Coffee Intake Interacted with the rs1944420, rs7236090, and rs2849382 Haplotype to Influence Breast Cancer Risk in Middle-Aged Women.

We hypothesized that the haplotype of genetic variants increases breast cancer risk and interacts with lifestyles in Korean women. We identified single nucleotide polymorphism (SNPs) of associated with breast cancer risk after adjusting for covariates in 390 breast cancer patients and 36,726 women without any cancer that participated in the Korean Genomic Epidemiology Study (KoGES). An allelic genetic model showed that three SNPs (rs1944420, rs7236090, and rs2849382) in the gene were significantly associated with breast cancer (ORs = 1.28, 0.84, and 0.79, respectively). The participants with the minor allele of the haplotype with three SNPs had 1.65-fold higher breast cancer risk than those with the major allele, after adjusting for covariates. Serum C-reactive protein concentration had a positive association with breast cancer risk. A significant interaction was also observed between the minor allele of the haplotype and coffee intake ( = 0.03). A low coffee intake in women with the minor allele presented a higher breast cancer risk than a low coffee intake in those with the major allele. In conclusion, the risk of breast cancer risk was higher in post-menopausal women with the minor allele of the haplotype, and consuming more than 1 cup of coffee per day reduced the risk. The results of this study could be applied to reduce the risk of breast cancer.