Breast cancer risk association with postmenopausal hormone therapy: Health Insurance Database in South Korea (HISK)-based cohort study.

This study suggests that the risk of breast cancer is increased by drugs in the CEPM group but not by tibolone, oral estrogen, CEPP, or topical estrogen. The mortality rate from breast cancer is lower with MHT (tibolone, CEPM, oral estrogen) than without MHT.