Causes of death in men with prevalent diabetes and newly diagnosed high- versus favorable-risk prostate cancer

Purpose: To determine whether prevalent diabetes mellitus (pDM) affects the presentation, extent of radiotherapy, or prostate cancer (PCa)-specific mortality (PCSM) and whether PCa aggressiveness affects the risk of non-PCSM, DM-related mortality, and all-cause mortality in men with pDM.

Methods: Between October 1997 and July 2907, 5,279 men treated at the Chicago Prostate Cancer Center with radiotherapy for PCa were included in the study. Logistic and competing risk regression analyses were performed to assess whether pDM was associated with high-grade PCa, less aggressive radiotherapy, and an increased risk of PCSM. Competing risks and Cox regression analyses were performed to assess whether PCa aggressiveness described by risk group in men with pDM was associated with the risk of non-PCSM, DM-related mortality, and all-cause mortality. Analyses were adjusted for predictors of high-grade PCa and factors that could affect treatment extent and mortality.

Results: Men with pDM were more likely (adjusted hazard ratio [AHR], 1.9; 95% confidence interval [CI], 1.3-2.7; p = .002) to present with high-grade PCa but were not treated less aggressively (p = .33) and did not have an increased risk of PCSM (p = .58) compared to men without pDM. Among the men with pDM, high-risk PCa was associated with a greater risk of non-PCSM (AHR, 2.2; 95% CI, 1.1-4.5; p = .035), DM-related mortality (AHR, 5.2; 95% CI, 2.0-14.0; p = .001), and all-cause mortality (AHR, 2.4; 95% CI, 1.2-4.7; p = .01) compared to favorable-risk PCa.

Conclusion: Aggressive management of pDM is warranted in men with high-risk PCa.