Long-term tamoxifen therapy may cause:

Long-term tamoxifen therapy is a predisposing factor for endometrial hyperplasia and cancers. Malignancies caused by Long-term tamoxifen therapy: Carcinoma endometrium-it is the most common carcinoma associated with it. Uterine sarcoma. Rarely liver cancer with a long-term high dose. Non-malignant effects of tamoxifen on uterus: Endometrial hyperplasia Endometriosis Fibroid uterus Ovarian cysts Menstrual irregularities or amenorrhea.