[A case of advanced breast cancer successfully treated with combined tamoxifen and epitiostanol].

A patient with stage IV advanced breast cancer with multiple metastasis (bones of the whole body, lungs) were treated by ovariectomy, administration of an non-steroidal antiestrogen (tamoxifen) and mild chemotherapeutic drugs, with favorable results. After four years, however, the patient had a relapse of the cancer. A steroidal antiestrogen (epitiostanol) was then administered with satisfactory results. When a breast cancer relapse occurs in patients once treated successfully with endocrinotherapy, a different form of endocrinotherapy should be tried. There is a possibility that the mechanism of action of Epitiostanol, which is regarded as a steroidal antiestrogen, is different from that of tamoxifen in which an estrogen receptor (ER) system is included.