Association of interleukin-10 gene polymorphisms with breast cancer in a Chinese population

BACKGROUND Interleukin-10(IL-10) is a multifunctional cytokine with both immunosuppressive and antiangiogenic functions. Polymorphisms in the IL-10 gene promoter genetically determine interindividual differences in IL-10 production. This study was performed to determined whether polymorphisms in the IL-10 gene promoter were associated with breast cancer in a Chinese Han population. METHODS We genotyped 315 patients with breast cancer and 322 healthy control subjects for -1082A/G, -819T/C and -592A/C single nucleotide polymorphisms in the promoter region of the IL-10 gene by polymerase chain reactionerestriction fragment length polymorphism (PCR-RFLP). RESULTS There were no significant differences in genotype, allele, or haplotype frequencies in all three loci between patients and healthy controls. Analysis of breast cancer prognostic and predictive factors revealed that the -1082AA genotype was associated with a significantly increased risk of lymph node (LN) involvement (P = 0.041) and larger tumor size (P = 0.039) at the time of diagnosis. Furthermore, in the haplotype analysis of IL-10 gene, we found that patients carrying ATA haplotype were in higher LN involvement (p = 0.022) and higher tumor stage(p = 0.028) of breast cancer at the time of diagnosis compared with others. CONCLUSIONS Our findings suggest that IL-10 promoter polymorphisms participate in the progression of breast cancer rather than in its initial development in Chinese Han women.