Uterine cancer is a disease in which cancer cells grow in the uterus (womb).
The lower portion of the uterus, which is closest to the vagina, is called the cervix. When cancer develops in this portion, it is called cervical cancer .
The walls of the uterus (not including the cervix) are made of the endometrium (the inner lining) and the myometrium (the muscular, outer lining). The most common type of uterine cancer, called adenocarcinoma, begins in the endometrium. Less common cancers, called sarcomas, begin in the myometrium. This fact sheet will focus on endometrial cancer.

Cancer occurs when cells in the body (in this case uterus cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. The term cancer refers to malignant tumors, which can invade nearby tissue and spread to other parts of the body. A benign tumor does not invade or spread.