[Clinicopathological features of endometrial carcinoma in tamoxifen- and toremifene-treated breast cancer patients].

Objective: Estrogen is involved in the development of breast and endometrial cancers, and tamoxifen, an antiestrogen, is associated with an increased risk of endometrial cancer. Recently, tamoxifen use is suggested to be associated with the development of aggressive endometrial tumors. We performed a retrospective study to clarify the effects of tamoxifen (TAM) and toremifene (TOR) on clinicopathological features of endometrial cancer subsequently developed in breast cancer patients.