancer relative to their non-diabetic counterparts (p<.03).

Conversely, short-term diabetes, diabetes without complications, and diabetes with complications were not independent predictors of poorly differentiated prostate cancer (odds ratio [OR]: 1.02-1.04, all p≥.2). Similarly, diabetes itself was not an independent predictor of locally advanced disease (OR: 0.94, p=.1), Dr. Nini noted.