Endometrial cancer is a disease in which malignant (cancer) cells form in the tissues of the endometrium.
The endometrium is the innermost lining of the uterus. The uterus is a hollow, muscular organ in a woman's pelvis. The uterus is where a fetus grows. In most nonpregnant women, the uterus is about 3 inches long.
Anatomy of the female reproductive system. The organs in the female reproductive system include the uterus, ovaries, fallopian tubes, cervix, and vagina. The uterus has a muscular outer layer called the myometrium and an inner lining called the endometrium.
Cancer of the endometrium is different from cancer of the muscle of the uterus, which is called uterine sarcoma. See the PDQ summary on Uterine Sarcoma Treatment for more information.
See the following PDQ summaries for more information about endometrial cancer:
- Endometrial Cancer Treatment
- Endometrial Cancer Prevention
In the United States, endometrial cancer is the most common invasive cancer of the female reproductive system.
Endometrial cancer is diagnosed most often in postmenopausal women at an average age of 60 years.
Since 1992, the number of white women diagnosed with endometrial cancer has remained stable, but the number of new cases in black women has increased slightly. Endometrial cancer occurs more often in white women than in black women. When endometrial cancer is diagnosed in black women, it is usually more advanced and less likely to be cured. The number of deaths from endometrial cancer has stayed about the same in white women but has increased slightly in black women each year since 1998.
Health history and certain medicines can affect the risk of developing endometrial cancer.
Anything that increases your chance of getting a disease is called a risk factor. Having a risk factor does not mean that you will get cancer; not having risk factors doesn't mean that you will not get cancer. People who think they may be at risk should discuss this with their doctor. Risk factors for endometrial cancer include the following:
- Taking tamoxifen for treatment or prevention of breast cancer.
- Taking estrogen alone. (Taking estrogen in combination with progesterone does not appear to increase the risk of endometrial cancer.)
- Being overweight.
- Eating a high-fat diet.
- Never giving birth.
- Beginning menstruation at an early age.
- Reaching menopause at an older age.
- Having the gene for hereditary non-polyposis colon cancer (HNPCC).
- Being white.