Association between the interleukin-6 gene polymorphisms and renal cancer risk

Abstract Introduction Interleukin-6 ( IL-6 ), a central proinflammatory cytokine, may be involved in the host response to cancer. We therefore aimed to evaluate the association of the IL-6 gene polymorphisms at positions -174 and -572 with predisposition to renal cancer. Materials and methods We conducted a hospital-based case–control study. A total of 432 subjects, including 216 pathologically-proven renal cancer cases and 216 age- and gender-matched healthy controls, were recruited in this study. Polymorphism for the IL-6 gene was genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Results Patients with renal cancer had a significantly higher frequency of IL-6 -174 CC genotype [odds ratio (OR) = 2.08, 95% confidence interval (CI) = 1.05, 4.13; P  = 0.04] than healthy controls. When stratifying by the grade, patients with higher grade (grade 3 or 4) renal cancer had a significantly higher frequency of IL-6 -174 CC genotype (OR = 2.33, 95% CI = 1.04, 5.23; P  = 0.04). Conclusion This study is, to our knowledge, the first to examine prospectively an increased risk role of IL-6 -174 CC genotype in renal cancer susceptibility.