Breast cancer risk was significantly associated with three SNPs located at 6q25.1—rs9383935 in CCDC170 and rs2228480 and rs3798758 in ESR1—with variant allele attributed odds ratios (ORs) of 1.38 (95% confidence interval (CI): 1.20 to 1.57, P = 2.21 × 10-6), 0.84 (95% CI: 0.72 to 0.98, P = 0.025) and 1.19 (95% CI: 1.04 to 1.37, P = 0.013), respectively. This evidence concerns the gene CCDC170 and breast cancer.