The uterus, or womb, is a pear-shaped muscular organ in a woman's lower abdominal (pelvic) area. This is where a fetus develops during pregnancy. Most cancers of the uterus occur in the inner lining of the uterus (endometrium). That is why uterine cancer is also called endometrial cancer or endometrial carcinoma.
Cancer can also grow in the muscle and supporting tissues of the uterus. These tumors are called uterine sarcomas. They are much less common than endometrial carcinomas and are not treated the same way.
How uterine cancer occurs
During a normal menstrual cycle, the endometrium undergoes a series of changes to prepare for a potential pregnancy. The ovaries release hormones that cause these changes. If pregnancy does not occur, the endometrial lining is shed during menstruation.
In endometrial cancer, the lining cells don't respond to hormone signals that tell them to stop growing. Instead, the endometrial cells grow out of control and form a tumor.
How common is uterine cancer?
In the U.S., uterine cancer is the most common cancer of the female reproductive organs. On average, more than 40,000 new cases of uterine cancer (mostly endometrial cancer) are diagnosed each year. The average woman's lifetime risk of uterine cancer is about one in 40.
For all cases of endometrial cancer combined, the five-year survival rate is about 85 percent. The survival rate rises to more than 96 percent when the disease is found and treated in its earliest stage.
Created on 11/16/1999
Updated on 09/22/2010
- National Cancer Institute. A snapshot of endometrial cancer.
- Bakkum-Gamez JN, Gonzalez-Bosquet J, Laack NN, Mariani A, Dowdy SC. Current issues in the management of endometrial cancer. Mayo Clinic Proceedings. 2008;83(1):97-112.
- WomensHealth.gov Cancer of the uterus.