stromal sarcoma survivalmetastatic endometrial stromal sarcomaendometrial stromal sarcoma cancerendometrial stromal sarcoma stage 4endometrial stromal cell sarcomaendometrial sarcomaendometrial stromalsarcoma uterine cancerendometrial carcinoma sarcomastromal sarcoma uterusundifferentiated endometrial sarcomametastatic endometrial sarcoma