Endometrial cancer or Cancer of the Uterue When cancer cells appear on the lining of the uterus which is called the endometrium. It is the most common type of cancer that affects the female reproductive organs. It occurs when the cells of the endometrium start to grow too rapidly. Risk factors include 1. Age: Most cases of endometrial cancer are diagnosed in women who are past menopause, especially women who are in their mid-60s; 2. When estrogen is present without enough progesterone, it can cause the endometrium to become too thick, such as when a woman uses estrogen-only therapy to treat menopause symptoms; 3. Obesity: having a body mass index (BMI) of 25 is a major risk factor for endometrial cancer (the higher the BMI, the greater the risk); 4. PCOS: Having a condition called polycystic ovary syndrome (PCOS); 5. Genitcs; 5. Taking tamoxifen to prevent or treat breast cancer; 6. Having metabolic syndrome; or 7. Having Type 2 Diabetes. The most common symptom of endometrial cancer is abnormal uterine bleeding. For women who are premenopausal, this can include irregular menstrual bleeding, spotting, and bleeding between menstrual periods. For women who are postmenopausal, any bleeding is considered to be abnormal. (While it is probably not cancer, if a woman has irregular bleeding, she should consult with a gynecologist given the importance of an early diagnosis.) A more rare form of uterine cancer is called Uterine Sarcoma, which develops in the myometrium or muscle wall of the uterus.