Stage IA and stage IB endometrial cancer shown in two cross-section drawings of the uterus and cervix. Drawing on the left shows stage IA, with cancer in the endometrium and myometrium of the uterus. Drawing on the right shows stage IB, with cancer more than halfway through the myometrium. Also shown are the fallopian tubes, ovaries, and vagina.
Stage IA and stage IB endometrial cancer. In stage IA, cancer is in the endometrium only or less than halfway through the myometrium (the muscle layer of the uterus). In stage IB, cancer has spread halfway or more into the myometrium.