Circulating IL-10 is associated with reduced risk of prostate cancer in a prospective cohort of elderly men: the MrOS Study.

PURPOSE: Prostate cancer (PCa) is the most commonly diagnosed cancer in men, resulting in a large cancer burden given a relatively higher 5-year survival rate of patients after cancer diagnosis. The underlying etiology of prostate cancer is not well understood. Chronic inflammation plays a significant role in carcinogenesis overall and may be involved in the development of PCa, but immune-related biomarker studies in prostate cancer are limited. METHODS: The associations of serum concentrations of cytokines, systemic immune biomarkers, with risk of PCa were assessed in a randomly selected sub-cohort (n = 798, mean age = 73 years) of the Osteoporotic Fractures in Men (MrOS) study, a prospective cohort of older men. At baseline, we measured serum interleukin (IL)-6, C-reactive protein (CRP), tumor necrosis factor alpha (TNFα), soluble receptors (SR) of IL-6 (IL-6SR) and TNF (TNFαSR1 and TNFαSR2), and IL-10. The risk of PCa was calculated for higher tertile levels of measured individual cytokines relative to the lowest tertile using Cox proportional hazards regression models. RESULTS: After an average 6 years of follow-up, 59 men developed incident PCa. Men in the middle or highest tertile of IL-10 had a statistically significant 50% lower risk of PCa compared to the lowest tertile (hazard ratio = 0.50, 95% confidence interval = 0.30-0.84). There was no significant association between any of the other cytokines measured and PCa risk. CONCLUSION: IL-10, an anti-inflammatory cytokine, was associated with lower risk of PCa. Further research of IL-10 and inflammation in relation to PCa development is warranted.