Definition

The tumor is found in the uterus only. Stage I is divided into stages IA, IB, and IC. In stage IA, the tumor is found in the endometrium or endocervix (the inner part of the cervix that forms a canal connecting the vagina to the uterus). In stage IB, the tumor has spread halfway or less into the myometrium (the muscular outer layer of the uterus). In stage IC, the tumor has spread more than halfway into the myometrium.