Diabetic men have high-grade prostate cancer, but die from other causes
MedWire News: Men undergoing treatment for prostate cancer are more likely to have high-grade disease if they also have diabetes mellitus (DM), show US study results.
However, high-risk prostate cancer patients with DM were not treated less aggressively, nor were they more likely to die from prostate cancer-specific causes, than high-risk patients without DM.
Anthony D'Amico, from Brigham and Women's Hospital in Boston, Massachusetts, and colleagues believe that their results therefore provide evidence to support "similar treatment efficacy in [prostate cancer patients] with and without DM."
The team investigated the effect of DM on prostate cancer presentation and treatment extent, and the risk for prostate cancer-specific mortality (PCSM) in a cohort of 5279 radiotherapy-treated patients. They also examined the effect of disease aggressiveness on the risk for non-PCSM, DM-related mortality, and all-cause mortality.
In all, 4947 men had favorable-risk disease (Gleason score ≤7, prostate-specific antigen [PSA] level ≤20 ng/ml, stage T2c or less), of whom 550 had DM. The remaining 332 men had high-risk disease (PSA >20 ng/ml, Gleason score 8-10, stage T3-4), of whom 58 had DM.
Adjusting for potential confounders such as PSA level and ethnicity, the researchers found that men with DM had a 1.9-fold increased risk for high-grade (Gleason 8-10) prostate cancer, compared with men without DM.
In addition, the extent of radiation delivered to the men was not significantly different between those with and without DM after adjusting for a history of myocardial infarction, age, year of brachytherapy, and prostate cancer risk group, note D'Amico et al.
After a median follow-up of 3.9 years, 357 men had died, with 43 prostate cancer-related, and 24 DM-related deaths.
While men with high-risk prostate cancer had a significant 4.8-fold increased risk for PCSM compared with men with favorable-risk PC, DM was not independently associated with a significantly increased risk for PCSM.
Unexpectedly, men with DM and high-risk prostate cancer had significant 2.2-fold and 5.2-fold increased risks for non-PCSM and DM-related morality, respectively, compared with those who had DM and favorable-risk prostate cancer, write the researchers in the International Journal of Radiation Oncology, Biology Physics.
They therefore believe this finding "should serve to raise awareness that for men with newly diagnosed high-risk prostate cancer, strict attention should be taken to ensure continued aggressive management of DM and its complications to avoid the potential for increased DM-related mortality."
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By Sarah Guy