[Association between IL-6-572 C/G polymorphism and breast cancer susceptibility].

Objective To explore the associations between breast cancer and three single nucleotide polymorphisms (-597 G/A, -572 C/G and -174 G/C) of interleukin-6 (IL-6) gene promoter. Methods The study enrolled 136 breast cancer cases and 150 healthy female controls. The single nucleotide polymorphisms (SNPs) of IL-6 were identified by Sanger method of DNA sequencing, and serum IL-6 levels were measured with electrochemiluminescence immunoassay. Chi-squared test was utilized to compare frequency of a given SNP between the two groups, and t-test was employed to compare serum IL-6 levels in different groups. Results Compared with healthy controls, the serum IL-6 levels were significantly elevated in the patients with breast cancer. The genotype frequency of -572 C/G was significantly higher in breast cancer group than in the control group (OR=1.841, 95%CI: 1.115-3.040, P=0.017). There was no significant difference of serum IL-6 level in the three genotypes of -572 C/G, in both the breast cancer cases and the healthy controls. Conclusion The serum level of IL-6 significantly increases in the patients with breast cancer. The -572 C/G polymorphism and the serum level of IL-6 may play a role in the development of breast cancer.