Definition of endometrial cancer: Cancer that forms in the tissue lining the uterus (the small, hollow, pear-shaped organ in a woman’s pelvis in which a fetus develops). Most endometrial cancers are adenocarcinomas (cancers that begin in cells that make and release mucus and other fluids)
The endometrium is the lining of the uterus, 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. The lower, narrow end of the uterus is the cervix, which leads to the vagina.
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 sarcoma of the uterus. See the PDQ summary onUterine Sarcoma Treatment for more information.
Anything that increases your risk 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. Talk with your doctor if you think you may be at risk. Risk factors for endometrial cancer include the following:
• Being obese.
• Having high blood pressure.
• Having diabetes mellitus.
Endometrial cancer may develop in breast cancer patients who have been treated with tamoxifen. A patient taking this drug should have a pelvic exam every year and report any vaginal bleeding (other than menstrual bleeding) as soon as possible. Women taking estrogen (a hormone that can affect the growth of some cancers) alone have an increased risk of endometrial cancer. Taking estrogen combined with progesterone (another hormone) does not increase a woman’s risk of this cancer.