Uterine cancer or endometrial cancer is the diseases of the uterus. The uterus is a pear-shaped hollow organ located a woman’s pelvis, between the bladder and rectum. The uterus is more commonly known as a womb. Uterine cancer is the most commonly occurring cancer in the women’s reproductive system. It begins in the healthy cells of the uterus and grows out of control, forming a mass called a tumor. A cancerous tumor is malignant, and it can grow and spread to other body parts too.