Association between interleukin-18 variants and prostate cancer in Slovak population

Interleukin-18 (IL-18), pro-inflammatory cytokine, plays important role in antitumor immunity. Polymorphisms in the IL-18 gene may lead to its altered production/activity and such modulate susceptibility to prostate cancer. The aim of this study was to evaluate the relationship between the -607 and +105 polymorphisms in the IL-18 gene and the risk of prostate cancer development and progression in Slovak population. The study was performed using 425 patients with prostate cancer, 270 patients with benign prostatic hyperplasia (BHP) and 263 healthy male controls. The statistically significant association of the -607 AC genotype (OR = 2.24; p < 0.001), CC genotype (OR = 1.86; p = 0.006), as well as C allele (OR = 1.27; p = 0.033) with the higher risk of prostate cancer development was observed. No association of the IL-18 -607 polymorphism and BHP was detected. The subset analysis revealed the significant association of the -607 AC genotype (OR = 2.01; p = 0.008) with development of higher-grade carcinomas (Gleason score ≥7) and the strong association of the -607 AC genotype (OR = 3.11; p < 0.001), CC genotype (OR = 2.96; p < 0.001) as well as C allele (OR = 1.51; p = 0.003) with the higher risk of prostate cancer development in the group of patients with PSA < 10 ng/ml. The -607 AC genotype was also connected with significantly higher IL-18 plasma concentrations. No association between the IL-18 +105 polymorphism and prostate cancer was observed. The analysis of the distribution of the -607 and +105 haplotypes showed significant association of the - 607 C/ + 105 A and - 607 C/ + 105 C haplotypes with the risk of prostate cancer. This study found that the IL-18 -607 promoter polymorphism could contribute to prostate cancer development in Slovak population. Its presence was also associated with development of higher-grade carcinomas and therefore may influences the prognosis and aggressiveness of the disease.