BACKGROUND: Diabetes mellitus (DM) increases the risk for cancer at almost all sites, but data on the association with prostate cancer (PC) are inconsistent.
METHODS: We assessed the risk of a PC diagnosis among men with type 2 (T2)DM in a nationwide case-control study including 44,352 men with PC identified through the Prostate Cancer data Base Sweden (PCBaSe) between 2002 and 2006, and 221,495 controls from the general population.
RESULTS: The risk of PC among men with T2DM was lower than among men without T2DM (OR=0.80, 95% CI: 0.76-0.85). The risk decreased with longer disease duration and was observed across all tumor risk categories, although most clearly among men with low risk tumors (OR=0.71, 95% CI=0.64-0.80). PC risk was reduced among diabetic men on dietary treatment only (OR=0.89 95% CI: 0.80-0.99), but more markedly among men on oral hypo-glycemic agents (OR=0.80 95% CI: 0.74-0.87) and insulin (OR=0.72 95% CI: 0.69-0.81). Obese diabetic men (BMI>30 kg/m2 ) showed a reduced risk (OR=0.72, 95%-CI:0.65-0.80) compared to men without diabetes. There was a trend of decreasing risk with rising levels of HbA1c (p< 0.05).
CONCLUSIONS: This nationwide study confirmed a reduced risk of being diagnosed with PC among men with T2DM, especially for low risk tumors. An altered hormonal milieu is a plausible explanation, although the possibility of decreased PC detection among diabetic men cannot be ruled out. Impact: This is the largest study to examine the association between diabetes type 2 and prostate cancer accounting for tumour risk group and diabetes treatment.
Written by:
Fall K, Garmo H, Gudbjornsdottir S, Stattin P, Zethelius BO. Are you the author?
Epidemiology and Biostatistics, Orebro Universitet.
Reference: Cancer Epidemiol Biomarkers Prev. 2013 Apr 11. Epub ahead of print.
doi: 10.1158/1055-9965.EPI-12-1046
PubMed Abstract
PMID: 23580698
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