[Recent progress of endocrine therapy in breast cancer]

Recent progresses of endocrine therapy for advanced and early breast cancer was reviewed. The mechanism (s) of an antiestrogen, tamoxifen has been noted at least partly as a stimulation of TGF beta action in ER-positive breast cancer cells. The Early Breast Cancer Trialists' Collaborative Group (EBC TCG) has recently reported the effectiveness of endocrine therapy, oophorectomy for premenopausal patients, and tamoxifen for pre- and post-menopausal patients in the adjuvant treatment for operable breast cancer patients. Two kinds of newly developed endocrine therapy were mentioned; LH-RH analogues for premenopausal patients, and aromatase inhibitors for postmenopausal patients. These agents decrease the plasma estrogen levels, acting like the ablative surgery, and make us more comprehensive combinations of endocrine therapy of breast cancer.