Association of interleukin-10 gene variation with breast cancer prognosis

Genetic polymorphisms are responsible for inter-individual variation and diversity and have been recently considered as the main genetic elements involved in the development and progression of cancer. We examined associations between common germline genetic variants in 7 genes involved in folate metabolism, cell proliferation and apoptosis, prostaglandin synthesis, detoxification of compounds and inflammation, and disease-free survival among women diagnosed with invasive breast cancer. DNA from up to 432 women was genotyped for 8 polymorphisms. The genotypes of each polymorphism were tested for association with disease-free survival using univariate and multivariate Cox regression analysis. The model was adjusted for known breast cancer prognostic factors. The rare allele of the IL-10 592C>A polymorphism was significantly associated with reduced disease-free survival (P = 0.018, risk ratio of recurrence (RR) = 1.45, 95% confidence interval (CI) = 1.06-1.98), which was not attenuated after adjusting for age at diagnosis, tumor size, lymph node status, clinical stage, histological grade, estrogen receptor status, progesterone receptor status, and treatment modalities (P = 0.019, RR = 1.48, 95% CI = 1.066-2.044). No association was found between MTHFR 677C>T, TGFB1 29T>C, FASLG 844C>T, FAS 1377G>A, FAS 670A>G, PTGS2 8473T>C and SULT1A1 638G>A polymorphisms and disease-free survival. Our data suggest that the rare allele of IL-10 592C>A may be a potential prognostic marker in breast cancer for disease-free survival.