This is a medical question of type : information 
 What is (are) Endometrial Cancer ? 
 Key Points
                    - Endometrial cancer is a disease in which malignant (cancer) cells form in the tissues of the endometrium.     - Obesity and having metabolic syndrome may increase the risk of endometrial cancer.    - Taking tamoxifen for breast cancer or taking estrogen alone (without progesterone) can increase the risk of endometrial cancer.     - Signs and symptoms of endometrial cancer include unusual vaginal bleeding or pain in the pelvis.     - Tests that examine the endometrium are used to detect (find) and diagnose endometrial cancer.    - Certain factors affect prognosis (chance of recovery) and treatment options.
                
                
                    Endometrial cancer is a disease in which malignant (cancer) cells form in the tissues of the endometrium.
                    The endometrium is the lining of the uterus, a hollow, muscular organ in a womans 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.     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 on Uterine Sarcoma Treatment for more information about uterine sarcoma.
                
                
                    Obesity and having metabolic syndrome may increase the risk of endometrial cancer.
                    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:         - Having endometrial hyperplasia.    - Being obese.    - Having metabolic syndrome, a set of conditions that occur together, including extra fat around the abdomen, high blood sugar, high blood pressure, high levels of triglycerides and low levels of high-density lipoproteins in the blood.    -  Never giving birth.    - Beginning menstruation at an early age.    - Reaching menopause at an older age.    - Having polycystic ovarian syndrome (PCOS).     -  Having a mother, sister, or daughter with uterine cancer.    - Having a certain gene change that is linked to Lynch syndrome (hereditary non-polyposis colon cancer).     - Having hyperinsulinemia (high levels of insulin in the blood).
                
                
                    Taking tamoxifen for breast cancer or taking estrogen alone (without progesterone) can increase the risk of endometrial cancer.
                    Endometrial cancer may develop in breast cancer patients who have been treated with tamoxifen. A patient who takes this drug and has abnormal vaginal bleeding should have a follow-up exam and a biopsy of the endometrial lining if needed. Women taking estrogen (a hormone that can affect the growth of some cancers) alone also have an increased risk of endometrial cancer. Taking estrogen combined with progesterone (another hormone) does not increase a womans risk of endometrial cancer.