In the present study, there was a significant interaction between CYP1A2 rs762551 and CYP19A1 rs4646 with a high risk for breast cancer events, especially within five years, among patients with any C-allele of CYP1A2 rs762551 and C/C-carriers of CYP19A1 rs4646. Here, CYP19A1 is linked to breast cancer.