Polymorphisms in cytokine genes and serum cytokine levels among New Mexican women with and without breast cancer

Among New Mexican Hispanic women, breast cancer is detected at a more advanced stage than compared to Non-Hispanic White women. One central factor that has been little studied is the role of critical cytokines. We genotyped incident breast cancer cases and their age-, gender- and smoking-matched controls (N=40 matched pairs) for 25 single nucleotide polymorphisms (SNPs) in cytokine genes. We measured corresponding serum cytokine levels as well. Five cytokines (IL-1beta, IL-5, TNF-alpha, IL-6 and IL-2) were significantly associated with disease and based on their serum levels, concentrations were higher in the cases than in the controls. Disease odds ratios corresponding to one standard deviation change in log-transformed concentrations of these cytokines were 18.87, 4.10, 3.61, 3.27 and 2.52. Three most statistically significant SNPs were rs2069705, located in the promoter region of the interferon gamma gene (INF-gamma); rs2243248, in the promoter of IL-4 (rs2243248); and rs1800925, in the promoter of the IL-13 gene. Increased serum cytokine levels at diagnosis are indicative for immunological alterations and possibly related to genetic susceptibility markers as well. These findings might guide us to understand the presence of SNPs in cytokine genes and serum concentrations among breast cancer patients and potentially in other cancers.