Endometrial Cancer Staging: The Role of Lymphadenectomy

Endometrial cancer is the most common gynecologic malignancy in the United States, with an estimated 49,560 new cases and 8190 cancer-related deaths in 2013. The lifetime risk of endometrial cancer is estimated to be 1 in 38 women, with a median age of diagnosis of 61 years. The incidence is on a slow rise secondary to increasing population age and increasing body mass index, with 39% of cases attributed to obesity. Endometrial cancer can be separated into 2 subtypes on the basis of pathology. Type I, or endometrioid adenocarcinoma, is the most common subtype comprising 80% of endometrial cancers. Type I typically occurs in preand perimenopausal women and is associated with obesity, excessive estrogen exposure, and endometrial hyperplasia. This type is seen more frequently in the white population, is typically well differentiated and low-grade, and has a favorable prognosis. Most patients present with stage I or II disease. Type II endometrial cancers comprise 20% of diagnoses. These cancers tend to occur in an older population of women and are not associated with estrogen exposure. Type II cancers are frequently high grade with deep myometrial invasion, and these patients have a worse prognosis. Some subtypes of type II endometrial cancer include clear-cell carcinoma, serous carcinoma, and poorly differentiated carcinoma. Most patients with type II cancers present with stage III or IV disease. At diagnosis, 75% of women with endometrial cancer have disease confined to the uterus and can be cured with surgery alone. Endometrial cancer spreads beyond the uterus by myometrial invasion, extension into the cervix, and metastasis to lymph nodes. The presence of extrauterine disease significantly impacts prognosis and increases recurrence rates. For this reason, proper identification of sites of disease spread and accurate staging is crucial. Reports of the surgical pathologic spread of endometrial cancer since the 1970s and 1980s ultimately led to the adoption of the International Federation of Gynecology and Obstetrics (FIGO) surgical staging system for endometrial cancer in 1988. Complete surgical staging includes surgical exploration, extrafascial hysterectomy, bilateral salpingo-oophorectomy, bilateral pelvic lymphadenectomy, bilateral para-aortic lymphadenectomy, pelvic washings, peritoneal biopsy, and omentectomy. On the basis of FIGO staging, the assessment of pelvic and para-aortic lymph nodes is a requirement for assigning stage in endometrial cancer. Most gynecologic oncologists agree that patients presenting with type II, high-risk subtypes of endometrial cancer such as clear-cell carcinoma, uterine Learning Objectives: After participating in this CME activity, the obstetrician/gynecologist should be better able to: 1. Stratify patients with endometrial cancer into groups at high and low risk for nodal metastasis. 2. Diagnose and have a better understanding of treatment and staging options for patients dependent on individual risk for lymph node involvement. 3. Counsel patients regarding the risks and benefits of complete surgical staging with lymph node dissection.