IL-1RN gene polymorphisms were associated with breast cancer risk in a Chinese Han population.

Background Interleukin (IL) is a large family of endogenous cytokine which are crucial in the regulation of inflammation and immunological responses. IL-1 receptor antagonist (IL-1RN) has been found to be associated with risk breast cancer (BC) in Korean and Indian women. However, little information is found about the polymorphisms of IL-1RN in Chinese Han BC patient. Methods We investigated the association between single-nucleotide polymorphisms (SNPs) in IL-1RN and BC risk in a case–control study that included 530 BC cases and 628 healthy controls. Six tag SNPs in IL-1RN were selected and genotyped using the Sequenom MassARRAY platform. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression after adjusting for age and gender. Results In the allele model, we found the frequency of the “T” allele of rs928940 was significantly lower in BC cases than in controls (OR= 0.776, 95%CI: 0.611-0.985, P= 0.037). In the genetic model analysis, five susceptibility SNPs were found to be associated with BC risk: the minor allele “G” of rs315919, rs3181052, and rs452204 were associated with decreased risk of BC under dominant model (p<0.05), the minor alleles “T” and “C” of rs928940 and rs4250027 were associated with decreased risk of BC under both codominant and dominant model (p<0.05), which suggested these SNPs may play a protective role against BC risk. The haplotype “TAGC” constructed by rs928940, rs3181052, rs452204 and rs4250027 was associated with decreased risk of BC (OR = 0.33; 95 % CI = 0.12-0.94; p = 0.038). Conclusion Our data shed new light on the association between genetic polymorphisms of IL-1RN and BC susceptibility in the Chinese Han population.