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

Background: The interleukins (ILs) are a large family of endogenous cytokines that are crucial in the regulation of inflammation and immunological responses. The 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 patients.

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 (Sequenom, San Diego, CA, USA). Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using unconditional logistic regression after adjusting for age and sex.

Results: In the allele model, we found that 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 a decreased risk of BC under dominant model (p < 0.05), whereas the minor alleles 'T' and 'C' of rs928940 and rs4252019 were associated with a decreased risk of BC under both the codominant and dominant models (p < 0.05), which suggested these SNPs may play a protective role against BC risk. The haplotype 'TAGC' constructed by rs928940, rs3181052, rs452204 and rs4252019 was associated with a decreased risk of BC (OR = 0.33; 95% CI = 0.12-0.94; p = 0.038).

Conclusions: The data obtained in the present study shed new light on the association between genetic polymorphisms of IL-1RN and BC susceptibility in the Chinese Han population.