Endometrial cancer is the most common cancer of the female reproductive system, with more than 49,500 United States women that are diagnosed with the disease each year. It tends to develop after menopause, when a woman is between the ages of 50 and 60. It is the sixth most common cancer in women worldwide (fourteenth most common cancer overall), with 320,000 new cases diagnosed in 2012, and it is the 13th most common cause of death from cancer with nearly 86,000 deaths worldwide. Endometrial cancer occurs when cells of the endometrium undergo a transformation and begin to grow and multiply without the control mechanisms that normally limit their growth. As the cells grow and multiply, they form the cancerous lesion. Cancerous tumors may encroach on and invade neighboring organs or lymph nodes, or they may enter the bloodstream and spread to the bones or distant organs, such as the lungs. This process is called metastasis. Metastatic tumors are the most aggressive and serious of all tumors. Two main types of endometrial cancers exist. Nearly all endometrial cancers are endometrial adenocarcinomas, as they originate from glandular (secreting) tissue. The other type of endometrial cancer, uterine sarcomas, originates in the connective tissue or muscle of the uterus. A subtype of endometrial adenocarcinomas, adenosquamous carcinoma, includes squamous cells (that is, the type of cells found on the surface of the skin and cervix). Other subtypes of endometrial adenocarcinomas are papillary serous adenocarcinomas and clear cell carcinomas. Multidisciplinary teams of experts including specialists in medical oncology, gynecologic oncology, radiology, urology, radiotherapy, and surgery are essential to utilize sophisticated imaging and laboratory tests, to confirm the diagnosis and identify the characteristics of the tumor. They all work together to determine the best treatment approach for the patient. Recent progress in the development of new surgical techniques has transformed the treatment of uterine cancer, resulting in greater surgical precision and fewer complications. In addition, targeted adjuvant therapy has become useful in improving the oncologic outcome of patients with this disease.