Endometrial cancer or uterine cancer when cancer starts in the uterus, it is called uterine cancer. The uterus is the pear-shaped organ in a woman’s pelvis. The uterus, also called the womb, is where the baby grows when a woman is pregnant. The most common type of uterine cancer is also called endometrial cancer because it forms in the lining of uterus, called the endometrium. When uterine cancer is found early, treatment works best.