Progestogen in menopausal hormone therapy and breast cancer risk

Menopausal hormone therapy (MHT) is widely used to treat menopausal symptoms, but concerns about breast cancer risk remain a major barrier, particularly following the Women's Health Initiative (WHI) involving conjugated equine estrogen (CEE)/medroxyprogesterone acetate (MPA) [1].Consequently, in Korea, there has been a notable decline in the prescription frequency of CEE+MPA, owing to its association with breast cancer [2].However, compared to CEE+MPA, estradiol hemihydrate (EH)/drospirenone (DRSP) (Angeliq ® , COMPANY, CITY, STATE, COUNTRY), EH/norethisterone acetate (NETA) (Clian ® , COMPANY, CITY, STATE, COUNTRY), EH/dydrogesterone (DYD) (Femoston conti ® , COMPANY, CITY, STATE, COUNTRY; Femoston 2/10 ® , COMPANY, CITY, STATE, COUNTRY; and Femoston 1/10 ® , COMPANY), and estradiol valerate (EV)/cyproterone acetate (CPA) (Climen ® ) have been prescribed more frequently in South Korea [2].This might be due to the lack of large-scale studies pertaining to the risk of breast cancer associated with these agents.